Hi
This patch is another partial fix for PR 84521. This is adding a
definition to one of the target hooks used in the SJLJ implemetation so
that AArch64 defines the hard_frame_pointer_rtx as the
TARGET_BUILTIN_SETJMP_FRAME_VALUE. As pointed out by Wilco there is
still a lot more work to be done for these builtins in the future.
Testing: Bootstrapped and regtested on aarch64-none-linux-gnu and added
new test.
Is this ok for trunk?
Sudi
*** gcc/ChangeLog ***
2018-03-14 Sudakshina Das <sudi....@arm.com>
* builtins.c (expand_builtin_setjmp_receiver): Update condition
to restore frame pointer.
* config/aarch64/aarch64.h (DONT_USE_BUILTIN_SETJMP): Update
comment.
* config/aarch64/aarch64.c (aarch64_builtin_setjmp_frame_value):
New.
(TARGET_BUILTIN_SETJMP_FRAME_VALUE): Define.
*** gcc/testsuite/ChangeLog ***
2018-03-14 Sudakshina Das <sudi....@arm.com>
* gcc.c-torture/execute/pr84521.c: New test.
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 85affa7..640f1a9 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -898,7 +898,8 @@ expand_builtin_setjmp_receiver (rtx receiver_label)
/* Now put in the code to restore the frame pointer, and argument
pointer, if needed. */
- if (! targetm.have_nonlocal_goto ())
+ if (! targetm.have_nonlocal_goto ()
+ && targetm.builtin_setjmp_frame_value () != hard_frame_pointer_rtx)
{
/* First adjust our frame pointer to its actual value. It was
previously set to the start of the virtual area corresponding to
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index e3c52f6..7a21c14 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -474,7 +474,9 @@ extern unsigned aarch64_architecture_version;
#define EH_RETURN_STACKADJ_RTX gen_rtx_REG (Pmode, R4_REGNUM)
#define EH_RETURN_HANDLER_RTX aarch64_eh_return_handler_rtx ()
-/* Don't use __builtin_setjmp until we've defined it. */
+/* Don't use __builtin_setjmp until we've defined it.
+ CAUTION: This macro is only used during exception unwinding.
+ Don't fall for its name. */
#undef DONT_USE_BUILTIN_SETJMP
#define DONT_USE_BUILTIN_SETJMP 1
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index e1fb87f..e7ac0fe 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -12128,6 +12128,13 @@ aarch64_expand_builtin_va_start (tree valist, rtx nextarg ATTRIBUTE_UNUSED)
expand_expr (t, const0_rtx, VOIDmode, EXPAND_NORMAL);
}
+/* Implement TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
+static rtx
+aarch64_builtin_setjmp_frame_value (void)
+{
+ return hard_frame_pointer_rtx;
+}
+
/* Implement TARGET_GIMPLIFY_VA_ARG_EXPR. */
static tree
@@ -17505,6 +17512,9 @@ aarch64_run_selftests (void)
#undef TARGET_FOLD_BUILTIN
#define TARGET_FOLD_BUILTIN aarch64_fold_builtin
+#undef TARGET_BUILTIN_SETJMP_FRAME_VALUE
+#define TARGET_BUILTIN_SETJMP_FRAME_VALUE aarch64_builtin_setjmp_frame_value
+
#undef TARGET_FUNCTION_ARG
#define TARGET_FUNCTION_ARG aarch64_function_arg
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr84521.c b/gcc/testsuite/gcc.c-torture/execute/pr84521.c
new file mode 100644
index 0000000..76b10d2
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr84521.c
@@ -0,0 +1,49 @@
+/* { dg-require-effective-target indirect_jumps } */
+
+#include <setjmp.h>
+
+jmp_buf buf;
+
+int uses_longjmp (void)
+{
+ __builtin_longjmp (buf, 1);
+}
+
+int gl;
+void after_longjmp (void)
+{
+ gl = 5;
+}
+
+int
+test_1 (int n)
+{
+ volatile int *p = alloca (n);
+ if (__builtin_setjmp (buf))
+ {
+ after_longjmp ();
+ }
+ else
+ {
+ uses_longjmp ();
+ }
+
+ return 0;
+}
+
+int __attribute__ ((optimize ("no-omit-frame-pointer")))
+test_2 (int n)
+{
+ int i;
+ int *ptr = (int *)__builtin_alloca (sizeof (int) * n);
+ for (i = 0; i < n; i++)
+ ptr[i] = i;
+ test_1 (n);
+ return 0;
+}
+
+int main (int argc, const char **argv)
+{
+ __builtin_memset (&buf, 0xaf, sizeof (buf));
+ test_2 (100);
+}
