[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #27 from LIU Hao --- Thank you!
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 Jakub Jelinek changed: What|Removed |Added Resolution|--- |FIXED Status|UNCONFIRMED |RESOLVED --- Comment #26 from Jakub Jelinek --- Fixed then.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #25 from GCC Commits ---
The releases/gcc-14 branch has been updated by Jakub Jelinek
:
https://gcc.gnu.org/g:a805de33f7be4f6886906ca5f4da493f3b743c76
commit r14-10193-ga805de33f7be4f6886906ca5f4da493f3b743c76
Author: Jakub Jelinek
Date: Fri May 10 09:21:38 2024 +0200
c++, mingw: Fix up types of dtor hooks to
__cxa_{,thread_}atexit/__cxa_throw on mingw ia32 [PR114968]
__cxa_atexit/__cxa_thread_atexit/__cxa_throw functions accept function
pointers to usually directly destructors rather than wrappers around
them.
Now, mingw ia32 uses implicitly __attribute__((thiscall)) calling
conventions for METHOD_TYPE (where the this pointer is passed in %ecx
register, the rest on the stack), so these functions use:
in config/os/mingw32/os_defines.h:
#if defined (__i386__)
#define _GLIBCXX_CDTOR_CALLABI __thiscall
#endif
in libsupc++/cxxabi.h
__cxa_atexit(void (_GLIBCXX_CDTOR_CALLABI *)(void*), void*, void*)
_GLIBCXX_NOTHROW;
__cxa_thread_atexit(void (_GLIBCXX_CDTOR_CALLABI *)(void*), void*, void *)
_GLIBCXX_NOTHROW;
__cxa_throw(void*, std::type_info*, void (_GLIBCXX_CDTOR_CALLABI *) (void
*))
__attribute__((__noreturn__));
Now, mingw for some weird reason uses
#define TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT hook_bool_void_true
so it never actually uses __cxa_atexit, but does use __cxa_thread_atexit
and __cxa_throw. Recent changes for modules result in more detailed
__cxa_*atexit/__cxa_throw prototypes precreated by the compiler, and if
that happens and one also includes , the compiler complains about
mismatches in the prototypes.
One thing is the missing thiscall attribute on the FUNCTION_TYPE, the
other problem is that all of atexit/__cxa_atexit/__cxa_thread_atexit
get function pointer types created by a single function,
get_atexit_fn_ptr_type (), which creates it depending on if atexit
or __cxa_atexit will be used as either void(*)(void) or void(*)(void *),
but when using atexit and __cxa_thread_atexit it uses the wrong function
type for __cxa_thread_atexit.
The following patch adds a target hook to add the thiscall attribute to the
function pointers, and splits the get_atexit_fn_ptr_type () function into
get_atexit_fn_ptr_type () and get_cxa_atexit_fn_ptr_type (), the former
always
creates shared void(*)(void) type, the latter creates either
void(*)(void*) (on most targets) or void(__attribute__((thiscall))*)(void*)
(on mingw ia32). So that we don't waiste another GTY global tree for it,
because cleanup_type used for the same purpose for __cxa_throw should be
the same, the code changes it to use that type too.
In register_dtor_fn then based on the decision whether to use atexit,
__cxa_atexit or __cxa_thread_atexit it picks the right function pointer
type, and also if it decides to emit a __tcf_* wrapper for the cleanup,
uses that type for that wrapper so that it agrees on calling convention.
2024-05-10 Jakub Jelinek
PR target/114968
gcc/
* target.def (use_atexit_for_cxa_atexit): Remove spurious space
from comment.
(adjust_cdtor_callabi_fntype): New cxx target hook.
* targhooks.h (default_cxx_adjust_cdtor_callabi_fntype): Declare.
* targhooks.cc (default_cxx_adjust_cdtor_callabi_fntype): New
function.
* doc/tm.texi.in (TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE): Add.
* doc/tm.texi: Regenerate.
* config/i386/i386.cc (ix86_cxx_adjust_cdtor_callabi_fntype): New
function.
(TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE): Redefine.
gcc/cp/
* cp-tree.h (atexit_fn_ptr_type_node, cleanup_type): Adjust macro
comments.
(get_cxa_atexit_fn_ptr_type): Declare.
* decl.cc (get_atexit_fn_ptr_type): Adjust function comment, only
build type for atexit argument.
(get_cxa_atexit_fn_ptr_type): New function.
(get_atexit_node): Call get_cxa_atexit_fn_ptr_type rather than
get_atexit_fn_ptr_type when using __cxa_atexit.
(get_thread_atexit_node): Call get_cxa_atexit_fn_ptr_type
rather than get_atexit_fn_ptr_type.
(start_cleanup_fn): Add ob_parm argument, call
get_cxa_atexit_fn_ptr_type or get_atexit_fn_ptr_type depending
on it and create PARM_DECL also based on that argument.
(register_dtor_fn): Adjust start_cleanup_fn caller, use
get_cxa_atexit_fn_ptr_type rather than get_atexit_fn_ptr_type
for use_dtor casts.
* except.cc (build_throw): Use get_cxa_atexit_fn_ptr_type ().
(cherry picked from commit e5d8fd9ce05611093191d500ebc39f150d0ece2b)
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #24 from LIU Hao --- GCC 14 branch built successfully on i686-w64-mingw32 with the backported commit. I have also built boost 1.84 successfully. I'm now trying to fix the LD fault..
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #23 from LIU Hao --- I am afraid I can't do a complete bootstrap any more due to https://sourceware.org/bugzilla/show_bug.cgi?id=31720. LD is segfaulting randomly. I will backport the commit to GCC 14 branch and make a non-bootstrapped build, then build others as usual.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #22 from Jakub Jelinek --- Does even the committed version work fine on mingw32?
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #21 from GCC Commits ---
The master branch has been updated by Jakub Jelinek :
https://gcc.gnu.org/g:e5d8fd9ce05611093191d500ebc39f150d0ece2b
commit r15-358-ge5d8fd9ce05611093191d500ebc39f150d0ece2b
Author: Jakub Jelinek
Date: Fri May 10 09:21:38 2024 +0200
c++, mingw: Fix up types of dtor hooks to
__cxa_{,thread_}atexit/__cxa_throw on mingw ia32 [PR114968]
__cxa_atexit/__cxa_thread_atexit/__cxa_throw functions accept function
pointers to usually directly destructors rather than wrappers around
them.
Now, mingw ia32 uses implicitly __attribute__((thiscall)) calling
conventions for METHOD_TYPE (where the this pointer is passed in %ecx
register, the rest on the stack), so these functions use:
in config/os/mingw32/os_defines.h:
#if defined (__i386__)
#define _GLIBCXX_CDTOR_CALLABI __thiscall
#endif
in libsupc++/cxxabi.h
__cxa_atexit(void (_GLIBCXX_CDTOR_CALLABI *)(void*), void*, void*)
_GLIBCXX_NOTHROW;
__cxa_thread_atexit(void (_GLIBCXX_CDTOR_CALLABI *)(void*), void*, void *)
_GLIBCXX_NOTHROW;
__cxa_throw(void*, std::type_info*, void (_GLIBCXX_CDTOR_CALLABI *) (void
*))
__attribute__((__noreturn__));
Now, mingw for some weird reason uses
#define TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT hook_bool_void_true
so it never actually uses __cxa_atexit, but does use __cxa_thread_atexit
and __cxa_throw. Recent changes for modules result in more detailed
__cxa_*atexit/__cxa_throw prototypes precreated by the compiler, and if
that happens and one also includes , the compiler complains about
mismatches in the prototypes.
One thing is the missing thiscall attribute on the FUNCTION_TYPE, the
other problem is that all of atexit/__cxa_atexit/__cxa_thread_atexit
get function pointer types created by a single function,
get_atexit_fn_ptr_type (), which creates it depending on if atexit
or __cxa_atexit will be used as either void(*)(void) or void(*)(void *),
but when using atexit and __cxa_thread_atexit it uses the wrong function
type for __cxa_thread_atexit.
The following patch adds a target hook to add the thiscall attribute to the
function pointers, and splits the get_atexit_fn_ptr_type () function into
get_atexit_fn_ptr_type () and get_cxa_atexit_fn_ptr_type (), the former
always
creates shared void(*)(void) type, the latter creates either
void(*)(void*) (on most targets) or void(__attribute__((thiscall))*)(void*)
(on mingw ia32). So that we don't waiste another GTY global tree for it,
because cleanup_type used for the same purpose for __cxa_throw should be
the same, the code changes it to use that type too.
In register_dtor_fn then based on the decision whether to use atexit,
__cxa_atexit or __cxa_thread_atexit it picks the right function pointer
type, and also if it decides to emit a __tcf_* wrapper for the cleanup,
uses that type for that wrapper so that it agrees on calling convention.
2024-05-10 Jakub Jelinek
PR target/114968
gcc/
* target.def (use_atexit_for_cxa_atexit): Remove spurious space
from comment.
(adjust_cdtor_callabi_fntype): New cxx target hook.
* targhooks.h (default_cxx_adjust_cdtor_callabi_fntype): Declare.
* targhooks.cc (default_cxx_adjust_cdtor_callabi_fntype): New
function.
* doc/tm.texi.in (TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE): Add.
* doc/tm.texi: Regenerate.
* config/i386/i386.cc (ix86_cxx_adjust_cdtor_callabi_fntype): New
function.
(TARGET_CXX_ADJUST_CDTOR_CALLABI_FNTYPE): Redefine.
gcc/cp/
* cp-tree.h (atexit_fn_ptr_type_node, cleanup_type): Adjust macro
comments.
(get_cxa_atexit_fn_ptr_type): Declare.
* decl.cc (get_atexit_fn_ptr_type): Adjust function comment, only
build type for atexit argument.
(get_cxa_atexit_fn_ptr_type): New function.
(get_atexit_node): Call get_cxa_atexit_fn_ptr_type rather than
get_atexit_fn_ptr_type when using __cxa_atexit.
(get_thread_atexit_node): Call get_cxa_atexit_fn_ptr_type
rather than get_atexit_fn_ptr_type.
(start_cleanup_fn): Add ob_parm argument, call
get_cxa_atexit_fn_ptr_type or get_atexit_fn_ptr_type depending
on it and create PARM_DECL also based on that argument.
(register_dtor_fn): Adjust start_cleanup_fn caller, use
get_cxa_atexit_fn_ptr_type rather than get_atexit_fn_ptr_type
for use_dtor casts.
* except.cc (build_throw): Use get_cxa_atexit_fn_ptr_type ().
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #20 from Jakub Jelinek --- Thanks, I'll test it myself on x86_64-linux/i686-linux and post if it succeeds.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #19 from LIU Hao ---
(In reply to Jakub Jelinek from comment #17)
> Created attachment 58125 [details]
> gcc15-pr114968.patch
>
> Here is an updated patch.
> Note, even when not taking thiscall attribute into consideration, the
> existing
> code was wrong on the !targetm.cxx.use_atexit_for_cxa_atexit () targets (aka
> mingw), because it would happily use the atexit function argument type (aka
> void (*) ()) for __cxa_thread_atexit.
Bootstrapped successfully on {i686,x86_64}-w64-mingw32. Also rebuilt mingw-w64
CRT, binutils, GDB and boost. Everything went well.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #18 from LIU Hao --- (In reply to Jakub Jelinek from comment #16) > What is the reason behind > /* mingw32 atexit function is safe to use in shared libraries. Use it >to register C++ static destructors. */ > #define TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT hook_bool_void_true > ? > Couldn't we just drop that? I think so. We have a statically linked `atexit()` much like glibc [1]. However we have added `__cxa_atexit()` a couple of years ago, so it might be preferred. As the Windows system library does not provide `__cxa_*` routines, those functions are also linked statically, so they ignore the DSO handle parameter. [1] https://github.com/mingw-w64/mingw-w64/blob/19cf5d171f6df208b27271b40014c66d2b44e38b/mingw-w64-crt/crt/crtdll.c#L205 [2] https://github.com/mingw-w64/mingw-w64/blob/19cf5d171f6df208b27271b40014c66d2b44e38b/mingw-w64-crt/crt/cxa_atexit.c#L11 > while with __cxa_atexit one can just pass the destructor itself to the > __cxa_atexit function (indeed with slightly more instructions there because > in addition to the function pointer it needs to pass the address of the > object and __dso_handle). > But it is still smaller. Can `./configure --enable-__cxa_atexit` be safely used? Documentation says it's only available with glibc [3], but I don't see any stuff specific to glibc. [3] https://gcc.gnu.org/install/configure.html > Anyway, if there is some strong reason to keep it, I think it would be > better to avoid adding yet another GTY tree, the __cxa_throw last argument > type is the same as __cxa_atexit/__cxa_thread_atexit. Maybe it can be kept for backward compatibility.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 Jakub Jelinek changed: What|Removed |Added Attachment #58123|0 |1 is obsolete|| --- Comment #17 from Jakub Jelinek --- Created attachment 58125 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58125=edit gcc15-pr114968.patch Here is an updated patch. Note, even when not taking thiscall attribute into consideration, the existing code was wrong on the !targetm.cxx.use_atexit_for_cxa_atexit () targets (aka mingw), because it would happily use the atexit function argument type (aka void (*) ()) for __cxa_thread_atexit.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #16 from Jakub Jelinek --- What is the reason behind /* mingw32 atexit function is safe to use in shared libraries. Use it to register C++ static destructors. */ #define TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT hook_bool_void_true ? Couldn't we just drop that? I mean, when using atexit, GCC needs to emit wrapper functions around the destructors, like __tcf_0: pushq %rbp .seh_pushreg%rbp movq%rsp, %rbp .seh_setframe %rbp, 0 subq$32, %rsp .seh_stackalloc 32 .seh_endprologue leaq_ZZ3foovE1s(%rip), %rax movq%rax, %rcx call_ZN1SD1Ev nop addq$32, %rsp popq%rbp ret while with __cxa_atexit one can just pass the destructor itself to the __cxa_atexit function (indeed with slightly more instructions there because in addition to the function pointer it needs to pass the address of the object and __dso_handle). But it is still smaller. Anyway, if there is some strong reason to keep it, I think it would be better to avoid adding yet another GTY tree, the __cxa_throw last argument type is the same as __cxa_atexit/__cxa_thread_atexit.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #15 from LIU Hao --- Created attachment 58124 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58124=edit proposed patch v2 Update the patch. Did a quick test on i686-w64-mingw32 and seemed to solve the issue. Rebuilding everything now.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #14 from LIU Hao --- I suspect it's because that `get_atexit_fn_ptr_type` is shared by `atexit` and `__cxa_thread_atexit` but the destructors for them do not use the same calling convention .. So I should make a copy of it, as well as `atexit_fn_ptr_type_node`.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #13 from LIU Hao ---
I am using a modified patch:
```
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 4d6b2b98761..fbd9b4dac2e 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -25799,6 +25799,24 @@ ix86_bitint_type_info (int n, struct bitint_info
*info)
return true;
}
+/* Returns modified FUNCTION_TYPE for cdtor callabi. */
+tree
+ix86_cxx_adjust_cdtor_callabi_fntype (tree fntype)
+{
+fprintf(stderr, "TARGET_64BIT = %d\n", (bool) TARGET_64BIT);
+fprintf(stderr, "TARGET_RTD = %d\n", (bool) TARGET_RTD);
+fprintf(stderr, "ix86_function_type_abi = %d\n", ix86_function_type_abi
(fntype));
+ if (TARGET_64BIT
+ || TARGET_RTD
+ || ix86_function_type_abi (fntype) != MS_ABI)
+return fntype;
+ /* For 32-bit MS ABI add thiscall attribute. */
+ tree attribs = tree_cons (get_identifier ("thiscall"), NULL_TREE,
+ TYPE_ATTRIBUTES (fntype));
+fprintf(stderr, "__thiscall applied!\n");
+ return build_type_attribute_variant (fntype, attribs);
+}
+
/* Implement PUSH_ROUNDING. On 386, we have pushw instruction that
decrements by exactly 2 no matter what the position was, there is no pushb.
```
There is no message when compiling the testcase:
```
E:\lh_mouse\Desktop>g++ test.cc -Wall -Wextra
: error: conflicting declaration of C function 'int
__cxxabiv1::__cxa_thread_atexit(void (*)(), void*, void*)'
test.cc:3:16: note: previous declaration 'int
__cxxabiv1::__cxa_thread_atexit(void (__attribute__((thiscall)) *)(void*),
void*, void*)'
3 | extern "C" int __cxa_thread_atexit(void (__thiscall* dtor)(void*),
void* obj, void* dso) noexcept;
|^~~
```
So I suspect this is a wrong place to look at.. ?
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #12 from LIU Hao ---
testcase:
```
namespace __cxxabiv1
{
extern "C" int __cxa_thread_atexit(void (__thiscall* dtor)(void*), void* obj,
void* dso) noexcept;
}
struct nontrivial
{
nontrivial();
~nontrivial();
};
void*
get_data()
{
thread_local nontrivial nt;
return
}
```
```
E:\lh_mouse\Desktop>g++ test.cc
: error: conflicting declaration of C function 'int
__cxxabiv1::__cxa_thread_atexit(void (*)(), void*, void*)'
test.cc:3:18: note: previous declaration 'int
__cxxabiv1::__cxa_thread_atexit(void (__attribute__((thiscall)) *)(void*),
void*, void*)'
3 | extern "C" int __cxa_thread_atexit(void (__thiscall* dtor)(void*),
void* obj, void* dso) noexcept;
| ^~~
```
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #11 from LIU Hao ---
(In reply to LIU Hao from comment #10)
> (In reply to Jakub Jelinek from comment #8)
> > Created attachment 58123 [details]
> > gcc15-pr114968.patch
> >
> > This is what I'd do, but completely untested...
>
> It does not solve the issue.
>
Wait, I can't reproduce the error with
```
namespace std {
class type_info;
} // namespace std
extern "C" {
int __cxa_at_quick_exit(void (__thiscall* dtor)(void*), void* obj, void* dso)
noexcept;
int __cxa_atexit(void (__thiscall* dtor)(void*), void* obj, void* dso)
noexcept;
int __cxa_thread_atexit(void (__thiscall* dtor)(void*), void* obj, void* dso)
noexcept;
void __cxa_throw(void* obj, std::type_info* type, void (__thiscall*
dtor)(void*));
} // extern "C"
```
Probably there's something wrong in boost configuration. Investigating.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #10 from LIU Hao --- (In reply to Jakub Jelinek from comment #8) > Created attachment 58123 [details] > gcc15-pr114968.patch > > This is what I'd do, but completely untested... It does not solve the issue. Side note: Although I think `-mrtd` should mostly not be useful, the MSVC `/Gz` and Clang `-mrtd` function do not affect the calling convention of non-static member functions; they are always `__thiscall`, which means `this` goes in ECX and the others are passed on stack and popped by callee like `__stdcall`.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #9 from LIU Hao --- (In reply to Jakub Jelinek from comment #8) > Created attachment 58123 [details] > gcc15-pr114968.patch > > This is what I'd do, but completely untested... Thanks. I am gonna give it a run.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #8 from Jakub Jelinek --- Created attachment 58123 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58123=edit gcc15-pr114968.patch This is what I'd do, but completely untested...
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #7 from Jakub Jelinek ---
(In reply to LIU Hao from comment #6)
> I suspect this isn't correct. I am getting strange errors like 'ld exited
> with code 5' not sure what could cause it (possibly also recent MSYS2
> updates):
>
> ```
> diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
> index 2af026d255d..f5dce6a93bc 100644
> --- a/gcc/cp/decl.cc
> +++ b/gcc/cp/decl.cc
> @@ -9669,6 +9669,16 @@ get_atexit_fn_ptr_type (void)
>
>fn_type = build_function_type_list (void_type_node,
> arg_type, NULL_TREE);
> +#ifdef IX86_CALLCVT_THISCALL
> + if (flag_use_cxa_atexit
> + && !targetm.cxx.use_atexit_for_cxa_atexit ())
> +{
> + fn_type = copy_node (fn_type);
> + TYPE_ATTRIBUTES (fn_type) = tree_cons (
> +get_identifier ("thiscall"), NULL_TREE,
> +TYPE_ATTRIBUTES (fn_type));
> +}
> +#endif
>atexit_fn_ptr_type_node = build_pointer_type (fn_type);
> }
>
> diff --git a/gcc/cp/except.cc b/gcc/cp/except.cc
> index f1ffda22fd3..00a8843fa2e 100644
> --- a/gcc/cp/except.cc
> +++ b/gcc/cp/except.cc
> @@ -648,6 +648,12 @@ build_throw (location_t loc, tree exp, tsubst_flags_t
> complain)
> {
> tree tmp = build_function_type_list (void_type_node,
> ptr_type_node, NULL_TREE);
> +#ifdef IX86_CALLCVT_THISCALL
> + tmp = copy_node (tmp);
> + TYPE_ATTRIBUTES (tmp) = tree_cons (
> +get_identifier ("thiscall"), NULL_TREE,
> +TYPE_ATTRIBUTES (tmp));
> +#endif
> cleanup_type = build_pointer_type (tmp);
> }
>
>
> ```
Besides wrong formatting and the case that you need to build_variant_type (or
build_distinct_type?, one needs to look at what will be normally done if you
do:
void (__attribute__((thiscall)) *fn) (void);
), you really can't do it like that. IX86_CALLCVT_THISCALL is defined on all
x86_64/i?86 targets, so not limited to mingw 32-bit.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #6 from LIU Hao ---
I suspect this isn't correct. I am getting strange errors like 'ld exited with
code 5' not sure what could cause it (possibly also recent MSYS2 updates):
```
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 2af026d255d..f5dce6a93bc 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -9669,6 +9669,16 @@ get_atexit_fn_ptr_type (void)
fn_type = build_function_type_list (void_type_node,
arg_type, NULL_TREE);
+#ifdef IX86_CALLCVT_THISCALL
+ if (flag_use_cxa_atexit
+ && !targetm.cxx.use_atexit_for_cxa_atexit ())
+{
+ fn_type = copy_node (fn_type);
+ TYPE_ATTRIBUTES (fn_type) = tree_cons (
+get_identifier ("thiscall"), NULL_TREE,
+TYPE_ATTRIBUTES (fn_type));
+}
+#endif
atexit_fn_ptr_type_node = build_pointer_type (fn_type);
}
diff --git a/gcc/cp/except.cc b/gcc/cp/except.cc
index f1ffda22fd3..00a8843fa2e 100644
--- a/gcc/cp/except.cc
+++ b/gcc/cp/except.cc
@@ -648,6 +648,12 @@ build_throw (location_t loc, tree exp, tsubst_flags_t
complain)
{
tree tmp = build_function_type_list (void_type_node,
ptr_type_node, NULL_TREE);
+#ifdef IX86_CALLCVT_THISCALL
+ tmp = copy_node (tmp);
+ TYPE_ATTRIBUTES (tmp) = tree_cons (
+get_identifier ("thiscall"), NULL_TREE,
+TYPE_ATTRIBUTES (tmp));
+#endif
cleanup_type = build_pointer_type (tmp);
}
```
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #5 from LIU Hao --- (In reply to LIU Hao from comment #4) > > (build_function_type_list returns a shared type, so if attributes are to be > > added, it needs to go on a variant of the type. > > Just saw this. So I would have to clone the tree..
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968
--- Comment #4 from LIU Hao ---
(In reply to Jakub Jelinek from comment #2)
> Guess you need to add a target hook next to use_aeabi_atexit and
> use_atexit_for_cxa_atexit which returns attributes that should be added to a
> FUNCTION_TYPE constructed by get_atexit_fn_ptr_type
> (build_function_type_list returns a shared type, so if attributes are to be
> added, it needs to go on a variant of the type.
>
> On all but mingw ia32 it shouldn't add anything, and guess it shouldn't be
> done if
> !flag_use_cxa_atexit || !targetm.cxx.use_atexit_for_cxa_atexit ()
> A question is what to do about the __tcf_* cleanup functions that might be
> sometimes created.
>
> Anyway, seems to be primarily mingw maintainer responsibility given that it
> is the only target with such requirements.
I think a quick and dirty solution should look like this?
```
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 2af026d255d..311f1ca780b 100644
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -9669,6 +9669,13 @@ get_atexit_fn_ptr_type (void)
fn_type = build_function_type_list (void_type_node,
arg_type, NULL_TREE);
+#ifdef IX86_CALLCVT_THISCALL
+ if (flag_use_cxa_atexit
+ && !targetm.cxx.use_atexit_for_cxa_atexit ())
+TYPE_ATTRIBUTES (fn_type) = tree_cons (
+ get_identifier ("thiscall"), NULL_TREE,
+ TYPE_ATTRIBUTES (fn_type));
+#endif
atexit_fn_ptr_type_node = build_pointer_type (fn_type);
}
```
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 --- Comment #3 from Jakub Jelinek --- Oh, the third argument type for __cxa_throw in cp/except.cc probably needs the same, so the target hook likely should be called similarly to the libstdc++ macro for that.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 Jakub Jelinek changed: What|Removed |Added CC||10walls at gmail dot com, ||jakub at gcc dot gnu.org, ||jason at gcc dot gnu.org --- Comment #2 from Jakub Jelinek --- Guess you need to add a target hook next to use_aeabi_atexit and use_atexit_for_cxa_atexit which returns attributes that should be added to a FUNCTION_TYPE constructed by get_atexit_fn_ptr_type (build_function_type_list returns a shared type, so if attributes are to be added, it needs to go on a variant of the type. On all but mingw ia32 it shouldn't add anything, and guess it shouldn't be done if !flag_use_cxa_atexit || !targetm.cxx.use_atexit_for_cxa_atexit () A question is what to do about the __tcf_* cleanup functions that might be sometimes created. Anyway, seems to be primarily mingw maintainer responsibility given that it is the only target with such requirements.
[Bug target/114968] [14/15 Regression] missing `__thiscall` attribute on builtin declaration of `__cxa_thread_atexit()`
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114968 Richard Biener changed: What|Removed |Added Summary|missing `__thiscall`|[14/15 Regression] missing |attribute on builtin|`__thiscall` attribute on |declaration of |builtin declaration of |`__cxa_thread_atexit()` |`__cxa_thread_atexit()` Keywords||rejects-valid Target Milestone|--- |14.2
