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[RFC] Re: Enable -fuse-linker-plugin by default when possible, take 2
On 01/12/2010 13:31, Jan Hubicka wrote:
>> On 01/12/2010 13:19, Jan Hubicka wrote:
>>
>>> To make lto-symtab possible, I think we need new hook
>>> targetm.mangle_assembler_name that will take char * and return identifier
>>> (or string buffer) containing the actual symbol name.
>>>
>>> The default definition calling targetm.strip_name_encoding and prepending
>>> user_label_prefix (if any) should work well enough for ELF targets and for
>>> cygwin we will define custom hook.
>>>
>>> For stage3 we will use it only for lto-symtab and lto-streamer-out
>>> purposes. In the next release we should work towards getting real symbol
>>> table everywhere
>> This sounds like a good plan. Did anyone volunteer to get started on it
>> during the IRC discussion? Otherwise I could do it.
>
> I implicitely added it to my TODO (at least adding the target hook and making
> lto-symtab and streamer-out to do the translation), but if you will do so, you
> are very, very welcome. I am somewhat swamped in the LTO issues at the moment
> :)
Aren't we all :)
Anyway this is a nearly-complete(*) but only partially-tested(**) draft
patch, not a submission. Not having written a new target hook before, I'd
appreciate advice; did I get all the bits in the right places and name them
the right ways?
Also, Honza, did I catch all the right places you were thinking this should
be used in the lto streamer and symtab code?
cheers,
DaveK
--
(*) - Needs completing the documentation hunk and removing that fixme comment.
Probably a testcase or two, too.
(**) - Passed an LTO bootstrap and test without regressions on x86_64 linux,
haven't tested on cygwin yet.
Index: gcc/doc/tm.texi
===================================================================
--- gcc/doc/tm.texi (revision 167443)
+++ gcc/doc/tm.texi (working copy)
@@ -8037,6 +8037,10 @@ is customary on your operating system, as it is in
systems. This macro is used in @code{assemble_name}.
@end defmac
+@deftypefn {Target Hook} tree TARGET_MANGLE_ASSEMBLER_NAME (const char *@var{name})
+Given a symbol @var{name}, perform same mangling as @code{ASM_OUTPUT_LABELREF}, returning result as an @code{IDENTIFIER_NODE}. Required for correct LTO symtabs. The default implementation calls the @code{}
+@end deftypefn
+
@defmac ASM_OUTPUT_SYMBOL_REF (@var{stream}, @var{sym})
A C statement (sans semicolon) to output a reference to
@code{SYMBOL_REF} @var{sym}. If not defined, @code{assemble_name}
Index: gcc/doc/tm.texi.in
===================================================================
--- gcc/doc/tm.texi.in (revision 167443)
+++ gcc/doc/tm.texi.in (working copy)
@@ -8011,6 +8011,8 @@ is customary on your operating system, as it is in
systems. This macro is used in @code{assemble_name}.
@end defmac
+@hook TARGET_MANGLE_ASSEMBLER_NAME
+
@defmac ASM_OUTPUT_SYMBOL_REF (@var{stream}, @var{sym})
A C statement (sans semicolon) to output a reference to
@code{SYMBOL_REF} @var{sym}. If not defined, @code{assemble_name}
Index: gcc/lto-symtab.c
===================================================================
--- gcc/lto-symtab.c (revision 167443)
+++ gcc/lto-symtab.c (working copy)
@@ -155,7 +155,8 @@ lto_symtab_register_decl (tree decl,
gcc_assert (!DECL_ABSTRACT (decl));
new_entry = ggc_alloc_cleared_lto_symtab_entry_def ();
- new_entry->id = DECL_ASSEMBLER_NAME (decl);
+ new_entry->id = (*targetm.asm_out.mangle_assembler_name)
+ (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)));
new_entry->decl = decl;
new_entry->resolution = resolution;
new_entry->file_data = file_data;
@@ -190,7 +191,8 @@ lto_symtab_get_resolution (tree decl)
gcc_assert (DECL_ASSEMBLER_NAME_SET_P (decl));
- e = lto_symtab_get (DECL_ASSEMBLER_NAME (decl));
+ e = lto_symtab_get ((*targetm.asm_out.mangle_assembler_name)
+ (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl))));
while (e && e->decl != decl)
e = e->next;
if (!e)
@@ -218,7 +220,8 @@ lto_cgraph_replace_node (struct cgraph_node *node,
cgraph_node_name (node), node->uid,
cgraph_node_name (prevailing_node),
prevailing_node->uid,
- IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->decl)));
+ IDENTIFIER_POINTER ((*targetm.asm_out.mangle_assembler_name)
+ (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node->decl)))));
}
if (prevailing_node->same_body_alias)
@@ -836,7 +839,8 @@ lto_symtab_prevailing_decl (tree decl)
gcc_assert (DECL_ASSEMBLER_NAME_SET_P (decl));
/* Walk through the list of candidates and return the one we merged to. */
- ret = lto_symtab_get (DECL_ASSEMBLER_NAME (decl));
+ ret = lto_symtab_get ((*targetm.asm_out.mangle_assembler_name)
+ (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl))));
if (!ret)
return NULL_TREE;
Index: gcc/targhooks.c
===================================================================
--- gcc/targhooks.c (revision 167443)
+++ gcc/targhooks.c (working copy)
@@ -358,6 +358,16 @@ default_print_operand_punct_valid_p (unsigned char
#endif
}
+/* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME. */
+tree
+default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
+{
+ const char *stripped = targetm.strip_name_encoding (name);
+ if (user_label_prefix[0])
+ stripped = ACONCAT ((user_label_prefix, stripped, NULL));
+ return get_identifier (stripped);
+}
+
/* The default implementation of TARGET_ASM_OUTPUT_ADDR_CONST_EXTRA. */
bool
Index: gcc/targhooks.h
===================================================================
--- gcc/targhooks.h (revision 167443)
+++ gcc/targhooks.h (working copy)
@@ -65,6 +65,8 @@ extern bool hook_callee_copies_named
extern void default_print_operand (FILE *, rtx, int);
extern void default_print_operand_address (FILE *, rtx);
extern bool default_print_operand_punct_valid_p (unsigned char);
+extern tree default_mangle_assembler_name (const char *);
+
extern bool default_asm_output_addr_const_extra (FILE *, rtx);
extern bool default_scalar_mode_supported_p (enum machine_mode);
Index: gcc/target.def
===================================================================
--- gcc/target.def (revision 167443)
+++ gcc/target.def (working copy)
@@ -524,6 +524,16 @@ DEFHOOK_UNDOC
bool ,(unsigned char code),
default_print_operand_punct_valid_p)
+/* Given a symbol name, perform same mangling as ASM_OUTPUT_LABELREF,
+ returning result as an IDENTIFIER_NODE. */
+DEFHOOK
+(mangle_assembler_name,
+ "Given a symbol @var{name}, perform same mangling as @code{ASM_OUTPUT_LABELREF},\
+ returning result as an @code{IDENTIFIER_NODE}. Required for correct LTO symtabs. \
+ The default implementation calls the @code{}",
+ tree, (const char *name),
+ default_mangle_assembler_name)
+
HOOK_VECTOR_END (asm_out)
/* Functions relating to instruction scheduling. All of these
Index: gcc/lto-streamer-out.c
===================================================================
--- gcc/lto-streamer-out.c (revision 167443)
+++ gcc/lto-streamer-out.c (working copy)
@@ -2375,8 +2375,7 @@ write_symbol (struct lto_streamer_cache_d *cache,
/* FIXME lto: this is from assemble_name_raw in varasm.c. For some
architectures we might have to do the same name manipulations that
ASM_OUTPUT_LABELREF does. */
- if (name[0] == '*')
- name = &name[1];
+ name = IDENTIFIER_POINTER ((*targetm.asm_out.mangle_assembler_name) (name));
lto_streamer_cache_lookup (cache, t, &slot_num);
gcc_assert (slot_num >= 0);
Index: gcc/config/i386/cygming.h
===================================================================
--- gcc/config/i386/cygming.h (revision 167443)
+++ gcc/config/i386/cygming.h (working copy)
@@ -252,6 +252,10 @@ do { \
fputs ((NAME), (STREAM)); \
} while (0)
+/* This does much the same in memory rather than to a stream. */
+#undef TARGET_MANGLE_ASSEMBLER_NAME
+#define TARGET_MANGLE_ASSEMBLER_NAME i386_pe_mangle_assembler_name
+
/* Emit code to check the stack when allocating more than 4000
bytes in one go. */
Index: gcc/config/i386/winnt.c
===================================================================
--- gcc/config/i386/winnt.c (revision 167443)
+++ gcc/config/i386/winnt.c (working copy)
@@ -244,6 +244,19 @@ i386_pe_mangle_decl_assembler_name (tree decl, tre
return (new_id ? new_id : id);
}
+/* This hook behaves the same as varasm.c/assemble_name(), but
+ generates the name into memory rather than outputting it to
+ a file stream. */
+
+tree
+i386_pe_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED)
+{
+ const char *stripped = targetm.strip_name_encoding (name);
+ if (user_label_prefix[0] && (stripped[0] != FASTCALL_PREFIX))
+ stripped = ACONCAT ((user_label_prefix, stripped, NULL));
+ return get_identifier (stripped);
+}
+
void
i386_pe_encode_section_info (tree decl, rtx rtl, int first)
{
Index: gcc/config/i386/i386-protos.h
===================================================================
--- gcc/config/i386/i386-protos.h (revision 167443)
+++ gcc/config/i386/i386-protos.h (working copy)
@@ -226,6 +226,7 @@ extern void i386_pe_file_end (void);
extern void i386_pe_start_function (FILE *, const char *, tree);
extern void i386_pe_end_function (FILE *, const char *, tree);
extern tree i386_pe_mangle_decl_assembler_name (tree, tree);
+extern tree i386_pe_mangle_assembler_name (const char *);
extern void i386_pe_seh_init (FILE *);
extern void i386_pe_seh_end_prologue (FILE *);