[patch] Fix ICE with stack checking emulation at -O2

[patch] Fix ICE with stack checking emulation at -O2

[Eric Botcazou]

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Hi,

this is a regression present on mainline, 11 and 10 branches: on bare-metal 
platforms, the Ada compiler emulates stack checking (it is required by the 
language and tested by ACATS) in the runtime via the stack_check_libfunc hook 
of the RTL middle-end.  Calls to the function are generated as libcalls but 
they now require a proper function type at -O2 or above.

Tested on powerpc-elf, OK for mainline, 11 and 10 branches?


2021-10-01  Eric Botcazou  <ebotcazou@adacore.com>

	* explow.c: Include langhooks.h.
	(set_stack_check_libfunc): Build a proper function type.

-- 
Eric Botcazou

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diff --git a/gcc/explow.c b/gcc/explow.c
index b6da277f689..a35423f5d16 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -34,6 +34,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "recog.h"
 #include "diagnostic-core.h"
 #include "stor-layout.h"
+#include "langhooks.h"
 #include "except.h"
 #include "dojump.h"
 #include "explow.h"
@@ -1641,8 +1642,14 @@ set_stack_check_libfunc (const char *libfunc_name)
 {
   gcc_assert (stack_check_libfunc == NULL_RTX);
   stack_check_libfunc = gen_rtx_SYMBOL_REF (Pmode, libfunc_name);
+  tree ptype
+    = Pmode == ptr_mode
+      ? ptr_type_node
+      : lang_hooks.types.type_for_mode (Pmode, 1);
+  tree ftype
+    = build_function_type_list (void_type_node, ptype, NULL_TREE);
   tree decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL,
-			  get_identifier (libfunc_name), void_type_node);
+			  get_identifier (libfunc_name), ftype);
   DECL_EXTERNAL (decl) = 1;
   SET_SYMBOL_REF_DECL (stack_check_libfunc, decl);
 }

Re: [patch] Fix ICE with stack checking emulation at -O2

[Richard Biener]

On Fri, Oct 1, 2021 at 10:17 AM Eric Botcazou via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Hi,
>
> this is a regression present on mainline, 11 and 10 branches: on bare-metal
> platforms, the Ada compiler emulates stack checking (it is required by the
> language and tested by ACATS) in the runtime via the stack_check_libfunc hook
> of the RTL middle-end.  Calls to the function are generated as libcalls but
> they now require a proper function type at -O2 or above.
>
> Tested on powerpc-elf, OK for mainline, 11 and 10 branches?

OK though I wonder if you could get away with using
built_function_type (void_type_node, NULL_TREE); aka
a non-prototype void f().

Did you track down what changed the requirement?

Thanks,
Richard.

>
> 2021-10-01  Eric Botcazou  <ebotcazou@adacore.com>
>
>         * explow.c: Include langhooks.h.
>         (set_stack_check_libfunc): Build a proper function type.
>
> --
> Eric Botcazou

Re: [patch] Fix ICE with stack checking emulation at -O2

[Eric Botcazou]

> OK though I wonder if you could get away with using
> built_function_type (void_type_node, NULL_TREE); aka
> a non-prototype void f().

See below.

> Did you track down what changed the requirement?

The new function-abi.cc module, so I'd rather have a correct prototype.

-- 
Eric Botcazou

Re: [patch] Fix ICE with stack checking emulation at -O2

[Richard Biener]

On Fri, Oct 1, 2021 at 10:30 AM Eric Botcazou <botcazou@adacore.com> wrote:
>
> > OK though I wonder if you could get away with using
> > built_function_type (void_type_node, NULL_TREE); aka
> > a non-prototype void f().
>
> See below.
>
> > Did you track down what changed the requirement?
>
> The new function-abi.cc module, so I'd rather have a correct prototype.

I see, yes that makes sense.

Thanks,
Richard.

> --
> Eric Botcazou
>
>