From a5ee536be2c16fcbe223490358dbe4d1914f0e1a Mon Sep 17 00:00:00 2001 From: Joel Brobecker Date: Fri, 2 Mar 2012 19:29:01 +0000 Subject: [PATCH] language-specific read_var_value for Ada renamings The purpose of this patch is to better support renamings in the "info locals" command. Consider ... procedure Foo is GV : Integer renames Pck.Global_Variable; begin Increment (GV); -- STOP end Foo; ... Pck.Global_Variable is just an integer. After having stopped at the "STOP" line, "info locals" yields: (gdb) info locals gv = In reality, two things are happening: (1) Variable "GV" does not exist, which is normal, since there is "GV" the renaming of another variable; (2) But to allow the user access to that renaming the same way the code has, the compiler produces an artificial variable whose name encodes the renaming: gv___XR_pck__global_variable___XE For practical reasons, the artificial variable itself is given irrelevant types and addresses. But the "info locals" command does not act as if it was a short-cut of "foreach VAR in locals, print VAR". Instead it gets the value of each VAR directly, which does not work in this case, since the variable is artificial and needs to be decoded first. This patch makes the "read_var_value" routine language-specific. The old implementation of "read_var_value" gets renamed to "default_read_var_value" and all languages now use it (unchanged behavior), except for Ada. In Ada, the new function ada_read_var_value checks if we have a renaming, and if so, evaluates its value, or else defers to default_read_var_value. gdb/ChangeLog: * language.h (struct language_defn): New "method" la_read_var_value. * findvar.c: #include "language.h". (default_read_var_value): Renames read_var_value. Rewrite function description. (read_var_value): New function. * value.h (default_read_var_value): Add prototype. * ada-lang.c (ada_read_renaming_var_value, ada_read_var_value): New functions. (ada_language_defn): Add entry for la_read_var_value. * c-lang.c, d-lang.c, f-lang.c, jv-lang.c, language.c, * m2-lang.c, objc-lang.c, opencl-lang.c, p-lang.c: Update language_defn structures to add entry for new la_read_var_value field. --- gdb/ChangeLog | 16 ++++++++++++++++ gdb/ada-lang.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++- gdb/c-lang.c | 4 ++++ gdb/d-lang.c | 1 + gdb/f-lang.c | 1 + gdb/findvar.c | 22 +++++++++++++++++----- gdb/jv-lang.c | 1 + gdb/language.c | 3 +++ gdb/language.h | 9 +++++++++ gdb/m2-lang.c | 1 + gdb/objc-lang.c | 1 + gdb/opencl-lang.c | 1 + gdb/p-lang.c | 1 + gdb/value.h | 3 +++ 14 files changed, 105 insertions(+), 6 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 41d0277a53f..a26e69423dd 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,19 @@ +2012-03-02 Joel Brobecker + + * language.h (struct language_defn): New "method" la_read_var_value. + * findvar.c: #include "language.h". + (default_read_var_value): Renames read_var_value. Rewrite + function description. + (read_var_value): New function. + * value.h (default_read_var_value): Add prototype. + * ada-lang.c (ada_read_renaming_var_value, ada_read_var_value): + New functions. + (ada_language_defn): Add entry for la_read_var_value. + * c-lang.c, d-lang.c, f-lang.c, jv-lang.c, language.c, + * m2-lang.c, objc-lang.c, opencl-lang.c, p-lang.c: Update + language_defn structures to add entry for new la_read_var_value + field. + 2012-03-02 Tom Tromey Pedro Alves diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c index 4c17eaaae39..040d606165d 100644 --- a/gdb/ada-lang.c +++ b/gdb/ada-lang.c @@ -4041,8 +4041,30 @@ parse_old_style_renaming (struct type *type, if (len != NULL) *len = suffix - info; return kind; -} +} + +/* Compute the value of the given RENAMING_SYM, which is expected to + be a symbol encoding a renaming expression. BLOCK is the block + used to evaluate the renaming. */ +static struct value * +ada_read_renaming_var_value (struct symbol *renaming_sym, + struct block *block) +{ + char *sym_name; + struct expression *expr; + struct value *value; + struct cleanup *old_chain = NULL; + + sym_name = xstrdup (SYMBOL_LINKAGE_NAME (renaming_sym)); + old_chain = make_cleanup (xfree, sym_name); + expr = parse_exp_1 (&sym_name, block, 0); + make_cleanup (free_current_contents, &expr); + value = evaluate_expression (expr); + + do_cleanups (old_chain); + return value; +} /* Evaluation: Function Calls */ @@ -12437,6 +12459,28 @@ ada_get_symbol_name_cmp (const char *lookup_name) return compare_names; } +/* Implement the "la_read_var_value" language_defn method for Ada. */ + +static struct value * +ada_read_var_value (struct symbol *var, struct frame_info *frame) +{ + struct block *frame_block = NULL; + struct symbol *renaming_sym = NULL; + + /* The only case where default_read_var_value is not sufficient + is when VAR is a renaming... */ + if (frame) + frame_block = get_frame_block (frame, NULL); + if (frame_block) + renaming_sym = ada_find_renaming_symbol (var, frame_block); + if (renaming_sym != NULL) + return ada_read_renaming_var_value (renaming_sym, frame_block); + + /* This is a typical case where we expect the default_read_var_value + function to work. */ + return default_read_var_value (var, frame); +} + const struct language_defn ada_language_defn = { "ada", /* Language name */ language_ada, @@ -12457,6 +12501,7 @@ const struct language_defn ada_language_defn = { ada_print_typedef, /* Print a typedef using appropriate syntax */ ada_val_print, /* Print a value using appropriate syntax */ ada_value_print, /* Print a top-level value */ + ada_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline */ NULL, /* name_of_this */ ada_lookup_symbol_nonlocal, /* Looking up non-local symbols. */ diff --git a/gdb/c-lang.c b/gdb/c-lang.c index 767d13acaf9..28dce8df6bd 100644 --- a/gdb/c-lang.c +++ b/gdb/c-lang.c @@ -847,6 +847,7 @@ const struct language_defn c_language_defn = c_print_typedef, /* Print a typedef using appropriate syntax */ c_val_print, /* Print a value using appropriate syntax */ c_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline */ NULL, /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ @@ -970,6 +971,7 @@ const struct language_defn cplus_language_defn = c_print_typedef, /* Print a typedef using appropriate syntax */ c_val_print, /* Print a value using appropriate syntax */ c_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ cplus_skip_trampoline, /* Language specific skip_trampoline */ "this", /* name_of_this */ cp_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ @@ -1011,6 +1013,7 @@ const struct language_defn asm_language_defn = c_print_typedef, /* Print a typedef using appropriate syntax */ c_val_print, /* Print a value using appropriate syntax */ c_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline */ NULL, /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ @@ -1057,6 +1060,7 @@ const struct language_defn minimal_language_defn = c_print_typedef, /* Print a typedef using appropriate syntax */ c_val_print, /* Print a value using appropriate syntax */ c_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline */ NULL, /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ diff --git a/gdb/d-lang.c b/gdb/d-lang.c index 202820ef2d4..9a8cf522c36 100644 --- a/gdb/d-lang.c +++ b/gdb/d-lang.c @@ -256,6 +256,7 @@ static const struct language_defn d_language_defn = syntax. */ d_val_print, /* Print a value using appropriate syntax. */ c_value_print, /* Print a top-level value. */ + default_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline. */ "this", basic_lookup_symbol_nonlocal, diff --git a/gdb/f-lang.c b/gdb/f-lang.c index ef78bc3295b..3368d01c105 100644 --- a/gdb/f-lang.c +++ b/gdb/f-lang.c @@ -289,6 +289,7 @@ const struct language_defn f_language_defn = default_print_typedef, /* Print a typedef using appropriate syntax */ f_val_print, /* Print a value using appropriate syntax */ c_value_print, /* FIXME */ + default_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline */ NULL, /* name_of_this */ cp_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ diff --git a/gdb/findvar.c b/gdb/findvar.c index 79c4221f736..9009e6f324b 100644 --- a/gdb/findvar.c +++ b/gdb/findvar.c @@ -34,6 +34,7 @@ #include "user-regs.h" #include "block.h" #include "objfiles.h" +#include "language.h" /* Basic byte-swapping routines. All 'extract' functions return a host-format integer from a target-format integer at ADDR which is @@ -405,13 +406,11 @@ symbol_read_needs_frame (struct symbol *sym) return 1; } -/* Given a struct symbol for a variable, - and a stack frame id, read the value of the variable - and return a (pointer to a) struct value containing the value. - If the variable cannot be found, throw error. */ +/* A default implementation for the "la_read_var_value" hook in + the language vector which should work in most situations. */ struct value * -read_var_value (struct symbol *var, struct frame_info *frame) +default_read_var_value (struct symbol *var, struct frame_info *frame) { struct value *v; struct type *type = SYMBOL_TYPE (var); @@ -594,6 +593,19 @@ read_var_value (struct symbol *var, struct frame_info *frame) return v; } +/* Calls VAR's language la_read_var_value hook with the given arguments. */ + +struct value * +read_var_value (struct symbol *var, struct frame_info *frame) +{ + const struct language_defn *lang = language_def (SYMBOL_LANGUAGE (var)); + + gdb_assert (lang != NULL); + gdb_assert (lang->la_read_var_value != NULL); + + return lang->la_read_var_value (var, frame); +} + /* Install default attributes for register values. */ struct value * diff --git a/gdb/jv-lang.c b/gdb/jv-lang.c index 18a7c195993..08ecf5f54ee 100644 --- a/gdb/jv-lang.c +++ b/gdb/jv-lang.c @@ -1181,6 +1181,7 @@ const struct language_defn java_language_defn = default_print_typedef, /* Print a typedef using appropriate syntax */ java_val_print, /* Print a value using appropriate syntax */ java_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline */ "this", /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ diff --git a/gdb/language.c b/gdb/language.c index ae341086113..f0a8697998f 100644 --- a/gdb/language.c +++ b/gdb/language.c @@ -917,6 +917,7 @@ const struct language_defn unknown_language_defn = default_print_typedef, /* Print a typedef using appropriate syntax */ unk_lang_val_print, /* Print a value using appropriate syntax */ unk_lang_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ unk_lang_trampoline, /* Language specific skip_trampoline */ "this", /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ @@ -960,6 +961,7 @@ const struct language_defn auto_language_defn = default_print_typedef, /* Print a typedef using appropriate syntax */ unk_lang_val_print, /* Print a value using appropriate syntax */ unk_lang_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ unk_lang_trampoline, /* Language specific skip_trampoline */ "this", /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ @@ -1001,6 +1003,7 @@ const struct language_defn local_language_defn = default_print_typedef, /* Print a typedef using appropriate syntax */ unk_lang_val_print, /* Print a value using appropriate syntax */ unk_lang_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ unk_lang_trampoline, /* Language specific skip_trampoline */ "this", /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ diff --git a/gdb/language.h b/gdb/language.h index 76dad325b5b..d612c70523a 100644 --- a/gdb/language.h +++ b/gdb/language.h @@ -252,6 +252,15 @@ struct language_defn void (*la_value_print) (struct value *, struct ui_file *, const struct value_print_options *); + /* Given a symbol VAR, and a stack frame id FRAME, read the value + of the variable an return (pointer to a) struct value containing + the value. + + Throw an error if the variable cannot be found. */ + + struct value *(*la_read_var_value) (struct symbol *var, + struct frame_info *frame); + /* PC is possibly an unknown languages trampoline. If that PC falls in a trampoline belonging to this language, return the address of the first pc in the real function, or 0 diff --git a/gdb/m2-lang.c b/gdb/m2-lang.c index 9cd27c9ea92..8faa6c1465b 100644 --- a/gdb/m2-lang.c +++ b/gdb/m2-lang.c @@ -385,6 +385,7 @@ const struct language_defn m2_language_defn = m2_print_typedef, /* Print a typedef using appropriate syntax */ m2_val_print, /* Print a value using appropriate syntax */ c_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline */ NULL, /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ diff --git a/gdb/objc-lang.c b/gdb/objc-lang.c index 74528c8b913..15bf792bc34 100644 --- a/gdb/objc-lang.c +++ b/gdb/objc-lang.c @@ -524,6 +524,7 @@ const struct language_defn objc_language_defn = { c_print_typedef, /* Print a typedef using appropriate syntax */ c_val_print, /* Print a value using appropriate syntax */ c_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ objc_skip_trampoline, /* Language specific skip_trampoline */ "self", /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ diff --git a/gdb/opencl-lang.c b/gdb/opencl-lang.c index 3554d182a75..54075a41947 100644 --- a/gdb/opencl-lang.c +++ b/gdb/opencl-lang.c @@ -1008,6 +1008,7 @@ const struct language_defn opencl_language_defn = c_print_typedef, /* Print a typedef using appropriate syntax */ c_val_print, /* Print a value using appropriate syntax */ c_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline */ NULL, /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ diff --git a/gdb/p-lang.c b/gdb/p-lang.c index 826d24fee16..c59ba0bd71d 100644 --- a/gdb/p-lang.c +++ b/gdb/p-lang.c @@ -444,6 +444,7 @@ const struct language_defn pascal_language_defn = pascal_print_typedef, /* Print a typedef using appropriate syntax */ pascal_val_print, /* Print a value using appropriate syntax */ pascal_value_print, /* Print a top-level value */ + default_read_var_value, /* la_read_var_value */ NULL, /* Language specific skip_trampoline */ "this", /* name_of_this */ basic_lookup_symbol_nonlocal, /* lookup_symbol_nonlocal */ diff --git a/gdb/value.h b/gdb/value.h index f0fdb4cac3b..3ce0f881383 100644 --- a/gdb/value.h +++ b/gdb/value.h @@ -536,6 +536,9 @@ extern int symbol_read_needs_frame (struct symbol *); extern struct value *read_var_value (struct symbol *var, struct frame_info *frame); +extern struct value *default_read_var_value (struct symbol *var, + struct frame_info *frame); + extern struct value *allocate_value (struct type *type); extern struct value *allocate_value_lazy (struct type *type); extern void allocate_value_contents (struct value *value); -- 2.30.2