mirror of
https://github.com/feather-wallet/feather.git
synced 2024-12-23 12:09:50 +00:00
69 lines
3.2 KiB
Diff
69 lines
3.2 KiB
Diff
|
commit eb5698897c52702498938592d7f76e67d126451f
|
||
|
|
Author: Eric Botcazou <ebotcazou@adacore.com>
|
||
|
|
Date: Wed May 5 22:48:51 2021 +0200
|
||
|
|
|
||
|
|
Fix PR target/100402
|
||
|
|
|
||
|
|
This is a regression for 64-bit Windows present from mainline down to the 9
|
||
|
|
branch and introduced by the fix for PR target/99234. Again SEH, but with
|
||
|
|
a twist related to the way MinGW implements setjmp/longjmp, which turns out
|
||
|
|
to be piggybacked on SEH with recent versions of MinGW, i.e. the longjmp
|
||
|
|
performs a bona-fide unwinding of the stack, because it calls RtlUnwindEx
|
||
|
|
with the second argument initially passed to setjmp, which is the result of
|
||
|
|
__builtin_frame_address (0) in the MinGW header file:
|
||
|
|
|
||
|
|
define setjmp(BUF) _setjmp((BUF), __builtin_frame_address (0))
|
||
|
|
|
||
|
|
This means that we directly expose the frame pointer to the SEH machinery
|
||
|
|
here (unlike with regular exception handling where we use an intermediate
|
||
|
|
CFA) and thus that we cannot do whatever we want with it. The old code
|
||
|
|
would leave it unaligned, i.e. not multiple of 16, whereas the new code
|
||
|
|
aligns it, but this breaks for some reason; at least it appears that a
|
||
|
|
.seh_setframe directive with 0 as second argument always works, so the
|
||
|
|
fix aligns it this way.
|
||
|
|
|
||
|
|
gcc/
|
||
|
|
PR target/100402
|
||
|
|
* config/i386/i386.c (ix86_compute_frame_layout): For a SEH target,
|
||
|
|
always return the establisher frame for __builtin_frame_address (0).
|
||
|
|
gcc/testsuite/
|
||
|
|
* gcc.c-torture/execute/20210505-1.c: New test.
|
||
|
|
|
||
|
|
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
|
||
|
|
index 2f838840e96..06ad1b2274e 100644
|
||
|
|
--- a/gcc/config/i386/i386.c
|
||
|
|
+++ b/gcc/config/i386/i386.c
|
||
|
|
@@ -6356,12 +6356,29 @@ ix86_compute_frame_layout (void)
|
||
|
|
area, see the SEH code in config/i386/winnt.c for the rationale. */
|
||
|
|
frame->hard_frame_pointer_offset = frame->sse_reg_save_offset;
|
||
|
|
|
||
|
|
- /* If we can leave the frame pointer where it is, do so. Also, return
|
||
|
|
+ /* If we can leave the frame pointer where it is, do so; however return
|
||
|
|
the establisher frame for __builtin_frame_address (0) or else if the
|
||
|
|
- frame overflows the SEH maximum frame size. */
|
||
|
|
+ frame overflows the SEH maximum frame size.
|
||
|
|
+
|
||
|
|
+ Note that the value returned by __builtin_frame_address (0) is quite
|
||
|
|
+ constrained, because setjmp is piggybacked on the SEH machinery with
|
||
|
|
+ recent versions of MinGW:
|
||
|
|
+
|
||
|
|
+ # elif defined(__SEH__)
|
||
|
|
+ # if defined(__aarch64__) || defined(_ARM64_)
|
||
|
|
+ # define setjmp(BUF) _setjmp((BUF), __builtin_sponentry())
|
||
|
|
+ # elif (__MINGW_GCC_VERSION < 40702)
|
||
|
|
+ # define setjmp(BUF) _setjmp((BUF), mingw_getsp())
|
||
|
|
+ # else
|
||
|
|
+ # define setjmp(BUF) _setjmp((BUF), __builtin_frame_address (0))
|
||
|
|
+ # endif
|
||
|
|
+
|
||
|
|
+ and the second argument passed to _setjmp, if not null, is forwarded
|
||
|
|
+ to the TargetFrame parameter of RtlUnwindEx by longjmp (after it has
|
||
|
|
+ built an ExceptionRecord on the fly describing the setjmp buffer). */
|
||
|
|
const HOST_WIDE_INT diff
|
||
|
|
= frame->stack_pointer_offset - frame->hard_frame_pointer_offset;
|
||
|
|
- if (diff <= 255)
|
||
|
|
+ if (diff <= 255 && !crtl->accesses_prior_frames)
|
||
|
|
{
|
||
|
|
/* The resulting diff will be a multiple of 16 lower than 255,
|
||
|
|
i.e. at most 240 as required by the unwind data structure. */
|