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collect2.c (DO_COLLECT_EXPORT_LIST): New internal macro, always defined.

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* collect2.c (DO_COLLECT_EXPORT_LIST): New internal macro,
        always defined.  Reflect definition or absence of such for
        COLLECT_EXPORT_LIST.  Readability helper.
        (scanfilter): New enum, to help control what symbols
        are to be considered or ignored by scan_prog_file.
        (enum pass): Rename as "scanpass", moved together with scanfilter
        prior to scan_prog_file's prototype.
        (scan_prog_file): Accept and honor scanpass and scanfilter arguments.
        Group prototype with the scanpass/scanfilter definitions, factorize
        head comments for the several implementations at the prototype.
        (main): Reorganize the first pass link control to let AIX
        drag only the needed frame tables in executables.  Prevent
        frame tables collection during the scan aimed at static ctors.
        Pre-link and scan for frame tables later to compensate.
        * doc/tm.texi (ASM_OUTPUT_DWARF_TABLE_REF): New macro.
        A C statement to issue assembly directives that create a reference
        to the given DWARF table identifier label from the current function
        section.
        * dwarf2out.c (switch_to_eh_frame_section): Add a BACK argument
        to differentiate first time section entry.  Only emit a .data
        tables start identifier label the first time around.
        (switch_to_frame_table_section): New function.  Helper for
        output_call_frame_info to switch possibly BACK into the eh_frame
        or the debug_frame section depending on FOR_EH.
        (output_call_frame_info): Use helper to first enter the proper
        frame section.
        (output_fde): Use ASM_OUTPUT_DWARF_TABLE_REF when defined to
        emit a link to the frame table start label from each function
        section.
        * config/rs6000/rs6000.c (rs6000_aix_asm_output_dwarf_table_ref):
        New function.  Implementation of ASM_OUTPUT_DWARF_TABLE_REF.
        * config/rs6000/rs6000-protos.h: Declare it.
        * config/rs6000/aix.h (ASM_OUTPUT_DWARF_TABLE_REF): Define.

From-SVN: r151157
This commit is contained in:
Olivier Hainque 2009-08-28 09:04:52 +00:00 • committed by Olivier Hainque
parent 72129a2509
commit 7e49a4b396
7 changed files with 258 additions and 89 deletions
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36
gcc/ChangeLog
View file

@ -1,3 +1,39 @@
2009-08-28 Olivier Hainque <hainque@adacore.com>
* collect2.c (DO_COLLECT_EXPORT_LIST): New internal macro,
always defined. Reflect definition or absence of such for
COLLECT_EXPORT_LIST. Readability helper.
(scanfilter): New enum, to help control what symbols
are to be considered or ignored by scan_prog_file.
(enum pass): Rename as "scanpass", moved together with scanfilter
prior to scan_prog_file's prototype.
(scan_prog_file): Accept and honor scanpass and scanfilter arguments.
Group prototype with the scanpass/scanfilter definitions, factorize
head comments for the several implementations at the prototype.
(main): Reorganize the first pass link control to let AIX
drag only the needed frame tables in executables. Prevent
frame tables collection during the scan aimed at static ctors.
Pre-link and scan for frame tables later to compensate.
* doc/tm.texi (ASM_OUTPUT_DWARF_TABLE_REF): New macro.
A C statement to issue assembly directives that create a reference
to the given DWARF table identifier label from the current function
section.
* dwarf2out.c (switch_to_eh_frame_section): Add a BACK argument
to differentiate first time section entry. Only emit a .data
tables start identifier label the first time around.
(switch_to_frame_table_section): New function. Helper for
output_call_frame_info to switch possibly BACK into the eh_frame
or the debug_frame section depending on FOR_EH.
(output_call_frame_info): Use helper to first enter the proper
frame section.
(output_fde): Use ASM_OUTPUT_DWARF_TABLE_REF when defined to
emit a link to the frame table start label from each function
section.
* config/rs6000/rs6000.c (rs6000_aix_asm_output_dwarf_table_ref):
New function. Implementation of ASM_OUTPUT_DWARF_TABLE_REF.
* config/rs6000/rs6000-protos.h: Declare it.
* config/rs6000/aix.h (ASM_OUTPUT_DWARF_TABLE_REF): Define.
2009-08-27 Kaz Kojima <kkojima@gcc.gnu.org>
* config/sh/sh.c (split_branches): Check the result of

224
gcc/collect2.c
View file

@ -145,6 +145,15 @@ int do_collecting = 1;
int do_collecting = 0;
#endif
/* Cook up an always defined indication of whether we proceed the
"EXPORT_LIST" way. */
#ifdef COLLECT_EXPORT_LIST
#define DO_COLLECT_EXPORT_LIST 1
#else
#define DO_COLLECT_EXPORT_LIST 0
#endif
/* Nonzero if we should suppress the automatic demangling of identifiers
in linker error messages. Set from COLLECT_NO_DEMANGLE. */
int no_demangle;
@ -165,15 +174,6 @@ struct head
int number;
};
/* Enumeration giving which pass this is for scanning the program file. */
enum pass {
PASS_FIRST, /* without constructors */
PASS_OBJ, /* individual objects */
PASS_LIB, /* looking for shared libraries */
PASS_SECOND /* with constructors linked in */
};
int vflag; /* true if -v */
static int rflag; /* true if -r */
static int strip_flag; /* true if -s */
@ -288,7 +288,6 @@ static void write_c_file_stat (FILE *, const char *);
#ifndef LD_INIT_SWITCH
static void write_c_file_glob (FILE *, const char *);
#endif
static void scan_prog_file (const char *, enum pass);
#ifdef SCAN_LIBRARIES
static void scan_libraries (const char *);
#endif
@ -303,6 +302,50 @@ static void write_aix_file (FILE *, struct id *);
static char *resolve_lib_name (const char *);
#endif
static char *extract_string (const char **);
/* Enumerations describing which pass this is for scanning the
program file ... */
typedef enum {
PASS_FIRST, /* without constructors */
PASS_OBJ, /* individual objects */
PASS_LIB, /* looking for shared libraries */
PASS_SECOND /* with constructors linked in */
} scanpass;
/* ... and which kinds of symbols are to be considered. */
enum scanfilter_masks {
SCAN_NOTHING = 0,
SCAN_CTOR = 1 << SYM_CTOR,
SCAN_DTOR = 1 << SYM_DTOR,
SCAN_INIT = 1 << SYM_INIT,
SCAN_FINI = 1 << SYM_FINI,
SCAN_DWEH = 1 << SYM_DWEH,
SCAN_ALL = ~0
};
/* This type is used for parameters and variables which hold
combinations of the flags in enum scanfilter_masks. */
typedef int scanfilter;
/* Scan the name list of the loaded program for the symbols g++ uses for
static constructors and destructors.
The SCANPASS argument tells which collect processing pass this is for and
the SCANFILTER argument tells which kinds of symbols to consider in this
pass. Symbols of a special kind not in the filter mask are considered as
regular ones.
The constructor table begins at __CTOR_LIST__ and contains a count of the
number of pointers (or -1 if the constructors are built in a separate
section by the linker), followed by the pointers to the constructor
functions, terminated with a null pointer. The destructor table has the
same format, and begins at __DTOR_LIST__. */
static void scan_prog_file (const char *, scanpass, scanfilter);
/* Delete tempfiles and exit function. */
@ -831,6 +874,15 @@ main (int argc, char **argv)
const char **c_ptr;
char **ld1_argv;
const char **ld1;
/* The kinds of symbols we will have to consider when scanning the
outcome of a first pass link. This is ALL to start with, then might
be adjusted before getting to the first pass link per se, typically on
AIX where we perform an early scan of objects and libraries to fetch
the list of global ctors/dtors and make sure they are not garbage
collected. */
scanfilter ld1_filter = SCAN_ALL;
char **ld2_argv;
const char **ld2;
char **object_lst;
@ -1279,19 +1331,31 @@ main (int argc, char **argv)
}
/* The AIX linker will discard static constructors in object files if
nothing else in the file is referenced, so look at them first. */
{
const char **export_object_lst
= CONST_CAST2 (const char **, char **, object_lst);
while (export_object_lst < object)
scan_prog_file (*export_object_lst++, PASS_OBJ);
}
nothing else in the file is referenced, so look at them first. Unless
we are building a shared object, ignore the eh frame tables, as we
would otherwise reference them all, hence drag all the corresponding
objects even if nothing else is referenced. */
{
const char **export_object_lst
= CONST_CAST2 (const char **, char **, object_lst);
struct id *list = libs.first;
/* Compute the filter to use from the current one, do scan, then adjust
the "current" filter to remove what we just included here. This will
control whether we need a first pass link later on or not, and what
will remain to be scanned there. */
scanfilter this_filter
= shared_obj ? ld1_filter : (ld1_filter & ~SCAN_DWEH);
while (export_object_lst < object)
scan_prog_file (*export_object_lst++, PASS_OBJ, this_filter);
for (; list; list = list->next)
scan_prog_file (list->name, PASS_FIRST);
scan_prog_file (list->name, PASS_FIRST, this_filter);
ld1_filter = ld1_filter & ~this_filter;
}
if (exports.first)
@ -1362,42 +1426,45 @@ main (int argc, char **argv)
}
/* Load the program, searching all libraries and attempting to provide
undefined symbols from repository information. */
undefined symbols from repository information.
If -r or they will be run via some other method, do not build the
constructor or destructor list, just return now. */
{
bool early_exit
= rflag || (! DO_COLLECT_EXPORT_LIST && ! do_collecting);
/* On AIX we do this later. */
#ifndef COLLECT_EXPORT_LIST
do_tlink (ld1_argv, object_lst);
#endif
/* Perform the first pass link now, if we're about to exit or if we need
to scan for things we haven't collected yet before pursuing further.
/* If -r or they will be run via some other method, do not build the
constructor or destructor list, just return now. */
if (rflag
#ifndef COLLECT_EXPORT_LIST
|| ! do_collecting
#endif
)
{
#ifdef COLLECT_EXPORT_LIST
/* Do the link we avoided above if we are exiting. */
On AIX, the latter typically includes nothing for shared objects or
frame tables for an executable, out of what the required early scan on
objects and libraries has performed above. In the !shared_obj case, we
expect the relevant tables to be dragged together with their associated
functions from precise cross reference insertions by the compiler. */
if (early_exit || ld1_filter != SCAN_NOTHING)
do_tlink (ld1_argv, object_lst);
/* But make sure we delete the export file we may have created. */
if (export_file != 0 && export_file[0])
maybe_unlink (export_file);
if (early_exit)
{
#ifdef COLLECT_EXPORT_LIST
/* Make sure we delete the export file we may have created. */
if (export_file != 0 && export_file[0])
maybe_unlink (export_file);
#endif
maybe_unlink (c_file);
maybe_unlink (o_file);
return 0;
}
maybe_unlink (c_file);
maybe_unlink (o_file);
return 0;
}
}
/* Examine the namelist with nm and search it for static constructors
and destructors to call.
Write the constructor and destructor tables to a .s file and reload. */
/* Unless we have done it all already, examine the namelist and search for
static constructors and destructors to call. Write the constructor and
destructor tables to a .s file and reload. */
/* On AIX we already scanned for global constructors/destructors. */
#ifndef COLLECT_EXPORT_LIST
scan_prog_file (output_file, PASS_FIRST);
#endif
if (ld1_filter != SCAN_NOTHING)
scan_prog_file (output_file, PASS_FIRST, ld1_filter);
#ifdef SCAN_LIBRARIES
scan_libraries (output_file);
@ -1410,6 +1477,9 @@ main (int argc, char **argv)
notice ("%d frame table(s) found\n", frame_tables.number);
}
/* If the scan exposed nothing of special interest, there's no need to
generate the glue code and relink so return now. */
if (constructors.number == 0 && destructors.number == 0
&& frame_tables.number == 0
#if defined (SCAN_LIBRARIES) || defined (COLLECT_EXPORT_LIST)
@ -1420,10 +1490,11 @@ main (int argc, char **argv)
#endif
)
{
#ifdef COLLECT_EXPORT_LIST
/* Do tlink without additional code generation. */
do_tlink (ld1_argv, object_lst);
#endif
/* Do tlink without additional code generation now if we didn't
do it earlier for scanning purposes. */
if (ld1_filter == SCAN_NOTHING)
do_tlink (ld1_argv, object_lst);
/* Strip now if it was requested on the command line. */
if (strip_flag)
{
@ -1523,7 +1594,7 @@ main (int argc, char **argv)
/* Let scan_prog_file do any final mods (OSF/rose needs this for
constructors/destructors in shared libraries. */
scan_prog_file (output_file, PASS_SECOND);
scan_prog_file (output_file, PASS_SECOND, SCAN_ALL);
#endif
maybe_unlink (c_file);
@ -2097,16 +2168,11 @@ write_aix_file (FILE *stream, struct id *list)
#ifdef OBJECT_FORMAT_NONE
/* Generic version to scan the name list of the loaded program for
the symbols g++ uses for static constructors and destructors.
The constructor table begins at __CTOR_LIST__ and contains a count
of the number of pointers (or -1 if the constructors are built in a
separate section by the linker), followed by the pointers to the
constructor functions, terminated with a null pointer. The
destructor table has the same format, and begins at __DTOR_LIST__. */
the symbols g++ uses for static constructors and destructors. */
static void
scan_prog_file (const char *prog_name, enum pass which_pass)
scan_prog_file (const char *prog_name, scanpass which_pass,
scanfilter filter)
{
void (*int_handler) (int);
#ifdef SIGQUIT
@ -2185,7 +2251,8 @@ scan_prog_file (const char *prog_name, enum pass which_pass)
char *name, *end;
/* If it contains a constructor or destructor name, add the name
to the appropriate list. */
to the appropriate list unless this is a kind of symbol we're
not supposed to even consider. */
for (p = buf; (ch = *p) != '\0' && ch != '\n' && ch != '_'; p++)
if (ch == ' ' && p[1] == 'U' && p[2] == ' ')
@ -2206,16 +2273,22 @@ scan_prog_file (const char *prog_name, enum pass which_pass)
switch (is_ctor_dtor (name))
{
case SYM_CTOR:
if (! (filter & SCAN_CTOR))
break;
if (which_pass != PASS_LIB)
add_to_list (&constructors, name);
break;
case SYM_DTOR:
if (! (filter & SCAN_DTOR))
break;
if (which_pass != PASS_LIB)
add_to_list (&destructors, name);
break;
case SYM_INIT:
if (! (filter & SCAN_INIT))
break;
if (which_pass != PASS_LIB)
fatal ("init function found in object %s", prog_name);
#ifndef LD_INIT_SWITCH
@ -2224,6 +2297,8 @@ scan_prog_file (const char *prog_name, enum pass which_pass)
break;
case SYM_FINI:
if (! (filter & SCAN_FINI))
break;
if (which_pass != PASS_LIB)
fatal ("fini function found in object %s", prog_name);
#ifndef LD_FINI_SWITCH
@ -2232,6 +2307,8 @@ scan_prog_file (const char *prog_name, enum pass which_pass)
break;
case SYM_DWEH:
if (! (filter & SCAN_DWEH))
break;
if (which_pass != PASS_LIB)
add_to_list (&frame_tables, name);
break;
@ -2488,16 +2565,11 @@ extern char *ldgetname (LDFILE *, GCC_SYMENT *);
#endif
/* COFF version to scan the name list of the loaded program for
the symbols g++ uses for static constructors and destructors.
The constructor table begins at __CTOR_LIST__ and contains a count
of the number of pointers (or -1 if the constructors are built in a
separate section by the linker), followed by the pointers to the
constructor functions, terminated with a null pointer. The
destructor table has the same format, and begins at __DTOR_LIST__. */
the symbols g++ uses for static constructors and destructors. */
static void
scan_prog_file (const char *prog_name, enum pass which_pass)
scan_prog_file (const char *prog_name, scanpass which_pass,
scanfilter filter)
{
LDFILE *ldptr = NULL;
int sym_index, sym_count;
@ -2561,6 +2633,8 @@ scan_prog_file (const char *prog_name, enum pass which_pass)
switch (is_ctor_dtor (name))
{
case SYM_CTOR:
if (! (filter & SCAN_CTOR))
break;
if (! is_shared)
add_to_list (&constructors, name);
#if defined (COLLECT_EXPORT_LIST) && !defined (LD_INIT_SWITCH)
@ -2570,6 +2644,8 @@ scan_prog_file (const char *prog_name, enum pass which_pass)
break;
case SYM_DTOR:
if (! (filter & SCAN_DTOR))
break;
if (! is_shared)
add_to_list (&destructors, name);
#if defined (COLLECT_EXPORT_LIST) && !defined (LD_INIT_SWITCH)
@ -2580,6 +2656,8 @@ scan_prog_file (const char *prog_name, enum pass which_pass)
#ifdef COLLECT_EXPORT_LIST
case SYM_INIT:
if (! (filter & SCAN_INIT))
break;
#ifndef LD_INIT_SWITCH
if (is_shared)
add_to_list (&constructors, name);
@ -2587,6 +2665,8 @@ scan_prog_file (const char *prog_name, enum pass which_pass)
break;
case SYM_FINI:
if (! (filter & SCAN_FINI))
break;
#ifndef LD_INIT_SWITCH
if (is_shared)
add_to_list (&destructors, name);
@ -2595,6 +2675,8 @@ scan_prog_file (const char *prog_name, enum pass which_pass)
#endif
case SYM_DWEH:
if (! (filter & SCAN_DWEH))
break;
if (! is_shared)
add_to_list (&frame_tables, name);
#if defined (COLLECT_EXPORT_LIST) && !defined (LD_INIT_SWITCH)

6
gcc/config/rs6000/aix.h
View file

@ -43,6 +43,12 @@
collect has a chance to see them, so scan the object files directly. */
#define COLLECT_EXPORT_LIST
/* Issue assembly directives that create a reference to the given DWARF table
identifier label from the current function section. This is defined to
ensure we drag frame frame tables associated with needed function bodies in
a link with garbage collection activated. */
#define ASM_OUTPUT_DWARF_TABLE_REF rs6000_aix_asm_output_dwarf_table_ref
/* Handle #pragma weak and #pragma pack. */
#define HANDLE_SYSV_PRAGMA 1

2
gcc/config/rs6000/rs6000-protos.h
View file

@ -179,6 +179,8 @@ extern int rs6000_memory_move_cost (enum machine_mode, enum reg_class, int);
extern bool rs6000_tls_referenced_p (rtx);
extern void rs6000_conditional_register_usage (void);
extern void rs6000_aix_asm_output_dwarf_table_ref (char *);
/* Declare functions in rs6000-c.c */
extern void rs6000_pragma_longcall (struct cpp_reader *);

9
gcc/config/rs6000/rs6000.c
View file

@ -17612,6 +17612,15 @@ create_TOC_reference (rtx symbol)
gen_rtx_UNSPEC (Pmode, gen_rtvec (1, symbol), UNSPEC_TOCREL)));
}
/* Issue assembly directives that create a reference to the given DWARF
FRAME_TABLE_LABEL from the current function section. */
void
rs6000_aix_asm_output_dwarf_table_ref (char * frame_table_label)
{
fprintf (asm_out_file, "\t.ref %s\n",
TARGET_STRIP_NAME_ENCODING (frame_table_label));
}
/* If _Unwind_* has been called from within the same module,
toc register is not guaranteed to be saved to 40(1) on function
entry. Save it there in that case. */

7
gcc/doc/tm.texi
View file

@ -9159,6 +9159,13 @@ A C statement to issue assembly directives that create a self-relative
reference to the given @var{label}, using an integer of the given @var{size}.
@end defmac
@defmac ASM_OUTPUT_DWARF_TABLE_REF (@var{label})
A C statement to issue assembly directives that create a reference to
the DWARF table identifier @var{label} from the current section. This
is used on some systems to avoid garbage collecting a DWARF table which
is referenced by a function.
@end defmac
@deftypefn {Target Hook} void TARGET_ASM_OUTPUT_DWARF_DTPREL (FILE *@var{FILE}, int @var{size}, rtx @var{x})
If defined, this target hook is a function which outputs a DTP-relative
reference to the given TLS symbol of the specified size.

63
gcc/dwarf2out.c
View file

@ -2932,12 +2932,12 @@ dw_cfi_oprnd2_desc (enum dwarf_call_frame_info cfi)
#if defined (DWARF2_DEBUGGING_INFO) || defined (DWARF2_UNWIND_INFO)
/* Switch to eh_frame_section. If we don't have an eh_frame_section,
switch to the data section instead, and write out a synthetic label
for collect2. */
/* Switch [BACK] to eh_frame_section. If we don't have an eh_frame_section,
switch to the data section instead, and write out a synthetic start label
for collect2 the first time around. */
static void
switch_to_eh_frame_section (void)
switch_to_eh_frame_section (bool back)
{
tree label;
@ -2980,11 +2980,15 @@ switch_to_eh_frame_section (void)
/* We have no special eh_frame section. Put the information in
the data section and emit special labels to guide collect2. */
switch_to_section (data_section);
label = get_file_function_name ("F");
ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (PTR_SIZE));
targetm.asm_out.globalize_label (asm_out_file,
IDENTIFIER_POINTER (label));
ASM_OUTPUT_LABEL (asm_out_file, IDENTIFIER_POINTER (label));
if (!back)
{
label = get_file_function_name ("F");
ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (PTR_SIZE));
targetm.asm_out.globalize_label (asm_out_file,
IDENTIFIER_POINTER (label));
ASM_OUTPUT_LABEL (asm_out_file, IDENTIFIER_POINTER (label));
}
}
}
@ -3534,6 +3538,20 @@ output_fde (dw_fde_ref fde, bool for_eh, bool second,
output_cfi (cfi, fde, for_eh);
}
/* If we are to emit a ref/link from function bodies to their frame tables,
do it now. This is typically performed to make sure that tables
associated with functions are dragged with them and not discarded in
garbage collecting links. We need to do this on a per function basis to
cope with -ffunction-sections. */
#ifdef ASM_OUTPUT_DWARF_TABLE_REF
/* Switch to the function section, emit the ref to the tables, and
switch *back* into the table section. */
switch_to_section (function_section (fde->decl));
ASM_OUTPUT_DWARF_TABLE_REF (section_start_label);
switch_to_frame_table_section (for_eh, true);
#endif
/* Pad the FDE out to an address sized boundary. */
ASM_OUTPUT_ALIGN (asm_out_file,
floor_log2 ((for_eh ? PTR_SIZE : DWARF2_ADDR_SIZE)));
@ -3543,6 +3561,22 @@ output_fde (dw_fde_ref fde, bool for_eh, bool second,
}
/* Switch [BACK] to the eh or debug frame table section, depending on
FOR_EH. */
static void
switch_to_frame_table_section (int for_eh, bool back)
{
if (for_eh)
switch_to_eh_frame_section (back);
else
{
if (!debug_frame_section)
debug_frame_section = get_section (DEBUG_FRAME_SECTION,
SECTION_DEBUG, NULL);
switch_to_section (debug_frame_section);
}
}
/* Output the call frame information used to record information
that relates to calculating the frame pointer, and records the
location of saved registers. */
@ -3613,15 +3647,8 @@ output_call_frame_info (int for_eh)
if (flag_debug_asm)
app_enable ();
if (for_eh)
switch_to_eh_frame_section ();
else
{
if (!debug_frame_section)
debug_frame_section = get_section (DEBUG_FRAME_SECTION,
SECTION_DEBUG, NULL);
switch_to_section (debug_frame_section);
}
/* Switch to the proper frame section, first time. */
switch_to_frame_table_section (for_eh, false);
ASM_GENERATE_INTERNAL_LABEL (section_start_label, FRAME_BEGIN_LABEL, for_eh);
ASM_OUTPUT_LABEL (asm_out_file, section_start_label);