[PATCH 2/2] DWARF: make it possible to emit debug info for declarations only
Pierre-Marie de Rodat
derodat@adacore.com
Mon May 29 08:05:00 GMT 2017
Hello,
The DWARF back-end used to systematically ignore file-scope function and
variable declarations. While this is justified in language like C/C++,
where such declarations can appear in several translation units and thus
bloat uselessly the debug info, this behavior is counter-productive in
languages with a well-defined module system. Specifically, it prevents
the description of imported entities, that belong to foreign languages,
making them unavailable from debuggers.
Take for instance:
package C_Binding is
function My_C_Function (I : Integer) return Integer;
pragma Import (C, My_C_Function, "my_c_function");
end C_Binding;
This makes available for Ada programs the C function "my_c_function"
under the following name: C_Binding.My_C_Function. When GCC compiles
it, though, it is represented as a FUNCTION_DECL node with DECL_EXTERNAL
set and a null DECL_INITIAL, which used to be discarded unconditionally
in the DWARF back-end.
This patch introduces a new DECL language hook:
emit_debug_info_for_decl_p, which the DWARF back-end uses to determine
whether it should emit debug info for some declaration. This makes it
possible for front-ends to decide the appropriate behavior.
This patch also updates the Ada front-end to override this hook, so that
declarations such as the above do generate debugging information.
Bootstrapped and reg-tested on x86_64-linux. Ok to commit? Thank you in
advance!
gcc/
* langhooks.h
(lang_hooks_for_decls::emit_debug_info_for_decl_p): New field.
* langhooks-def.h
(LANG_HOOKS_EMIT_DEBUG_INFO_FOR_DECL_P): New macro.
* dwarf2out.c (gen_decl_die): Use the new hook to determine
whether to ignore file-scope declarations.
(dwarf2out_early_global_decl): Likewise.
(dwaf2out_decl): Likewise.
gcc/ada
* gcc-interface/ada-tree.h (DECL_FUNCTION_IS_DEF): New macro.
* gcc-interface/misc.c (gnat_emit_debug_info_for_decl_p): New
function.
(LANG_HOOKS_EMIT_DEBUG_INFO_FOR_DECL_P): Override macro.
* gcc-interface/trans.c (Compilation_Unit_to_gnu): Tag the
elaboration procedure as a definition.
(Subprogram_Body_to_gnu): Tag the subprogram as a definition.
* gcc-interface/decl.c (gnat_to_gnu_entity): Tag declarations of
imported subprograms for the current compilation unit as
definitions. Disable debug info for references to variables.
* gcc-interface/utils.c (create_subprog_decl): Add a DEFINITION
parameter. If it is true, tag the function as a definition.
Update all callers.
(gnat_pushdecl): Add external DECLs that are not built-in
functions to their binding scope.
(gnat_write_global_declarations): Emit debug info for imported
functions. Filter out external variables for which debug info
is disabled.
* gcc-interface/gigi.c (create_subprog_decl): Update
declaration.
git-svn-id: svn+ssh://svn.us.adacore.com/Dev/trunk/gcc-interfaces@328405 f8352e7e-cb20-0410-8ce7-b5d9e71c585c
---
gcc/ada/gcc-interface/ada-tree.h | 7 +++++-
gcc/ada/gcc-interface/decl.c | 19 +++++++++------
gcc/ada/gcc-interface/gigi.h | 5 +++-
gcc/ada/gcc-interface/misc.c | 11 +++++++++
gcc/ada/gcc-interface/trans.c | 52 ++++++++++++++++++++++++----------------
gcc/ada/gcc-interface/utils.c | 34 +++++++++++++++++++-------
gcc/dwarf2out.c | 13 ++++++----
gcc/langhooks-def.h | 2 ++
gcc/langhooks.h | 9 +++++++
9 files changed, 109 insertions(+), 43 deletions(-)
diff --git a/gcc/ada/gcc-interface/ada-tree.h b/gcc/ada/gcc-interface/ada-tree.h
index a3d38b1b22e..511a0bd8173 100644
--- a/gcc/ada/gcc-interface/ada-tree.h
+++ b/gcc/ada/gcc-interface/ada-tree.h
@@ -6,7 +6,7 @@
* *
* C Header File *
* *
- * Copyright (C) 1992-2016, Free Software Foundation, Inc. *
+ * Copyright (C) 1992-2017, Free Software Foundation, Inc. *
* *
* GNAT is free software; you can redistribute it and/or modify it under *
* terms of the GNU General Public License as published by the Free Soft- *
@@ -463,6 +463,11 @@ do { \
a discriminant of a discriminated type without default expression. */
#define DECL_INVARIANT_P(NODE) DECL_LANG_FLAG_4 (FIELD_DECL_CHECK (NODE))
+/* Nonzero in a FUNCTION_DECL if this is a definition, i.e. if it was created
+ by a call to gnat_to_gnu_entity with definition set to True. */
+#define DECL_FUNCTION_IS_DEF(NODE) \
+ DECL_LANG_FLAG_4 (FUNCTION_DECL_CHECK (NODE))
+
/* Nonzero in a VAR_DECL if it is a temporary created to hold the return
value of a function call or 'reference to a function call. */
#define DECL_RETURN_VALUE_P(NODE) DECL_LANG_FLAG_5 (VAR_DECL_CHECK (NODE))
diff --git a/gcc/ada/gcc-interface/decl.c b/gcc/ada/gcc-interface/decl.c
index eab244e910c..83b9d0749fe 100644
--- a/gcc/ada/gcc-interface/decl.c
+++ b/gcc/ada/gcc-interface/decl.c
@@ -1392,7 +1392,8 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
= create_var_decl (create_concat_name (gnat_entity, "ALIGN"),
NULL_TREE, gnu_new_type, NULL_TREE,
false, false, false, false, false,
- true, debug_info_p, NULL, gnat_entity);
+ true, debug_info_p && definition, NULL,
+ gnat_entity);
/* Initialize the aligned field if we have an initializer. */
if (gnu_expr)
@@ -1441,7 +1442,8 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
NULL_TREE, gnu_type, gnu_expr,
const_flag, Is_Public (gnat_entity),
imported_p || !definition, static_flag,
- volatile_flag, true, debug_info_p,
+ volatile_flag, true,
+ debug_info_p && definition,
NULL, gnat_entity);
gnu_expr = build_unary_op (ADDR_EXPR, NULL_TREE, gnu_unc_var);
TREE_CONSTANT (gnu_expr) = 1;
@@ -1492,8 +1494,9 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
= create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type,
gnu_expr, const_flag, Is_Public (gnat_entity),
imported_p || !definition, static_flag,
- volatile_flag, artificial_p, debug_info_p,
- attr_list, gnat_entity, !renamed_obj);
+ volatile_flag, artificial_p,
+ debug_info_p && definition, attr_list,
+ gnat_entity, !renamed_obj);
DECL_BY_REF_P (gnu_decl) = used_by_ref;
DECL_POINTS_TO_READONLY_P (gnu_decl) = used_by_ref && inner_const_flag;
DECL_CAN_NEVER_BE_NULL_P (gnu_decl) = Can_Never_Be_Null (gnat_entity);
@@ -1545,8 +1548,8 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
= create_var_decl (gnu_entity_name, gnu_ext_name, gnu_type,
gnu_expr, true, Is_Public (gnat_entity),
!definition, static_flag, volatile_flag,
- artificial_p, debug_info_p, attr_list,
- gnat_entity, false);
+ artificial_p, debug_info_p && definition,
+ attr_list, gnat_entity, false);
SET_DECL_CONST_CORRESPONDING_VAR (gnu_decl, gnu_corr_var);
}
@@ -4083,7 +4086,9 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, bool definition)
gnu_type, gnu_param_list,
inline_status, public_flag,
extern_flag, artificial_p,
- debug_info_p, attr_list, gnat_entity);
+ debug_info_p,
+ definition && imported_p, attr_list,
+ gnat_entity);
DECL_STUBBED_P (gnu_decl)
= (Convention (gnat_entity) == Convention_Stubbed);
diff --git a/gcc/ada/gcc-interface/gigi.h b/gcc/ada/gcc-interface/gigi.h
index b1fb34ad620..0e25b6129a3 100644
--- a/gcc/ada/gcc-interface/gigi.h
+++ b/gcc/ada/gcc-interface/gigi.h
@@ -720,6 +720,8 @@ extern tree create_label_decl (tree name, Node_Id gnat_node);
DEBUG_INFO_P is true if we need to write debug information for it.
+ DEFINITION is true if the subprogram is to be considered as a definition.
+
ATTR_LIST is the list of attributes to be attached to the subprogram.
GNAT_NODE is used for the position of the decl. */
@@ -728,7 +730,8 @@ extern tree create_subprog_decl (tree name, tree asm_name, tree type,
enum inline_status_t inline_status,
bool public_flag, bool extern_flag,
bool artificial_p, bool debug_info_p,
- struct attrib *attr_list, Node_Id gnat_node);
+ bool definition, struct attrib *attr_list,
+ Node_Id gnat_node);
/* Given a subprogram declaration DECL, its assembler name and its type,
finish constructing the subprogram declaration from ASM_NAME and TYPE. */
diff --git a/gcc/ada/gcc-interface/misc.c b/gcc/ada/gcc-interface/misc.c
index 18c825ca13e..cd0467ef8d9 100644
--- a/gcc/ada/gcc-interface/misc.c
+++ b/gcc/ada/gcc-interface/misc.c
@@ -1348,6 +1348,15 @@ gnat_eh_personality (void)
return gnat_eh_personality_decl;
}
+/* Given DECL, which is a reference (we don't have a definition for it in this
+ compilation unit), return whether we should emit debug info for it. */
+
+static bool
+gnat_emit_debug_info_for_decl_p (tree decl)
+{
+ return TREE_CODE (decl) != FUNCTION_DECL || DECL_FUNCTION_IS_DEF (decl);
+}
+
/* Initialize language-specific bits of tree_contains_struct. */
static void
@@ -1451,6 +1460,8 @@ get_lang_specific (tree node)
#define LANG_HOOKS_DEEP_UNSHARING true
#undef LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS
#define LANG_HOOKS_CUSTOM_FUNCTION_DESCRIPTORS true
+#undef LANG_HOOKS_EMIT_DEBUG_INFO_FOR_DECL_P
+#define LANG_HOOKS_EMIT_DEBUG_INFO_FOR_DECL_P gnat_emit_debug_info_for_decl_p
struct lang_hooks lang_hooks = LANG_HOOKS_INITIALIZER;
diff --git a/gcc/ada/gcc-interface/trans.c b/gcc/ada/gcc-interface/trans.c
index 2542626d0ca..79d099538c9 100644
--- a/gcc/ada/gcc-interface/trans.c
+++ b/gcc/ada/gcc-interface/trans.c
@@ -398,7 +398,7 @@ gigi (Node_Id gnat_root,
= create_subprog_decl (get_identifier ("__gnat_malloc"), NULL_TREE,
ftype,
NULL_TREE, is_disabled, true, true, true, false,
- NULL, Empty);
+ false, NULL, Empty);
DECL_IS_MALLOC (malloc_decl) = 1;
ftype = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);
@@ -406,7 +406,7 @@ gigi (Node_Id gnat_root,
= create_subprog_decl (get_identifier ("__gnat_free"), NULL_TREE,
ftype,
NULL_TREE, is_disabled, true, true, true, false,
- NULL, Empty);
+ false, NULL, Empty);
ftype = build_function_type_list (ptr_type_node, ptr_type_node, sizetype,
NULL_TREE);
@@ -414,7 +414,7 @@ gigi (Node_Id gnat_root,
= create_subprog_decl (get_identifier ("__gnat_realloc"), NULL_TREE,
ftype,
NULL_TREE, is_disabled, true, true, true, false,
- NULL, Empty);
+ false, NULL, Empty);
/* This is used for 64-bit multiplication with overflow checking. */
int64_type = gnat_type_for_size (64, 0);
@@ -423,7 +423,7 @@ gigi (Node_Id gnat_root,
build_function_type_list (int64_type, int64_type,
int64_type, NULL_TREE),
NULL_TREE, is_disabled, true, true, true, false,
- NULL, Empty);
+ false, NULL, Empty);
/* Name of the _Parent field in tagged record types. */
parent_name_id = get_identifier (Get_Name_String (Name_uParent));
@@ -446,21 +446,21 @@ gigi (Node_Id gnat_root,
= create_subprog_decl
(get_identifier ("system__soft_links__get_jmpbuf_address_soft"),
NULL_TREE, build_function_type_list (jmpbuf_ptr_type, NULL_TREE),
- NULL_TREE, is_disabled, true, true, true, false, NULL, Empty);
+ NULL_TREE, is_disabled, true, true, true, false, false, NULL, Empty);
set_jmpbuf_decl
= create_subprog_decl
(get_identifier ("system__soft_links__set_jmpbuf_address_soft"),
NULL_TREE, build_function_type_list (void_type_node, jmpbuf_ptr_type,
NULL_TREE),
- NULL_TREE, is_disabled, true, true, true, false, NULL, Empty);
+ NULL_TREE, is_disabled, true, true, true, false, false, NULL, Empty);
get_excptr_decl
= create_subprog_decl
(get_identifier ("system__soft_links__get_gnat_exception"), NULL_TREE,
build_function_type_list (build_pointer_type (except_type_node),
NULL_TREE),
- NULL_TREE, is_disabled, true, true, true, false, NULL, Empty);
+ NULL_TREE, is_disabled, true, true, true, false, false, NULL, Empty);
not_handled_by_others_decl = get_identifier ("not_handled_by_others");
for (t = TYPE_FIELDS (except_type_node); t; t = DECL_CHAIN (t))
@@ -478,7 +478,7 @@ gigi (Node_Id gnat_root,
(get_identifier ("__builtin_setjmp"), NULL_TREE,
build_function_type_list (integer_type_node, jmpbuf_ptr_type,
NULL_TREE),
- NULL_TREE, is_disabled, true, true, true, false, NULL, Empty);
+ NULL_TREE, is_disabled, true, true, true, false, false, NULL, Empty);
DECL_BUILT_IN_CLASS (setjmp_decl) = BUILT_IN_NORMAL;
DECL_FUNCTION_CODE (setjmp_decl) = BUILT_IN_SETJMP;
@@ -488,7 +488,7 @@ gigi (Node_Id gnat_root,
= create_subprog_decl
(get_identifier ("__builtin_update_setjmp_buf"), NULL_TREE,
build_function_type_list (void_type_node, jmpbuf_ptr_type, NULL_TREE),
- NULL_TREE, is_disabled, true, true, true, false, NULL, Empty);
+ NULL_TREE, is_disabled, true, true, true, false, false, NULL, Empty);
DECL_BUILT_IN_CLASS (update_setjmp_buf_decl) = BUILT_IN_NORMAL;
DECL_FUNCTION_CODE (update_setjmp_buf_decl) = BUILT_IN_UPDATE_SETJMP_BUF;
@@ -500,14 +500,14 @@ gigi (Node_Id gnat_root,
raise_nodefer_decl
= create_subprog_decl
(get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE, ftype,
- NULL_TREE, is_disabled, true, true, true, false, NULL, Empty);
+ NULL_TREE, is_disabled, true, true, true, false, false, NULL, Empty);
set_exception_parameter_decl
= create_subprog_decl
(get_identifier ("__gnat_set_exception_parameter"), NULL_TREE,
build_function_type_list (void_type_node, ptr_type_node, ptr_type_node,
NULL_TREE),
- NULL_TREE, is_disabled, true, true, true, false, NULL, Empty);
+ NULL_TREE, is_disabled, true, true, true, false, false, NULL, Empty);
/* Hooks to call when entering/leaving an exception handler. */
ftype = build_function_type_list (void_type_node, ptr_type_node, NULL_TREE);
@@ -515,26 +515,30 @@ gigi (Node_Id gnat_root,
begin_handler_decl
= create_subprog_decl (get_identifier ("__gnat_begin_handler"), NULL_TREE,
ftype, NULL_TREE,
- is_disabled, true, true, true, false, NULL, Empty);
+ is_disabled, true, true, true, false, false, NULL,
+ Empty);
/* __gnat_begin_handler is a dummy procedure. */
TREE_NOTHROW (begin_handler_decl) = 1;
end_handler_decl
= create_subprog_decl (get_identifier ("__gnat_end_handler"), NULL_TREE,
ftype, NULL_TREE,
- is_disabled, true, true, true, false, NULL, Empty);
+ is_disabled, true, true, true, false, false, NULL,
+ Empty);
unhandled_except_decl
= create_subprog_decl (get_identifier ("__gnat_unhandled_except_handler"),
NULL_TREE, ftype, NULL_TREE,
- is_disabled, true, true, true, false, NULL, Empty);
+ is_disabled, true, true, true, false, false, NULL,
+ Empty);
/* Indicate that it never returns. */
ftype = build_qualified_type (ftype, TYPE_QUAL_VOLATILE);
reraise_zcx_decl
= create_subprog_decl (get_identifier ("__gnat_reraise_zcx"), NULL_TREE,
ftype, NULL_TREE,
- is_disabled, true, true, true, false, NULL, Empty);
+ is_disabled, true, true, true, false, false, NULL,
+ Empty);
/* Dummy objects to materialize "others" and "all others" in the exception
tables. These are exported by a-exexpr-gcc.adb, so see this unit for
@@ -573,7 +577,8 @@ gigi (Node_Id gnat_root,
tree decl
= create_subprog_decl
(get_identifier ("__gnat_last_chance_handler"), NULL_TREE, ftype,
- NULL_TREE, is_disabled, true, true, true, false, NULL, Empty);
+ NULL_TREE, is_disabled, true, true, true, false, false, NULL,
+ Empty);
for (i = 0; i < (int) ARRAY_SIZE (gnat_raise_decls); i++)
gnat_raise_decls[i] = decl;
}
@@ -739,7 +744,7 @@ build_raise_check (int check, enum exception_info_kind kind)
result
= create_subprog_decl (get_identifier (Name_Buffer), NULL_TREE, ftype,
NULL_TREE, is_disabled, true, true, true, false,
- NULL, Empty);
+ false, NULL, Empty);
return result;
}
@@ -3745,6 +3750,7 @@ Subprogram_Body_to_gnu (Node_Id gnat_node)
= gnat_to_gnu_entity (gnat_subprog_id, NULL_TREE,
Acts_As_Spec (gnat_node)
&& !present_gnu_tree (gnat_subprog_id));
+ DECL_FUNCTION_IS_DEF (gnu_subprog_decl) = true;
gnu_result_decl = DECL_RESULT (gnu_subprog_decl);
gnu_subprog_type = TREE_TYPE (gnu_subprog_decl);
gnu_cico_list = TYPE_CI_CO_LIST (gnu_subprog_type);
@@ -5417,12 +5423,15 @@ Compilation_Unit_to_gnu (Node_Id gnat_node)
const Entity_Id gnat_unit_entity = Defining_Entity (gnat_unit);
Entity_Id gnat_entity;
Node_Id gnat_pragma;
- /* Make the decl for the elaboration procedure. */
+ /* Make the decl for the elaboration procedure. Emit debug info for it, so
+ that users can break into their elaboration code in debuggers. Kludge:
+ don't consider it as a definition so that we have a line map for its body,
+ but no subprogram description in debug info. */
tree gnu_elab_proc_decl
= create_subprog_decl
(create_concat_name (gnat_unit_entity, body_p ? "elabb" : "elabs"),
NULL_TREE, void_ftype, NULL_TREE,
- is_disabled, true, false, true, true, NULL, gnat_unit);
+ is_disabled, true, false, true, true, false, NULL, gnat_unit);
struct elab_info *info;
vec_safe_push (gnu_elab_proc_stack, gnu_elab_proc_decl);
@@ -6453,7 +6462,7 @@ gnat_to_gnu (Node_Id gnat_node)
gnu_prefix = gnat_to_gnu (gnat_prefix);
gnu_prefix = maybe_implicit_deref (gnu_prefix);
}
-
+
gnu_result
= build_component_ref (gnu_prefix, gnu_field,
(Nkind (Parent (gnat_node))
@@ -6484,7 +6493,8 @@ gnat_to_gnu (Node_Id gnat_node)
(Entity (Prefix (gnat_node)),
attr == Attr_Elab_Body ? "elabb" : "elabs"),
NULL_TREE, void_ftype, NULL_TREE, is_disabled,
- true, true, true, true, NULL, gnat_node);
+ true, true, true, true, false, NULL,
+ gnat_node);
gnu_result = Attribute_to_gnu (gnat_node, &gnu_result_type, attr);
}
diff --git a/gcc/ada/gcc-interface/utils.c b/gcc/ada/gcc-interface/utils.c
index b8c5d3d31f6..af53edcfa3f 100644
--- a/gcc/ada/gcc-interface/utils.c
+++ b/gcc/ada/gcc-interface/utils.c
@@ -763,11 +763,13 @@ gnat_pushdecl (tree decl, Node_Id gnat_node)
if (!(TREE_CODE (decl) == TYPE_DECL
&& TREE_CODE (TREE_TYPE (decl)) == UNCONSTRAINED_ARRAY_TYPE))
{
- if (DECL_EXTERNAL (decl))
- {
- if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl))
- vec_safe_push (builtin_decls, decl);
- }
+ /* External declarations must go to the binding level they belong to.
+ This will make corresponding imported entities are available in the
+ debugger at the proper time. */
+ if (DECL_EXTERNAL (decl)
+ && TREE_CODE (decl) == FUNCTION_DECL
+ && DECL_BUILT_IN (decl))
+ vec_safe_push (builtin_decls, decl);
else if (global_bindings_p ())
vec_safe_push (global_decls, decl);
else
@@ -3189,6 +3191,8 @@ create_label_decl (tree name, Node_Id gnat_node)
DEBUG_INFO_P is true if we need to write debug information for it.
+ DEFINITION is true if the subprogram is to be considered as a definition.
+
ATTR_LIST is the list of attributes to be attached to the subprogram.
GNAT_NODE is used for the position of the decl. */
@@ -3197,7 +3201,8 @@ tree
create_subprog_decl (tree name, tree asm_name, tree type, tree param_decl_list,
enum inline_status_t inline_status, bool public_flag,
bool extern_flag, bool artificial_p, bool debug_info_p,
- struct attrib *attr_list, Node_Id gnat_node)
+ bool definition, struct attrib *attr_list,
+ Node_Id gnat_node)
{
tree subprog_decl = build_decl (input_location, FUNCTION_DECL, name, type);
DECL_ARGUMENTS (subprog_decl) = param_decl_list;
@@ -3208,6 +3213,8 @@ create_subprog_decl (tree name, tree asm_name, tree type, tree param_decl_list,
if (!debug_info_p)
DECL_IGNORED_P (subprog_decl) = 1;
+ if (definition)
+ DECL_FUNCTION_IS_DEF (subprog_decl) = 1;
switch (inline_status)
{
@@ -5523,10 +5530,21 @@ gnat_write_global_declarations (void)
if (TREE_CODE (iter) == TYPE_DECL && !DECL_IGNORED_P (iter))
debug_hooks->type_decl (iter, false);
+ /* Output imported functions. */
+ FOR_EACH_VEC_SAFE_ELT (global_decls, i, iter)
+ if (TREE_CODE (iter) == FUNCTION_DECL
+ && DECL_EXTERNAL (iter)
+ && DECL_INITIAL (iter) == NULL
+ && !DECL_IGNORED_P (iter))
+ debug_hooks->early_global_decl (iter);
+
/* Then output the global variables. We need to do that after the debug
- information for global types is emitted so that they are finalized. */
+ information for global types is emitted so that they are finalized. Skip
+ external global variables, unless we need to emit debug info for them:
+ this is useful for imported variables, for instance. */
FOR_EACH_VEC_SAFE_ELT (global_decls, i, iter)
- if (TREE_CODE (iter) == VAR_DECL)
+ if (TREE_CODE (iter) == VAR_DECL
+ && (!DECL_EXTERNAL (iter) || !DECL_IGNORED_P (iter)))
rest_of_decl_compilation (iter, true, 0);
/* Output the imported modules/declarations. In GNAT, these are only
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 5ff45eb4efd..e2a7f546034 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -25271,7 +25271,8 @@ gen_decl_die (tree decl, tree origin, struct vlr_context *ctx,
if (DECL_INITIAL (decl_or_origin) == NULL_TREE
&& DECL_FILE_SCOPE_P (decl_or_origin)
&& (current_function_decl == NULL_TREE
- || DECL_ARTIFICIAL (decl_or_origin)))
+ || DECL_ARTIFICIAL (decl_or_origin))
+ && !lang_hooks.decls.emit_debug_info_for_decl_p (decl_or_origin))
break;
#if 0
@@ -25478,9 +25479,10 @@ dwarf2out_early_global_decl (tree decl)
tree save_fndecl = current_function_decl;
if (TREE_CODE (decl) == FUNCTION_DECL)
{
- /* No cfun means the symbol has no body, so there's nothing
- to emit. */
- if (!DECL_STRUCT_FUNCTION (decl))
+ /* Unless we are asked to emit debug info for declarations, no cfun
+ means the symbol has no body, so there's nothing to emit. */
+ if (!DECL_STRUCT_FUNCTION (decl)
+ && !lang_hooks.decls.emit_debug_info_for_decl_p (decl))
goto early_decl_exit;
/* For nested functions, make sure we have DIEs for the parents first
@@ -25770,7 +25772,8 @@ dwarf2out_decl (tree decl)
where the inlined function is output in a different LTRANS unit
or not at all. */
if (DECL_INITIAL (decl) == NULL_TREE
- && ! DECL_ABSTRACT_P (decl))
+ && ! DECL_ABSTRACT_P (decl)
+ && ! lang_hooks.decls.emit_debug_info_for_decl_p (decl))
return;
/* If we're a nested function, initially use a parent of NULL; if we're
diff --git a/gcc/langhooks-def.h b/gcc/langhooks-def.h
index ea2006ccec5..e210e9e61ca 100644
--- a/gcc/langhooks-def.h
+++ b/gcc/langhooks-def.h
@@ -225,6 +225,7 @@ extern tree lhd_unit_size_without_reusable_padding (tree);
/* Declaration hooks. */
#define LANG_HOOKS_GLOBAL_BINDINGS_P global_bindings_p
+#define LANG_HOOKS_EMIT_DEBUG_INFO_FOR_DECL_P hook_bool_tree_false
#define LANG_HOOKS_PUSHDECL pushdecl
#define LANG_HOOKS_GETDECLS getdecls
#define LANG_HOOKS_DECL_DWARF_ATTRIBUTE lhd_decl_dwarf_attribute
@@ -247,6 +248,7 @@ extern tree lhd_unit_size_without_reusable_padding (tree);
#define LANG_HOOKS_DECLS { \
LANG_HOOKS_GLOBAL_BINDINGS_P, \
+ LANG_HOOKS_EMIT_DEBUG_INFO_FOR_DECL_P, \
LANG_HOOKS_PUSHDECL, \
LANG_HOOKS_GETDECLS, \
LANG_HOOKS_DECL_DWARF_ATTRIBUTE, \
diff --git a/gcc/langhooks.h b/gcc/langhooks.h
index b2f0f922b89..27fd5638d21 100644
--- a/gcc/langhooks.h
+++ b/gcc/langhooks.h
@@ -181,6 +181,15 @@ struct lang_hooks_for_decls
level, i.e. declared outside subprograms. */
bool (*global_bindings_p) (void);
+ /* Given some declaration, if this returns true, we should produce debug info
+ for it. We should not do this for languages with poor modules definition
+ like C/C++ because translation units make us process a lot of declarations
+ that are common to a lot of translation units, bloating the debug info.
+ However this is desirable in languages like Ada, where we know we must not
+ produce debug info for the declaration of functions that come from other
+ units (unless in special cases, like cross-unit inlining). */
+ bool (*emit_debug_info_for_decl_p) (tree);
+
/* Function to add a decl to the current scope level. Takes one
argument, a decl to add. Returns that decl, or, if the same
symbol is already declared, may return a different decl for that
--
2.13.0
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