--- /dev/null
+/* Subroutines shared by all languages that are variants of C.
+ Copyright (C) 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. */
+
+#include "config.h"
+#include "tree.h"
+#include "c-lex.h"
+#include "c-tree.h"
+#include "flags.h"
+#include <stdio.h>
+
+#undef NULL
+#define NULL 0
+
+/* Given a chain of STRING_CST nodes,
+ concatenate them into one STRING_CST
+ and give it a suitable array-of-chars data type. */
+
+tree
+combine_strings (strings)
+ tree strings;
+{
+ register tree value, t;
+ register int length = 1;
+ int wide_length = 0;
+ int wide_flag = 0;
+ int wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
+ int nchars;
+
+ if (TREE_CHAIN (strings))
+ {
+ /* More than one in the chain, so concatenate. */
+ register char *p, *q;
+
+ /* Don't include the \0 at the end of each substring,
+ except for the last one.
+ Count wide strings and ordinary strings separately. */
+ for (t = strings; t; t = TREE_CHAIN (t))
+ {
+ if (TREE_TYPE (t) == wchar_array_type_node)
+ {
+ wide_length += (TREE_STRING_LENGTH (t) - wchar_bytes);
+ wide_flag = 1;
+ }
+ else
+ length += (TREE_STRING_LENGTH (t) - 1);
+ }
+
+ /* If anything is wide, the non-wides will be converted,
+ which makes them take more space. */
+ if (wide_flag)
+ length = length * wchar_bytes + wide_length;
+
+ p = savealloc (length);
+
+ /* Copy the individual strings into the new combined string.
+ If the combined string is wide, convert the chars to ints
+ for any individual strings that are not wide. */
+
+ q = p;
+ for (t = strings; t; t = TREE_CHAIN (t))
+ {
+ int len = (TREE_STRING_LENGTH (t)
+ - ((TREE_TYPE (t) == wchar_array_type_node)
+ ? wchar_bytes : 1));
+ if ((TREE_TYPE (t) == wchar_array_type_node) == wide_flag)
+ {
+ bcopy (TREE_STRING_POINTER (t), q, len);
+ q += len;
+ }
+ else
+ {
+ int i;
+ for (i = 0; i < len; i++)
+ ((int *) q)[i] = TREE_STRING_POINTER (t)[i];
+ q += len * wchar_bytes;
+ }
+ }
+ if (wide_flag)
+ {
+ int i;
+ for (i = 0; i < wchar_bytes; i++)
+ *q++ = 0;
+ }
+ else
+ *q = 0;
+
+ value = make_node (STRING_CST);
+ TREE_STRING_POINTER (value) = p;
+ TREE_STRING_LENGTH (value) = length;
+ TREE_CONSTANT (value) = 1;
+ }
+ else
+ {
+ value = strings;
+ length = TREE_STRING_LENGTH (value);
+ if (TREE_TYPE (value) == wchar_array_type_node)
+ wide_flag = 1;
+ }
+
+ /* Compute the number of elements, for the array type. */
+ nchars = wide_flag ? length / wchar_bytes : length;
+
+ /* Create the array type for the string constant.
+ -Wwrite-strings says make the string constant an array of const char
+ so that copying it to a non-const pointer will get a warning. */
+ if (warn_write_strings
+ && (! flag_traditional && ! flag_writable_strings))
+ {
+ tree elements
+ = build_type_variant (wide_flag ? wchar_type_node : char_type_node,
+ 1, 0);
+ TREE_TYPE (value)
+ = build_array_type (elements,
+ build_index_type (build_int_2 (nchars - 1, 0)));
+ }
+ else
+ TREE_TYPE (value)
+ = build_array_type (wide_flag ? wchar_type_node : char_type_node,
+ build_index_type (build_int_2 (nchars - 1, 0)));
+ TREE_CONSTANT (value) = 1;
+ TREE_STATIC (value) = 1;
+ return value;
+}
+\f
+/* Process the attributes listed in ATTRIBUTES
+ and install them in DECL. */
+
+void
+decl_attributes (decl, attributes)
+ tree decl, attributes;
+{
+ tree a;
+ for (a = attributes; a; a = TREE_CHAIN (a))
+ if (TREE_VALUE (a) != 0
+ && TREE_CODE (TREE_VALUE (a)) == TREE_LIST
+ && TREE_PURPOSE (TREE_VALUE (a)) == get_identifier ("aligned"))
+ {
+ int align = TREE_INT_CST_LOW (TREE_VALUE (TREE_VALUE (a)))
+ * BITS_PER_UNIT;
+
+ if (exact_log2 (align) == -1)
+ warning_with_decl (decl,
+ "requested alignment of `%s' is not a power of 2");
+ else if (TREE_CODE (decl) != VAR_DECL
+ && TREE_CODE (decl) != FIELD_DECL)
+ warning_with_decl (decl,
+ "alignment specified for `%s' which is not a variable");
+
+ /* ??? The maximum alignment gcc can currently handle is 16 bytes!
+ We should change the representation to be the log of the
+ actual alignment since we only handle powers of 2 anyway. */
+ else if (align > 255)
+ warning_with_decl (decl,
+ "requested alignment of `%s' exceeds compiler limits");
+ else
+ DECL_ALIGN (decl) = align;
+ }
+ else if (TREE_VALUE (a) != 0
+ && TREE_CODE (TREE_VALUE (a)) == TREE_LIST
+ && TREE_PURPOSE (TREE_VALUE (a)) == get_identifier ("packed"))
+ {
+ if (TREE_CODE (decl) == FIELD_DECL)
+ DECL_PACKED (decl) = 1;
+ }
+ else if (TREE_VALUE (a) != 0
+ && TREE_CODE (TREE_VALUE (a)) == TREE_LIST
+ && TREE_PURPOSE (TREE_VALUE (a)) == get_identifier ("format"))
+ {
+ tree list = TREE_VALUE (TREE_VALUE (a));
+ tree format_type = TREE_PURPOSE (list);
+ int format_num = TREE_INT_CST_LOW (TREE_PURPOSE (TREE_VALUE (list)));
+ int first_arg_num = TREE_INT_CST_LOW (TREE_VALUE (TREE_VALUE (list)));
+ int is_scan;
+
+ if (TREE_CODE (decl) != FUNCTION_DECL)
+ {
+ warning_with_decl (decl,
+ "argument format specified for non-function `%s'");
+ return;
+ }
+
+ if (format_type == get_identifier ("printf"))
+ is_scan = 0;
+ else if (format_type == get_identifier ("scanf"))
+ is_scan = 1;
+ else
+ {
+ warning_with_decl (decl,"unrecognized format specifier for `%s'");
+ return;
+ }
+
+ if (first_arg_num != 0 && first_arg_num <= format_num)
+ {
+ warning_with_decl (decl,
+ "format string arg follows the args to be formatted, for `%s'");
+ return;
+ }
+
+ record_format_info (DECL_NAME (decl), is_scan, format_num,
+ first_arg_num);
+ }
+}
+\f
+void
+c_expand_expr_stmt (expr)
+ tree expr;
+{
+ /* Do default conversion if safe and possibly important,
+ in case within ({...}). */
+ if ((TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE && lvalue_p (expr))
+ || TREE_CODE (TREE_TYPE (expr)) == FUNCTION_TYPE)
+ expr = default_conversion (expr);
+
+ if (TREE_TYPE (expr) != error_mark_node
+ && TYPE_SIZE (TREE_TYPE (expr)) == 0
+ && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
+ error ("expression statement has incomplete type");
+
+ expand_expr_stmt (expr);
+}
+\f
+/* Validate the expression after `case' and apply default promotions. */
+
+tree
+check_case_value (value)
+ tree value;
+{
+ if (value == NULL_TREE)
+ return value;
+
+ /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
+ if (TREE_CODE (value) == NON_LVALUE_EXPR)
+ value = TREE_OPERAND (value, 0);
+
+ if (TREE_CODE (value) != INTEGER_CST
+ && value != error_mark_node)
+ {
+ error ("case label does not reduce to an integer constant");
+ value = error_mark_node;
+ }
+ else
+ /* Promote char or short to int. */
+ value = default_conversion (value);
+
+ return value;
+}
+\f
+/* Return an integer type with BITS bits of precision,
+ that is unsigned if UNSIGNEDP is nonzero, otherwise signed. */
+
+tree
+type_for_size (bits, unsignedp)
+ unsigned bits;
+ int unsignedp;
+{
+ if (bits <= TYPE_PRECISION (signed_char_type_node))
+ return unsignedp ? unsigned_char_type_node : signed_char_type_node;
+
+ if (bits <= TYPE_PRECISION (short_integer_type_node))
+ return unsignedp ? short_unsigned_type_node : short_integer_type_node;
+
+ if (bits <= TYPE_PRECISION (integer_type_node))
+ return unsignedp ? unsigned_type_node : integer_type_node;
+
+ if (bits <= TYPE_PRECISION (long_integer_type_node))
+ return unsignedp ? long_unsigned_type_node : long_integer_type_node;
+
+ if (bits <= TYPE_PRECISION (long_long_integer_type_node))
+ return (unsignedp ? long_long_unsigned_type_node
+ : long_long_integer_type_node);
+
+ return 0;
+}
+
+/* Return a data type that has machine mode MODE.
+ If the mode is an integer,
+ then UNSIGNEDP selects between signed and unsigned types. */
+
+tree
+type_for_mode (mode, unsignedp)
+ enum machine_mode mode;
+ int unsignedp;
+{
+ if (mode == TYPE_MODE (signed_char_type_node))
+ return unsignedp ? unsigned_char_type_node : signed_char_type_node;
+
+ if (mode == TYPE_MODE (short_integer_type_node))
+ return unsignedp ? short_unsigned_type_node : short_integer_type_node;
+
+ if (mode == TYPE_MODE (integer_type_node))
+ return unsignedp ? unsigned_type_node : integer_type_node;
+
+ if (mode == TYPE_MODE (long_integer_type_node))
+ return unsignedp ? long_unsigned_type_node : long_integer_type_node;
+
+ if (mode == TYPE_MODE (long_long_integer_type_node))
+ return unsignedp ? long_long_unsigned_type_node : long_long_integer_type_node;
+
+ if (mode == TYPE_MODE (float_type_node))
+ return float_type_node;
+
+ if (mode == TYPE_MODE (double_type_node))
+ return double_type_node;
+
+ if (mode == TYPE_MODE (long_double_type_node))
+ return long_double_type_node;
+
+ if (mode == TYPE_MODE (build_pointer_type (char_type_node)))
+ return build_pointer_type (char_type_node);
+
+ if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
+ return build_pointer_type (integer_type_node);
+
+ return 0;
+}
+\f
+/* Print an error message for invalid operands to arith operation CODE.
+ NOP_EXPR is used as a special case (see truthvalue_conversion). */
+
+void
+binary_op_error (code)
+ enum tree_code code;
+{
+ register char *opname;
+ switch (code)
+ {
+ case NOP_EXPR:
+ error ("invalid truth-value expression");
+ return;
+
+ case PLUS_EXPR:
+ opname = "+"; break;
+ case MINUS_EXPR:
+ opname = "-"; break;
+ case MULT_EXPR:
+ opname = "*"; break;
+ case MAX_EXPR:
+ opname = "max"; break;
+ case MIN_EXPR:
+ opname = "min"; break;
+ case EQ_EXPR:
+ opname = "=="; break;
+ case NE_EXPR:
+ opname = "!="; break;
+ case LE_EXPR:
+ opname = "<="; break;
+ case GE_EXPR:
+ opname = ">="; break;
+ case LT_EXPR:
+ opname = "<"; break;
+ case GT_EXPR:
+ opname = ">"; break;
+ case LSHIFT_EXPR:
+ opname = "<<"; break;
+ case RSHIFT_EXPR:
+ opname = ">>"; break;
+ case TRUNC_MOD_EXPR:
+ opname = "%"; break;
+ case TRUNC_DIV_EXPR:
+ opname = "/"; break;
+ case BIT_AND_EXPR:
+ opname = "&"; break;
+ case BIT_IOR_EXPR:
+ opname = "|"; break;
+ case TRUTH_ANDIF_EXPR:
+ opname = "&&"; break;
+ case TRUTH_ORIF_EXPR:
+ opname = "||"; break;
+ case BIT_XOR_EXPR:
+ opname = "^"; break;
+ }
+ error ("invalid operands to binary %s", opname);
+}
+\f
+/* Subroutine of build_binary_op, used for comparison operations.
+ See if the operands have both been converted from subword integer types
+ and, if so, perhaps change them both back to their original type.
+
+ The arguments of this function are all pointers to local variables
+ of build_binary_op: OP0_PTR is &OP0, OP1_PTR is &OP1,
+ RESTYPE_PTR is &RESULT_TYPE and RESCODE_PTR is &RESULTCODE.
+
+ If this function returns nonzero, it means that the comparison has
+ a constant value. What this function returns is an expression for
+ that value. */
+
+tree
+shorten_compare (op0_ptr, op1_ptr, restype_ptr, rescode_ptr)
+ tree *op0_ptr, *op1_ptr;
+ tree *restype_ptr;
+ enum tree_code *rescode_ptr;
+{
+ register tree type;
+ tree op0 = *op0_ptr;
+ tree op1 = *op1_ptr;
+ int unsignedp0, unsignedp1;
+ int real1, real2;
+ tree primop0, primop1;
+ enum tree_code code = *rescode_ptr;
+
+ /* Throw away any conversions to wider types
+ already present in the operands. */
+
+ primop0 = get_narrower (op0, &unsignedp0);
+ primop1 = get_narrower (op1, &unsignedp1);
+
+ /* Handle the case that OP0 does not *contain* a conversion
+ but it *requires* conversion to FINAL_TYPE. */
+
+ if (op0 == primop0 && TREE_TYPE (op0) != *restype_ptr)
+ unsignedp0 = TREE_UNSIGNED (TREE_TYPE (op0));
+ if (op1 == primop1 && TREE_TYPE (op1) != *restype_ptr)
+ unsignedp1 = TREE_UNSIGNED (TREE_TYPE (op1));
+
+ /* If one of the operands must be floated, we cannot optimize. */
+ real1 = TREE_CODE (TREE_TYPE (primop0)) == REAL_TYPE;
+ real2 = TREE_CODE (TREE_TYPE (primop1)) == REAL_TYPE;
+
+ /* If first arg is constant, swap the args (changing operation
+ so value is preserved), for canonicalization. */
+
+ if (TREE_CONSTANT (primop0))
+ {
+ register tree tem = primop0;
+ register int temi = unsignedp0;
+ primop0 = primop1;
+ primop1 = tem;
+ tem = op0;
+ op0 = op1;
+ op1 = tem;
+ *op0_ptr = op0;
+ *op1_ptr = op1;
+ unsignedp0 = unsignedp1;
+ unsignedp1 = temi;
+ temi = real1;
+ real1 = real2;
+ real2 = temi;
+
+ switch (code)
+ {
+ case LT_EXPR:
+ code = GT_EXPR;
+ break;
+ case GT_EXPR:
+ code = LT_EXPR;
+ break;
+ case LE_EXPR:
+ code = GE_EXPR;
+ break;
+ case GE_EXPR:
+ code = LE_EXPR;
+ break;
+ }
+ *rescode_ptr = code;
+ }
+
+ /* If comparing an integer against a constant more bits wide,
+ maybe we can deduce a value of 1 or 0 independent of the data.
+ Or else truncate the constant now
+ rather than extend the variable at run time.
+
+ This is only interesting if the constant is the wider arg.
+ Also, it is not safe if the constant is unsigned and the
+ variable arg is signed, since in this case the variable
+ would be sign-extended and then regarded as unsigned.
+ Our technique fails in this case because the lowest/highest
+ possible unsigned results don't follow naturally from the
+ lowest/highest possible values of the variable operand.
+ For just EQ_EXPR and NE_EXPR there is another technique that
+ could be used: see if the constant can be faithfully represented
+ in the other operand's type, by truncating it and reextending it
+ and see if that preserves the constant's value. */
+
+ if (!real1 && !real2
+ && TREE_CODE (primop1) == INTEGER_CST
+ && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr))
+ {
+ int min_gt, max_gt, min_lt, max_lt;
+ tree maxval, minval;
+ /* 1 if comparison is nominally unsigned. */
+ int unsignedp = TREE_UNSIGNED (*restype_ptr);
+ tree val;
+
+ type = signed_or_unsigned_type (unsignedp0, TREE_TYPE (primop0));
+
+ maxval = TYPE_MAX_VALUE (type);
+ minval = TYPE_MIN_VALUE (type);
+
+ if (unsignedp && !unsignedp0)
+ *restype_ptr = signed_type (*restype_ptr);
+
+ if (TREE_TYPE (primop1) != *restype_ptr)
+ primop1 = convert (*restype_ptr, primop1);
+ if (type != *restype_ptr)
+ {
+ minval = convert (*restype_ptr, minval);
+ maxval = convert (*restype_ptr, maxval);
+ }
+
+ if (unsignedp && unsignedp0)
+ {
+ min_gt = INT_CST_LT_UNSIGNED (primop1, minval);
+ max_gt = INT_CST_LT_UNSIGNED (primop1, maxval);
+ min_lt = INT_CST_LT_UNSIGNED (minval, primop1);
+ max_lt = INT_CST_LT_UNSIGNED (maxval, primop1);
+ }
+ else
+ {
+ min_gt = INT_CST_LT (primop1, minval);
+ max_gt = INT_CST_LT (primop1, maxval);
+ min_lt = INT_CST_LT (minval, primop1);
+ max_lt = INT_CST_LT (maxval, primop1);
+ }
+
+ val = 0;
+ /* This used to be a switch, but Genix compiler can't handle that. */
+ if (code == NE_EXPR)
+ {
+ if (max_lt || min_gt)
+ val = integer_one_node;
+ }
+ else if (code == EQ_EXPR)
+ {
+ if (max_lt || min_gt)
+ val = integer_zero_node;
+ }
+ else if (code == LT_EXPR)
+ {
+ if (max_lt)
+ val = integer_one_node;
+ if (!min_lt)
+ val = integer_zero_node;
+ }
+ else if (code == GT_EXPR)
+ {
+ if (min_gt)
+ val = integer_one_node;
+ if (!max_gt)
+ val = integer_zero_node;
+ }
+ else if (code == LE_EXPR)
+ {
+ if (!max_gt)
+ val = integer_one_node;
+ if (min_gt)
+ val = integer_zero_node;
+ }
+ else if (code == GE_EXPR)
+ {
+ if (!min_lt)
+ val = integer_one_node;
+ if (max_lt)
+ val = integer_zero_node;
+ }
+
+ /* If primop0 was sign-extended and unsigned comparison specd,
+ we did a signed comparison above using the signed type bounds.
+ But the comparison we output must be unsigned.
+
+ Also, for inequalities, VAL is no good; but if the signed
+ comparison had *any* fixed result, it follows that the
+ unsigned comparison just tests the sign in reverse
+ (positive values are LE, negative ones GE).
+ So we can generate an unsigned comparison
+ against an extreme value of the signed type. */
+
+ if (unsignedp && !unsignedp0)
+ {
+ if (val != 0)
+ switch (code)
+ {
+ case LT_EXPR:
+ case GE_EXPR:
+ primop1 = TYPE_MIN_VALUE (type);
+ val = 0;
+ break;
+
+ case LE_EXPR:
+ case GT_EXPR:
+ primop1 = TYPE_MAX_VALUE (type);
+ val = 0;
+ break;
+ }
+ type = unsigned_type (type);
+ }
+
+ if (max_lt && !unsignedp0)
+ {
+ /* This is the case of (char)x >?< 0x80, which people used to use
+ expecting old C compilers to change the 0x80 into -0x80. */
+ if (val == integer_zero_node)
+ warning ("comparison is always 0 due to limited range of data type");
+ if (val == integer_one_node)
+ warning ("comparison is always 1 due to limited range of data type");
+ }
+
+ if (min_gt && unsignedp0)
+ {
+ /* This is the case of (unsigned char)x >?< -1. */
+ if (val == integer_zero_node)
+ warning ("comparison is always 0 due to limited range of data type");
+ if (val == integer_one_node)
+ warning ("comparison is always 1 due to limited range of data type");
+ }
+
+ if (val != 0)
+ {
+ /* Don't forget to evaluate PRIMOP0 if it has side effects. */
+ if (TREE_SIDE_EFFECTS (primop0))
+ return build (COMPOUND_EXPR, TREE_TYPE (val), primop0, val);
+ return val;
+ }
+
+ /* Value is not predetermined, but do the comparison
+ in the type of the operand that is not constant.
+ TYPE is already properly set. */
+ }
+ else if (real1 && real2
+ && TYPE_PRECISION (TREE_TYPE (primop0)) == TYPE_PRECISION (TREE_TYPE (primop1)))
+ type = TREE_TYPE (primop0);
+
+ /* If args' natural types are both narrower than nominal type
+ and both extend in the same manner, compare them
+ in the type of the wider arg.
+ Otherwise must actually extend both to the nominal
+ common type lest different ways of extending
+ alter the result.
+ (eg, (short)-1 == (unsigned short)-1 should be 0.) */
+
+ else if (unsignedp0 == unsignedp1 && real1 == real2
+ && TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (*restype_ptr)
+ && TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (*restype_ptr))
+ {
+ type = common_type (TREE_TYPE (primop0), TREE_TYPE (primop1));
+ type = signed_or_unsigned_type (unsignedp0
+ || TREE_UNSIGNED (*restype_ptr),
+ type);
+ /* Make sure shorter operand is extended the right way
+ to match the longer operand. */
+ primop0 = convert (signed_or_unsigned_type (unsignedp0, TREE_TYPE (primop0)),
+ primop0);
+ primop1 = convert (signed_or_unsigned_type (unsignedp1, TREE_TYPE (primop1)),
+ primop1);
+ }
+ else
+ {
+ /* Here we must do the comparison on the nominal type
+ using the args exactly as we received them. */
+ type = *restype_ptr;
+ primop0 = op0;
+ primop1 = op1;
+
+ if (!real1 && !real2 && integer_zerop (primop1)
+ && TREE_UNSIGNED (TREE_TYPE (primop0)))
+ {
+ tree value = 0;
+ switch (code)
+ {
+ case GE_EXPR:
+ if (extra_warnings)
+ warning ("unsigned value >= 0 is always 1");
+ value = integer_one_node;
+ break;
+
+ case LT_EXPR:
+ if (extra_warnings)
+ warning ("unsigned value < 0 is always 0");
+ value = integer_zero_node;
+ }
+
+ if (value != 0)
+ {
+ /* Don't forget to evaluate PRIMOP0 if it has side effects. */
+ if (TREE_SIDE_EFFECTS (primop0))
+ return build (COMPOUND_EXPR, TREE_TYPE (value),
+ primop0, value);
+ return value;
+ }
+ }
+ }
+
+ *op0_ptr = convert (type, primop0);
+ *op1_ptr = convert (type, primop1);
+
+ *restype_ptr = integer_type_node;
+
+ return 0;
+}
+\f
+/* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
+ or validate its data type for an `if' or `while' statement or ?..: exp.
+
+ This preparation consists of taking the ordinary
+ representation of an expression expr and producing a valid tree
+ boolean expression describing whether expr is nonzero. We could
+ simply always do build_binary_op (NE_EXPR, expr, integer_zero_node, 1),
+ but we optimize comparisons, &&, ||, and !.
+
+ The resulting type should always be `integer_type_node'. */
+
+tree
+truthvalue_conversion (expr)
+ tree expr;
+{
+ register enum tree_code code;
+
+ switch (TREE_CODE (expr))
+ {
+ /* It is simpler and generates better code to have only TRUTH_*_EXPR
+ or comparison expressions as truth values at this level. */
+#if 0
+ case COMPONENT_REF:
+ /* A one-bit unsigned bit-field is already acceptable. */
+ if (1 == TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (expr, 1)))
+ && TREE_UNSIGNED (TREE_OPERAND (expr, 1)))
+ return expr;
+ break;
+#endif
+
+ case EQ_EXPR:
+ /* It is simpler and generates better code to have only TRUTH_*_EXPR
+ or comparison expressions as truth values at this level. */
+#if 0
+ if (integer_zerop (TREE_OPERAND (expr, 1)))
+ return build_unary_op (TRUTH_NOT_EXPR, TREE_OPERAND (expr, 0), 0);
+#endif
+ case NE_EXPR: case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR:
+ case TRUTH_ANDIF_EXPR:
+ case TRUTH_ORIF_EXPR:
+ case TRUTH_AND_EXPR:
+ case TRUTH_OR_EXPR:
+ case ERROR_MARK:
+ return expr;
+
+ case INTEGER_CST:
+ return integer_zerop (expr) ? integer_zero_node : integer_one_node;
+
+ case REAL_CST:
+ return real_zerop (expr) ? integer_zero_node : integer_one_node;
+
+ case ADDR_EXPR:
+ if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0)))
+ return build (COMPOUND_EXPR, integer_type_node,
+ TREE_OPERAND (expr, 0), integer_one_node);
+ else
+ return integer_one_node;
+
+ case NEGATE_EXPR:
+ case ABS_EXPR:
+ case FLOAT_EXPR:
+ case FFS_EXPR:
+ /* These don't change whether an object is non-zero or zero. */
+ return truthvalue_conversion (TREE_OPERAND (expr, 0));
+
+ case LROTATE_EXPR:
+ case RROTATE_EXPR:
+ /* These don't change whether an object is zero or non-zero, but
+ we can't ignore them if their second arg has side-effects. */
+ if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1)))
+ return build (COMPOUND_EXPR, integer_type_node, TREE_OPERAND (expr, 1),
+ truthvalue_conversion (TREE_OPERAND (expr, 0)));
+ else
+ return truthvalue_conversion (TREE_OPERAND (expr, 0));
+
+ case COND_EXPR:
+ /* Distribute the conversion into the arms of a COND_EXPR. */
+ return fold (build (COND_EXPR, integer_type_node, TREE_OPERAND (expr, 0),
+ truthvalue_conversion (TREE_OPERAND (expr, 1)),
+ truthvalue_conversion (TREE_OPERAND (expr, 2))));
+
+ case CONVERT_EXPR:
+ /* Don't cancel the effect of a CONVERT_EXPR from a REFERENCE_TYPE,
+ since that affects how `default_conversion' will behave. */
+ if (TREE_CODE (TREE_TYPE (expr)) == REFERENCE_TYPE
+ || TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == REFERENCE_TYPE)
+ break;
+ /* fall through... */
+ case NOP_EXPR:
+ /* If this is widening the argument, we can ignore it. */
+ if (TYPE_PRECISION (TREE_TYPE (expr))
+ >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (expr, 0))))
+ return truthvalue_conversion (TREE_OPERAND (expr, 0));
+ break;
+
+ case BIT_XOR_EXPR:
+ case MINUS_EXPR:
+ /* These can be changed into a comparison of the two objects. */
+ if (TREE_TYPE (TREE_OPERAND (expr, 0))
+ == TREE_TYPE (TREE_OPERAND (expr, 1)))
+ return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
+ TREE_OPERAND (expr, 1), 1);
+ return build_binary_op (NE_EXPR, TREE_OPERAND (expr, 0),
+ fold (build1 (NOP_EXPR,
+ TREE_TYPE (TREE_OPERAND (expr, 0)),
+ TREE_OPERAND (expr, 1))), 1);
+ }
+
+ return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
+}
+\f
+/* Read the rest of a #-directive from input stream FINPUT.
+ In normal use, the directive name and the white space after it
+ have already been read, so they won't be included in the result.
+ We allow for the fact that the directive line may contain
+ a newline embedded within a character or string literal which forms
+ a part of the directive.
+
+ The value is a string in a reusable buffer. It remains valid
+ only until the next time this function is called. */
+
+char *
+get_directive_line (finput)
+ register FILE *finput;
+{
+ static char *directive_buffer = NULL;
+ static unsigned buffer_length = 0;
+ register char *p;
+ register char *buffer_limit;
+ register int looking_for = 0;
+ register int char_escaped = 0;
+
+ if (buffer_length == 0)
+ {
+ directive_buffer = (char *)xmalloc (128);
+ buffer_length = 128;
+ }
+
+ buffer_limit = &directive_buffer[buffer_length];
+
+ for (p = directive_buffer; ; )
+ {
+ int c;
+
+ /* Make buffer bigger if it is full. */
+ if (p >= buffer_limit)
+ {
+ register unsigned bytes_used = (p - directive_buffer);
+
+ buffer_length *= 2;
+ directive_buffer
+ = (char *)xrealloc (directive_buffer, buffer_length);
+ p = &directive_buffer[bytes_used];
+ buffer_limit = &directive_buffer[buffer_length];
+ }
+
+ c = getc (finput);
+
+ /* Discard initial whitespace. */
+ if ((c == ' ' || c == '\t') && p == directive_buffer)
+ continue;
+
+ /* Detect the end of the directive. */
+ if (c == '\n' && looking_for == 0)
+ {
+ ungetc (c, finput);
+ c = '\0';
+ }
+
+ *p++ = c;
+
+ if (c == 0)
+ return directive_buffer;
+
+ /* Handle string and character constant syntax. */
+ if (looking_for)
+ {
+ if (looking_for == c && !char_escaped)
+ looking_for = 0; /* Found terminator... stop looking. */
+ }
+ else
+ if (c == '\'' || c == '"')
+ looking_for = c; /* Don't stop buffering until we see another
+ another one of these (or an EOF). */
+
+ /* Handle backslash. */
+ char_escaped = (c == '\\' && ! char_escaped);
+ }
+}
projects / gcc.git / commitdiff