Hi,
libgo currently does not build because of duplicated symbols. This is because of
confusion in the output machinery, where comdat local is output as a global
symbol. This is because of confusing use of DECL_ONE_ONLY. This bug seems to be
there since introduction of comdat locals in gcc 4.9, but it was not harmful,
because
all symbols C++ produce have unique name.
Instead of one-liner to special case comdat locals in elfos.h, it seems better
to make DECL_ONE_ONLY more meaningful and make it return true only on real
comdats,
not on comdat locals.
This patch does that and revisits its use in the back-end. Basically all tests
that care about the fact if function should go into special section needs to
be DECL_COMDAT_GROUP (decl), because we care if function is in comdat group.
All tests that care about special semantic of comdats needs to be DECL_ONE_ONLY.
For those who are interested, the oneliner is:
Index: config/elfos.h
===================================================================
--- config/elfos.h (revision 210623)
+++ config/elfos.h (working copy)
@@ -303,6 +303,7 @@
RTLD_LOCAL. Don't use gnu_unique_object for typeinfo, \
vtables and other read-only artificial decls. */ \
if (USE_GNU_UNIQUE_OBJECT && DECL_ONE_ONLY (DECL)
\
+ && TREE_PUBLIC (DECL) \
&& (!DECL_ARTIFICIAL (DECL) || !TREE_READONLY (DECL))) \
ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "gnu_unique_object"); \
else \
Bootstrapped/regtested x86_64-linux, I will give it some further testing and
commit
at afternoon if there are no complains.
Honza
PR go/61232
* tree.h (DECL_ONE_ONLY): Return true only for externally visible
symbols.
* except.c (switch_to_exception_section, resolve_unique_section,
get_named_text_section, default_function_rodata_section,
align_variable, get_block_for_decl, default_section_type_flags):
Use DECL_COMDAT_GROUP instead of DECL_ONE_ONLY.
* symtab.c (symtab_add_to_same_comdat_group,
symtab_make_decl_local, fixup_same_cpp_alias_visibility,
symtab_nonoverwritable_alias, symtab_get_symbol_partitioning_class):
Likewise.
* cgraphclones.c (cgraph_create_virtual_clone): Likewise.
* bb-reorder.c (pass_partition_blocks::gate): Likewise.
* config/c6x/c6x.c (c6x_elf_unique_section): Likewise.
(c6x_function_in_section_p): Likewise.
* config/darwin.c (machopic_select_section): Likewise.
* config/arm/arm.c (arm_function_in_section_p): Likewise.
* config/mips/mips.c (mips_function_rodata_section): Likewise.
* config/mep/mep.c (mep_select_section): LIkewise.
* config/i386/i386.c (x86_64_elf_unique_section): Likewise.
Index: tree.h
===================================================================
--- tree.h (revision 210521)
+++ tree.h (working copy)
@@ -2327,7 +2327,8 @@ extern void decl_value_expr_insert (tree
/* Used in TREE_PUBLIC decls to indicate that copies of this DECL in
multiple translation units should be merged. */
-#define DECL_ONE_ONLY(NODE) (DECL_COMDAT_GROUP (NODE) != NULL_TREE)
+#define DECL_ONE_ONLY(NODE) (DECL_COMDAT_GROUP (NODE) != NULL_TREE \
+ && (TREE_PUBLIC (NODE) || DECL_EXTERNAL (NODE)))
/* The name of the object as the assembler will see it (but before any
translations made by ASM_OUTPUT_LABELREF). Often this is the same
Index: except.c
===================================================================
--- except.c (revision 210521)
+++ except.c (working copy)
@@ -2854,12 +2854,12 @@ switch_to_exception_section (const char
#ifdef HAVE_LD_EH_GC_SECTIONS
if (flag_function_sections
- || (DECL_ONE_ONLY (current_function_decl) && HAVE_COMDAT_GROUP))
+ || (DECL_COMDAT_GROUP (current_function_decl) &&
HAVE_COMDAT_GROUP))
{
char *section_name = XNEWVEC (char, strlen (fnname) + 32);
/* The EH table must match the code section, so only mark
it linkonce if we have COMDAT groups to tie them together. */
- if (DECL_ONE_ONLY (current_function_decl) && HAVE_COMDAT_GROUP)
+ if (DECL_COMDAT_GROUP (current_function_decl) &&
HAVE_COMDAT_GROUP)
flags |= SECTION_LINKONCE;
sprintf (section_name, ".gcc_except_table.%s", fnname);
s = get_section (section_name, flags, current_function_decl);
Index: varasm.c
===================================================================
--- varasm.c (revision 210521)
+++ varasm.c (working copy)
@@ -428,7 +428,7 @@ resolve_unique_section (tree decl, int r
if (DECL_SECTION_NAME (decl) == NULL_TREE
&& targetm_common.have_named_sections
&& (flag_function_or_data_sections
- || DECL_ONE_ONLY (decl)))
+ || DECL_COMDAT_GROUP (decl)))
{
targetm.asm_out.unique_section (decl, reloc);
DECL_HAS_IMPLICIT_SECTION_NAME_P (decl) = true;
@@ -517,7 +517,7 @@ get_named_text_section (tree decl,
/* Do not try to split gnu_linkonce functions. This gets somewhat
slipperly. */
- if (DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP)
+ if (DECL_COMDAT_GROUP (decl) && !HAVE_COMDAT_GROUP)
return NULL;
name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
name = targetm.strip_name_encoding (name);
@@ -687,7 +687,7 @@ default_function_rodata_section (tree de
{
const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
- if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP)
+ if (DECL_COMDAT_GROUP (decl) && HAVE_COMDAT_GROUP)
{
const char *dot;
size_t len;
@@ -704,7 +704,7 @@ default_function_rodata_section (tree de
return get_section (rname, SECTION_LINKONCE, decl);
}
/* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
- else if (DECL_ONE_ONLY (decl)
+ else if (DECL_COMDAT_GROUP (decl)
&& strncmp (name, ".gnu.linkonce.t.", 16) == 0)
{
size_t len = strlen (name) + 1;
@@ -996,7 +996,8 @@ align_variable (tree decl, bool dont_out
and for code accessing the variable as guaranteed alignment, we
can only increase the alignment if it is a performance optimization
if the references to it must bind to the current definition. */
- if (decl_binds_to_current_def_p (decl))
+ if (decl_binds_to_current_def_p (decl)
+ && !DECL_VIRTUAL_P (decl))
{
#ifdef DATA_ALIGNMENT
unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align);
@@ -1142,7 +1143,7 @@ get_block_for_decl (tree decl)
/* There's no point using object blocks for something that is
isolated by definition. */
- if (DECL_ONE_ONLY (decl))
+ if (DECL_COMDAT_GROUP (decl))
return NULL;
}
@@ -6076,7 +6077,7 @@ default_section_type_flags (tree decl, c
flags |= SECTION_RELRO;
}
- if (decl && DECL_P (decl) && DECL_ONE_ONLY (decl))
+ if (decl && DECL_P (decl) && DECL_COMDAT_GROUP (decl))
flags |= SECTION_LINKONCE;
if (strcmp (name, ".vtable_map_vars") == 0)
Index: symtab.c
===================================================================
--- symtab.c (revision 210598)
+++ symtab.c (working copy)
@@ -513,7 +513,7 @@ void
symtab_add_to_same_comdat_group (symtab_node *new_node,
symtab_node *old_node)
{
- gcc_assert (DECL_ONE_ONLY (old_node->decl));
+ gcc_assert (DECL_COMDAT_GROUP (old_node->decl));
gcc_assert (!new_node->same_comdat_group);
gcc_assert (new_node != old_node);
@@ -832,9 +832,9 @@ verify_symtab_base (symtab_node *node)
{
symtab_node *n = node->same_comdat_group;
- if (!DECL_ONE_ONLY (n->decl))
+ if (!DECL_COMDAT_GROUP (n->decl))
{
- error ("non-DECL_ONE_ONLY node in a same_comdat_group list");
+ error ("node is in same_comdat_group list but has no
DECL_COMDAT_GROUP");
error_found = true;
}
if (DECL_COMDAT_GROUP (n->decl) != DECL_COMDAT_GROUP
(node->same_comdat_group->decl))
@@ -958,7 +958,7 @@ symtab_make_decl_local (tree decl)
DECL_COMMON (decl) = 0;
else gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
- if (DECL_ONE_ONLY (decl) || DECL_COMDAT (decl))
+ if (DECL_COMDAT_GROUP (decl) || DECL_COMDAT (decl))
{
DECL_SECTION_NAME (decl) = 0;
DECL_COMDAT (decl) = 0;
@@ -1101,7 +1101,7 @@ fixup_same_cpp_alias_visibility (symtab_
DECL_COMDAT (node->decl) = DECL_COMDAT (target->decl);
DECL_COMDAT_GROUP (node->decl)
= DECL_COMDAT_GROUP (target->decl);
- if (DECL_ONE_ONLY (target->decl)
+ if (DECL_COMDAT_GROUP (target->decl)
&& !node->same_comdat_group)
symtab_add_to_same_comdat_group (node, target);
}
@@ -1231,7 +1231,7 @@ symtab_nonoverwritable_alias (symtab_nod
/* Update the properties. */
DECL_EXTERNAL (new_decl) = 0;
- if (DECL_ONE_ONLY (node->decl))
+ if (DECL_COMDAT_GROUP (node->decl))
DECL_SECTION_NAME (new_decl) = NULL;
DECL_COMDAT_GROUP (new_decl) = 0;
TREE_PUBLIC (new_decl) = 0;
@@ -1328,8 +1328,7 @@ symtab_get_symbol_partitioning_class (sy
return SYMBOL_EXTERNAL;
/* Linker discardable symbols are duplicated to every use unless they are
- keyed.
- Keyed symbols or those. */
+ keyed. */
if (DECL_ONE_ONLY (node->decl)
&& !node->force_output
&& !node->forced_by_abi
Index: cgraphclones.c
===================================================================
--- cgraphclones.c (revision 210521)
+++ cgraphclones.c (working copy)
@@ -558,7 +558,7 @@ cgraph_create_virtual_clone (struct cgra
that is not weak also.
??? We cannot use COMDAT linkage because there is no
ABI support for this. */
- if (DECL_ONE_ONLY (old_decl))
+ if (DECL_COMDAT_GROUP (old_decl))
DECL_SECTION_NAME (new_node->decl) = NULL;
set_new_clone_decl_and_node_flags (new_node);
new_node->clone.tree_map = tree_map;
Index: bb-reorder.c
===================================================================
--- bb-reorder.c (revision 210521)
+++ bb-reorder.c (working copy)
@@ -2667,7 +2667,7 @@ pass_partition_blocks::gate (function *f
/* See gate_handle_reorder_blocks. We should not partition if
we are going to omit the reordering. */
&& optimize_function_for_speed_p (fun)
- && !DECL_ONE_ONLY (current_function_decl)
+ && !DECL_COMDAT_GROUP (current_function_decl)
&& !user_defined_section_attribute);
}
Index: config/c6x/c6x.c
===================================================================
--- config/c6x/c6x.c (revision 210521)
+++ config/c6x/c6x.c (working copy)
@@ -985,7 +985,7 @@ c6x_elf_unique_section (tree decl, int r
{
const char *prefix = NULL;
/* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
- bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
+ bool one_only = DECL_COMDAT_GROUP (decl) && !HAVE_COMDAT_GROUP;
if (c6x_in_small_data_p (decl))
{
@@ -1202,7 +1202,7 @@ c6x_function_in_section_p (tree decl, se
if (!DECL_SECTION_NAME (decl))
{
/* Make sure that we will not create a unique section for DECL. */
- if (flag_function_sections || DECL_ONE_ONLY (decl))
+ if (flag_function_sections || DECL_COMDAT_GROUP (decl))
return false;
}
Index: config/darwin.c
===================================================================
--- config/darwin.c (revision 210521)
+++ config/darwin.c (working copy)
@@ -1521,7 +1521,7 @@ machopic_select_section (tree decl,
one = DECL_P (decl)
&& TREE_CODE (decl) == VAR_DECL
- && DECL_ONE_ONLY (decl);
+ && DECL_COMDAT_GROUP (decl);
ro = TREE_READONLY (decl) || TREE_CONSTANT (decl) ;
Index: config/arm/arm.c
===================================================================
--- config/arm/arm.c (revision 210521)
+++ config/arm/arm.c (working copy)
@@ -6154,7 +6154,7 @@ arm_function_in_section_p (tree decl, se
if (!DECL_SECTION_NAME (decl))
{
/* Make sure that we will not create a unique section for DECL. */
- if (flag_function_sections || DECL_ONE_ONLY (decl))
+ if (flag_function_sections || DECL_COMDAT_GROUP (decl))
return false;
}
Index: config/mips/mips.c
===================================================================
--- config/mips/mips.c (revision 210521)
+++ config/mips/mips.c (working copy)
@@ -8469,7 +8469,7 @@ mips_function_rodata_section (tree decl)
if (decl && DECL_SECTION_NAME (decl))
{
const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl));
- if (DECL_ONE_ONLY (decl) && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
+ if (DECL_COMDAT_GROUP (decl) && strncmp (name, ".gnu.linkonce.t.", 16)
== 0)
{
char *rname = ASTRDUP (name);
rname[14] = 'd';
Index: config/mep/mep.c
===================================================================
--- config/mep/mep.c (revision 210521)
+++ config/mep/mep.c (working copy)
@@ -4532,7 +4532,7 @@ mep_select_section (tree decl, int reloc
else
encoding = 0;
- if (flag_function_sections || DECL_ONE_ONLY (decl))
+ if (flag_function_sections || DECL_COMDAT_GROUP (decl))
mep_unique_section (decl, 0);
else if (lookup_attribute ("vliw", TYPE_ATTRIBUTES (TREE_TYPE (decl))))
{
@@ -4651,7 +4651,7 @@ mep_unique_section (tree decl, int reloc
name += 3;
}
- prefix = prefixes[sec][DECL_ONE_ONLY(decl)];
+ prefix = prefixes[sec][DECL_COMDAT_GROUP(decl) != NULL];
len = strlen (name) + strlen (prefix);
string = (char *) alloca (len + 1);
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c (revision 210521)
+++ config/i386/i386.c (working copy)
@@ -5147,7 +5147,7 @@ x86_64_elf_unique_section (tree decl, in
{
const char *prefix = NULL;
/* We only need to use .gnu.linkonce if we don't have COMDAT groups. */
- bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP;
+ bool one_only = DECL_COMDAT_GROUP (decl) && !HAVE_COMDAT_GROUP;
switch (categorize_decl_for_section (decl, reloc))
{
