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Re: [PATCH] Add proper handling for non-local references in nested functions
- From: Pierre-Marie de Rodat <derodat at adacore dot com>
- To: Doug Evans <xdje42 at gmail dot com>
- Cc: Kevin Buettner <kevinb at redhat dot com>, gdb-patches at sourceware dot org
- Date: Mon, 17 Aug 2015 15:33:41 +0200
- Subject: Re: [PATCH] Add proper handling for non-local references in nested functions
- Authentication-results: sourceware.org; auth=none
- References: <54F47563 dot 4050103 at adacore dot com> <54FF0D05 dot 70907 at redhat dot com> <550C1170 dot 9070208 at adacore dot com> <55685B60 dot 3000004 at redhat dot com> <55775EB0 dot 4080701 at adacore dot com> <55AF5F7E dot 5000600 at adacore dot com> <20150722173957 dot 7ed51f18 at pinnacle dot lan> <55B0C583 dot 6050601 at adacore dot com> <m3380azmij dot fsf at sspiff dot org> <55BB538B dot 7090104 at adacore dot com> <m3mvxt5eb5 dot fsf at sspiff dot org>
Doug,
Once again, thanks for the review!
On 08/15/2015 07:08 AM, Doug Evans wrote:
+/* Implement the struct symbol_block_ops::get_frame_base method. */
+
+static CORE_ADDR
+block_op_get_frame_base (struct symbol *framefunc, struct frame_info *frame)
+{
+ if (SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location != NULL)
====
It's hard for this reader to figure out why this test is here.
If the code gets here, when would find_frame_base_location be NULL?
Seems like we could just assert find_frame_base_location is non-NULL.
Good catch! This is fixed, now, with a comment explaining this.
+ /* Old compilers may not provide a static link, or they may provide an
+ invalid one. For such cases, fallback on the old way to evaluate
+ non-local references: just climb up the call stack and pick the first
+ frame that contains the variable we are looking for. */
+ if (frame == NULL)
+ {
+ frame = block_innermost_frame (var_block);
+ if (!frame)
====
frame == NULL
Done.
Ok with them fixed (not sure what the right fix for the first one is
though, I could be missing something).
As said in my previous mail, I'm not sure I want to commit it: I tried
to investigate this 4% unexpected performance drop, at least to see what
happens with a profiler but I could not reproduce.
--
Pierre-Marie de Rodat
>From f8cb12e93bc4b317bf03dd31fc158cc05fc60367 Mon Sep 17 00:00:00 2001
From: Pierre-Marie de Rodat <derodat@adacore.com>
Date: Thu, 5 Feb 2015 17:00:06 +0100
Subject: [PATCH] DWARF: handle non-local references in nested functions
GDB's current behavior when dealing with non-local references in the
context of nested fuctions is approximative:
- code using valops.c:value_of_variable read the first available stack
frame that holds the corresponding variable (whereas there can be
multiple candidates for this);
- code directly relying on read_var_value will instead read non-local
variables in frames where they are not even defined.
This change adds the necessary context to symbol reads (to get the block
they belong to) and to blocks (the static link property, if any) so that
GDB can make the proper decisions when dealing with non-local varibale
references.
gdb/ChangeLog:
* ada-lang.c (ada_read_var_value): Add a var_block argument
and pass it to default_read_var_value.
* block.c (block_static_link): New accessor.
* block.h (block_static_link): Declare it.
* buildsym.c (finish_block_internal): Add a static_link
argument. If there is a static link, associate it to the new
block.
(finish_block): Add a static link argument and pass it to
finish_block_internal.
(end_symtab_get_static_block): Update calls to finish_block and
to finish_block_internal.
(end_symtab_with_blockvector): Update call to
finish_block_internal.
* buildsym.h: Forward-declare struct dynamic_prop.
(struct context_stack): Add a static_link field.
(finish_block): Add a static link argument.
* c-exp.y: Remove an obsolete comment (evaluation of variables
already start from the selected frame, and now they climb *up*
the call stack) and propagate the block information to the
produced expression.
* d-exp.y: Likewise.
* f-exp.y: Likewise.
* go-exp.y: Likewise.
* jv-exp.y: Likewise.
* m2-exp.y: Likewise.
* p-exp.y: Likewise.
* coffread.c (coff_symtab_read): Update calls to finish_block.
* dbxread.c (process_one_symbol): Likewise.
* xcoffread.c (read_xcoff_symtab): Likewise.
* compile/compile-c-symbols.c (convert_one_symbol): Promote the
"sym" parameter to struct block_symbol, update its uses and pass
its block to calls to read_var_value.
(convert_symbol_sym): Update the calls to convert_one_symbol.
* compile/compile-loc2c.c (do_compile_dwarf_expr_to_c): Update
call to read_var_value.
* dwarf2loc.c (block_op_get_frame_base): New.
(dwarf2_block_frame_base_locexpr_funcs): Implement the
get_frame_base method.
(dwarf2_block_frame_base_loclist_funcs): Likewise.
(dwarf2locexpr_baton_eval): Add a frame argument and use it
instead of the selected frame in order to evaluate the
expression.
(dwarf2_evaluate_property): Add a frame argument. Update call
to dwarf2_locexpr_baton_eval to provide a frame in available and
to handle the absence of address stack.
* dwarf2loc.h (dwarf2_evaluate_property): Add a frame argument.
* dwarf2read.c (attr_to_dynamic_prop): Add a forward
declaration.
(read_func_scope): Record any available static link description.
Update call to finish_block.
(read_lexical_block_scope): Update call to finish_block.
* findvar.c (follow_static_link): New.
(get_hosting_frame): New.
(default_read_var_value): Add a var_block argument. Use
get_hosting_frame to handle non-local references.
(read_var_value): Add a var_block argument and pass it to the
LA_READ_VAR_VALUE method.
* gdbtypes.c (resolve_dynamic_range): Update calls to
dwarf2_evaluate_property.
(resolve_dynamic_type_internal): Likewise.
* guile/scm-frame.c (gdbscm_frame_read_var): Update call to
read_var_value, passing it the block coming from symbol lookup.
* guile/scm-symbol.c (gdbscm_symbol_value): Update call to
read_var_value (TODO).
* infcmd.c (finish_command_continuation): Update call to
read_var_value, passing it the block coming from symbol lookup.
* infrun.c (insert_exception_resume_breakpoint): Likewise.
* language.h (struct language_defn): Add a var_block argument to
the LA_READ_VAR_VALUE method.
* objfiles.c (struct static_link_htab_entry): New.
(static_link_htab_entry_hash): New.
(static_link_htab_entry_eq): New.
(objfile_register_static_link): New.
(objfile_lookup_static_link): New.
(free_objfile): Free the STATIC_LINKS hashed map if needed.
* objfiles.h: Include hashtab.h.
(struct objfile): Add a static_links field.
(objfile_register_static_link): New.
(objfile_lookup_static_link): New.
* printcmd.c (print_variable_and_value): Update call to
read_var_value.
* python/py-finishbreakpoint.c (bpfinishpy_init): Likewise.
* python/py-frame.c (frapy_read_var): Update call to
read_var_value, passing it the block coming from symbol lookup.
* python/py-framefilter.c (extract_sym): Add a sym_block
parameter and set the pointed value to NULL (TODO).
(enumerate_args): Update call to extract_sym.
(enumerate_locals): Update calls to extract_sym and to
read_var_value.
* python/py-symbol.c (sympy_value): Update call to
read_var_value (TODO).
* stack.c (read_frame_local): Update call to read_var_value.
(read_frame_arg): Likewise.
(return_command): Likewise.
* symtab.h (struct symbol_block_ops): Add a get_frame_base
method.
(struct symbol): Add a block field.
(SYMBOL_BLOCK): New accessor.
* valops.c (value_of_variable): Remove frame/block handling and
pass the block argument to read_var_value, which does this job
now.
(value_struct_elt_for_reference): Update calls to
read_var_value.
(value_of_this): Pass the block found to read_var_value.
* value.h (read_var_value): Add a var_block argument.
(default_read_var_value): Likewise.
gdb/testsuite/ChangeLog:
* gdb.base/nested-subp1.exp: New file.
* gdb.base/nested-subp1.c: New file.
* gdb.base/nested-subp2.exp: New file.
* gdb.base/nested-subp2.c: New file.
* gdb.base/nested-subp3.exp: New file.
* gdb.base/nested-subp3.c: New file.
---
gdb/ada-lang.c | 5 +-
gdb/block.c | 15 +++
gdb/block.h | 11 +++
gdb/buildsym.c | 19 ++--
gdb/buildsym.h | 15 ++-
gdb/c-exp.y | 5 +-
gdb/coffread.c | 6 +-
gdb/compile/compile-c-symbols.c | 74 +++++++-------
gdb/compile/compile-loc2c.c | 2 +-
gdb/dbxread.c | 8 +-
gdb/dwarf2loc.c | 57 +++++++++--
gdb/dwarf2loc.h | 11 ++-
gdb/dwarf2read.c | 18 +++-
gdb/f-exp.y | 5 +-
gdb/findvar.c | 168 +++++++++++++++++++++++++++++++-
gdb/gdbtypes.c | 7 +-
gdb/go-exp.y | 5 +-
gdb/guile/scm-frame.c | 9 +-
gdb/guile/scm-symbol.c | 6 +-
gdb/infcmd.c | 2 +-
gdb/infrun.c | 7 +-
gdb/jv-exp.y | 4 +-
gdb/language.h | 12 ++-
gdb/m2-exp.y | 5 +-
gdb/objfiles.c | 91 +++++++++++++++++
gdb/objfiles.h | 22 +++++
gdb/p-exp.y | 5 +-
gdb/printcmd.c | 6 +-
gdb/python/py-finishbreakpoint.c | 2 +-
gdb/python/py-frame.c | 9 +-
gdb/python/py-framefilter.c | 29 ++++--
gdb/python/py-symbol.c | 6 +-
gdb/stack.c | 8 +-
gdb/symtab.h | 19 ++++
gdb/testsuite/gdb.base/nested-subp1.c | 37 +++++++
gdb/testsuite/gdb.base/nested-subp1.exp | 55 +++++++++++
gdb/testsuite/gdb.base/nested-subp2.c | 48 +++++++++
gdb/testsuite/gdb.base/nested-subp2.exp | 64 ++++++++++++
gdb/testsuite/gdb.base/nested-subp3.c | 66 +++++++++++++
gdb/testsuite/gdb.base/nested-subp3.exp | 55 +++++++++++
gdb/valops.c | 35 ++-----
gdb/value.h | 2 +
gdb/xcoffread.c | 5 +-
43 files changed, 885 insertions(+), 155 deletions(-)
create mode 100644 gdb/testsuite/gdb.base/nested-subp1.c
create mode 100644 gdb/testsuite/gdb.base/nested-subp1.exp
create mode 100644 gdb/testsuite/gdb.base/nested-subp2.c
create mode 100644 gdb/testsuite/gdb.base/nested-subp2.exp
create mode 100644 gdb/testsuite/gdb.base/nested-subp3.c
create mode 100644 gdb/testsuite/gdb.base/nested-subp3.exp
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 1fa65244..4d7d22e 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -13844,7 +13844,8 @@ ada_get_symbol_name_cmp (const char *lookup_name)
/* 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)
+ada_read_var_value (struct symbol *var, const struct block *var_block,
+ struct frame_info *frame)
{
const struct block *frame_block = NULL;
struct symbol *renaming_sym = NULL;
@@ -13860,7 +13861,7 @@ ada_read_var_value (struct symbol *var, struct frame_info *frame)
/* This is a typical case where we expect the default_read_var_value
function to work. */
- return default_read_var_value (var, frame);
+ return default_read_var_value (var, var_block, frame);
}
const struct language_defn ada_language_defn = {
diff --git a/gdb/block.c b/gdb/block.c
index f7621aa..f4b8e4f 100644
--- a/gdb/block.c
+++ b/gdb/block.c
@@ -428,6 +428,21 @@ set_block_compunit_symtab (struct block *block, struct compunit_symtab *cu)
gb->compunit_symtab = cu;
}
+/* See block.h. */
+
+struct dynamic_prop *
+block_static_link (const struct block *block)
+{
+ struct objfile *objfile = block_objfile (block);
+
+ /* Only objfile-owned blocks that materialize top function scopes can have
+ static links. */
+ if (objfile == NULL || BLOCK_FUNCTION (block) == NULL)
+ return NULL;
+
+ return (struct dynamic_prop *) objfile_lookup_static_link (objfile, block);
+}
+
/* Return the compunit of the global block. */
static struct compunit_symtab *
diff --git a/gdb/block.h b/gdb/block.h
index 3dbcbcb..c15114b 100644
--- a/gdb/block.h
+++ b/gdb/block.h
@@ -179,6 +179,17 @@ extern struct block *allocate_global_block (struct obstack *obstack);
extern void set_block_compunit_symtab (struct block *,
struct compunit_symtab *);
+/* Return a property to evaluate the static link associated to BLOCK.
+
+ In the context of nested functions (available in Pascal, Ada and GNU C, for
+ instance), a static link (as in DWARF's DW_AT_static_link attribute) for a
+ function is a way to get the frame corresponding to the enclosing function.
+
+ Note that only objfile-owned and function-level blocks can have a static
+ link. Return NULL if there is no such property. */
+
+extern struct dynamic_prop *block_static_link (const struct block *block);
+
/* A block iterator. This structure should be treated as though it
were opaque; it is only defined here because we want to support
stack allocation of iterators. */
diff --git a/gdb/buildsym.c b/gdb/buildsym.c
index 92c42d5..36ec62f 100644
--- a/gdb/buildsym.c
+++ b/gdb/buildsym.c
@@ -331,8 +331,10 @@ free_pending_blocks (void)
file). Put the block on the list of pending blocks. */
static struct block *
-finish_block_internal (struct symbol *symbol, struct pending **listhead,
+finish_block_internal (struct symbol *symbol,
+ struct pending **listhead,
struct pending_block *old_blocks,
+ const struct dynamic_prop *static_link,
CORE_ADDR start, CORE_ADDR end,
int is_global, int expandable)
{
@@ -422,6 +424,9 @@ finish_block_internal (struct symbol *symbol, struct pending **listhead,
BLOCK_FUNCTION (block) = NULL;
}
+ if (static_link != NULL)
+ objfile_register_static_link (objfile, block, static_link);
+
/* Now "free" the links of the list, and empty the list. */
for (next = *listhead; next; next = next1)
@@ -519,11 +524,13 @@ finish_block_internal (struct symbol *symbol, struct pending **listhead,
}
struct block *
-finish_block (struct symbol *symbol, struct pending **listhead,
+finish_block (struct symbol *symbol,
+ struct pending **listhead,
struct pending_block *old_blocks,
+ const struct dynamic_prop *static_link,
CORE_ADDR start, CORE_ADDR end)
{
- return finish_block_internal (symbol, listhead, old_blocks,
+ return finish_block_internal (symbol, listhead, old_blocks, static_link,
start, end, 0, 0);
}
@@ -1229,7 +1236,7 @@ end_symtab_get_static_block (CORE_ADDR end_addr, int expandable, int required)
struct context_stack *cstk = pop_context ();
/* Make a block for the local symbols within. */
- finish_block (cstk->name, &local_symbols, cstk->old_blocks,
+ finish_block (cstk->name, &local_symbols, cstk->old_blocks, NULL,
cstk->start_addr, end_addr);
if (context_stack_depth > 0)
@@ -1301,7 +1308,7 @@ end_symtab_get_static_block (CORE_ADDR end_addr, int expandable, int required)
else
{
/* Define the STATIC_BLOCK. */
- return finish_block_internal (NULL, &file_symbols, NULL,
+ return finish_block_internal (NULL, &file_symbols, NULL, NULL,
last_source_start_addr, end_addr,
0, expandable);
}
@@ -1329,7 +1336,7 @@ end_symtab_with_blockvector (struct block *static_block,
end_addr = BLOCK_END (static_block);
/* Create the GLOBAL_BLOCK and build the blockvector. */
- finish_block_internal (NULL, &global_symbols, NULL,
+ finish_block_internal (NULL, &global_symbols, NULL, NULL,
last_source_start_addr, end_addr,
1, expandable);
blockvector = make_blockvector ();
diff --git a/gdb/buildsym.h b/gdb/buildsym.h
index 4c0ec15..b1eda8c 100644
--- a/gdb/buildsym.h
+++ b/gdb/buildsym.h
@@ -39,6 +39,8 @@ struct compunit_symtab;
struct block;
struct pending_block;
+struct dynamic_prop;
+
#ifndef EXTERN
#define EXTERN extern
#endif
@@ -145,6 +147,11 @@ struct context_stack
struct symbol *name;
+ /* Expression that computes the frame base of the lexically enclosing
+ function, if any. NULL otherwise. */
+
+ struct dynamic_prop *static_link;
+
/* PC where this context starts */
CORE_ADDR start_addr;
@@ -196,9 +203,11 @@ extern struct symbol *find_symbol_in_list (struct pending *list,
char *name, int length);
extern struct block *finish_block (struct symbol *symbol,
- struct pending **listhead,
- struct pending_block *old_blocks,
- CORE_ADDR start, CORE_ADDR end);
+ struct pending **listhead,
+ struct pending_block *old_blocks,
+ const struct dynamic_prop *static_link,
+ CORE_ADDR start,
+ CORE_ADDR end);
extern void record_block_range (struct block *,
CORE_ADDR start, CORE_ADDR end_inclusive);
diff --git a/gdb/c-exp.y b/gdb/c-exp.y
index a8a4caf..351505e 100644
--- a/gdb/c-exp.y
+++ b/gdb/c-exp.y
@@ -1072,10 +1072,7 @@ variable: name_not_typename
}
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
- /* We want to use the selected frame, not
- another more inner frame which happens to
- be in the same block. */
- write_exp_elt_block (pstate, NULL);
+ write_exp_elt_block (pstate, sym.block);
write_exp_elt_sym (pstate, sym.symbol);
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
}
diff --git a/gdb/coffread.c b/gdb/coffread.c
index 7722cdb..c0f4267 100644
--- a/gdb/coffread.c
+++ b/gdb/coffread.c
@@ -1144,8 +1144,8 @@ coff_symtab_read (long symtab_offset, unsigned int nsyms,
enter_linenos (fcn_line_ptr, fcn_first_line,
fcn_last_line, objfile);
- finish_block (newobj->name, &local_symbols,
- newobj->old_blocks, newobj->start_addr,
+ finish_block (newobj->name, &local_symbols, newobj->old_blocks,
+ NULL, newobj->start_addr,
fcn_cs_saved.c_value
+ fcn_aux_saved.x_sym.x_misc.x_fsize
+ ANOFFSET (objfile->section_offsets,
@@ -1188,7 +1188,7 @@ coff_symtab_read (long symtab_offset, unsigned int nsyms,
cs->c_value + ANOFFSET (objfile->section_offsets,
SECT_OFF_TEXT (objfile));
/* Make a block for the local symbols within. */
- finish_block (0, &local_symbols, newobj->old_blocks,
+ finish_block (0, &local_symbols, newobj->old_blocks, NULL,
newobj->start_addr, tmpaddr);
}
/* Now pop locals of block just finished. */
diff --git a/gdb/compile/compile-c-symbols.c b/gdb/compile/compile-c-symbols.c
index 21ce655..355b063 100644
--- a/gdb/compile/compile-c-symbols.c
+++ b/gdb/compile/compile-c-symbols.c
@@ -143,26 +143,26 @@ symbol_substitution_name (struct symbol *sym)
static void
convert_one_symbol (struct compile_c_instance *context,
- struct symbol *sym,
+ struct block_symbol sym,
int is_global,
int is_local)
{
gcc_type sym_type;
- const char *filename = symbol_symtab (sym)->filename;
- unsigned short line = SYMBOL_LINE (sym);
+ const char *filename = symbol_symtab (sym.symbol)->filename;
+ unsigned short line = SYMBOL_LINE (sym.symbol);
- error_symbol_once (context, sym);
+ error_symbol_once (context, sym.symbol);
- if (SYMBOL_CLASS (sym) == LOC_LABEL)
+ if (SYMBOL_CLASS (sym.symbol) == LOC_LABEL)
sym_type = 0;
else
- sym_type = convert_type (context, SYMBOL_TYPE (sym));
+ sym_type = convert_type (context, SYMBOL_TYPE (sym.symbol));
- if (SYMBOL_DOMAIN (sym) == STRUCT_DOMAIN)
+ if (SYMBOL_DOMAIN (sym.symbol) == STRUCT_DOMAIN)
{
/* Binding a tag, so we don't need to build a decl. */
C_CTX (context)->c_ops->tagbind (C_CTX (context),
- SYMBOL_NATURAL_NAME (sym),
+ SYMBOL_NATURAL_NAME (sym.symbol),
sym_type, filename, line);
}
else
@@ -172,7 +172,7 @@ convert_one_symbol (struct compile_c_instance *context,
CORE_ADDR addr = 0;
char *symbol_name = NULL;
- switch (SYMBOL_CLASS (sym))
+ switch (SYMBOL_CLASS (sym.symbol))
{
case LOC_TYPEDEF:
kind = GCC_C_SYMBOL_TYPEDEF;
@@ -180,45 +180,46 @@ convert_one_symbol (struct compile_c_instance *context,
case LOC_LABEL:
kind = GCC_C_SYMBOL_LABEL;
- addr = SYMBOL_VALUE_ADDRESS (sym);
+ addr = SYMBOL_VALUE_ADDRESS (sym.symbol);
break;
case LOC_BLOCK:
kind = GCC_C_SYMBOL_FUNCTION;
- addr = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
- if (is_global && TYPE_GNU_IFUNC (SYMBOL_TYPE (sym)))
+ addr = BLOCK_START (SYMBOL_BLOCK_VALUE (sym.symbol));
+ if (is_global && TYPE_GNU_IFUNC (SYMBOL_TYPE (sym.symbol)))
addr = gnu_ifunc_resolve_addr (target_gdbarch (), addr);
break;
case LOC_CONST:
- if (TYPE_CODE (SYMBOL_TYPE (sym)) == TYPE_CODE_ENUM)
+ if (TYPE_CODE (SYMBOL_TYPE (sym.symbol)) == TYPE_CODE_ENUM)
{
/* Already handled by convert_enum. */
return;
}
- C_CTX (context)->c_ops->build_constant (C_CTX (context), sym_type,
- SYMBOL_NATURAL_NAME (sym),
- SYMBOL_VALUE (sym),
- filename, line);
+ C_CTX (context)->c_ops->build_constant
+ (C_CTX (context),
+ sym_type, SYMBOL_NATURAL_NAME (sym.symbol),
+ SYMBOL_VALUE (sym.symbol),
+ filename, line);
return;
case LOC_CONST_BYTES:
error (_("Unsupported LOC_CONST_BYTES for symbol \"%s\"."),
- SYMBOL_PRINT_NAME (sym));
+ SYMBOL_PRINT_NAME (sym.symbol));
case LOC_UNDEF:
internal_error (__FILE__, __LINE__, _("LOC_UNDEF found for \"%s\"."),
- SYMBOL_PRINT_NAME (sym));
+ SYMBOL_PRINT_NAME (sym.symbol));
case LOC_COMMON_BLOCK:
error (_("Fortran common block is unsupported for compilation "
"evaluaton of symbol \"%s\"."),
- SYMBOL_PRINT_NAME (sym));
+ SYMBOL_PRINT_NAME (sym.symbol));
case LOC_OPTIMIZED_OUT:
error (_("Symbol \"%s\" cannot be used for compilation evaluation "
"as it is optimized out."),
- SYMBOL_PRINT_NAME (sym));
+ SYMBOL_PRINT_NAME (sym.symbol));
case LOC_COMPUTED:
if (is_local)
@@ -227,7 +228,7 @@ convert_one_symbol (struct compile_c_instance *context,
warning (_("Symbol \"%s\" is thread-local and currently can only "
"be referenced from the current thread in "
"compiled code."),
- SYMBOL_PRINT_NAME (sym));
+ SYMBOL_PRINT_NAME (sym.symbol));
/* FALLTHROUGH */
case LOC_UNRESOLVED:
/* 'symbol_name' cannot be used here as that one is used only for
@@ -238,20 +239,20 @@ convert_one_symbol (struct compile_c_instance *context,
struct value *val;
struct frame_info *frame = NULL;
- if (symbol_read_needs_frame (sym))
+ if (symbol_read_needs_frame (sym.symbol))
{
frame = get_selected_frame (NULL);
if (frame == NULL)
error (_("Symbol \"%s\" cannot be used because "
"there is no selected frame"),
- SYMBOL_PRINT_NAME (sym));
+ SYMBOL_PRINT_NAME (sym.symbol));
}
- val = read_var_value (sym, frame);
+ val = read_var_value (sym.symbol, sym.block, frame);
if (VALUE_LVAL (val) != lval_memory)
error (_("Symbol \"%s\" cannot be used for compilation "
"evaluation as its address has not been found."),
- SYMBOL_PRINT_NAME (sym));
+ SYMBOL_PRINT_NAME (sym.symbol));
kind = GCC_C_SYMBOL_VARIABLE;
addr = value_address (val);
@@ -266,12 +267,12 @@ convert_one_symbol (struct compile_c_instance *context,
case LOC_LOCAL:
substitution:
kind = GCC_C_SYMBOL_VARIABLE;
- symbol_name = symbol_substitution_name (sym);
+ symbol_name = symbol_substitution_name (sym.symbol);
break;
case LOC_STATIC:
kind = GCC_C_SYMBOL_VARIABLE;
- addr = SYMBOL_VALUE_ADDRESS (sym);
+ addr = SYMBOL_VALUE_ADDRESS (sym.symbol);
break;
case LOC_FINAL_VALUE:
@@ -284,12 +285,13 @@ convert_one_symbol (struct compile_c_instance *context,
if (context->base.scope != COMPILE_I_RAW_SCOPE
|| symbol_name == NULL)
{
- decl = C_CTX (context)->c_ops->build_decl (C_CTX (context),
- SYMBOL_NATURAL_NAME (sym),
- kind,
- sym_type,
- symbol_name, addr,
- filename, line);
+ decl = C_CTX (context)->c_ops->build_decl
+ (C_CTX (context),
+ SYMBOL_NATURAL_NAME (sym.symbol),
+ kind,
+ sym_type,
+ symbol_name, addr,
+ filename, line);
C_CTX (context)->c_ops->bind (C_CTX (context), decl, is_global);
}
@@ -338,7 +340,7 @@ convert_symbol_sym (struct compile_c_instance *context, const char *identifier,
fprintf_unfiltered (gdb_stdlog,
"gcc_convert_symbol \"%s\": global symbol\n",
identifier);
- convert_one_symbol (context, global_sym.symbol, 1, 0);
+ convert_one_symbol (context, global_sym, 1, 0);
}
}
@@ -346,7 +348,7 @@ convert_symbol_sym (struct compile_c_instance *context, const char *identifier,
fprintf_unfiltered (gdb_stdlog,
"gcc_convert_symbol \"%s\": local symbol\n",
identifier);
- convert_one_symbol (context, sym.symbol, 0, is_local_symbol);
+ convert_one_symbol (context, sym, 0, is_local_symbol);
}
/* Convert a minimal symbol to its gcc form. CONTEXT is the compiler
diff --git a/gdb/compile/compile-loc2c.c b/gdb/compile/compile-loc2c.c
index b201d13..8058cbd 100644
--- a/gdb/compile/compile-loc2c.c
+++ b/gdb/compile/compile-loc2c.c
@@ -636,7 +636,7 @@ do_compile_dwarf_expr_to_c (int indent, struct ui_file *stream,
"there is no selected frame"),
SYMBOL_PRINT_NAME (sym));
- val = read_var_value (sym, frame);
+ val = read_var_value (sym, NULL, frame);
if (VALUE_LVAL (val) != lval_memory)
error (_("Symbol \"%s\" cannot be used for compilation evaluation "
"as its address has not been found."),
diff --git a/gdb/dbxread.c b/gdb/dbxread.c
index 1d00432..fdf4e09 100644
--- a/gdb/dbxread.c
+++ b/gdb/dbxread.c
@@ -2756,7 +2756,7 @@ process_one_symbol (int type, int desc, CORE_ADDR valu, char *name,
/* Make a block for the local symbols within. */
block = finish_block (newobj->name, &local_symbols,
- newobj->old_blocks,
+ newobj->old_blocks, NULL,
newobj->start_addr, newobj->start_addr + valu);
/* For C++, set the block's scope. */
@@ -2857,7 +2857,7 @@ process_one_symbol (int type, int desc, CORE_ADDR valu, char *name,
newobj->start_addr = valu;
}
/* Make a block for the local symbols within. */
- finish_block (0, &local_symbols, newobj->old_blocks,
+ finish_block (0, &local_symbols, newobj->old_blocks, NULL,
newobj->start_addr, valu);
}
}
@@ -3155,8 +3155,8 @@ process_one_symbol (int type, int desc, CORE_ADDR valu, char *name,
newobj = pop_context ();
/* Make a block for the local symbols within. */
block = finish_block (newobj->name, &local_symbols,
- newobj->old_blocks, newobj->start_addr,
- valu);
+ newobj->old_blocks, NULL,
+ newobj->start_addr, valu);
/* For C++, set the block's scope. */
if (SYMBOL_LANGUAGE (newobj->name) == language_cplus)
diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c
index d8e432e..efe4357 100644
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -381,12 +381,47 @@ locexpr_find_frame_base_location (struct symbol *framefunc, CORE_ADDR pc,
*start = symbaton->data;
}
+/* Implement the struct symbol_block_ops::get_frame_base method. */
+
+static CORE_ADDR
+block_op_get_frame_base (struct symbol *framefunc, struct frame_info *frame)
+{
+ struct gdbarch *gdbarch;
+ struct type *type;
+ struct dwarf2_locexpr_baton *dlbaton;
+ const gdb_byte *start;
+ size_t length;
+ struct value *result;
+
+ /* If this method is called, then FRAMEFUNC is supposed to be a DWARF block.
+ Thus, it's supposed to provide the find_frame_base_location method as
+ well. */
+ gdb_assert (SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location != NULL);
+
+ gdbarch = get_frame_arch (frame);
+ type = builtin_type (gdbarch)->builtin_data_ptr;
+ dlbaton = SYMBOL_LOCATION_BATON (framefunc);
+
+ SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location
+ (framefunc, get_frame_pc (frame), &start, &length);
+ result = dwarf2_evaluate_loc_desc (type, frame, start, length,
+ dlbaton->per_cu);
+
+ /* The DW_AT_frame_base attribute contains a location description which
+ computes the base address itself. However, the call to
+ dwarf2_evaluate_loc_desc returns a value representing a variable at
+ that address. The frame base address is thus this variable's
+ address. */
+ return value_address (result);
+}
+
/* Vector for inferior functions as represented by LOC_BLOCK, if the inferior
function uses DWARF expression for its DW_AT_frame_base. */
const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs =
{
- locexpr_find_frame_base_location
+ locexpr_find_frame_base_location,
+ block_op_get_frame_base
};
/* Implement find_frame_base_location method for LOC_BLOCK functions using
@@ -406,7 +441,8 @@ loclist_find_frame_base_location (struct symbol *framefunc, CORE_ADDR pc,
const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs =
{
- loclist_find_frame_base_location
+ loclist_find_frame_base_location,
+ block_op_get_frame_base
};
/* See dwarf2loc.h. */
@@ -2396,13 +2432,14 @@ dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame,
}
/* Evaluates a dwarf expression and stores the result in VAL, expecting
- that the dwarf expression only produces a single CORE_ADDR. ADDR is a
- context (location of a variable) and might be needed to evaluate the
- location expression.
+ that the dwarf expression only produces a single CORE_ADDR. FRAME is the
+ frame in which the expression is evaluated. ADDR is a context (location of
+ a variable) and might be needed to evaluate the location expression.
Returns 1 on success, 0 otherwise. */
static int
dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
+ struct frame_info *frame,
CORE_ADDR addr,
CORE_ADDR *valp)
{
@@ -2417,7 +2454,7 @@ dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
ctx = new_dwarf_expr_context ();
cleanup = make_cleanup_free_dwarf_expr_context (ctx);
- baton.frame = get_selected_frame (NULL);
+ baton.frame = frame;
baton.per_cu = dlbaton->per_cu;
baton.obj_address = addr;
@@ -2461,19 +2498,24 @@ dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
int
dwarf2_evaluate_property (const struct dynamic_prop *prop,
+ struct frame_info *frame,
struct property_addr_info *addr_stack,
CORE_ADDR *value)
{
if (prop == NULL)
return 0;
+ if (frame == NULL && has_stack_frames ())
+ frame = get_selected_frame (NULL);
+
switch (prop->kind)
{
case PROP_LOCEXPR:
{
const struct dwarf2_property_baton *baton = prop->data.baton;
- if (dwarf2_locexpr_baton_eval (&baton->locexpr, addr_stack->addr,
+ if (dwarf2_locexpr_baton_eval (&baton->locexpr, frame,
+ addr_stack ? addr_stack->addr : 0,
value))
{
if (baton->referenced_type)
@@ -2490,7 +2532,6 @@ dwarf2_evaluate_property (const struct dynamic_prop *prop,
case PROP_LOCLIST:
{
struct dwarf2_property_baton *baton = prop->data.baton;
- struct frame_info *frame = get_selected_frame (NULL);
CORE_ADDR pc = get_frame_address_in_block (frame);
const gdb_byte *data;
struct value *val;
diff --git a/gdb/dwarf2loc.h b/gdb/dwarf2loc.h
index f3630ac..2415656 100644
--- a/gdb/dwarf2loc.h
+++ b/gdb/dwarf2loc.h
@@ -122,12 +122,19 @@ struct property_addr_info
struct property_addr_info *next;
};
-/* Converts a dynamic property into a static one. ADDR_STACK is the stack
- of addresses that might be needed to evaluate the property.
+/* Converts a dynamic property into a static one. FRAME is the frame in which
+ the property is evaluated; if NULL, the selected frame (if any) is used
+ instead.
+
+ ADDR_STACK is the stack of addresses that might be needed to evaluate the
+ property. When evaluating a property that is not related to a type, it can
+ be NULL.
+
Returns 1 if PROP could be converted and the static value is passed back
into VALUE, otherwise returns 0. */
int dwarf2_evaluate_property (const struct dynamic_prop *prop,
+ struct frame_info *frame,
struct property_addr_info *addr_stack,
CORE_ADDR *value);
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 445ad86..60578a2 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -1740,6 +1740,10 @@ static void load_full_type_unit (struct dwarf2_per_cu_data *per_cu);
static void read_signatured_type (struct signatured_type *);
+static int attr_to_dynamic_prop (const struct attribute *attr,
+ struct die_info *die, struct dwarf2_cu *cu,
+ struct dynamic_prop *prop);
+
/* memory allocation interface */
static struct dwarf_block *dwarf_alloc_block (struct dwarf2_cu *);
@@ -11411,6 +11415,16 @@ read_func_scope (struct die_info *die, struct dwarf2_cu *cu)
if (attr)
dwarf2_symbol_mark_computed (attr, newobj->name, cu, 1);
+ /* If there is a location for the static link, record it. */
+ newobj->static_link = NULL;
+ attr = dwarf2_attr (die, DW_AT_static_link, cu);
+ if (attr)
+ {
+ newobj->static_link = obstack_alloc (&objfile->objfile_obstack,
+ sizeof (*newobj->static_link));
+ attr_to_dynamic_prop (attr, die, cu, newobj->static_link);
+ }
+
cu->list_in_scope = &local_symbols;
if (die->child != NULL)
@@ -11462,7 +11476,7 @@ read_func_scope (struct die_info *die, struct dwarf2_cu *cu)
newobj = pop_context ();
/* Make a block for the local symbols within. */
block = finish_block (newobj->name, &local_symbols, newobj->old_blocks,
- lowpc, highpc);
+ newobj->static_link, lowpc, highpc);
/* For C++, set the block's scope. */
if ((cu->language == language_cplus
@@ -11547,7 +11561,7 @@ read_lexical_block_scope (struct die_info *die, struct dwarf2_cu *cu)
if (local_symbols != NULL || local_using_directives != NULL)
{
struct block *block
- = finish_block (0, &local_symbols, newobj->old_blocks,
+ = finish_block (0, &local_symbols, newobj->old_blocks, NULL,
newobj->start_addr, highpc);
/* Note that recording ranges after traversing children, as we
diff --git a/gdb/f-exp.y b/gdb/f-exp.y
index 3c486ef..56629dc 100644
--- a/gdb/f-exp.y
+++ b/gdb/f-exp.y
@@ -521,10 +521,7 @@ variable: name_not_typename
innermost_block = sym.block;
}
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
- /* We want to use the selected frame, not
- another more inner frame which happens to
- be in the same block. */
- write_exp_elt_block (pstate, NULL);
+ write_exp_elt_block (pstate, sym.block);
write_exp_elt_sym (pstate, sym.symbol);
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
break;
diff --git a/gdb/findvar.c b/gdb/findvar.c
index 83b4fca..1c077f7 100644
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -32,6 +32,7 @@
#include "block.h"
#include "objfiles.h"
#include "language.h"
+#include "dwarf2loc.h"
/* Basic byte-swapping routines. All 'extract' functions return a
host-format integer from a target-format integer at ADDR which is
@@ -409,11 +410,166 @@ minsym_lookup_iterator_cb (struct objfile *objfile, void *cb_data)
return (data->result.minsym != NULL);
}
+/* Given static link expression and the frame it lives in, look for the frame
+ the static links points to and return it. Return NULL if we could not find
+ such a frame. */
+
+static struct frame_info *
+follow_static_link (struct frame_info *frame,
+ const struct dynamic_prop *static_link)
+{
+ CORE_ADDR upper_frame_base;
+
+ if (!dwarf2_evaluate_property (static_link, frame, NULL, &upper_frame_base))
+ return NULL;
+
+ /* Now climb up the stack frame until we reach the frame we are interested
+ in. */
+ for (; frame != NULL; frame = get_prev_frame (frame))
+ {
+ struct symbol *framefunc = get_frame_function (frame);
+
+ /* Stacks can be quite deep: give the user a chance to stop this. */
+ QUIT;
+
+ /* If we don't know how to compute FRAME's base address, don't give up:
+ maybe the frame we are looking for is upper in the stace frame. */
+ if (framefunc != NULL
+ && SYMBOL_BLOCK_OPS (framefunc)->get_frame_base != NULL
+ && (SYMBOL_BLOCK_OPS (framefunc)->get_frame_base (framefunc, frame)
+ == upper_frame_base))
+ break;
+ }
+
+ return frame;
+}
+
+/* Assuming VAR is a symbol that can be reached from FRAME thanks to lexical
+ rules, look for the frame that is actually hosting VAR and return it. If,
+ for some reason, we found no such frame, return NULL.
+
+ This kind of computation is necessary to correctly handle lexically nested
+ functions.
+
+ Note that in some cases, we know what scope VAR comes from but we cannot
+ reach the specific frame that hosts the instance of VAR we are looking for.
+ For backward compatibility purposes (with old compilers), we then look for
+ the first frame that can host it. */
+
+static struct frame_info *
+get_hosting_frame (struct symbol *var, const struct block *var_block,
+ struct frame_info *frame)
+{
+ const struct block *frame_block = NULL;
+
+ if (!symbol_read_needs_frame (var))
+ return NULL;
+
+ /* Some symbols for local variables have no block: this happens when they are
+ not produced by a debug information reader, for instance when GDB creates
+ synthetic symbols. Without block information, we must assume they are
+ local to FRAME. In this case, there is nothing to do. */
+ else if (var_block == NULL)
+ return frame;
+
+ /* We currently assume that all symbols with a location list need a frame.
+ This is true in practice because selecting the location description
+ requires to compute the CFA, hence requires a frame. However we have
+ tests that embed global/static symbols with null location lists.
+ We want to get <optimized out> instead of <frame required> when evaluating
+ them so return a frame instead of raising an error. */
+ else if (var_block == block_global_block (var_block)
+ || var_block == block_static_block (var_block))
+ return frame;
+
+ /* We have to handle the "my_func::my_local_var" notation. This requires us
+ to look for upper frames when we find no block for the current frame: here
+ and below, handle when frame_block == NULL. */
+ if (frame != NULL)
+ frame_block = get_frame_block (frame, NULL);
+
+ /* Climb up the call stack until reaching the frame we are looking for. */
+ while (frame != NULL && frame_block != var_block)
+ {
+ /* Stacks can be quite deep: give the user a chance to stop this. */
+ QUIT;
+
+ if (frame_block == NULL)
+ {
+ frame = get_prev_frame (frame);
+ if (frame == NULL)
+ break;
+ frame_block = get_frame_block (frame, NULL);
+ }
+
+ /* If we failed to find the proper frame, fallback to the heuristic
+ method below. */
+ else if (frame_block == block_global_block (frame_block))
+ {
+ frame = NULL;
+ break;
+ }
+
+ /* Assuming we have a block for this frame: if we are at the function
+ level, the immediate upper lexical block is in an outer function:
+ follow the static link. */
+ else if (BLOCK_FUNCTION (frame_block))
+ {
+ const struct dynamic_prop *static_link
+ = block_static_link (frame_block);
+ int could_climb_up = 0;
+
+ if (static_link != NULL)
+ {
+ frame = follow_static_link (frame, static_link);
+ if (frame != NULL)
+ {
+ frame_block = get_frame_block (frame, NULL);
+ could_climb_up = frame_block != NULL;
+ }
+ }
+ if (!could_climb_up)
+ {
+ frame = NULL;
+ break;
+ }
+ }
+
+ else
+ /* We must be in some function nested lexical block. Just get the
+ outer block: both must share the same frame. */
+ frame_block = BLOCK_SUPERBLOCK (frame_block);
+ }
+
+ /* Old compilers may not provide a static link, or they may provide an
+ invalid one. For such cases, fallback on the old way to evaluate
+ non-local references: just climb up the call stack and pick the first
+ frame that contains the variable we are looking for. */
+ if (frame == NULL)
+ {
+ frame = block_innermost_frame (var_block);
+ if (frame == NULL)
+ {
+ if (BLOCK_FUNCTION (var_block)
+ && !block_inlined_p (var_block)
+ && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (var_block)))
+ error (_("No frame is currently executing in block %s."),
+ SYMBOL_PRINT_NAME (BLOCK_FUNCTION (var_block)));
+ else
+ error (_("No frame is currently executing in specified"
+ " block"));
+ }
+ }
+
+ return frame;
+}
+
/* A default implementation for the "la_read_var_value" hook in
the language vector which should work in most situations. */
struct value *
-default_read_var_value (struct symbol *var, struct frame_info *frame)
+default_read_var_value (struct symbol *var, const struct block *var_block,
+ struct frame_info *frame)
{
struct value *v;
struct type *type = SYMBOL_TYPE (var);
@@ -427,7 +583,10 @@ default_read_var_value (struct symbol *var, struct frame_info *frame)
check_typedef (type);
if (symbol_read_needs_frame (var))
- gdb_assert (frame);
+ gdb_assert (frame != NULL);
+
+ if (frame != NULL)
+ frame = get_hosting_frame (var, var_block, frame);
if (SYMBOL_COMPUTED_OPS (var) != NULL)
return SYMBOL_COMPUTED_OPS (var)->read_variable (var, frame);
@@ -610,14 +769,15 @@ default_read_var_value (struct symbol *var, struct frame_info *frame)
/* 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)
+read_var_value (struct symbol *var, const struct block *var_block,
+ 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);
+ return lang->la_read_var_value (var, var_block, frame);
}
/* Install default attributes for register values. */
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 125af01..301c6fc 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -1885,7 +1885,7 @@ resolve_dynamic_range (struct type *dyn_range_type,
gdb_assert (TYPE_CODE (dyn_range_type) == TYPE_CODE_RANGE);
prop = &TYPE_RANGE_DATA (dyn_range_type)->low;
- if (dwarf2_evaluate_property (prop, addr_stack, &value))
+ if (dwarf2_evaluate_property (prop, NULL, addr_stack, &value))
{
low_bound.kind = PROP_CONST;
low_bound.data.const_val = value;
@@ -1897,7 +1897,7 @@ resolve_dynamic_range (struct type *dyn_range_type,
}
prop = &TYPE_RANGE_DATA (dyn_range_type)->high;
- if (dwarf2_evaluate_property (prop, addr_stack, &value))
+ if (dwarf2_evaluate_property (prop, NULL, addr_stack, &value))
{
high_bound.kind = PROP_CONST;
high_bound.data.const_val = value;
@@ -2139,7 +2139,8 @@ resolve_dynamic_type_internal (struct type *type,
/* Resolve data_location attribute. */
prop = TYPE_DATA_LOCATION (resolved_type);
- if (prop != NULL && dwarf2_evaluate_property (prop, addr_stack, &value))
+ if (prop != NULL
+ && dwarf2_evaluate_property (prop, NULL, addr_stack, &value))
{
TYPE_DYN_PROP_ADDR (prop) = value;
TYPE_DYN_PROP_KIND (prop) = PROP_CONST;
diff --git a/gdb/go-exp.y b/gdb/go-exp.y
index c1ddfa9..4e017fe 100644
--- a/gdb/go-exp.y
+++ b/gdb/go-exp.y
@@ -611,10 +611,7 @@ variable: name_not_typename
}
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
- /* We want to use the selected frame, not
- another more inner frame which happens to
- be in the same block. */
- write_exp_elt_block (pstate, NULL);
+ write_exp_elt_block (pstate, sym.block);
write_exp_elt_sym (pstate, sym.symbol);
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
}
diff --git a/gdb/guile/scm-frame.c b/gdb/guile/scm-frame.c
index 64ac0c0..de77c21 100644
--- a/gdb/guile/scm-frame.c
+++ b/gdb/guile/scm-frame.c
@@ -855,6 +855,7 @@ gdbscm_frame_read_var (SCM self, SCM symbol_scm, SCM rest)
SCM block_scm = SCM_UNDEFINED;
struct frame_info *frame = NULL;
struct symbol *var = NULL;
+ const struct block *block = NULL;
struct value *value = NULL;
f_smob = frscm_get_frame_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);
@@ -909,9 +910,13 @@ gdbscm_frame_read_var (SCM self, SCM symbol_scm, SCM rest)
TRY
{
+ struct block_symbol lookup_sym;
+
if (block == NULL)
block = get_frame_block (frame, NULL);
- var = lookup_symbol (var_name, block, VAR_DOMAIN, NULL).symbol;
+ lookup_sym = lookup_symbol (var_name, block, VAR_DOMAIN, NULL);
+ var = lookup_sym.symbol;
+ block = lookup_sym.block;
}
CATCH (ex, RETURN_MASK_ALL)
{
@@ -940,7 +945,7 @@ gdbscm_frame_read_var (SCM self, SCM symbol_scm, SCM rest)
TRY
{
- value = read_var_value (var, frame);
+ value = read_var_value (var, block, frame);
}
CATCH (except, RETURN_MASK_ALL)
{
diff --git a/gdb/guile/scm-symbol.c b/gdb/guile/scm-symbol.c
index 01c9eb1..0970a72 100644
--- a/gdb/guile/scm-symbol.c
+++ b/gdb/guile/scm-symbol.c
@@ -550,7 +550,11 @@ gdbscm_symbol_value (SCM self, SCM rest)
if (symbol_read_needs_frame (symbol) && frame_info == NULL)
error (_("Symbol requires a frame to compute its value"));
- value = read_var_value (symbol, frame_info);
+ /* TODO: currently, we have no way to recover the block in which SYMBOL
+ was found, so we have no block to pass to read_var_value. This will
+ yield an incorrect value when symbol is not local to FRAME_INFO (this
+ can happen with nested functions). */
+ value = read_var_value (symbol, NULL, frame_info);
}
CATCH (except, RETURN_MASK_ALL)
{
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 82399a4..393ccb9 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -1662,7 +1662,7 @@ finish_command_continuation (void *arg, int err)
{
struct value *func;
- func = read_var_value (a->function, get_current_frame ());
+ func = read_var_value (a->function, NULL, get_current_frame ());
TRY
{
/* print_return_value can throw an exception in some
diff --git a/gdb/infrun.c b/gdb/infrun.c
index a695f2e..cbacece 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -7198,14 +7198,13 @@ insert_exception_resume_breakpoint (struct thread_info *tp,
{
TRY
{
- struct symbol *vsym;
+ struct block_symbol vsym;
struct value *value;
CORE_ADDR handler;
struct breakpoint *bp;
- vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN,
- NULL).symbol;
- value = read_var_value (vsym, frame);
+ vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
+ value = read_var_value (vsym.symbol, vsym.block, frame);
/* If the value was optimized out, revert to the old behavior. */
if (! value_optimized_out (value))
{
diff --git a/gdb/jv-exp.y b/gdb/jv-exp.y
index 4999848..60b7d2e 100644
--- a/gdb/jv-exp.y
+++ b/gdb/jv-exp.y
@@ -1284,9 +1284,7 @@ push_variable (struct parser_state *par_state, struct stoken name)
}
write_exp_elt_opcode (par_state, OP_VAR_VALUE);
- /* We want to use the selected frame, not another more inner frame
- which happens to be in the same block. */
- write_exp_elt_block (par_state, NULL);
+ write_exp_elt_block (par_state, sym.block);
write_exp_elt_sym (par_state, sym.symbol);
write_exp_elt_opcode (par_state, OP_VAR_VALUE);
return 1;
diff --git a/gdb/language.h b/gdb/language.h
index 2265afc..8b579a2 100644
--- a/gdb/language.h
+++ b/gdb/language.h
@@ -241,13 +241,19 @@ 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.
+ /* Given a symbol VAR, the corresponding block VAR_BLOCK (if any) and a
+ stack frame id FRAME, read the value of the variable and return (pointer
+ to a) struct value containing the value.
+
+ VAR_BLOCK is needed if there's a possibility for VAR to be outside
+ FRAME. This is what happens if FRAME correspond to a nested function
+ and VAR is defined in the outer function. If callers know that VAR is
+ located in FRAME or is global/static, NULL can be passed as VAR_BLOCK.
Throw an error if the variable cannot be found. */
struct value *(*la_read_var_value) (struct symbol *var,
+ const struct block *var_block,
struct frame_info *frame);
/* PC is possibly an unknown languages trampoline.
diff --git a/gdb/m2-exp.y b/gdb/m2-exp.y
index 633c354..360fdea 100644
--- a/gdb/m2-exp.y
+++ b/gdb/m2-exp.y
@@ -637,10 +637,7 @@ variable: NAME
}
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
- /* We want to use the selected frame, not
- another more inner frame which happens to
- be in the same block. */
- write_exp_elt_block (pstate, NULL);
+ write_exp_elt_block (pstate, sym.block);
write_exp_elt_sym (pstate, sym.symbol);
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
}
diff --git a/gdb/objfiles.c b/gdb/objfiles.c
index c6f9f00..93d8b7d 100644
--- a/gdb/objfiles.c
+++ b/gdb/objfiles.c
@@ -199,6 +199,92 @@ set_objfile_main_name (struct objfile *objfile,
objfile->per_bfd->language_of_main = lang;
}
+/* Helper structure to map blocks to static link properties in hash tables. */
+
+struct static_link_htab_entry
+{
+ const struct block *block;
+ const struct dynamic_prop *static_link;
+};
+
+/* Return a hash code for struct static_link_htab_entry *P. */
+
+static hashval_t
+static_link_htab_entry_hash (const void *p)
+{
+ const struct static_link_htab_entry *e
+ = (const struct static_link_htab_entry *) p;
+
+ return htab_hash_pointer (e->block);
+}
+
+/* Return whether P1 an P2 (pointers to struct static_link_htab_entry) are
+ mappings for the same block. */
+
+static int
+static_link_htab_entry_eq (const void *p1, const void *p2)
+{
+ const struct static_link_htab_entry *e1
+ = (const struct static_link_htab_entry *) p1;
+ const struct static_link_htab_entry *e2
+ = (const struct static_link_htab_entry *) p2;
+
+ return e1->block == e2->block;
+}
+
+/* Register STATIC_LINK as the static link for BLOCK, which is part of OBJFILE.
+ Must not be called more than once for each BLOCK. */
+
+void
+objfile_register_static_link (struct objfile *objfile,
+ const struct block *block,
+ const struct dynamic_prop *static_link)
+{
+ void **slot;
+ struct static_link_htab_entry lookup_entry;
+ struct static_link_htab_entry *entry;
+
+ if (objfile->static_links == NULL)
+ objfile->static_links = htab_create_alloc
+ (1, &static_link_htab_entry_hash, static_link_htab_entry_eq, NULL,
+ xcalloc, xfree);
+
+ /* Create a slot for the mapping, make sure it's the first mapping for this
+ block and then create the mapping itself. */
+ lookup_entry.block = block;
+ slot = htab_find_slot (objfile->static_links, &lookup_entry, INSERT);
+ gdb_assert (*slot == NULL);
+
+ entry = (struct static_link_htab_entry *) obstack_alloc
+ (&objfile->objfile_obstack, sizeof (*entry));
+ entry->block = block;
+ entry->static_link = static_link;
+ *slot = (void *) entry;
+}
+
+/* Look for a static link for BLOCK, which is part of OBJFILE. Return NULL if
+ none was found. */
+
+const struct dynamic_prop *
+objfile_lookup_static_link (struct objfile *objfile,
+ const struct block *block)
+{
+ struct static_link_htab_entry *entry;
+ struct static_link_htab_entry lookup_entry;
+
+ if (objfile->static_links == NULL)
+ return NULL;
+ lookup_entry.block = block;
+ entry
+ = (struct static_link_htab_entry *) htab_find (objfile->static_links,
+ &lookup_entry);
+ if (entry == NULL)
+ return NULL;
+
+ gdb_assert (entry->block == block);
+ return entry->static_link;
+}
+
/* Called via bfd_map_over_sections to build up the section table that
@@ -653,6 +739,11 @@ free_objfile (struct objfile *objfile)
/* Rebuild section map next time we need it. */
get_objfile_pspace_data (objfile->pspace)->section_map_dirty = 1;
+ /* Free the map for static links. There's no need to free static link
+ themselves since they were allocated on the objstack. */
+ if (objfile->static_links != NULL)
+ htab_delete (objfile->static_links);
+
/* The last thing we do is free the objfile struct itself. */
xfree (objfile);
}
diff --git a/gdb/objfiles.h b/gdb/objfiles.h
index af70715..be2a5ef 100644
--- a/gdb/objfiles.h
+++ b/gdb/objfiles.h
@@ -20,6 +20,7 @@
#if !defined (OBJFILES_H)
#define OBJFILES_H
+#include "hashtab.h"
#include "gdb_obstack.h" /* For obstack internals. */
#include "symfile.h" /* For struct psymbol_allocation_list. */
#include "progspace.h"
@@ -428,6 +429,19 @@ struct objfile
properly. */
struct symbol *template_symbols;
+
+ /* Associate a static link (struct dynamic_prop *) to all blocks (struct
+ block *) that have one.
+
+ In the context of nested functions (available in Pascal, Ada and GNU C,
+ for instance), a static link (as in DWARF's DW_AT_static_link attribute)
+ for a function is a way to get the frame corresponding to the enclosing
+ function.
+
+ Very few blocks have a static link, so it's more memory efficient to
+ store these here rather than in struct block. Static links must be
+ allocated on the objfile's obstack. */
+ htab_t static_links;
};
/* Defines for the objfile flag word. */
@@ -735,4 +749,12 @@ extern const char *objfile_debug_name (const struct objfile *objfile);
extern void set_objfile_main_name (struct objfile *objfile,
const char *name, enum language lang);
+extern void objfile_register_static_link
+ (struct objfile *objfile,
+ const struct block *block,
+ const struct dynamic_prop *static_link);
+
+extern const struct dynamic_prop *objfile_lookup_static_link
+ (struct objfile *objfile, const struct block *block);
+
#endif /* !defined (OBJFILES_H) */
diff --git a/gdb/p-exp.y b/gdb/p-exp.y
index 191b3d3..c255a57 100644
--- a/gdb/p-exp.y
+++ b/gdb/p-exp.y
@@ -772,10 +772,7 @@ variable: name_not_typename
}
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
- /* We want to use the selected frame, not
- another more inner frame which happens to
- be in the same block. */
- write_exp_elt_block (pstate, NULL);
+ write_exp_elt_block (pstate, sym.block);
write_exp_elt_sym (pstate, sym.symbol);
write_exp_elt_opcode (pstate, OP_VAR_VALUE);
current_type = sym.symbol->type; }
diff --git a/gdb/printcmd.c b/gdb/printcmd.c
index f51e25c..553cc71 100644
--- a/gdb/printcmd.c
+++ b/gdb/printcmd.c
@@ -1988,7 +1988,11 @@ print_variable_and_value (const char *name, struct symbol *var,
struct value *val;
struct value_print_options opts;
- val = read_var_value (var, frame);
+ /* READ_VAR_VALUE needs a block in order to deal with non-local
+ references (i.e. to handle nested functions). In this context, we
+ print variables that are local to this frame, so we can avoid passing
+ a block to it. */
+ val = read_var_value (var, NULL, frame);
get_user_print_options (&opts);
opts.deref_ref = 1;
common_val_print (val, stream, indent, &opts, current_language);
diff --git a/gdb/python/py-finishbreakpoint.c b/gdb/python/py-finishbreakpoint.c
index e543bb3..351f68c 100644
--- a/gdb/python/py-finishbreakpoint.c
+++ b/gdb/python/py-finishbreakpoint.c
@@ -265,7 +265,7 @@ bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
/* Ignore Python errors at this stage. */
self_bpfinish->return_type = type_to_type_object (ret_type);
PyErr_Clear ();
- func_value = read_var_value (function, frame);
+ func_value = read_var_value (function, NULL, frame);
self_bpfinish->function_value =
value_to_value_object (func_value);
PyErr_Clear ();
diff --git a/gdb/python/py-frame.c b/gdb/python/py-frame.c
index 7e5dd17..b448686 100644
--- a/gdb/python/py-frame.c
+++ b/gdb/python/py-frame.c
@@ -504,6 +504,7 @@ frapy_read_var (PyObject *self, PyObject *args)
struct frame_info *frame;
PyObject *sym_obj, *block_obj = NULL;
struct symbol *var = NULL; /* gcc-4.3.2 false warning. */
+ const struct block *block = NULL;
struct value *val = NULL;
if (!PyArg_ParseTuple (args, "O|O", &sym_obj, &block_obj))
@@ -514,7 +515,6 @@ frapy_read_var (PyObject *self, PyObject *args)
else if (gdbpy_is_string (sym_obj))
{
char *var_name;
- const struct block *block = NULL;
struct cleanup *cleanup;
var_name = python_string_to_target_string (sym_obj);
@@ -536,11 +536,14 @@ frapy_read_var (PyObject *self, PyObject *args)
TRY
{
+ struct block_symbol lookup_sym;
FRAPY_REQUIRE_VALID (self, frame);
if (!block)
block = get_frame_block (frame, NULL);
- var = lookup_symbol (var_name, block, VAR_DOMAIN, NULL).symbol;
+ lookup_sym = lookup_symbol (var_name, block, VAR_DOMAIN, NULL);
+ var = lookup_sym.symbol;
+ block = lookup_sym.block;
}
CATCH (except, RETURN_MASK_ALL)
{
@@ -572,7 +575,7 @@ frapy_read_var (PyObject *self, PyObject *args)
{
FRAPY_REQUIRE_VALID (self, frame);
- val = read_var_value (var, frame);
+ val = read_var_value (var, block, frame);
}
CATCH (except, RETURN_MASK_ALL)
{
diff --git a/gdb/python/py-framefilter.c b/gdb/python/py-framefilter.c
index e3336b1..ac97723 100644
--- a/gdb/python/py-framefilter.c
+++ b/gdb/python/py-framefilter.c
@@ -43,16 +43,17 @@ enum mi_print_types
NAME is a pass-through argument where the name of the symbol will
be written. NAME is allocated in this function, but the caller is
responsible for clean up. SYM is a pass-through argument where the
- symbol will be written. In the case of the API returning a string,
- this will be set to NULL. LANGUAGE is also a pass-through argument
- denoting the language attributed to the Symbol. In the case of SYM
- being NULL, this will be set to the current language. Returns
- EXT_LANG_BT_ERROR on error with the appropriate Python exception set, and
- EXT_LANG_BT_OK on success. */
+ symbol will be written and SYM_BLOCK is a pass-through argument to
+ write the block where the symbol lies in. In the case of the API
+ returning a string, this will be set to NULL. LANGUAGE is also a
+ pass-through argument denoting the language attributed to the
+ Symbol. In the case of SYM being NULL, this will be set to the
+ current language. Returns EXT_LANG_BT_ERROR on error with the
+ appropriate Python exception set, and EXT_LANG_BT_OK on success. */
static enum ext_lang_bt_status
extract_sym (PyObject *obj, char **name, struct symbol **sym,
- const struct language_defn **language)
+ struct block **sym_block, const struct language_defn **language)
{
PyObject *result = PyObject_CallMethod (obj, "symbol", NULL);
@@ -75,12 +76,18 @@ extract_sym (PyObject *obj, char **name, struct symbol **sym,
python_language. */
*language = python_language;
*sym = NULL;
+ *sym_block = NULL;
}
else
{
/* This type checks 'result' during the conversion so we
just call it unconditionally and check the return. */
*sym = symbol_object_to_symbol (result);
+ /* TODO: currently, we have no way to recover the block in which SYMBOL
+ was found, so we have no block to return. Trying to evaluate SYMBOL
+ will yield an incorrect value when it's located in a FRAME and
+ evaluated from another frame (as permitted in nested functions). */
+ *sym_block = NULL;
Py_DECREF (result);
@@ -537,10 +544,11 @@ enumerate_args (PyObject *iter,
const struct language_defn *language;
char *sym_name;
struct symbol *sym;
+ struct block *sym_block;
struct value *val;
enum ext_lang_bt_status success = EXT_LANG_BT_ERROR;
- success = extract_sym (item, &sym_name, &sym, &language);
+ success = extract_sym (item, &sym_name, &sym, &sym_block, &language);
if (success == EXT_LANG_BT_ERROR)
{
Py_DECREF (item);
@@ -736,12 +744,13 @@ enumerate_locals (PyObject *iter,
struct value *val;
enum ext_lang_bt_status success = EXT_LANG_BT_ERROR;
struct symbol *sym;
+ struct block *sym_block;
int local_indent = 8 + (8 * indent);
struct cleanup *locals_cleanups;
locals_cleanups = make_cleanup_py_decref (item);
- success = extract_sym (item, &sym_name, &sym, &language);
+ success = extract_sym (item, &sym_name, &sym, &sym_block, &language);
if (success == EXT_LANG_BT_ERROR)
{
do_cleanups (locals_cleanups);
@@ -769,7 +778,7 @@ enumerate_locals (PyObject *iter,
{
TRY
{
- val = read_var_value (sym, frame);
+ val = read_var_value (sym, sym_block, frame);
}
CATCH (except, RETURN_MASK_ERROR)
{
diff --git a/gdb/python/py-symbol.c b/gdb/python/py-symbol.c
index f6466bd..3d2fa91 100644
--- a/gdb/python/py-symbol.c
+++ b/gdb/python/py-symbol.c
@@ -278,7 +278,11 @@ sympy_value (PyObject *self, PyObject *args)
if (symbol_read_needs_frame (symbol) && frame_info == NULL)
error (_("symbol requires a frame to compute its value"));
- value = read_var_value (symbol, frame_info);
+ /* TODO: currently, we have no way to recover the block in which SYMBOL
+ was found, so we have no block to pass to read_var_value. This will
+ yield an incorrect value when symbol is not local to FRAME_INFO (this
+ can happen with nested functions). */
+ value = read_var_value (symbol, NULL, frame_info);
}
CATCH (except, RETURN_MASK_ALL)
{
diff --git a/gdb/stack.c b/gdb/stack.c
index ae53ec8..6d87f6f 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -318,7 +318,7 @@ read_frame_local (struct symbol *sym, struct frame_info *frame,
TRY
{
- argp->val = read_var_value (sym, frame);
+ argp->val = read_var_value (sym, NULL, frame);
}
CATCH (except, RETURN_MASK_ERROR)
{
@@ -344,7 +344,7 @@ read_frame_arg (struct symbol *sym, struct frame_info *frame,
{
TRY
{
- val = read_var_value (sym, frame);
+ val = read_var_value (sym, NULL, frame);
}
CATCH (except, RETURN_MASK_ERROR)
{
@@ -471,7 +471,7 @@ read_frame_arg (struct symbol *sym, struct frame_info *frame,
TRY
{
- val = read_var_value (sym, frame);
+ val = read_var_value (sym, NULL, frame);
}
CATCH (except, RETURN_MASK_ERROR)
{
@@ -2424,7 +2424,7 @@ return_command (char *retval_exp, int from_tty)
value_fetch_lazy (return_value);
if (thisfun != NULL)
- function = read_var_value (thisfun, thisframe);
+ function = read_var_value (thisfun, NULL, thisframe);
rv_conv = RETURN_VALUE_REGISTER_CONVENTION;
if (TYPE_CODE (return_type) == TYPE_CODE_VOID)
diff --git a/gdb/symtab.h b/gdb/symtab.h
index e67151f..c6f26e7 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -686,6 +686,25 @@ struct symbol_block_ops
uninitialized in such case. */
void (*find_frame_base_location) (struct symbol *framefunc, CORE_ADDR pc,
const gdb_byte **start, size_t *length);
+
+ /* Return the frame base address. FRAME is the frame for which we want to
+ compute the base address while FRAMEFUNC is the symbol for the
+ corresponding function. Return 0 on failure (FRAMEFUNC may not hold the
+ information we need).
+
+ This method is designed to work with static links (nested functions
+ handling). Static links are function properties whose evaluation returns
+ the frame base address for the enclosing frame. However, there are
+ multiple definitions for "frame base": the content of the frame base
+ register, the CFA as defined by DWARF unwinding information, ...
+
+ So this specific method is supposed to compute the frame base address such
+ as for nested fuctions, the static link computes the same address. For
+ instance, considering DWARF debugging information, the static link is
+ computed with DW_AT_static_link and this method must be used to compute
+ the corresponding DW_AT_frame_base attribute. */
+ CORE_ADDR (*get_frame_base) (struct symbol *framefunc,
+ struct frame_info *frame);
};
/* Functions used with LOC_REGISTER and LOC_REGPARM_ADDR. */
diff --git a/gdb/testsuite/gdb.base/nested-subp1.c b/gdb/testsuite/gdb.base/nested-subp1.c
new file mode 100644
index 0000000..967eb2f
--- /dev/null
+++ b/gdb/testsuite/gdb.base/nested-subp1.c
@@ -0,0 +1,37 @@
+/* This test program is part of GDB, the GNU debugger.
+
+ Copyright 2015 Free Software Foundation, Inc.
+
+ This program 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 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */
+
+int
+foo (int i1)
+{
+ int
+ nested (int i2)
+ {
+ /* Here with i1 and i2, we can test that GDB can fetch both a local and a
+ non-local variable in the most simple nested function situation: the
+ parent block instance is accessible as the directly upper frame. */
+ return i1 * i2; /* STOP */
+ }
+
+ return nested (i1 + 1);
+}
+
+int
+main ()
+{
+ return !foo (1);
+}
diff --git a/gdb/testsuite/gdb.base/nested-subp1.exp b/gdb/testsuite/gdb.base/nested-subp1.exp
new file mode 100644
index 0000000..9720f5b
--- /dev/null
+++ b/gdb/testsuite/gdb.base/nested-subp1.exp
@@ -0,0 +1,55 @@
+# Copyright 2015 Free Software Foundation, Inc.
+
+# This program 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 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
+
+# This file is part of the gdb testsuite.
+
+#
+# Test nested functions related functionality.
+#
+
+standard_testfile
+
+
+set testcase "nested-subp1"
+
+if { [gdb_compile "${srcdir}/${subdir}/${testcase}.c" \
+ [standard_output_file "${testcase}"] \
+ "${testcase}" \
+ [list debug "additional_flags=-std=gnu99"]] != "" } {
+ return -1
+}
+
+
+# Run until the variables we are interested in are visible.
+
+clean_restart "${testcase}"
+if ![runto_main] {
+ perror "could not run to main"
+ continue
+}
+
+set bp_location [gdb_get_line_number "STOP" "${testcase}.c"]
+gdb_test "break ${testcase}.c:${bp_location}" \
+ "Breakpoint \[0-9\]+ at 0x\[0-9a-fA-F\]+: .*" \
+ "breakpoint to the STOP marker"
+gdb_test "continue" \
+ "Breakpoint \[0-9\]+, nested .*" \
+ "continue to the STOP marker"
+
+
+# Check we get correct values for both local and non-local variable references.
+
+gdb_test "print i1" "1"
+gdb_test "print i2" "2"
diff --git a/gdb/testsuite/gdb.base/nested-subp2.c b/gdb/testsuite/gdb.base/nested-subp2.c
new file mode 100644
index 0000000..a6449e34
--- /dev/null
+++ b/gdb/testsuite/gdb.base/nested-subp2.c
@@ -0,0 +1,48 @@
+/* This test program is part of GDB, the GNU debugger.
+
+ Copyright 2015 Free Software Foundation, Inc.
+
+ This program 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 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */
+
+void
+iter_str (const char *str, void (*callback) (char c))
+{
+ for (; *str != '\0'; ++str)
+ callback (*str);
+}
+
+int
+length_str (const char *str)
+{
+ int count = 0;
+
+ void
+ increment (char c)
+ {
+ /* Here with COUNT, we can test that GDB can read a non-local variable even
+ though it's not directly in the upper stack frame. */
+ count += 1; /* STOP */
+ }
+
+ iter_str (str, &increment);
+ return count;
+}
+
+int
+main ()
+{
+ if (length_str ("foo") == 3)
+ return 0;
+ return 1;
+}
diff --git a/gdb/testsuite/gdb.base/nested-subp2.exp b/gdb/testsuite/gdb.base/nested-subp2.exp
new file mode 100644
index 0000000..a107d1c
--- /dev/null
+++ b/gdb/testsuite/gdb.base/nested-subp2.exp
@@ -0,0 +1,64 @@
+# Copyright 2015 Free Software Foundation, Inc.
+
+# This program 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 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
+
+# This file is part of the gdb testsuite.
+
+#
+# Test nested functions related functionality.
+#
+
+standard_testfile
+
+
+set testcase "nested-subp2"
+
+if { [gdb_compile "${srcdir}/${subdir}/${testcase}.c" \
+ [standard_output_file "${testcase}"] \
+ "${testcase}" \
+ [list debug "additional_flags=-std=gnu99"]] != "" } {
+ return -1
+}
+
+
+# Run until the variables we are interested in are visible.
+
+clean_restart "${testcase}"
+if ![runto_main] {
+ perror "could not run to main"
+ continue
+}
+
+set bp_location [gdb_get_line_number "STOP" "${testcase}.c"]
+gdb_test "break ${testcase}.c:${bp_location}" \
+ "Breakpoint \[0-9\]+ at 0x\[0-9a-fA-F\]+: .*" \
+ "breakpoint to the STOP marker"
+gdb_test "continue" \
+ "Breakpoint \[0-9\]+, increment .*" \
+ "continue to the STOP marker"
+
+
+# Check we get correct values for both local and non-local variable references.
+
+gdb_test "print c" "102 'f'"
+gdb_test "print count" "0"
+
+
+# Same but a little later: make sure we were looking at the proper places.
+
+gdb_test "continue" \
+ "Breakpoint \[0-9\]+, increment .*" \
+ "continue to the STOP marker"
+gdb_test "print c" "111 'o'"
+gdb_test "print count" "1"
diff --git a/gdb/testsuite/gdb.base/nested-subp3.c b/gdb/testsuite/gdb.base/nested-subp3.c
new file mode 100644
index 0000000..a51f417
--- /dev/null
+++ b/gdb/testsuite/gdb.base/nested-subp3.c
@@ -0,0 +1,66 @@
+/* This test program is part of GDB, the GNU debugger.
+
+ Copyright 2015 Free Software Foundation, Inc.
+
+ This program 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 3 of the License, or
+ (at your option) any later version.
+
+ This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <stdlib.h>
+
+typedef void (*callback_t) (void);
+
+extern void process (callback_t cb);
+extern void parent (int first, callback_t cb);
+
+void
+ignore (int unused)
+{
+ (void) unused;
+}
+
+void
+process (callback_t cb)
+{
+ parent (0, cb);
+}
+
+void
+parent (int first, callback_t cb)
+{
+ void child (void)
+ {
+ /* When reaching this, there are two block instances for PARENT on the
+ stack: the one that is right in the upper frame is not the one actually
+ used for non-local references, so GDB has to follow the static link in
+ order to get the correct instance, and thus in order to read the proper
+ variables.
+
+ As a simple check, we can verify that under GDB, the following is true:
+ parent_first == first (which should be one: see the IF block below). */
+ const int parent_first = first;
+ ignore (parent_first); /* STOP */
+ ignore (first);
+ }
+
+ if (first)
+ process (&child);
+ else
+ cb ();
+}
+
+int
+main ()
+{
+ parent (1, NULL);
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.base/nested-subp3.exp b/gdb/testsuite/gdb.base/nested-subp3.exp
new file mode 100644
index 0000000..8f9b522
--- /dev/null
+++ b/gdb/testsuite/gdb.base/nested-subp3.exp
@@ -0,0 +1,55 @@
+# Copyright 2015 Free Software Foundation, Inc.
+
+# This program 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 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
+
+# This file is part of the gdb testsuite.
+
+#
+# Test nested functions related functionality.
+#
+
+standard_testfile
+
+
+set testcase "nested-subp3"
+
+if { [gdb_compile "${srcdir}/${subdir}/${testcase}.c" \
+ [standard_output_file "${testcase}"] \
+ "${testcase}" \
+ [list debug "additional_flags=-std=gnu99"]] != "" } {
+ return -1
+}
+
+
+# Run until the variables we are interested in are visible.
+
+clean_restart "${testcase}"
+if ![runto_main] {
+ perror "could not run to main"
+ continue
+}
+
+set bp_location [gdb_get_line_number "STOP" "${testcase}.c"]
+gdb_test "break ${testcase}.c:${bp_location}" \
+ "Breakpoint \[0-9\]+ at 0x\[0-9a-fA-F\]+: .*" \
+ "breakpoint to the STOP marker"
+gdb_test "continue" \
+ "Breakpoint \[0-9\]+, child .*" \
+ "continue to the STOP marker"
+
+
+# Check we get correct values for both local and non-local variable references.
+
+gdb_test "print first" "1"
+gdb_test "print parent_first" "1"
diff --git a/gdb/valops.c b/gdb/valops.c
index acaf027..26fdfa6 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -1291,27 +1291,12 @@ value_repeat (struct value *arg1, int count)
struct value *
value_of_variable (struct symbol *var, const struct block *b)
{
- struct frame_info *frame;
+ struct frame_info *frame = NULL;
- if (!symbol_read_needs_frame (var))
- frame = NULL;
- else if (!b)
+ if (symbol_read_needs_frame (var))
frame = get_selected_frame (_("No frame selected."));
- else
- {
- frame = block_innermost_frame (b);
- if (!frame)
- {
- if (BLOCK_FUNCTION (b) && !block_inlined_p (b)
- && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)))
- error (_("No frame is currently executing in block %s."),
- SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)));
- else
- error (_("No frame is currently executing in specified block"));
- }
- }
- return read_var_value (var, frame);
+ return read_var_value (var, b, frame);
}
struct value *
@@ -3463,9 +3448,9 @@ value_struct_elt_for_reference (struct type *domain, int offset,
return NULL;
if (want_address)
- return value_addr (read_var_value (s, 0));
+ return value_addr (read_var_value (s, 0, 0));
else
- return read_var_value (s, 0);
+ return read_var_value (s, 0, 0);
}
if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
@@ -3493,7 +3478,7 @@ value_struct_elt_for_reference (struct type *domain, int offset,
if (s == NULL)
return NULL;
- v = read_var_value (s, 0);
+ v = read_var_value (s, 0, 0);
if (!want_address)
result = v;
else
@@ -3729,7 +3714,7 @@ value_full_object (struct value *argp,
struct value *
value_of_this (const struct language_defn *lang)
{
- struct symbol *sym;
+ struct block_symbol sym;
const struct block *b;
struct frame_info *frame;
@@ -3740,12 +3725,12 @@ value_of_this (const struct language_defn *lang)
b = get_frame_block (frame, NULL);
- sym = lookup_language_this (lang, b).symbol;
- if (sym == NULL)
+ sym = lookup_language_this (lang, b);
+ if (sym.symbol == NULL)
error (_("current stack frame does not contain a variable named `%s'"),
lang->la_name_of_this);
- return read_var_value (sym, frame);
+ return read_var_value (sym.symbol, sym.block, frame);
}
/* Return the value of the local variable, if one exists. Return NULL
diff --git a/gdb/value.h b/gdb/value.h
index 82deaf2..0a4bc47 100644
--- a/gdb/value.h
+++ b/gdb/value.h
@@ -674,9 +674,11 @@ struct value *value_of_register_lazy (struct frame_info *frame, int regnum);
extern int symbol_read_needs_frame (struct symbol *);
extern struct value *read_var_value (struct symbol *var,
+ const struct block *var_block,
struct frame_info *frame);
extern struct value *default_read_var_value (struct symbol *var,
+ const struct block *var_block,
struct frame_info *frame);
extern struct value *allocate_value (struct type *type);
diff --git a/gdb/xcoffread.c b/gdb/xcoffread.c
index 2edf8bd..7a0f074 100644
--- a/gdb/xcoffread.c
+++ b/gdb/xcoffread.c
@@ -1389,7 +1389,7 @@ read_xcoff_symtab (struct objfile *objfile, struct partial_symtab *pst)
}
finish_block (newobj->name, &local_symbols, newobj->old_blocks,
- newobj->start_addr,
+ NULL, newobj->start_addr,
(fcn_cs_saved.c_value
+ fcn_aux_saved.x_sym.x_misc.x_fsize
+ ANOFFSET (objfile->section_offsets,
@@ -1480,7 +1480,8 @@ read_xcoff_symtab (struct objfile *objfile, struct partial_symtab *pst)
if (local_symbols && context_stack_depth > 0)
{
/* Make a block for the local symbols within. */
- finish_block (newobj->name, &local_symbols, newobj->old_blocks,
+ finish_block (newobj->name, &local_symbols,
+ newobj->old_blocks, NULL,
newobj->start_addr,
(cs->c_value
+ ANOFFSET (objfile->section_offsets,
--
2.4.6