From c6a1db6c73b62b058031476c867cd734a815e273 Mon Sep 17 00:00:00 2001 From: Richard Stallman Date: Sat, 15 Feb 1992 03:55:11 +0000 Subject: [PATCH] Initial revision From-SVN: r324 --- gcc/tree.c | 3178 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 3178 insertions(+) create mode 100644 gcc/tree.c diff --git a/gcc/tree.c b/gcc/tree.c new file mode 100644 index 00000000000..e67b0934704 --- /dev/null +++ b/gcc/tree.c @@ -0,0 +1,3178 @@ +/* Language-independent node constructors for parse phase of GNU compiler. + Copyright (C) 1987, 1988, 1992 Free Software Foundation, Inc. + +This file is part of GNU CC. + +GNU CC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU CC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU CC; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + + +/* This file contains the low level primitives for operating on tree nodes, + including allocation, list operations, interning of identifiers, + construction of data type nodes and statement nodes, + and construction of type conversion nodes. It also contains + tables index by tree code that describe how to take apart + nodes of that code. + + It is intended to be language-independent, but occasionally + calls language-dependent routines defined (for C) in typecheck.c. + + The low-level allocation routines oballoc and permalloc + are used also for allocating many other kinds of objects + by all passes of the compiler. */ + +#include "config.h" +#include +#include "flags.h" +#include "function.h" +#include "tree.h" +#include "obstack.h" +#include "gvarargs.h" + +#define obstack_chunk_alloc xmalloc +#define obstack_chunk_free free + +extern int xmalloc (); +extern void free (); + +/* Tree nodes of permanent duration are allocated in this obstack. + They are the identifier nodes, and everything outside of + the bodies and parameters of function definitions. */ + +struct obstack permanent_obstack; + +/* The initial RTL, and all ..._TYPE nodes, in a function + are allocated in this obstack. Usually they are freed at the + end of the function, but if the function is inline they are saved. + For top-level functions, this is maybepermanent_obstack. + Separate obstacks are made for nested functions. */ + +struct obstack *function_maybepermanent_obstack; + +/* This is the function_maybepermanent_obstack for top-level functions. */ + +struct obstack maybepermanent_obstack; + +/* The contents of the current function definition are allocated + in this obstack, and all are freed at the end of the function. + For top-level functions, this is temporary_obstack. + Separate obstacks are made for nested functions. */ + +struct obstack *function_obstack; + +/* This is used for reading initializers of global variables. */ + +struct obstack temporary_obstack; + +/* The tree nodes of an expression are allocated + in this obstack, and all are freed at the end of the expression. */ + +struct obstack momentary_obstack; + +/* The tree nodes of a declarator are allocated + in this obstack, and all are freed when the declarator + has been parsed. */ + +static struct obstack temp_decl_obstack; + +/* This points at either permanent_obstack + or the current function_maybepermanent_obstack. */ + +struct obstack *saveable_obstack; + +/* This is same as saveable_obstack during parse and expansion phase; + it points to the current function's obstack during optimization. + This is the obstack to be used for creating rtl objects. */ + +struct obstack *rtl_obstack; + +/* This points at either permanent_obstack or the current function_obstack. */ + +struct obstack *current_obstack; + +/* This points at either permanent_obstack or the current function_obstack + or momentary_obstack. */ + +struct obstack *expression_obstack; + +/* Stack of obstack selections for push_obstacks and pop_obstacks. */ + +struct obstack_stack +{ + struct obstack_stack *next; + struct obstack *current; + struct obstack *saveable; + struct obstack *expression; + struct obstack *rtl; +}; + +struct obstack_stack *obstack_stack; + +/* Obstack for allocating struct obstack_stack entries. */ + +static struct obstack obstack_stack_obstack; + +/* Addresses of first objects in some obstacks. + This is for freeing their entire contents. */ +char *maybepermanent_firstobj; +char *temporary_firstobj; +char *momentary_firstobj; +char *temp_decl_firstobj; + +/* Nonzero means all ..._TYPE nodes should be allocated permanently. */ + +int all_types_permanent; + +/* Stack of places to restore the momentary obstack back to. */ + +struct momentary_level +{ + /* Pointer back to previous such level. */ + struct momentary_level *prev; + /* First object allocated within this level. */ + char *base; + /* Value of expression_obstack saved at entry to this level. */ + struct obstack *obstack; +}; + +struct momentary_level *momentary_stack; + +/* Table indexed by tree code giving a string containing a character + classifying the tree code. Possibilities are + t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */ + +#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE, + +char *standard_tree_code_type[] = { +#include "tree.def" +}; +#undef DEFTREECODE + +/* Table indexed by tree code giving number of expression + operands beyond the fixed part of the node structure. + Not used for types or decls. */ + +#define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH, + +int standard_tree_code_length[] = { +#include "tree.def" +}; +#undef DEFTREECODE + +/* Names of tree components. + Used for printing out the tree and error messages. */ +#define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME, + +char *standard_tree_code_name[] = { +#include "tree.def" +}; +#undef DEFTREECODE + +/* Table indexed by tree code giving a string containing a character + classifying the tree code. Possibilities are + t, d, s, c, r, e, <, 1 and 2. See tree.def for details. */ + +char **tree_code_type; + +/* Table indexed by tree code giving number of expression + operands beyond the fixed part of the node structure. + Not used for types or decls. */ + +int *tree_code_length; + +/* Table indexed by tree code giving name of tree code, as a string. */ + +char **tree_code_name; + +/* Statistics-gathering stuff. */ +typedef enum +{ + d_kind, t_kind, s_kind, r_kind, e_kind, c_kind, + id_kind, op_id_kind, perm_list_kind, temp_list_kind, + vec_kind, x_kind, lang_decl, lang_type, all_kinds +} tree_node_kind; +int tree_node_counts[(int)all_kinds]; +int tree_node_sizes[(int)all_kinds]; +int id_string_size = 0; +char *tree_node_kind_names[] = { "decls", "types", "stmts", "refs", "exprs", "constants", + "identifiers", "op_identifiers", "perm_tree_lists", "temp_tree_lists", + "vecs", "random kinds", "lang_decl kinds", "lang_type kinds" }; + +/* Hash table for uniquizing IDENTIFIER_NODEs by name. */ + +#define MAX_HASH_TABLE 1009 +static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */ + +/* 0 while creating built-in identifiers. */ +static int do_identifier_warnings; + +extern char *mode_name[]; + +void gcc_obstack_init (); +static tree stabilize_reference_1 (); + +/* Init the principal obstacks. */ + +void +init_obstacks () +{ + gcc_obstack_init (&obstack_stack_obstack); + gcc_obstack_init (&permanent_obstack); + + gcc_obstack_init (&temporary_obstack); + temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0); + gcc_obstack_init (&momentary_obstack); + momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0); + gcc_obstack_init (&maybepermanent_obstack); + maybepermanent_firstobj + = (char *) obstack_alloc (&maybepermanent_obstack, 0); + gcc_obstack_init (&temp_decl_obstack); + temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0); + + function_obstack = &temporary_obstack; + function_maybepermanent_obstack = &maybepermanent_obstack; + current_obstack = &permanent_obstack; + expression_obstack = &permanent_obstack; + rtl_obstack = saveable_obstack = &permanent_obstack; + + /* Init the hash table of identifiers. */ + bzero (hash_table, sizeof hash_table); +} + +void +gcc_obstack_init (obstack) + struct obstack *obstack; +{ + /* Let particular systems override the size of a chunk. */ +#ifndef OBSTACK_CHUNK_SIZE +#define OBSTACK_CHUNK_SIZE 0 +#endif + /* Let them override the alloc and free routines too. */ +#ifndef OBSTACK_CHUNK_ALLOC +#define OBSTACK_CHUNK_ALLOC xmalloc +#endif +#ifndef OBSTACK_CHUNK_FREE +#define OBSTACK_CHUNK_FREE free +#endif + _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0, + (void *(*) ()) OBSTACK_CHUNK_ALLOC, + (void (*) ()) OBSTACK_CHUNK_FREE); +} + +/* Save all variables describing the current status into the structure *P. + This is used before starting a nested function. */ + +void +save_tree_status (p) + struct function *p; +{ + p->all_types_permanent = all_types_permanent; + p->momentary_stack = momentary_stack; + p->maybepermanent_firstobj = maybepermanent_firstobj; + p->momentary_firstobj = momentary_firstobj; + p->function_obstack = function_obstack; + p->function_maybepermanent_obstack = function_maybepermanent_obstack; + p->current_obstack = current_obstack; + p->expression_obstack = expression_obstack; + p->saveable_obstack = saveable_obstack; + p->rtl_obstack = rtl_obstack; + + function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack)); + gcc_obstack_init (function_obstack); + + function_maybepermanent_obstack + = (struct obstack *) xmalloc (sizeof (struct obstack)); + gcc_obstack_init (function_maybepermanent_obstack); + + current_obstack = &permanent_obstack; + expression_obstack = &permanent_obstack; + rtl_obstack = saveable_obstack = &permanent_obstack; + + momentary_firstobj = (char *) obstack_finish (&momentary_obstack); + maybepermanent_firstobj + = (char *) obstack_finish (function_maybepermanent_obstack); +} + +/* Restore all variables describing the current status from the structure *P. + This is used after a nested function. */ + +void +restore_tree_status (p) + struct function *p; +{ + all_types_permanent = p->all_types_permanent; + momentary_stack = p->momentary_stack; + + obstack_free (&momentary_obstack, momentary_firstobj); + obstack_free (function_obstack, 0); + obstack_free (function_maybepermanent_obstack, 0); + free (function_obstack); + + momentary_firstobj = p->momentary_firstobj; + maybepermanent_firstobj = p->maybepermanent_firstobj; + function_obstack = p->function_obstack; + function_maybepermanent_obstack = p->function_maybepermanent_obstack; + current_obstack = p->current_obstack; + expression_obstack = p->expression_obstack; + saveable_obstack = p->saveable_obstack; + rtl_obstack = p->rtl_obstack; +} + +/* Start allocating on the temporary (per function) obstack. + This is done in start_function before parsing the function body, + and before each initialization at top level, and to go back + to temporary allocation after doing end_temporary_allocation. */ + +void +temporary_allocation () +{ + /* Note that function_obstack at top level points to temporary_obstack. + But within a nested function context, it is a separate obstack. */ + current_obstack = function_obstack; + expression_obstack = function_obstack; + rtl_obstack = saveable_obstack = function_maybepermanent_obstack; + momentary_stack = 0; +} + +/* Start allocating on the permanent obstack but don't + free the temporary data. After calling this, call + `permanent_allocation' to fully resume permanent allocation status. */ + +void +end_temporary_allocation () +{ + current_obstack = &permanent_obstack; + expression_obstack = &permanent_obstack; + rtl_obstack = saveable_obstack = &permanent_obstack; +} + +/* Resume allocating on the temporary obstack, undoing + effects of `end_temporary_allocation'. */ + +void +resume_temporary_allocation () +{ + current_obstack = function_obstack; + expression_obstack = function_obstack; + rtl_obstack = saveable_obstack = function_maybepermanent_obstack; +} + +/* While doing temporary allocation, switch to allocating in such a + way as to save all nodes if the function is inlined. Call + resume_temporary_allocation to go back to ordinary temporary + allocation. */ + +void +saveable_allocation () +{ + /* Note that function_obstack at top level points to temporary_obstack. + But within a nested function context, it is a separate obstack. */ + expression_obstack = current_obstack = saveable_obstack; +} + +/* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE, + recording the previously current obstacks on a stack. + This does not free any storage in any obstack. */ + +void +push_obstacks (current, saveable) + struct obstack *current, *saveable; +{ + struct obstack_stack *p + = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack, + (sizeof (struct obstack_stack))); + + p->current = current_obstack; + p->saveable = saveable_obstack; + p->expression = expression_obstack; + p->rtl = rtl_obstack; + p->next = obstack_stack; + obstack_stack = p; + + current_obstack = current; + expression_obstack = current; + rtl_obstack = saveable_obstack = saveable; +} + +/* Save the current set of obstacks, but don't change them. */ + +void +push_obstacks_nochange () +{ + struct obstack_stack *p + = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack, + (sizeof (struct obstack_stack))); + + p->current = current_obstack; + p->saveable = saveable_obstack; + p->expression = expression_obstack; + p->rtl = rtl_obstack; + p->next = obstack_stack; + obstack_stack = p; +} + +/* Pop the obstack selection stack. */ + +void +pop_obstacks () +{ + struct obstack_stack *p = obstack_stack; + obstack_stack = p->next; + + current_obstack = p->current; + saveable_obstack = p->saveable; + expression_obstack = p->expression; + rtl_obstack = p->rtl; + + obstack_free (&obstack_stack_obstack, p); +} + +/* Nonzero if temporary allocation is currently in effect. + Zero if currently doing permanent allocation. */ + +int +allocation_temporary_p () +{ + return current_obstack != &permanent_obstack; +} + +/* Go back to allocating on the permanent obstack + and free everything in the temporary obstack. + This is done in finish_function after fully compiling a function. */ + +void +permanent_allocation () +{ + /* Free up previous temporary obstack data */ + obstack_free (&temporary_obstack, temporary_firstobj); + obstack_free (&momentary_obstack, momentary_firstobj); + obstack_free (&maybepermanent_obstack, maybepermanent_firstobj); + obstack_free (&temp_decl_obstack, temp_decl_firstobj); + + current_obstack = &permanent_obstack; + expression_obstack = &permanent_obstack; + rtl_obstack = saveable_obstack = &permanent_obstack; +} + +/* Save permanently everything on the maybepermanent_obstack. */ + +void +preserve_data () +{ + maybepermanent_firstobj + = (char *) obstack_alloc (function_maybepermanent_obstack, 0); +} + +void +preserve_initializer () +{ + temporary_firstobj + = (char *) obstack_alloc (&temporary_obstack, 0); + momentary_firstobj + = (char *) obstack_alloc (&momentary_obstack, 0); + maybepermanent_firstobj + = (char *) obstack_alloc (function_maybepermanent_obstack, 0); +} + +/* Start allocating new rtl in current_obstack. + Use resume_temporary_allocation + to go back to allocating rtl in saveable_obstack. */ + +void +rtl_in_current_obstack () +{ + rtl_obstack = current_obstack; +} + +/* Temporarily allocate rtl from saveable_obstack. Return 1 if we were + previously allocating it from current_obstack. */ + +int +rtl_in_saveable_obstack () +{ + if (rtl_obstack == current_obstack) + { + rtl_obstack = saveable_obstack; + return 1; + } + else + return 0; +} + +/* Allocate SIZE bytes in the current obstack + and return a pointer to them. + In practice the current obstack is always the temporary one. */ + +char * +oballoc (size) + int size; +{ + return (char *) obstack_alloc (current_obstack, size); +} + +/* Free the object PTR in the current obstack + as well as everything allocated since PTR. + In practice the current obstack is always the temporary one. */ + +void +obfree (ptr) + char *ptr; +{ + obstack_free (current_obstack, ptr); +} + +/* Allocate SIZE bytes in the permanent obstack + and return a pointer to them. */ + +char * +permalloc (size) + long size; +{ + return (char *) obstack_alloc (&permanent_obstack, size); +} + +/* Allocate NELEM items of SIZE bytes in the permanent obstack + and return a pointer to them. The storage is cleared before + returning the value. */ + +char * +perm_calloc (nelem, size) + int nelem; + long size; +{ + char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size); + bzero (rval, nelem * size); + return rval; +} + +/* Allocate SIZE bytes in the saveable obstack + and return a pointer to them. */ + +char * +savealloc (size) + int size; +{ + return (char *) obstack_alloc (saveable_obstack, size); +} + +/* Print out which obstack an object is in. */ + +void +debug_obstack (object) + char *object; +{ + struct obstack *obstack = NULL; + char *obstack_name = NULL; + struct function *p; + + for (p = outer_function_chain; p; p = p->next) + { + if (_obstack_allocated_p (p->function_obstack, object)) + { + obstack = p->function_obstack; + obstack_name = "containing function obstack"; + } + if (_obstack_allocated_p (p->function_maybepermanent_obstack, object)) + { + obstack = p->function_maybepermanent_obstack; + obstack_name = "containing function maybepermanent obstack"; + } + } + + if (_obstack_allocated_p (&obstack_stack_obstack, object)) + { + obstack = &obstack_stack_obstack; + obstack_name = "obstack_stack_obstack"; + } + else if (_obstack_allocated_p (function_obstack, object)) + { + obstack = function_obstack; + obstack_name = "function obstack"; + } + else if (_obstack_allocated_p (&permanent_obstack, object)) + { + obstack = &permanent_obstack; + obstack_name = "permanent_obstack"; + } + else if (_obstack_allocated_p (&momentary_obstack, object)) + { + obstack = &momentary_obstack; + obstack_name = "momentary_obstack"; + } + else if (_obstack_allocated_p (function_maybepermanent_obstack, object)) + { + obstack = function_maybepermanent_obstack; + obstack_name = "function maybepermanent obstack"; + } + else if (_obstack_allocated_p (&temp_decl_obstack, object)) + { + obstack = &temp_decl_obstack; + obstack_name = "temp_decl_obstack"; + } + + /* Check to see if the object is in the free area of the obstack. */ + if (obstack != NULL) + { + if (object >= obstack->next_free + && object < obstack->chunk_limit) + fprintf (stderr, "object in free portion of obstack %s.\n", + obstack_name); + else + fprintf (stderr, "object allocated from %s.\n", obstack_name); + } + else + fprintf (stderr, "object not allocated from any obstack.\n"); +} + +/* Return 1 if OBJ is in the permanent obstack. + This is slow, and should be used only for debugging. + Use TREE_PERMANENT for other purposes. */ + +int +object_permanent_p (obj) + tree obj; +{ + return _obstack_allocated_p (&permanent_obstack, obj); +} + +/* Start a level of momentary allocation. + In C, each compound statement has its own level + and that level is freed at the end of each statement. + All expression nodes are allocated in the momentary allocation level. */ + +void +push_momentary () +{ + struct momentary_level *tem + = (struct momentary_level *) obstack_alloc (&momentary_obstack, + sizeof (struct momentary_level)); + tem->prev = momentary_stack; + tem->base = (char *) obstack_base (&momentary_obstack); + tem->obstack = expression_obstack; + momentary_stack = tem; + expression_obstack = &momentary_obstack; +} + +/* Free all the storage in the current momentary-allocation level. + In C, this happens at the end of each statement. */ + +void +clear_momentary () +{ + obstack_free (&momentary_obstack, momentary_stack->base); +} + +/* Discard a level of momentary allocation. + In C, this happens at the end of each compound statement. + Restore the status of expression node allocation + that was in effect before this level was created. */ + +void +pop_momentary () +{ + struct momentary_level *tem = momentary_stack; + momentary_stack = tem->prev; + expression_obstack = tem->obstack; + obstack_free (&momentary_obstack, tem); +} + +/* Call when starting to parse a declaration: + make expressions in the declaration last the length of the function. + Returns an argument that should be passed to resume_momentary later. */ + +int +suspend_momentary () +{ + register int tem = expression_obstack == &momentary_obstack; + expression_obstack = saveable_obstack; + return tem; +} + +/* Call when finished parsing a declaration: + restore the treatment of node-allocation that was + in effect before the suspension. + YES should be the value previously returned by suspend_momentary. */ + +void +resume_momentary (yes) + int yes; +{ + if (yes) + expression_obstack = &momentary_obstack; +} + +/* Init the tables indexed by tree code. + Note that languages can add to these tables to define their own codes. */ + +void +init_tree_codes () +{ + tree_code_type = (char **) xmalloc (sizeof (standard_tree_code_type)); + tree_code_length = (int *) xmalloc (sizeof (standard_tree_code_length)); + tree_code_name = (char **) xmalloc (sizeof (standard_tree_code_name)); + bcopy (standard_tree_code_type, tree_code_type, + sizeof (standard_tree_code_type)); + bcopy (standard_tree_code_length, tree_code_length, + sizeof (standard_tree_code_length)); + bcopy (standard_tree_code_name, tree_code_name, + sizeof (standard_tree_code_name)); +} + +/* Return a newly allocated node of code CODE. + Initialize the node's unique id and its TREE_PERMANENT flag. + For decl and type nodes, some other fields are initialized. + The rest of the node is initialized to zero. + + Achoo! I got a code in the node. */ + +tree +make_node (code) + enum tree_code code; +{ + register tree t; + register int type = TREE_CODE_CLASS (code); + register int length; + register struct obstack *obstack = current_obstack; + register int i; + register tree_node_kind kind; + + switch (type) + { + case 'd': /* A decl node */ +#ifdef GATHER_STATISTICS + kind = d_kind; +#endif + length = sizeof (struct tree_decl); + /* All decls in an inline function need to be saved. */ + if (obstack != &permanent_obstack) + obstack = saveable_obstack; + /* PARM_DECLs always go on saveable_obstack, not permanent, + even though we may make them before the function turns + on temporary allocation. */ + else if (code == PARM_DECL) + obstack = function_maybepermanent_obstack; + break; + + case 't': /* a type node */ +#ifdef GATHER_STATISTICS + kind = t_kind; +#endif + length = sizeof (struct tree_type); + /* All data types are put where we can preserve them if nec. */ + if (obstack != &permanent_obstack) + obstack = all_types_permanent ? &permanent_obstack : saveable_obstack; + break; + + case 's': /* an expression with side effects */ +#ifdef GATHER_STATISTICS + kind = s_kind; + goto usual_kind; +#endif + case 'r': /* a reference */ +#ifdef GATHER_STATISTICS + kind = r_kind; + goto usual_kind; +#endif + case 'e': /* an expression */ + case '<': /* a comparison expression */ + case '1': /* a unary arithmetic expression */ + case '2': /* a binary arithmetic expression */ +#ifdef GATHER_STATISTICS + kind = e_kind; + usual_kind: +#endif + obstack = expression_obstack; + /* All BLOCK nodes are put where we can preserve them if nec. + Also their potential controllers. */ + if ((code == BLOCK || code == BIND_EXPR) + && obstack != &permanent_obstack) + obstack = saveable_obstack; + length = sizeof (struct tree_exp) + + (tree_code_length[(int) code] - 1) * sizeof (char *); + break; + + case 'c': /* a constant */ +#ifdef GATHER_STATISTICS + kind = c_kind; +#endif + obstack = expression_obstack; + /* We can't use tree_code_length for this, since the number of words + is machine-dependent due to varying alignment of `double'. */ + if (code == REAL_CST) + { + length = sizeof (struct tree_real_cst); + break; + } + + case 'x': /* something random, like an identifier. */ +#ifdef GATHER_STATISTICS + if (code == IDENTIFIER_NODE) + kind = id_kind; + else if (code == OP_IDENTIFIER) + kind = op_id_kind; + else if (code == TREE_VEC) + kind = vec_kind; + else + kind = x_kind; +#endif + length = sizeof (struct tree_common) + + tree_code_length[(int) code] * sizeof (char *); + /* Identifier nodes are always permanent since they are + unique in a compiler run. */ + if (code == IDENTIFIER_NODE) obstack = &permanent_obstack; + } + + t = (tree) obstack_alloc (obstack, length); + +#ifdef GATHER_STATISTICS + tree_node_counts[(int)kind]++; + tree_node_sizes[(int)kind] += length; +#endif + + TREE_TYPE (t) = 0; + TREE_CHAIN (t) = 0; + for (i = (length / sizeof (int)) - 1; + i >= sizeof (struct tree_common) / sizeof (int) - 1; + i--) + ((int *) t)[i] = 0; + + TREE_SET_CODE (t, code); + if (obstack == &permanent_obstack) + TREE_PERMANENT (t) = 1; + + switch (type) + { + case 's': + TREE_SIDE_EFFECTS (t) = 1; + TREE_TYPE (t) = void_type_node; + break; + + case 'd': + DECL_ALIGN (t) = 1; + DECL_SOURCE_LINE (t) = lineno; + DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : ""; + break; + + case 't': + { + static unsigned next_type_uid = 1; + + TYPE_UID (t) = next_type_uid++; + } + TYPE_ALIGN (t) = 1; + TYPE_MAIN_VARIANT (t) = t; + break; + + case 'c': + TREE_CONSTANT (t) = 1; + break; + } + + return t; +} + +/* Return a new node with the same contents as NODE + except that its TREE_CHAIN is zero and it has a fresh uid. */ + +tree +copy_node (node) + tree node; +{ + register tree t; + register enum tree_code code = TREE_CODE (node); + register int length; + register int i; + + switch (TREE_CODE_CLASS (code)) + { + case 'd': /* A decl node */ + length = sizeof (struct tree_decl); + break; + + case 't': /* a type node */ + length = sizeof (struct tree_type); + break; + + case 'r': /* a reference */ + case 'e': /* a expression */ + case 's': /* an expression with side effects */ + case '<': /* a comparison expression */ + case '1': /* a unary arithmetic expression */ + case '2': /* a binary arithmetic expression */ + length = sizeof (struct tree_exp) + + (tree_code_length[(int) code] - 1) * sizeof (char *); + break; + + case 'c': /* a constant */ + /* We can't use tree_code_length for this, since the number of words + is machine-dependent due to varying alignment of `double'. */ + if (code == REAL_CST) + { + length = sizeof (struct tree_real_cst); + break; + } + + case 'x': /* something random, like an identifier. */ + length = sizeof (struct tree_common) + + tree_code_length[(int) code] * sizeof (char *); + if (code == TREE_VEC) + length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *); + } + + t = (tree) obstack_alloc (current_obstack, length); + + for (i = ((length + sizeof (int) - 1) / sizeof (int)) - 1; + i >= 0; + i--) + ((int *) t)[i] = ((int *) node)[i]; + + TREE_CHAIN (t) = 0; + + TREE_PERMANENT (t) = (current_obstack == &permanent_obstack); + + return t; +} + +/* Return a copy of a chain of nodes, chained through the TREE_CHAIN field. + For example, this can copy a list made of TREE_LIST nodes. */ + +tree +copy_list (list) + tree list; +{ + tree head; + register tree prev, next; + + if (list == 0) + return 0; + + head = prev = copy_node (list); + next = TREE_CHAIN (list); + while (next) + { + TREE_CHAIN (prev) = copy_node (next); + prev = TREE_CHAIN (prev); + next = TREE_CHAIN (next); + } + return head; +} + +#define HASHBITS 30 + +/* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string). + If an identifier with that name has previously been referred to, + the same node is returned this time. */ + +tree +get_identifier (text) + register char *text; +{ + register int hi; + register int i; + register tree idp; + register int len, hash_len; + + /* Compute length of text in len. */ + for (len = 0; text[len]; len++); + + /* Decide how much of that length to hash on */ + hash_len = len; + if (warn_id_clash && len > id_clash_len) + hash_len = id_clash_len; + + /* Compute hash code */ + hi = hash_len * 613 + (unsigned)text[0]; + for (i = 1; i < hash_len; i += 2) + hi = ((hi * 613) + (unsigned)(text[i])); + + hi &= (1 << HASHBITS) - 1; + hi %= MAX_HASH_TABLE; + + /* Search table for identifier */ + for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp)) + if (IDENTIFIER_LENGTH (idp) == len + && IDENTIFIER_POINTER (idp)[0] == text[0] + && !bcmp (IDENTIFIER_POINTER (idp), text, len)) + return idp; /* <-- return if found */ + + /* Not found; optionally warn about a similar identifier */ + if (warn_id_clash && do_identifier_warnings && len >= id_clash_len) + for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp)) + if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len)) + { + warning ("`%s' and `%s' identical in first %d characters", + IDENTIFIER_POINTER (idp), text, id_clash_len); + break; + } + + if (tree_code_length[(int) IDENTIFIER_NODE] < 0) + abort (); /* set_identifier_size hasn't been called. */ + + /* Not found, create one, add to chain */ + idp = make_node (IDENTIFIER_NODE); + IDENTIFIER_LENGTH (idp) = len; +#ifdef GATHER_STATISTICS + id_string_size += len; +#endif + + IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len); + + TREE_CHAIN (idp) = hash_table[hi]; + hash_table[hi] = idp; + return idp; /* <-- return if created */ +} + +/* Enable warnings on similar identifiers (if requested). + Done after the built-in identifiers are created. */ + +void +start_identifier_warnings () +{ + do_identifier_warnings = 1; +} + +/* Record the size of an identifier node for the language in use. + SIZE is the total size in bytes. + This is called by the language-specific files. This must be + called before allocating any identifiers. */ + +void +set_identifier_size (size) + int size; +{ + tree_code_length[(int) IDENTIFIER_NODE] + = (size - sizeof (struct tree_common)) / sizeof (tree); +} + +/* Return a newly constructed INTEGER_CST node whose constant value + is specified by the two ints LOW and HI. + The TREE_TYPE is set to `int'. */ + +tree +build_int_2 (low, hi) + int low, hi; +{ + register tree t = make_node (INTEGER_CST); + TREE_INT_CST_LOW (t) = low; + TREE_INT_CST_HIGH (t) = hi; + TREE_TYPE (t) = integer_type_node; + return t; +} + +/* Return a new REAL_CST node whose type is TYPE and value is D. */ + +tree +build_real (type, d) + tree type; + REAL_VALUE_TYPE d; +{ + tree v; + + /* Check for valid float value for this type on this target machine; + if not, can print error message and store a valid value in D. */ +#ifdef CHECK_FLOAT_VALUE + CHECK_FLOAT_VALUE (TYPE_MODE (type), d); +#endif + + v = make_node (REAL_CST); + TREE_TYPE (v) = type; + TREE_REAL_CST (v) = d; + return v; +} + +/* Return a new REAL_CST node whose type is TYPE + and whose value is the integer value of the INTEGER_CST node I. */ + +#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) + +REAL_VALUE_TYPE +real_value_from_int_cst (i) + tree i; +{ + REAL_VALUE_TYPE d; +#ifdef REAL_ARITHMETIC + REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i)); +#else /* not REAL_ARITHMETIC */ + if (TREE_INT_CST_HIGH (i) < 0) + { + d = (double) (~ TREE_INT_CST_HIGH (i)); + d *= ((double) (1 << (HOST_BITS_PER_INT / 2)) + * (double) (1 << (HOST_BITS_PER_INT / 2))); + d += (double) (unsigned) (~ TREE_INT_CST_LOW (i)); + d = (- d - 1.0); + } + else + { + d = (double) TREE_INT_CST_HIGH (i); + d *= ((double) (1 << (HOST_BITS_PER_INT / 2)) + * (double) (1 << (HOST_BITS_PER_INT / 2))); + d += (double) (unsigned) TREE_INT_CST_LOW (i); + } +#endif /* not REAL_ARITHMETIC */ + return d; +} + +/* This function can't be implemented if we can't do arithmetic + on the float representation. */ + +tree +build_real_from_int_cst (type, i) + tree type; + tree i; +{ + tree v; + REAL_VALUE_TYPE d; + + v = make_node (REAL_CST); + TREE_TYPE (v) = type; + + d = real_value_from_int_cst (i); + /* Check for valid float value for this type on this target machine; + if not, can print error message and store a valid value in D. */ +#ifdef CHECK_FLOAT_VALUE + CHECK_FLOAT_VALUE (TYPE_MODE (type), d); +#endif + + TREE_REAL_CST (v) = d; + return v; +} + +#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ + +/* Return a newly constructed STRING_CST node whose value is + the LEN characters at STR. + The TREE_TYPE is not initialized. */ + +tree +build_string (len, str) + int len; + char *str; +{ + register tree s = make_node (STRING_CST); + TREE_STRING_LENGTH (s) = len; + TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len); + return s; +} + +/* Return a newly constructed COMPLEX_CST node whose value is + specified by the real and imaginary parts REAL and IMAG. + Both REAL and IMAG should be constant nodes. + The TREE_TYPE is not initialized. */ + +tree +build_complex (real, imag) + tree real, imag; +{ + register tree t = make_node (COMPLEX_CST); + TREE_REALPART (t) = real; + TREE_IMAGPART (t) = imag; + return t; +} + +/* Build a newly constructed TREE_VEC node of length LEN. */ +tree +make_tree_vec (len) + int len; +{ + register tree t; + register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec); + register struct obstack *obstack = current_obstack; + register int i; + +#ifdef GATHER_STATISTICS + tree_node_counts[(int)vec_kind]++; + tree_node_sizes[(int)vec_kind] += length; +#endif + + t = (tree) obstack_alloc (obstack, length); + + TREE_TYPE (t) = 0; + TREE_CHAIN (t) = 0; + for (i = (length / sizeof (int)) - 1; + i >= sizeof (struct tree_common) / sizeof (int) - 1; + i--) + ((int *) t)[i] = 0; + TREE_SET_CODE (t, TREE_VEC); + TREE_VEC_LENGTH (t) = len; + if (obstack == &permanent_obstack) + TREE_PERMANENT (t) = 1; + + return t; +} + +/* Return 1 if EXPR is the integer constant zero. */ + +int +integer_zerop (expr) + tree expr; +{ + while (TREE_CODE (expr) == NON_LVALUE_EXPR) + expr = TREE_OPERAND (expr, 0); + + return (TREE_CODE (expr) == INTEGER_CST + && TREE_INT_CST_LOW (expr) == 0 + && TREE_INT_CST_HIGH (expr) == 0); +} + +/* Return 1 if EXPR is the integer constant one. */ + +int +integer_onep (expr) + tree expr; +{ + while (TREE_CODE (expr) == NON_LVALUE_EXPR) + expr = TREE_OPERAND (expr, 0); + + return (TREE_CODE (expr) == INTEGER_CST + && TREE_INT_CST_LOW (expr) == 1 + && TREE_INT_CST_HIGH (expr) == 0); +} + +/* Return 1 if EXPR is an integer containing all 1's + in as much precision as it contains. */ + +int +integer_all_onesp (expr) + tree expr; +{ + register int prec; + register int uns; + + while (TREE_CODE (expr) == NON_LVALUE_EXPR) + expr = TREE_OPERAND (expr, 0); + + if (TREE_CODE (expr) != INTEGER_CST) + return 0; + + uns = TREE_UNSIGNED (TREE_TYPE (expr)); + if (!uns) + return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1; + + prec = TYPE_PRECISION (TREE_TYPE (expr)); + if (prec >= HOST_BITS_PER_INT) + { + int high_value, shift_amount; + + shift_amount = prec - HOST_BITS_PER_INT; + + if (shift_amount > HOST_BITS_PER_INT) + /* Can not handle precisions greater than twice the host int size. */ + abort (); + else if (shift_amount == HOST_BITS_PER_INT) + /* Shifting by the host word size is undefined according to the ANSI + standard, so we must handle this as a special case. */ + high_value = -1; + else + high_value = (1 << shift_amount) - 1; + + return TREE_INT_CST_LOW (expr) == -1 + && TREE_INT_CST_HIGH (expr) == high_value; + } + else + return TREE_INT_CST_LOW (expr) == (1 << prec) - 1; +} + +/* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only + one bit on). */ + +int +integer_pow2p (expr) + tree expr; +{ + int high, low; + + while (TREE_CODE (expr) == NON_LVALUE_EXPR) + expr = TREE_OPERAND (expr, 0); + + if (TREE_CODE (expr) != INTEGER_CST) + return 0; + + high = TREE_INT_CST_HIGH (expr); + low = TREE_INT_CST_LOW (expr); + + if (high == 0 && low == 0) + return 0; + + return ((high == 0 && (low & (low - 1)) == 0) + || (low == 0 && (high & (high - 1)) == 0)); +} + +/* Return 1 if EXPR is the real constant zero. */ + +int +real_zerop (expr) + tree expr; +{ + while (TREE_CODE (expr) == NON_LVALUE_EXPR) + expr = TREE_OPERAND (expr, 0); + + return (TREE_CODE (expr) == REAL_CST + && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0)); +} + +/* Return 1 if EXPR is the real constant one. */ + +int +real_onep (expr) + tree expr; +{ + while (TREE_CODE (expr) == NON_LVALUE_EXPR) + expr = TREE_OPERAND (expr, 0); + + return (TREE_CODE (expr) == REAL_CST + && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1)); +} + +/* Return 1 if EXPR is the real constant two. */ + +int +real_twop (expr) + tree expr; +{ + while (TREE_CODE (expr) == NON_LVALUE_EXPR) + expr = TREE_OPERAND (expr, 0); + + return (TREE_CODE (expr) == REAL_CST + && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2)); +} + +/* Nonzero if EXP is a constant or a cast of a constant. */ + +int +really_constant_p (exp) + tree exp; +{ + while (TREE_CODE (exp) == NOP_EXPR + || TREE_CODE (exp) == CONVERT_EXPR + || TREE_CODE (exp) == NON_LVALUE_EXPR) + exp = TREE_OPERAND (exp, 0); + return TREE_CONSTANT (exp); +} + +/* Return first list element whose TREE_VALUE is ELEM. + Return 0 if ELEM is not it LIST. */ + +tree +value_member (elem, list) + tree elem, list; +{ + while (list) + { + if (elem == TREE_VALUE (list)) + return list; + list = TREE_CHAIN (list); + } + return NULL_TREE; +} + +/* Return first list element whose TREE_PURPOSE is ELEM. + Return 0 if ELEM is not it LIST. */ + +tree +purpose_member (elem, list) + tree elem, list; +{ + while (list) + { + if (elem == TREE_PURPOSE (list)) + return list; + list = TREE_CHAIN (list); + } + return NULL_TREE; +} + +/* Return first list element whose BINFO_TYPE is ELEM. + Return 0 if ELEM is not it LIST. */ + +tree +binfo_member (elem, list) + tree elem, list; +{ + while (list) + { + if (elem == BINFO_TYPE (list)) + return list; + list = TREE_CHAIN (list); + } + return NULL_TREE; +} + +/* Return nonzero if ELEM is part of the chain CHAIN. */ + +int +chain_member (elem, chain) + tree elem, chain; +{ + while (chain) + { + if (elem == chain) + return 1; + chain = TREE_CHAIN (chain); + } + + return 0; +} + +/* Return the length of a chain of nodes chained through TREE_CHAIN. + We expect a null pointer to mark the end of the chain. + This is the Lisp primitive `length'. */ + +int +list_length (t) + tree t; +{ + register tree tail; + register int len = 0; + + for (tail = t; tail; tail = TREE_CHAIN (tail)) + len++; + + return len; +} + +/* Concatenate two chains of nodes (chained through TREE_CHAIN) + by modifying the last node in chain 1 to point to chain 2. + This is the Lisp primitive `nconc'. */ + +tree +chainon (op1, op2) + tree op1, op2; +{ + tree t; + + if (op1) + { + for (t = op1; TREE_CHAIN (t); t = TREE_CHAIN (t)) + if (t == op2) abort (); /* Circularity being created */ + TREE_CHAIN (t) = op2; + return op1; + } + else return op2; +} + +/* Return the last node in a chain of nodes (chained through TREE_CHAIN). */ + +tree +tree_last (chain) + register tree chain; +{ + register tree next; + if (chain) + while (next = TREE_CHAIN (chain)) + chain = next; + return chain; +} + +/* Reverse the order of elements in the chain T, + and return the new head of the chain (old last element). */ + +tree +nreverse (t) + tree t; +{ + register tree prev = 0, decl, next; + for (decl = t; decl; decl = next) + { + next = TREE_CHAIN (decl); + TREE_CHAIN (decl) = prev; + prev = decl; + } + return prev; +} + +/* Given a chain CHAIN of tree nodes, + construct and return a list of those nodes. */ + +tree +listify (chain) + tree chain; +{ + tree result = NULL_TREE; + tree in_tail = chain; + tree out_tail = NULL_TREE; + + while (in_tail) + { + tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE); + if (out_tail) + TREE_CHAIN (out_tail) = next; + else + result = next; + out_tail = next; + in_tail = TREE_CHAIN (in_tail); + } + + return result; +} + +/* Return a newly created TREE_LIST node whose + purpose and value fields are PARM and VALUE. */ + +tree +build_tree_list (parm, value) + tree parm, value; +{ + register tree t = make_node (TREE_LIST); + TREE_PURPOSE (t) = parm; + TREE_VALUE (t) = value; + return t; +} + +/* Similar, but build on the temp_decl_obstack. */ + +tree +build_decl_list (parm, value) + tree parm, value; +{ + register tree node; + register struct obstack *ambient_obstack = current_obstack; + current_obstack = &temp_decl_obstack; + node = build_tree_list (parm, value); + current_obstack = ambient_obstack; + return node; +} + +/* Return a newly created TREE_LIST node whose + purpose and value fields are PARM and VALUE + and whose TREE_CHAIN is CHAIN. */ + +tree +tree_cons (purpose, value, chain) + tree purpose, value, chain; +{ +#if 0 + register tree node = make_node (TREE_LIST); +#else + register int i; + register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list)); +#ifdef GATHER_STATISTICS + tree_node_counts[(int)x_kind]++; + tree_node_sizes[(int)x_kind] += sizeof (struct tree_list); +#endif + + ((int *)node)[(sizeof (struct tree_common)/sizeof (int)) - 1] = 0; + TREE_SET_CODE (node, TREE_LIST); + if (current_obstack == &permanent_obstack) + TREE_PERMANENT (node) = 1; + TREE_TYPE (node) = 0; +#endif + + TREE_CHAIN (node) = chain; + TREE_PURPOSE (node) = purpose; + TREE_VALUE (node) = value; + return node; +} + +/* Similar, but build on the temp_decl_obstack. */ + +tree +decl_tree_cons (purpose, value, chain) + tree purpose, value, chain; +{ + register tree node; + register struct obstack *ambient_obstack = current_obstack; + current_obstack = &temp_decl_obstack; + node = tree_cons (purpose, value, chain); + current_obstack = ambient_obstack; + return node; +} + +/* Same as `tree_cons' but make a permanent object. */ + +tree +perm_tree_cons (purpose, value, chain) + tree purpose, value, chain; +{ + register tree node; + register struct obstack *ambient_obstack = current_obstack; + current_obstack = &permanent_obstack; + + node = tree_cons (purpose, value, chain); + current_obstack = ambient_obstack; + return node; +} + +/* Same as `tree_cons', but make this node temporary, regardless. */ + +tree +temp_tree_cons (purpose, value, chain) + tree purpose, value, chain; +{ + register tree node; + register struct obstack *ambient_obstack = current_obstack; + current_obstack = &temporary_obstack; + + node = tree_cons (purpose, value, chain); + current_obstack = ambient_obstack; + return node; +} + +/* Same as `tree_cons', but save this node if the function's RTL is saved. */ + +tree +saveable_tree_cons (purpose, value, chain) + tree purpose, value, chain; +{ + register tree node; + register struct obstack *ambient_obstack = current_obstack; + current_obstack = saveable_obstack; + + node = tree_cons (purpose, value, chain); + current_obstack = ambient_obstack; + return node; +} + +/* Return the size nominally occupied by an object of type TYPE + when it resides in memory. The value is measured in units of bytes, + and its data type is that normally used for type sizes + (which is the first type created by make_signed_type or + make_unsigned_type). */ + +tree +size_in_bytes (type) + tree type; +{ + if (type == error_mark_node) + return integer_zero_node; + type = TYPE_MAIN_VARIANT (type); + if (TYPE_SIZE (type) == 0) + { + incomplete_type_error (0, type); + return integer_zero_node; + } + return size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type), + size_int (BITS_PER_UNIT)); +} + +/* Return the size of TYPE (in bytes) as an integer, + or return -1 if the size can vary. */ + +int +int_size_in_bytes (type) + tree type; +{ + int size; + if (type == error_mark_node) + return 0; + type = TYPE_MAIN_VARIANT (type); + if (TYPE_SIZE (type) == 0) + return -1; + if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) + return -1; + size = TREE_INT_CST_LOW (TYPE_SIZE (type)); + return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT; +} + +/* Return, as an INTEGER_CST node, the number of elements for + TYPE (which is an ARRAY_TYPE). */ + +tree +array_type_nelts (type) + tree type; +{ + tree index_type = TYPE_DOMAIN (type); + return (tree_int_cst_equal (TYPE_MIN_VALUE (index_type), integer_zero_node) + ? TYPE_MAX_VALUE (index_type) + : fold (build (MINUS_EXPR, integer_type_node, + TYPE_MAX_VALUE (index_type), + TYPE_MIN_VALUE (index_type)))); +} + +/* Return nonzero if arg is static -- a reference to an object in + static storage. This is not the same as the C meaning of `static'. */ + +int +staticp (arg) + tree arg; +{ + switch (TREE_CODE (arg)) + { + case VAR_DECL: + case FUNCTION_DECL: + case CONSTRUCTOR: + return TREE_STATIC (arg) || TREE_EXTERNAL (arg); + + case STRING_CST: + return 1; + + case COMPONENT_REF: + case BIT_FIELD_REF: + return staticp (TREE_OPERAND (arg, 0)); + + case INDIRECT_REF: + return TREE_CONSTANT (TREE_OPERAND (arg, 0)); + + case ARRAY_REF: + if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST + && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST) + return staticp (TREE_OPERAND (arg, 0)); + } + + return 0; +} + +/* This should be applied to any node which may be used in more than one place, + but must be evaluated only once. Normally, the code generator would + reevaluate the node each time; this forces it to compute it once and save + the result. This is done by encapsulating the node in a SAVE_EXPR. */ + +tree +save_expr (expr) + tree expr; +{ + register tree t = fold (expr); + + /* We don't care about whether this can be used as an lvalue in this + context. */ + while (TREE_CODE (t) == NON_LVALUE_EXPR) + t = TREE_OPERAND (t, 0); + + /* If the tree evaluates to a constant, then we don't want to hide that + fact (i.e. this allows further folding, and direct checks for constants). + Since it is no problem to reevaluate literals, we just return the + literal node. */ + + if (TREE_CONSTANT (t) || TREE_READONLY (t) || TREE_CODE (t) == SAVE_EXPR) + return t; + + t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL); + + /* This expression might be placed ahead of a jump to ensure that the + value was computed on both sides of the jump. So make sure it isn't + eliminated as dead. */ + TREE_SIDE_EFFECTS (t) = 1; + return t; +} + +/* Stabilize a reference so that we can use it any number of times + without causing its operands to be evaluated more than once. + Returns the stabilized reference. + + Also allows conversion expressions whose operands are references. + Any other kind of expression is returned unchanged. */ + +tree +stabilize_reference (ref) + tree ref; +{ + register tree result; + register enum tree_code code = TREE_CODE (ref); + + switch (code) + { + case VAR_DECL: + case PARM_DECL: + case RESULT_DECL: + /* No action is needed in this case. */ + return ref; + + case NOP_EXPR: + case CONVERT_EXPR: + case FLOAT_EXPR: + case FIX_TRUNC_EXPR: + case FIX_FLOOR_EXPR: + case FIX_ROUND_EXPR: + case FIX_CEIL_EXPR: + result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0))); + break; + + case INDIRECT_REF: + result = build_nt (INDIRECT_REF, + stabilize_reference_1 (TREE_OPERAND (ref, 0))); + break; + + case COMPONENT_REF: + result = build_nt (COMPONENT_REF, + stabilize_reference (TREE_OPERAND (ref, 0)), + TREE_OPERAND (ref, 1)); + break; + + case BIT_FIELD_REF: + result = build_nt (BIT_FIELD_REF, + stabilize_reference (TREE_OPERAND (ref, 0)), + stabilize_reference_1 (TREE_OPERAND (ref, 1)), + stabilize_reference_1 (TREE_OPERAND (ref, 2))); + break; + + case ARRAY_REF: + result = build_nt (ARRAY_REF, + stabilize_reference (TREE_OPERAND (ref, 0)), + stabilize_reference_1 (TREE_OPERAND (ref, 1))); + break; + + /* If arg isn't a kind of lvalue we recognize, make no change. + Caller should recognize the error for an invalid lvalue. */ + default: + return ref; + + case ERROR_MARK: + return error_mark_node; + } + + TREE_TYPE (result) = TREE_TYPE (ref); + TREE_READONLY (result) = TREE_READONLY (ref); + TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref); + TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref); + TREE_RAISES (result) = TREE_RAISES (ref); + + return result; +} + +/* Subroutine of stabilize_reference; this is called for subtrees of + references. Any expression with side-effects must be put in a SAVE_EXPR + to ensure that it is only evaluated once. + + We don't put SAVE_EXPR nodes around everything, because assigning very + simple expressions to temporaries causes us to miss good opportunities + for optimizations. Among other things, the opportunity to fold in the + addition of a constant into an addressing mode often gets lost, e.g. + "y[i+1] += x;". In general, we take the approach that we should not make + an assignment unless we are forced into it - i.e., that any non-side effect + operator should be allowed, and that cse should take care of coalescing + multiple utterances of the same expression should that prove fruitful. */ + +static tree +stabilize_reference_1 (e) + tree e; +{ + register tree result; + register int length; + register enum tree_code code = TREE_CODE (e); + + if (TREE_CONSTANT (e) || TREE_READONLY (e) || code == SAVE_EXPR) + return e; + + switch (TREE_CODE_CLASS (code)) + { + case 'x': + case 't': + case 'd': + case '<': + case 's': + case 'e': + case 'r': + /* If the expression has side-effects, then encase it in a SAVE_EXPR + so that it will only be evaluated once. */ + /* The reference (r) and comparison (<) classes could be handled as + below, but it is generally faster to only evaluate them once. */ + if (TREE_SIDE_EFFECTS (e)) + return save_expr (e); + return e; + + case 'c': + /* Constants need no processing. In fact, we should never reach + here. */ + return e; + + case '2': + /* Recursively stabilize each operand. */ + result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)), + stabilize_reference_1 (TREE_OPERAND (e, 1))); + break; + + case '1': + /* Recursively stabilize each operand. */ + result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0))); + break; + } + + TREE_TYPE (result) = TREE_TYPE (e); + TREE_READONLY (result) = TREE_READONLY (e); + TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e); + TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e); + TREE_RAISES (result) = TREE_RAISES (e); + + return result; +} + +/* Low-level constructors for expressions. */ + +/* Build an expression of code CODE, data type TYPE, + and operands as specified by the arguments ARG1 and following arguments. + Expressions and reference nodes can be created this way. + Constants, decls, types and misc nodes cannot be. */ + +tree +build (va_alist) + va_dcl +{ + va_list p; + enum tree_code code; + register tree t; + register int length; + register int i; + + va_start (p); + + code = va_arg (p, enum tree_code); + t = make_node (code); + length = tree_code_length[(int) code]; + TREE_TYPE (t) = va_arg (p, tree); + + if (length == 2) + { + /* This is equivalent to the loop below, but faster. */ + register tree arg0 = va_arg (p, tree); + register tree arg1 = va_arg (p, tree); + TREE_OPERAND (t, 0) = arg0; + TREE_OPERAND (t, 1) = arg1; + if ((arg0 && TREE_SIDE_EFFECTS (arg0)) + || (arg1 && TREE_SIDE_EFFECTS (arg1))) + TREE_SIDE_EFFECTS (t) = 1; + TREE_RAISES (t) + = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1)); + } + else if (length == 1) + { + register tree arg0 = va_arg (p, tree); + + /* Call build1 for this! */ + if (TREE_CODE_CLASS (code) != 's') + abort (); + TREE_OPERAND (t, 0) = arg0; + if (arg0 && TREE_SIDE_EFFECTS (arg0)) + TREE_SIDE_EFFECTS (t) = 1; + TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0)); + } + else + { + for (i = 0; i < length; i++) + { + register tree operand = va_arg (p, tree); + TREE_OPERAND (t, i) = operand; + if (operand) + { + if (TREE_SIDE_EFFECTS (operand)) + TREE_SIDE_EFFECTS (t) = 1; + if (TREE_RAISES (operand)) + TREE_RAISES (t) = 1; + } + } + } + va_end (p); + return t; +} + +/* Same as above, but only builds for unary operators. + Saves lions share of calls to `build'; cuts down use + of varargs, which is expensive for RISC machines. */ +tree +build1 (code, type, node) + enum tree_code code; + tree type; + tree node; +{ + register struct obstack *obstack = current_obstack; + register int i, length; + register tree_node_kind kind; + register tree t; + +#ifdef GATHER_STATISTICS + if (TREE_CODE_CLASS (code) == 'r') + kind = r_kind; + else + kind = e_kind; +#endif + + obstack = expression_obstack; + length = sizeof (struct tree_exp); + + t = (tree) obstack_alloc (obstack, length); + +#ifdef GATHER_STATISTICS + tree_node_counts[(int)kind]++; + tree_node_sizes[(int)kind] += length; +#endif + + TREE_TYPE (t) = type; + TREE_CHAIN (t) = 0; + + for (i = (length / sizeof (int)) - 2; + i >= sizeof (struct tree_common) / sizeof (int) - 1; + i--) + ((int *) t)[i] = 0; + TREE_SET_CODE (t, code); + + if (obstack == &permanent_obstack) + TREE_PERMANENT (t) = 1; + + TREE_OPERAND (t, 0) = node; + if (node) + { + if (TREE_SIDE_EFFECTS (node)) + TREE_SIDE_EFFECTS (t) = 1; + if (TREE_RAISES (node)) + TREE_RAISES (t) = 1; + } + + return t; +} + +/* Similar except don't specify the TREE_TYPE + and leave the TREE_SIDE_EFFECTS as 0. + It is permissible for arguments to be null, + or even garbage if their values do not matter. */ + +tree +build_nt (va_alist) + va_dcl +{ + va_list p; + register enum tree_code code; + register tree t; + register int length; + register int i; + + va_start (p); + + code = va_arg (p, enum tree_code); + t = make_node (code); + length = tree_code_length[(int) code]; + + for (i = 0; i < length; i++) + TREE_OPERAND (t, i) = va_arg (p, tree); + + va_end (p); + return t; +} + +/* Similar to `build_nt', except we build + on the temp_decl_obstack, regardless. */ + +tree +build_parse_node (va_alist) + va_dcl +{ + register struct obstack *ambient_obstack = expression_obstack; + va_list p; + register enum tree_code code; + register tree t; + register int length; + register int i; + + expression_obstack = &temp_decl_obstack; + + va_start (p); + + code = va_arg (p, enum tree_code); + t = make_node (code); + length = tree_code_length[(int) code]; + + for (i = 0; i < length; i++) + TREE_OPERAND (t, i) = va_arg (p, tree); + + va_end (p); + expression_obstack = ambient_obstack; + return t; +} + +#if 0 +/* Commented out because this wants to be done very + differently. See cp-lex.c. */ +tree +build_op_identifier (op1, op2) + tree op1, op2; +{ + register tree t = make_node (OP_IDENTIFIER); + TREE_PURPOSE (t) = op1; + TREE_VALUE (t) = op2; + return t; +} +#endif + +/* Create a DECL_... node of code CODE, name NAME and data type TYPE. + We do NOT enter this node in any sort of symbol table. + + layout_decl is used to set up the decl's storage layout. + Other slots are initialized to 0 or null pointers. */ + +tree +build_decl (code, name, type) + enum tree_code code; + tree name, type; +{ + register tree t; + + t = make_node (code); + +/* if (type == error_mark_node) + type = integer_type_node; */ +/* That is not done, deliberately, so that having error_mark_node + as the type can suppress useless errors in the use of this variable. */ + + DECL_NAME (t) = name; + DECL_ASSEMBLER_NAME (t) = name; + TREE_TYPE (t) = type; + + if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL) + layout_decl (t, 0); + else if (code == FUNCTION_DECL) + DECL_MODE (t) = FUNCTION_MODE; + + return t; +} + +/* BLOCK nodes are used to represent the structure of binding contours + and declarations, once those contours have been exited and their contents + compiled. This information is used for outputting debugging info. + A BLOCK may have a "controller" which is a BIND_EXPR node. + Then the BLOCK is ignored unless the controller has the TREE_USED flag. */ + +tree +build_block (vars, tags, subblocks, supercontext, chain) + tree vars, tags, subblocks, supercontext, chain; +{ + register tree block = make_node (BLOCK); + BLOCK_VARS (block) = vars; + BLOCK_TYPE_TAGS (block) = tags; + BLOCK_SUBBLOCKS (block) = subblocks; + BLOCK_SUPERCONTEXT (block) = supercontext; + BLOCK_CHAIN (block) = chain; + return block; +} + +/* Return a type like TYPE except that its TYPE_READONLY is CONSTP + and its TYPE_VOLATILE is VOLATILEP. + + Such variant types already made are recorded so that duplicates + are not made. + + A variant types should never be used as the type of an expression. + Always copy the variant information into the TREE_READONLY + and TREE_THIS_VOLATILE of the expression, and then give the expression + as its type the "main variant", the variant whose TYPE_READONLY + and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the + main variant. */ + +tree +build_type_variant (type, constp, volatilep) + tree type; + int constp, volatilep; +{ + register tree t, m = TYPE_MAIN_VARIANT (type); + register struct obstack *ambient_obstack = current_obstack; + + /* Treat any nonzero argument as 1. */ + constp = !!constp; + volatilep = !!volatilep; + + /* If not generating auxilliary info, search the chain of variants to see + if there is already one there just like the one we need to have. If so, + use that existing one. + + We don't do this in the case where we are generating aux info because + in that case we want each typedef names to get it's own distinct type + node, even if the type of this new typedef is the same as some other + (existing) type. */ + + if (!flag_gen_aux_info) + for (t = m; t; t = TYPE_NEXT_VARIANT (t)) + if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t)) + return t; + + /* We need a new one. */ + current_obstack + = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack; + + t = copy_node (type); + TYPE_READONLY (t) = constp; + TYPE_VOLATILE (t) = volatilep; + TYPE_POINTER_TO (t) = 0; + TYPE_REFERENCE_TO (t) = 0; + + /* Add this type to the chain of variants of TYPE. */ + TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m); + TYPE_NEXT_VARIANT (m) = t; + + current_obstack = ambient_obstack; + return t; +} + +/* Hashing of types so that we don't make duplicates. + The entry point is `type_hash_canon'. */ + +/* Each hash table slot is a bucket containing a chain + of these structures. */ + +struct type_hash +{ + struct type_hash *next; /* Next structure in the bucket. */ + int hashcode; /* Hash code of this type. */ + tree type; /* The type recorded here. */ +}; + +/* Now here is the hash table. When recording a type, it is added + to the slot whose index is the hash code mod the table size. + Note that the hash table is used for several kinds of types + (function types, array types and array index range types, for now). + While all these live in the same table, they are completely independent, + and the hash code is computed differently for each of these. */ + +#define TYPE_HASH_SIZE 59 +struct type_hash *type_hash_table[TYPE_HASH_SIZE]; + +/* Here is how primitive or already-canonicalized types' hash + codes are made. */ +#define TYPE_HASH(TYPE) ((int) (TYPE) & 0777777) + +/* Compute a hash code for a list of types (chain of TREE_LIST nodes + with types in the TREE_VALUE slots), by adding the hash codes + of the individual types. */ + +int +type_hash_list (list) + tree list; +{ + register int hashcode; + register tree tail; + for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail)) + hashcode += TYPE_HASH (TREE_VALUE (tail)); + return hashcode; +} + +/* Look in the type hash table for a type isomorphic to TYPE. + If one is found, return it. Otherwise return 0. */ + +tree +type_hash_lookup (hashcode, type) + int hashcode; + tree type; +{ + register struct type_hash *h; + for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next) + if (h->hashcode == hashcode + && TREE_CODE (h->type) == TREE_CODE (type) + && TREE_TYPE (h->type) == TREE_TYPE (type) + && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type) + || tree_int_cst_equal (TYPE_MAX_VALUE (h->type), + TYPE_MAX_VALUE (type))) + && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type) + || tree_int_cst_equal (TYPE_MIN_VALUE (h->type), + TYPE_MIN_VALUE (type))) + && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type) + || (TYPE_DOMAIN (h->type) + && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST + && TYPE_DOMAIN (type) + && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST + && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type))))) + return h->type; + return 0; +} + +/* Add an entry to the type-hash-table + for a type TYPE whose hash code is HASHCODE. */ + +void +type_hash_add (hashcode, type) + int hashcode; + tree type; +{ + register struct type_hash *h; + + h = (struct type_hash *) oballoc (sizeof (struct type_hash)); + h->hashcode = hashcode; + h->type = type; + h->next = type_hash_table[hashcode % TYPE_HASH_SIZE]; + type_hash_table[hashcode % TYPE_HASH_SIZE] = h; +} + +/* Given TYPE, and HASHCODE its hash code, return the canonical + object for an identical type if one already exists. + Otherwise, return TYPE, and record it as the canonical object + if it is a permanent object. + + To use this function, first create a type of the sort you want. + Then compute its hash code from the fields of the type that + make it different from other similar types. + Then call this function and use the value. + This function frees the type you pass in if it is a duplicate. */ + +/* Set to 1 to debug without canonicalization. Never set by program. */ +int debug_no_type_hash = 0; + +tree +type_hash_canon (hashcode, type) + int hashcode; + tree type; +{ + tree t1; + + if (debug_no_type_hash) + return type; + + t1 = type_hash_lookup (hashcode, type); + if (t1 != 0) + { + struct obstack *o + = TREE_PERMANENT (type) ? &permanent_obstack : saveable_obstack; + obstack_free (o, type); +#ifdef GATHER_STATISTICS + tree_node_counts[(int)t_kind]--; + tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type); +#endif + return t1; + } + + /* If this is a new type, record it for later reuse. */ + if (current_obstack == &permanent_obstack) + type_hash_add (hashcode, type); + + return type; +} + +/* Given two lists of types + (chains of TREE_LIST nodes with types in the TREE_VALUE slots) + return 1 if the lists contain the same types in the same order. + Also, the TREE_PURPOSEs must match. */ + +int +type_list_equal (l1, l2) + tree l1, l2; +{ + register tree t1, t2; + for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2)) + { + if (TREE_VALUE (t1) != TREE_VALUE (t2)) + return 0; + if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)) + { + int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2)); + if (cmp < 0) + abort (); + if (cmp == 0) + return 0; + } + } + + return t1 == t2; +} + +/* Nonzero if integer constants T1 and T2 + represent the same constant value. */ + +int +tree_int_cst_equal (t1, t2) + tree t1, t2; +{ + if (t1 == t2) + return 1; + if (t1 == 0 || t2 == 0) + return 0; + if (TREE_CODE (t1) == INTEGER_CST + && TREE_CODE (t2) == INTEGER_CST + && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2) + && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2)) + return 1; + return 0; +} + +/* Nonzero if integer constants T1 and T2 represent values that satisfy <. + The precise way of comparison depends on their data type. */ + +int +tree_int_cst_lt (t1, t2) + tree t1, t2; +{ + if (t1 == t2) + return 0; + + if (!TREE_UNSIGNED (TREE_TYPE (t1))) + return INT_CST_LT (t1, t2); + return INT_CST_LT_UNSIGNED (t1, t2); +} + +/* Compare two constructor-element-type constants. */ +int +simple_cst_list_equal (l1, l2) + tree l1, l2; +{ + while (l1 != NULL_TREE && l2 != NULL_TREE) + { + int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)); + if (cmp < 0) + abort (); + if (cmp == 0) + return 0; + l1 = TREE_CHAIN (l1); + l2 = TREE_CHAIN (l2); + } + return (l1 == l2); +} + +/* Return truthvalue of whether T1 is the same tree structure as T2. + Return 1 if they are the same. + Return 0 if they are understandably different. + Return -1 if either contains tree structure not understood by + this function. */ + +int +simple_cst_equal (t1, t2) + tree t1, t2; +{ + register enum tree_code code1, code2; + int cmp; + + if (t1 == t2) + return 1; + if (t1 == 0 || t2 == 0) + return 0; + + code1 = TREE_CODE (t1); + code2 = TREE_CODE (t2); + + if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR) + if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR) + return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); + else + return simple_cst_equal (TREE_OPERAND (t1, 0), t2); + else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR + || code2 == NON_LVALUE_EXPR) + return simple_cst_equal (t1, TREE_OPERAND (t2, 0)); + + if (code1 != code2) + return 0; + + switch (code1) + { + case INTEGER_CST: + return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2) + && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2); + + case REAL_CST: + return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2)); + + case STRING_CST: + return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2) + && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2), + TREE_STRING_LENGTH (t1)); + + case CONSTRUCTOR: + abort (); + + case SAVE_EXPR: + return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); + + case CALL_EXPR: + cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); + if (cmp <= 0) + return cmp; + return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)); + + case TARGET_EXPR: + /* Special case: if either target is an unallocated VAR_DECL, + it means that it's going to be unified with whatever the + TARGET_EXPR is really supposed to initialize, so treat it + as being equivalent to anything. */ + if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL + && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE + && DECL_RTL (TREE_OPERAND (t1, 0)) == 0) + || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL + && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE + && DECL_RTL (TREE_OPERAND (t2, 0)) == 0)) + cmp = 1; + else + cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); + if (cmp <= 0) + return cmp; + return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)); + + case WITH_CLEANUP_EXPR: + cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); + if (cmp <= 0) + return cmp; + return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2)); + + case COMPONENT_REF: + if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1)) + return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); + return 0; + + case BIT_FIELD_REF: + return (simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)) + && simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)) + && simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t2, 2))); + + case VAR_DECL: + case PARM_DECL: + case CONST_DECL: + case FUNCTION_DECL: + return 0; + + case PLUS_EXPR: + case MINUS_EXPR: + case MULT_EXPR: + case TRUNC_DIV_EXPR: + case TRUNC_MOD_EXPR: + case LSHIFT_EXPR: + case RSHIFT_EXPR: + cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); + if (cmp <= 0) + return cmp; + return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)); + + case NEGATE_EXPR: + case ADDR_EXPR: + case REFERENCE_EXPR: + case INDIRECT_REF: + return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); + + default: +#if 0 + return lang_simple_cst_equal (t1, t2); +#else + return -1; +#endif + } +} + +/* Constructors for pointer, array and function types. + (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are + constructed by language-dependent code, not here.) */ + +/* Construct, lay out and return the type of pointers to TO_TYPE. + If such a type has already been constructed, reuse it. */ + +tree +build_pointer_type (to_type) + tree to_type; +{ + register tree t = TYPE_POINTER_TO (to_type); + register struct obstack *ambient_obstack = current_obstack; + register struct obstack *ambient_saveable_obstack = saveable_obstack; + + /* First, if we already have a type for pointers to TO_TYPE, use it. */ + + if (t) + return t; + + /* We need a new one. If TO_TYPE is permanent, make this permanent too. */ + if (TREE_PERMANENT (to_type)) + { + current_obstack = &permanent_obstack; + saveable_obstack = &permanent_obstack; + } + + t = make_node (POINTER_TYPE); + TREE_TYPE (t) = to_type; + + /* Record this type as the pointer to TO_TYPE. */ + TYPE_POINTER_TO (to_type) = t; + + /* Lay out the type. This function has many callers that are concerned + with expression-construction, and this simplifies them all. + Also, it guarantees the TYPE_SIZE is permanent if the type is. */ + layout_type (t); + + current_obstack = ambient_obstack; + saveable_obstack = ambient_saveable_obstack; + return t; +} + +/* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE. + MAXVAL should be the maximum value in the domain + (one less than the length of the array). */ + +tree +build_index_type (maxval) + tree maxval; +{ + register tree itype = make_node (INTEGER_TYPE); + TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype); + TYPE_MIN_VALUE (itype) = build_int_2 (0, 0); + TREE_TYPE (TYPE_MIN_VALUE (itype)) = sizetype; + TYPE_MAX_VALUE (itype) = convert (sizetype, maxval); + TYPE_MODE (itype) = TYPE_MODE (sizetype); + TYPE_SIZE (itype) = TYPE_SIZE (sizetype); + TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype); + if (TREE_CODE (maxval) == INTEGER_CST) + { + int maxint = TREE_INT_CST_LOW (maxval); + return type_hash_canon (maxint > 0 ? maxint : - maxint, itype); + } + else + return itype; +} + +/* Just like build_index_type, but takes lowval and highval instead + of just highval (maxval). */ + +tree +build_index_2_type (lowval,highval) + tree lowval, highval; +{ + register tree itype = make_node (INTEGER_TYPE); + TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype); + TYPE_MIN_VALUE (itype) = convert (sizetype, lowval); + TYPE_MAX_VALUE (itype) = convert (sizetype, highval); + TYPE_MODE (itype) = TYPE_MODE (sizetype); + TYPE_SIZE (itype) = TYPE_SIZE (sizetype); + TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype); + if ((TREE_CODE (lowval) == INTEGER_CST) + && (TREE_CODE (highval) == INTEGER_CST)) + { + int highint = TREE_INT_CST_LOW (highval); + int lowint = TREE_INT_CST_LOW (lowval); + int maxint = highint - lowint; + return type_hash_canon (maxint > 0 ? maxint : - maxint, itype); + } + else + return itype; +} + +/* Return nonzero iff ITYPE1 and ITYPE2 are equal (in the LISP sense). + Needed because when index types are not hashed, equal index types + built at different times appear distinct, even though structurally, + they are not. */ + +int +index_type_equal (itype1, itype2) + tree itype1, itype2; +{ + if (TREE_CODE (itype1) != TREE_CODE (itype2)) + return 0; + if (TREE_CODE (itype1) == INTEGER_TYPE) + { + if (TYPE_PRECISION (itype1) != TYPE_PRECISION (itype2) + || TYPE_MODE (itype1) != TYPE_MODE (itype2) + || ! simple_cst_equal (TYPE_SIZE (itype1), TYPE_SIZE (itype2)) + || TYPE_ALIGN (itype1) != TYPE_ALIGN (itype2)) + return 0; + if (simple_cst_equal (TYPE_MIN_VALUE (itype1), TYPE_MIN_VALUE (itype2)) + && simple_cst_equal (TYPE_MAX_VALUE (itype1), TYPE_MAX_VALUE (itype2))) + return 1; + } + return 0; +} + +/* Construct, lay out and return the type of arrays of elements with ELT_TYPE + and number of elements specified by the range of values of INDEX_TYPE. + If such a type has already been constructed, reuse it. */ + +tree +build_array_type (elt_type, index_type) + tree elt_type, index_type; +{ + register tree t; + int hashcode; + + if (TREE_CODE (elt_type) == FUNCTION_TYPE) + { + error ("arrays of functions are not meaningful"); + elt_type = integer_type_node; + } + + /* Make sure TYPE_POINTER_TO (elt_type) is filled in. */ + build_pointer_type (elt_type); + + /* Allocate the array after the pointer type, + in case we free it in type_hash_canon. */ + t = make_node (ARRAY_TYPE); + TREE_TYPE (t) = elt_type; + TYPE_DOMAIN (t) = index_type; + + if (index_type == 0) + return t; + + hashcode = TYPE_HASH (elt_type) + TYPE_HASH (index_type); + t = type_hash_canon (hashcode, t); + + if (TYPE_SIZE (t) == 0) + layout_type (t); + return t; +} + +/* Construct, lay out and return + the type of functions returning type VALUE_TYPE + given arguments of types ARG_TYPES. + ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs + are data type nodes for the arguments of the function. + If such a type has already been constructed, reuse it. */ + +tree +build_function_type (value_type, arg_types) + tree value_type, arg_types; +{ + register tree t; + int hashcode; + + if (TREE_CODE (value_type) == FUNCTION_TYPE + || TREE_CODE (value_type) == ARRAY_TYPE) + { + error ("function return type cannot be function or array"); + value_type = integer_type_node; + } + + /* Make a node of the sort we want. */ + t = make_node (FUNCTION_TYPE); + TREE_TYPE (t) = value_type; + TYPE_ARG_TYPES (t) = arg_types; + + /* If we already have such a type, use the old one and free this one. */ + hashcode = TYPE_HASH (value_type) + type_hash_list (arg_types); + t = type_hash_canon (hashcode, t); + + if (TYPE_SIZE (t) == 0) + layout_type (t); + return t; +} + +/* Build the node for the type of references-to-TO_TYPE. */ + +tree +build_reference_type (to_type) + tree to_type; +{ + register tree t = TYPE_REFERENCE_TO (to_type); + register struct obstack *ambient_obstack = current_obstack; + register struct obstack *ambient_saveable_obstack = saveable_obstack; + + /* First, if we already have a type for pointers to TO_TYPE, use it. */ + + if (t) + return t; + + /* We need a new one. If TO_TYPE is permanent, make this permanent too. */ + if (TREE_PERMANENT (to_type)) + { + current_obstack = &permanent_obstack; + saveable_obstack = &permanent_obstack; + } + + t = make_node (REFERENCE_TYPE); + TREE_TYPE (t) = to_type; + + /* Record this type as the pointer to TO_TYPE. */ + TYPE_REFERENCE_TO (to_type) = t; + + layout_type (t); + + current_obstack = ambient_obstack; + saveable_obstack = ambient_saveable_obstack; + return t; +} + +/* Construct, lay out and return the type of methods belonging to class + BASETYPE and whose arguments and values are described by TYPE. + If that type exists already, reuse it. + TYPE must be a FUNCTION_TYPE node. */ + +tree +build_method_type (basetype, type) + tree basetype, type; +{ + register tree t; + int hashcode; + + /* Make a node of the sort we want. */ + t = make_node (METHOD_TYPE); + + if (TREE_CODE (type) != FUNCTION_TYPE) + abort (); + + TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype); + TREE_TYPE (t) = TREE_TYPE (type); + + /* The actual arglist for this function includes a "hidden" argument + which is "this". Put it into the list of argument types. */ + + TYPE_ARG_TYPES (t) + = tree_cons (NULL, build_pointer_type (basetype), TYPE_ARG_TYPES (type)); + + /* If we already have such a type, use the old one and free this one. */ + hashcode = TYPE_HASH (basetype) + TYPE_HASH (type); + t = type_hash_canon (hashcode, t); + + if (TYPE_SIZE (t) == 0) + layout_type (t); + + return t; +} + +/* Construct, lay out and return the type of methods belonging to class + BASETYPE and whose arguments and values are described by TYPE. + If that type exists already, reuse it. + TYPE must be a FUNCTION_TYPE node. */ + +tree +build_offset_type (basetype, type) + tree basetype, type; +{ + register tree t; + int hashcode; + + /* Make a node of the sort we want. */ + t = make_node (OFFSET_TYPE); + + TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype); + TREE_TYPE (t) = type; + + /* If we already have such a type, use the old one and free this one. */ + hashcode = TYPE_HASH (basetype) + TYPE_HASH (type); + t = type_hash_canon (hashcode, t); + + if (TYPE_SIZE (t) == 0) + layout_type (t); + + return t; +} + +/* Create a complex type whose components are COMPONENT_TYPE. */ + +tree +build_complex_type (component_type) + tree component_type; +{ + register tree t; + int hashcode; + + /* Make a node of the sort we want. */ + t = make_node (COMPLEX_TYPE); + + TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type); + TYPE_VOLATILE (t) = TYPE_VOLATILE (component_type); + TYPE_READONLY (t) = TYPE_READONLY (component_type); + + /* If we already have such a type, use the old one and free this one. */ + hashcode = TYPE_HASH (component_type); + t = type_hash_canon (hashcode, t); + + if (TYPE_SIZE (t) == 0) + layout_type (t); + + return t; +} + +/* Return OP, stripped of any conversions to wider types as much as is safe. + Converting the value back to OP's type makes a value equivalent to OP. + + If FOR_TYPE is nonzero, we return a value which, if converted to + type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE. + + If FOR_TYPE is nonzero, unaligned bit-field references may be changed to the + narrowest type that can hold the value, even if they don't exactly fit. + Otherwise, bit-field references are changed to a narrower type + only if they can be fetched directly from memory in that type. + + OP must have integer, real or enumeral type. Pointers are not allowed! + + There are some cases where the obvious value we could return + would regenerate to OP if converted to OP's type, + but would not extend like OP to wider types. + If FOR_TYPE indicates such extension is contemplated, we eschew such values. + For example, if OP is (unsigned short)(signed char)-1, + we avoid returning (signed char)-1 if FOR_TYPE is int, + even though extending that to an unsigned short would regenerate OP, + since the result of extending (signed char)-1 to (int) + is different from (int) OP. */ + +tree +get_unwidened (op, for_type) + register tree op; + tree for_type; +{ + /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension. */ + /* TYPE_PRECISION is safe in place of type_precision since + pointer types are not allowed. */ + register tree type = TREE_TYPE (op); + register unsigned final_prec + = TYPE_PRECISION (for_type != 0 ? for_type : type); + register int uns + = (for_type != 0 && for_type != type + && final_prec > TYPE_PRECISION (type) + && TREE_UNSIGNED (type)); + register tree win = op; + + while (TREE_CODE (op) == NOP_EXPR) + { + register int bitschange + = TYPE_PRECISION (TREE_TYPE (op)) + - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0))); + + /* Truncations are many-one so cannot be removed. + Unless we are later going to truncate down even farther. */ + if (bitschange < 0 + && final_prec > TYPE_PRECISION (TREE_TYPE (op))) + break; + + /* See what's inside this conversion. If we decide to strip it, + we will set WIN. */ + op = TREE_OPERAND (op, 0); + + /* If we have not stripped any zero-extensions (uns is 0), + we can strip any kind of extension. + If we have previously stripped a zero-extension, + only zero-extensions can safely be stripped. + Any extension can be stripped if the bits it would produce + are all going to be discarded later by truncating to FOR_TYPE. */ + + if (bitschange > 0) + { + if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op))) + win = op; + /* TREE_UNSIGNED says whether this is a zero-extension. + Let's avoid computing it if it does not affect WIN + and if UNS will not be needed again. */ + if ((uns || TREE_CODE (op) == NOP_EXPR) + && TREE_UNSIGNED (TREE_TYPE (op))) + { + uns = 1; + win = op; + } + } + } + + if (TREE_CODE (op) == COMPONENT_REF + /* Since type_for_size always gives an integer type. */ + && TREE_CODE (type) != REAL_TYPE) + { + unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1))); + type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1))); + + /* We can get this structure field in the narrowest type it fits in. + If FOR_TYPE is 0, do this only for a field that matches the + narrower type exactly and is aligned for it + The resulting extension to its nominal type (a fullword type) + must fit the same conditions as for other extensions. */ + + if (innerprec < TYPE_PRECISION (TREE_TYPE (op)) + && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))) + && (! uns || final_prec <= innerprec + || TREE_UNSIGNED (TREE_OPERAND (op, 1))) + && type != 0) + { + win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0), + TREE_OPERAND (op, 1)); + TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op); + TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op); + TREE_RAISES (win) = TREE_RAISES (op); + } + } + return win; +} + +/* Return OP or a simpler expression for a narrower value + which can be sign-extended or zero-extended to give back OP. + Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended + or 0 if the value should be sign-extended. */ + +tree +get_narrower (op, unsignedp_ptr) + register tree op; + int *unsignedp_ptr; +{ + register int uns = 0; + int first = 1; + register tree win = op; + + while (TREE_CODE (op) == NOP_EXPR) + { + register int bitschange + = TYPE_PRECISION (TREE_TYPE (op)) + - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0))); + + /* Truncations are many-one so cannot be removed. */ + if (bitschange < 0) + break; + + /* See what's inside this conversion. If we decide to strip it, + we will set WIN. */ + op = TREE_OPERAND (op, 0); + + if (bitschange > 0) + { + /* An extension: the outermost one can be stripped, + but remember whether it is zero or sign extension. */ + if (first) + uns = TREE_UNSIGNED (TREE_TYPE (op)); + /* Otherwise, if a sign extension has been stripped, + only sign extensions can now be stripped; + if a zero extension has been stripped, only zero-extensions. */ + else if (uns != TREE_UNSIGNED (TREE_TYPE (op))) + break; + first = 0; + } + /* A change in nominal type can always be stripped. */ + + win = op; + } + + if (TREE_CODE (op) == COMPONENT_REF + /* Since type_for_size always gives an integer type. */ + && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE) + { + unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1))); + tree type = type_for_size (innerprec, TREE_UNSIGNED (op)); + + /* We can get this structure field in a narrower type that fits it, + but the resulting extension to its nominal type (a fullword type) + must satisfy the same conditions as for other extensions. + + Do this only for fields that are aligned (not bit-fields), + because when bit-field insns will be used there is no + advantage in doing this. */ + + if (innerprec < TYPE_PRECISION (TREE_TYPE (op)) + && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)) + && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1))) + && type != 0) + { + if (first) + uns = TREE_UNSIGNED (TREE_OPERAND (op, 1)); + win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0), + TREE_OPERAND (op, 1)); + TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op); + TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op); + TREE_RAISES (win) = TREE_RAISES (op); + } + } + *unsignedp_ptr = uns; + return win; +} + +/* Return the precision of a type, for arithmetic purposes. + Supports all types on which arithmetic is possible + (including pointer types). + It's not clear yet what will be right for complex types. */ + +int +type_precision (type) + register tree type; +{ + return ((TREE_CODE (type) == INTEGER_TYPE + || TREE_CODE (type) == ENUMERAL_TYPE + || TREE_CODE (type) == REAL_TYPE) + ? TYPE_PRECISION (type) : POINTER_SIZE); +} + +/* Nonzero if integer constant C has a value that is permissible + for type TYPE (an INTEGER_TYPE). */ + +int +int_fits_type_p (c, type) + tree c, type; +{ + if (TREE_UNSIGNED (type)) + return (!INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c) + && !INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type))); + else + return (!INT_CST_LT (TYPE_MAX_VALUE (type), c) + && !INT_CST_LT (c, TYPE_MIN_VALUE (type))); +} + +/* Return the innermost context enclosing FNDECL that is + a FUNCTION_DECL, or zero if none. */ + +tree +decl_function_context (fndecl) + tree fndecl; +{ + tree context; + + if (TREE_CODE (fndecl) == ERROR_MARK) + return 0; + + if (TREE_CODE (fndecl) == SAVE_EXPR) + context = SAVE_EXPR_CONTEXT (fndecl); + else + context = DECL_CONTEXT (fndecl); + + while (context && TREE_CODE (context) != FUNCTION_DECL) + { + if (TREE_CODE (context) == RECORD_TYPE + || TREE_CODE (context) == UNION_TYPE) + context = TYPE_CONTEXT (context); + else if (TREE_CODE (context) == TYPE_DECL) + context = DECL_CONTEXT (context); + else if (TREE_CODE (context) == BLOCK) + context = BLOCK_SUPERCONTEXT (context); + else + /* Unhandled CONTEXT !? */ + abort (); + } + + return context; +} + +/* Return the innermost context enclosing FNDECL that is + a RECORD_TYPE or UNION_TYPE, or zero if none. + TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */ + +tree +decl_type_context (fndecl) + tree fndecl; +{ + tree context = DECL_CONTEXT (fndecl); + + while (context) + { + if (TREE_CODE (context) == RECORD_TYPE + || TREE_CODE (context) == UNION_TYPE) + return context; + if (TREE_CODE (context) == TYPE_DECL + || TREE_CODE (context) == FUNCTION_DECL) + context = DECL_CONTEXT (context); + else if (TREE_CODE (context) == BLOCK) + context = BLOCK_SUPERCONTEXT (context); + else + /* Unhandled CONTEXT!? */ + abort (); + } + return NULL_TREE; +} + +void +print_obstack_statistics (str, o) + char *str; + struct obstack *o; +{ + struct _obstack_chunk *chunk = o->chunk; + int n_chunks = 0; + int n_alloc = 0; + + while (chunk) + { + n_chunks += 1; + n_alloc += chunk->limit - &chunk->contents[0]; + chunk = chunk->prev; + } + fprintf (stderr, "obstack %s: %d bytes, %d chunks\n", + str, n_alloc, n_chunks); +} +void +dump_tree_statistics () +{ + int i; + int total_nodes, total_bytes; + + fprintf (stderr, "\n??? tree nodes created\n\n"); +#ifdef GATHER_STATISTICS + fprintf (stderr, "Kind Nodes Bytes\n"); + fprintf (stderr, "-------------------------------------\n"); + total_nodes = total_bytes = 0; + for (i = 0; i < (int) all_kinds; i++) + { + fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i], + tree_node_counts[i], tree_node_sizes[i]); + total_nodes += tree_node_counts[i]; + total_bytes += tree_node_sizes[i]; + } + fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size); + fprintf (stderr, "-------------------------------------\n"); + fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes); + fprintf (stderr, "-------------------------------------\n"); +#else + fprintf (stderr, "(No per-node statistics)\n"); +#endif + print_lang_statistics (); +} -- 2.30.2