Re: [PATCH] gcc: implement AIX-style constructors
> Hi David, > > Here is the new version of the patch. > I've moved the startup function in crtcdtors files. > > I'm just wondering if the part dealing with the > __init_aix_libgcc_cxa_atexit is needed. I'm adding it because > the destructor created in crtcxa.o is following GCC format and > thus won't be launched if the flag "-mcdtors=aix" is passed. > However, as you said, this option might not operate correctly > if the GCC runtime isn't rebuild with it. Gentle Ping. Thanks, Clément
Re: [PATCH] gcc: implement AIX-style constructors
Hi David,
Here is the new version of the patch.
I've moved the startup function in crtcdtors files.
I'm just wondering if the part dealing with the
__init_aix_libgcc_cxa_atexit is needed. I'm adding it because
the destructor created in crtcxa.o is following GCC format and
thus won't be launched if the flag "-mcdtors=aix" is passed.
However, as you said, this option might not operate correctly
if the GCC runtime isn't rebuild with it.
Thanks,
Clément
From 8a14b0eb312628ad9cce8ac9f439c420b12b33c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Chigot?=
Date: Mon, 4 Oct 2021 09:24:43 +0200
Subject: [PATCH] gcc: implement AIX-style constructors
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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AIX linker now supports constructors and destructors detection. For such
functions to be detected, their name must starts with __sinit or __sterm.
and -bcdtors must be passed to linker calls. It will create "_cdtors"
symbol which can be used to launch the initialization.
This patch creates a new RS6000 flag "-mcdtors=".
With "-mcdtors=aix", gcc will generate these new constructors/destructors.
With "-mcdtors=gcc", which is currently the default, gcc will continue
to generate "gcc" format for constructors (ie _GLOBAL__I and _GLOBAL__D
symbols).
Ideally, it would have been better to enable the AIX format by default
instead of using collect2. However, the compatibility between the
previously-built binaries and the new ones is too complex to be done.
gcc/ChangeLog:
2021-10-04 Clément Chigot
* collect2.c (aixbcdtors_flags): New variable.
(main): Use it to detect -bcdtors and remove -binitfini flag.
(write_c_file_stat): Adapt to new AIX format.
* config/rs6000/aix.h (FILE_SINIT_FORMAT): New define.
(FILE_STERM_FORMAT): New define.
(TARGET_FILE_FUNCTION_FORMAT): New define.
* config/rs6000/aix64.opt: Add -mcdtors flag.
* config/rs6000/aix71.h (LINK_SPEC_COMMON): Pass -bcdtors when
-mcdtors=aix is passed.
(STARTFILE_SPEC): Add crtcdtors.o with -mcdtors=aix.
* config/rs6000/aix72.h (LINK_SPEC_COMMON): Likewise.
(STARTFILE_SPEC): Likewise.
* config/rs6000/aix73.h (LINK_SPEC_COMMON): Likewise.
(STARTFILE_SPEC): Likewise.
* config/rs6000/rs6000-opts.h (enum rs6000_cdtors): New enum.
* doc/invoke.texi: Add -mcdtors flag.
* tree.c (get_file_function_name): Add
TARGET_FILE_FUNCTION_FORMAT support.
libgcc/ChangeLog:
* config.host: Add crtcdtors.o files.
* config/rs6000/t-aix-cxa: Likewise.
* config/rs6000/crtcdtors.c: New file.
gcc/testsuite/ChangeLog:
2021-10-04 Clément Chigot
* gcc.target/powerpc/constructor-aix.c: New test.
---
gcc/collect2.c| 63 ---
gcc/config/rs6000/aix.h | 56 +
gcc/config/rs6000/aix64.opt | 17 +
gcc/config/rs6000/aix71.h | 10 ++-
gcc/config/rs6000/aix72.h | 10 ++-
gcc/config/rs6000/aix73.h | 10 ++-
gcc/config/rs6000/rs6000-opts.h | 8 +++
gcc/doc/invoke.texi | 21 ++-
.../gcc.target/powerpc/constructor-aix.c | 12
gcc/tree.c| 5 ++
libgcc/config.host| 2 +-
libgcc/config/rs6000/crtcdtors.c | 53
libgcc/config/rs6000/t-aix-cxa| 12
13 files changed, 260 insertions(+), 19 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/powerpc/constructor-aix.c
create mode 100644 libgcc/config/rs6000/crtcdtors.c
diff --git a/gcc/collect2.c b/gcc/collect2.c
index 33114322f01..3d04bc8465f 100644
--- a/gcc/collect2.c
+++ b/gcc/collect2.c
@@ -186,6 +186,7 @@ static int aix64_flag; /* true if -b64 */
static int aixrtl_flag; /* true if -brtl */
static int aixlazy_flag; /* true if -blazy */
static int visibility_flag; /* true if -fvisibility */
+static int aixbcdtors_flag;/* True if -bcdtors */
#endif
enum lto_mode_d {
@@ -984,6 +985,8 @@ main (int argc, char **argv)
aixrtl_flag = 0;
else if (strcmp (argv[i], "-blazy") == 0)
aixlazy_flag = 1;
+ else if (strcmp (argv[i], "-bcdtors") == 0)
+ aixbcdtors_flag = 1;
#endif
}
@@ -1731,7 +1734,9 @@ main (int argc, char **argv)
/* Tell the linker that we have initializer and finalizer functions. */
#ifdef LD_INIT_SWITCH
#ifdef COLLECT_EXPORT_LIST
- *ld2++ = concat (LD_INIT_SWITCH, ":", initname, ":", fininame, NULL);
+ /* Do not emit -binitfini when -bcdtors is enabled. */
+ if (!aixbcdtors_flag)
+*ld2++ = concat (LD_INIT_SWITCH, ":", initname, ":", fininame, NULL);
#else
*ld2++ = LD_INIT_SWITCH;
*ld2++ = initname;
@@ -2020,6 +2025,7 @@ write_c_file_stat (FILE *stream, const char *name ATTRIBUTE_UNUSED)
{
const char *p, *q;
char *p
Re: [PATCH] gcc: implement AIX-style constructors
On Thu, Oct 21, 2021 at 8:39 AM CHIGOT, CLEMENT wrote: > > Hi David, > > The problem is that cdtors is created by the linker only when the -bcdtors > flag is provided. Thus, if we add "extern void (* _cdtors[]) (void);" to > the "crtcxa.c", we can't use it without using the new constructor types. > One solution would be to create another crtcxa (eg crtcxa_cdtors.o) which will > be replacing the default crtcxa.o when needed. I didn't think about that > when creating the patch. But it might be a better approach. What do you think > ? Hi, Clement Another, optional object file in libgcc seems like a cleaner solution than collect2.c emitting all of the code. The file should not be called crtcxa_cdtors.o because "cxa" came from the name of the libstdc++ support functions. Maybe crtcdtors.o or crt_cdtors.o or aixcdtors.o or aix_cdtors.o . Thanks, David
Re: [PATCH] gcc: implement AIX-style constructors
Hi David, The problem is that cdtors is created by the linker only when -bcdtors flag is provided. Thus, if we add "extern void (* _cdtors[]) (void);" to the "crtcxa.c", we can't used it without using the new constructor types. One solution would be to create another crtcxa (eg crtcxa_cdtors.o) which will be replacing the default crtcxa.o when needed. I didn't thought about that when creating the patch. But it might be a better approach. What do you think ? About documentation, I wasn't aware of that. I'll do it. Clément From: David Edelsohn Sent: Tuesday, October 19, 2021 10:14 PM To: CHIGOT, CLEMENT Cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH] gcc: implement AIX-style constructors Caution! External email. Do not open attachments or click links, unless this email comes from a known sender and you know the content is safe. Clement, + /* Use __C_runtime_pstartup to run ctors and register dtors. + This whole part should normally be in libgcc but as + AIX cdtors format is currently not the default, managed + that in collect2. */ Why are you emitting the special startup function call in collect2.c instead of placing it in libgcc. The comment mentions that the special startup function should be defined in libgcc. Yes, the AIX ld bcdtors mechanism is not the default, but what is the harm? The symbol will be defined and exported by libgcc. If the AIX linker -bcdtors functionality is not invoked, the symbol is not used. And if a user does invoke the AIX linker with -bcdtors, the behavior will be the same (either the program was compiled to use AIX cdtors or not, which is the same if the startup function is emitted by collect2.c. Also, the patch should include documentation of the option. The documentation should mention that this is for interoperability with IBM XL Compiler, and the option will not operate correctly unless the application and the GCC runtime are built with the option. Thanks, David On Mon, Oct 18, 2021 at 3:55 AM CHIGOT, CLEMENT wrote: > > AIX linker now supports constructors and destructors detection. For such > functions to be detected, their name must starts with __sinit or __sterm. > and -bcdtors must be passed to linker calls. It will create "_cdtors" > symbol which can be used to launch the initialization. > > This patch creates a new RS6000 flag "-mcdtors=". > With "-mcdtors=aix", gcc will generate these new constructors/destructors. > With "-mcdtors=gcc", which is currently the default, gcc will continue > to generate "gcc" format for constructors (ie _GLOBAL__I and _GLOBAL__D > symbols). > Ideally, it would have been better to enable the AIX format by default > instead of using collect2. However, the compatibility between the > previously-built binaries and the new ones is too complex to be done. > > gcc/ChangeLog: > 2021-10-04 Clément Chigot > > * collect2.c (aixbcdtors_flags): New variable. > (main): Use it to detect -bcdtors and remove -binitfini flag. > (write_c_file_stat): Adapt to new AIX format. > * config/rs6000/aix.h (FILE_SINIT_FORMAT): New define. > (FILE_STERM_FORMAT): New define. > (TARGET_FILE_FUNCTION_FORMAT): New define. > * config/rs6000/aix64.opt: Add -mcdtors flag. > * config/rs6000/aix71.h (LINK_SPEC_COMMON): Pass -bcdtors when > -mcdtors=aix is passed. > * config/rs6000/aix72.h (LINK_SPEC_COMMON): Likewise. > * config/rs6000/aix73.h (LINK_SPEC_COMMON): Likewise. > * config/rs6000/rs6000-opts.h (enum rs6000_cdtors): New enum. > * tree.c (get_file_function_name): Add > TARGET_FILE_FUNCTION_FORMAT support. > > gcc/testsuite/ChangeLog: > 2021-10-04 Clément Chigot > > * gcc.target/powerpc/constructor-aix.c: New test. > >
Re: [PATCH] gcc: implement AIX-style constructors
Clement, + /* Use __C_runtime_pstartup to run ctors and register dtors. + This whole part should normally be in libgcc but as + AIX cdtors format is currently not the default, managed + that in collect2. */ Why are you emitting the special startup function call in collect2.c instead of placing it in libgcc. The comment mentions that the special startup function should be defined in libgcc. Yes, the AIX ld bcdtors mechanism is not the default, but what is the harm? The symbol will be defined and exported by libgcc. If the AIX linker -bcdtors functionality is not invoked, the symbol is not used. And if a user does invoke the AIX linker with -bcdtors, the behavior will be the same (either the program was compiled to use AIX cdtors or not, which is the same if the startup function is emitted by collect2.c. Also, the patch should include documentation of the option. The documentation should mention that this is for interoperability with IBM XL Compiler, and the option will not operate correctly unless the application and the GCC runtime are built with the option. Thanks, David On Mon, Oct 18, 2021 at 3:55 AM CHIGOT, CLEMENT wrote: > > AIX linker now supports constructors and destructors detection. For such > functions to be detected, their name must starts with __sinit or __sterm. > and -bcdtors must be passed to linker calls. It will create "_cdtors" > symbol which can be used to launch the initialization. > > This patch creates a new RS6000 flag "-mcdtors=". > With "-mcdtors=aix", gcc will generate these new constructors/destructors. > With "-mcdtors=gcc", which is currently the default, gcc will continue > to generate "gcc" format for constructors (ie _GLOBAL__I and _GLOBAL__D > symbols). > Ideally, it would have been better to enable the AIX format by default > instead of using collect2. However, the compatibility between the > previously-built binaries and the new ones is too complex to be done. > > gcc/ChangeLog: > 2021-10-04 Clément Chigot > > * collect2.c (aixbcdtors_flags): New variable. > (main): Use it to detect -bcdtors and remove -binitfini flag. > (write_c_file_stat): Adapt to new AIX format. > * config/rs6000/aix.h (FILE_SINIT_FORMAT): New define. > (FILE_STERM_FORMAT): New define. > (TARGET_FILE_FUNCTION_FORMAT): New define. > * config/rs6000/aix64.opt: Add -mcdtors flag. > * config/rs6000/aix71.h (LINK_SPEC_COMMON): Pass -bcdtors when > -mcdtors=aix is passed. > * config/rs6000/aix72.h (LINK_SPEC_COMMON): Likewise. > * config/rs6000/aix73.h (LINK_SPEC_COMMON): Likewise. > * config/rs6000/rs6000-opts.h (enum rs6000_cdtors): New enum. > * tree.c (get_file_function_name): Add > TARGET_FILE_FUNCTION_FORMAT support. > > gcc/testsuite/ChangeLog: > 2021-10-04 Clément Chigot > > * gcc.target/powerpc/constructor-aix.c: New test. > >
[PATCH] gcc: implement AIX-style constructors
AIX linker now supports constructors and destructors detection. For such
functions to be detected, their name must starts with __sinit or __sterm.
and -bcdtors must be passed to linker calls. It will create "_cdtors"
symbol which can be used to launch the initialization.
This patch creates a new RS6000 flag "-mcdtors=".
With "-mcdtors=aix", gcc will generate these new constructors/destructors.
With "-mcdtors=gcc", which is currently the default, gcc will continue
to generate "gcc" format for constructors (ie _GLOBAL__I and _GLOBAL__D
symbols).
Ideally, it would have been better to enable the AIX format by default
instead of using collect2. However, the compatibility between the
previously-built binaries and the new ones is too complex to be done.
gcc/ChangeLog:
2021-10-04 Clément Chigot
* collect2.c (aixbcdtors_flags): New variable.
(main): Use it to detect -bcdtors and remove -binitfini flag.
(write_c_file_stat): Adapt to new AIX format.
* config/rs6000/aix.h (FILE_SINIT_FORMAT): New define.
(FILE_STERM_FORMAT): New define.
(TARGET_FILE_FUNCTION_FORMAT): New define.
* config/rs6000/aix64.opt: Add -mcdtors flag.
* config/rs6000/aix71.h (LINK_SPEC_COMMON): Pass -bcdtors when
-mcdtors=aix is passed.
* config/rs6000/aix72.h (LINK_SPEC_COMMON): Likewise.
* config/rs6000/aix73.h (LINK_SPEC_COMMON): Likewise.
* config/rs6000/rs6000-opts.h (enum rs6000_cdtors): New enum.
* tree.c (get_file_function_name): Add
TARGET_FILE_FUNCTION_FORMAT support.
gcc/testsuite/ChangeLog:
2021-10-04 Clément Chigot
* gcc.target/powerpc/constructor-aix.c: New test.
From e1297880a2abe53db6422bcf25dcd883a2658260 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Chigot?=
Date: Mon, 4 Oct 2021 09:24:43 +0200
Subject: [PATCH] gcc: implement AIX-style constructors
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
AIX linker now supports constructors and destructors detection. For such
functions to be detected, their name must starts with __sinit or __sterm.
and -bcdtors must be passed to linker calls. It will create "_cdtors"
symbol which can be used to launch the initialization.
This patch creates a new RS6000 flag "-mcdtors=".
With "-mcdtors=aix", gcc will generate these new constructors/destructors.
With "-mcdtors=gcc", which is currently the default, gcc will continue
to generate "gcc" format for constructors (ie _GLOBAL__I and _GLOBAL__D
symbols).
Ideally, it would have been better to enable the AIX format by default
instead of using collect2. However, the compatibility between the
previously-built binaries and the new ones is too complex to be done.
gcc/ChangeLog:
2021-10-04 Clément Chigot
* collect2.c (aixbcdtors_flags): New variable.
(main): Use it to detect -bcdtors and remove -binitfini flag.
(write_c_file_stat): Adapt to new AIX format.
* config/rs6000/aix.h (FILE_SINIT_FORMAT): New define.
(FILE_STERM_FORMAT): New define.
(TARGET_FILE_FUNCTION_FORMAT): New define.
* config/rs6000/aix64.opt: Add -mcdtors flag.
* config/rs6000/aix71.h (LINK_SPEC_COMMON): Pass -bcdtors when
-mcdtors=aix is passed.
* config/rs6000/aix72.h (LINK_SPEC_COMMON): Likewise.
* config/rs6000/aix73.h (LINK_SPEC_COMMON): Likewise.
* config/rs6000/rs6000-opts.h (enum rs6000_cdtors): New enum.
* tree.c (get_file_function_name): Add
TARGET_FILE_FUNCTION_FORMAT support.
gcc/testsuite/ChangeLog:
2021-10-04 Clément Chigot
* gcc.target/powerpc/constructor-aix.c: New test.
---
gcc/collect2.c| 91 +--
gcc/config/rs6000/aix.h | 56
gcc/config/rs6000/aix64.opt | 17
gcc/config/rs6000/aix71.h | 2 +-
gcc/config/rs6000/aix72.h | 2 +-
gcc/config/rs6000/aix73.h | 2 +-
gcc/config/rs6000/rs6000-opts.h | 8 ++
.../gcc.target/powerpc/constructor-aix.c | 12 +++
gcc/tree.c| 5 +
9 files changed, 184 insertions(+), 11 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/powerpc/constructor-aix.c
diff --git a/gcc/collect2.c b/gcc/collect2.c
index 6f913041f26..59658cbadb7 100644
--- a/gcc/collect2.c
+++ b/gcc/collect2.c
@@ -186,6 +186,7 @@ static int aix64_flag; /* true if -b64 */
static int aixrtl_flag; /* true if -brtl */
static int aixlazy_flag; /* true if -blazy */
static int visibility_flag; /* true if -fvisibility */
+static int aixbcdtors_flag;/* True if -bcdtors */
#endif
enum lto_mode_d {
@@ -984,6 +985,8 @@ main (int argc, char **argv)
aixrtl_flag = 0;
else if (strcmp (argv[i], "-blazy") == 0)
aixlazy_flag = 1;
+ else if (strcmp (argv[i], "-bcdtors") == 0)
+ aixbc
