On Thu, May 13, 2021 at 9:15 AM Bernd Edlinger
<bernd.edlin...@hotmail.de> wrote:
>
> On 5/13/21 3:37 PM, H.J. Lu via Gcc-patches wrote:
> > Warn for excessive argument alignment in main instead of ICE.
> >
> > gcc/
> >
> > PR c/100575
> > * cfgexpand.c (expand_stack_alignment): Add a bool argument for
> > expanding main. Warn for excessive argument alignment in main.
> > (pass_expand::execute): Pass true to expand_stack_alignment when
> > expanding main.
> >
> > gcc/testsuite/
> >
> > PR c/100575
> > * c-c++-common/pr100575.c: New test.
> > ---
> > gcc/cfgexpand.c | 26 ++++++++++++++++++++------
> > gcc/testsuite/c-c++-common/pr100575.c | 11 +++++++++++
> > 2 files changed, 31 insertions(+), 6 deletions(-)
> > create mode 100644 gcc/testsuite/c-c++-common/pr100575.c
> >
> > diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
> > index e3814ee9d06..50ccb720e6c 100644
> > --- a/gcc/cfgexpand.c
> > +++ b/gcc/cfgexpand.c
> > @@ -6363,7 +6363,7 @@ discover_nonconstant_array_refs (void)
> > virtual_incoming_args_rtx with the virtual register. */
> >
> > static void
> > -expand_stack_alignment (void)
> > +expand_stack_alignment (bool expanding_main)
> > {
> > rtx drap_rtx;
> > unsigned int preferred_stack_boundary;
> > @@ -6385,9 +6385,18 @@ expand_stack_alignment (void)
> > if (targetm.calls.update_stack_boundary)
> > targetm.calls.update_stack_boundary ();
> >
> > - /* The incoming stack frame has to be aligned at least at
> > - parm_stack_boundary. */
> > - gcc_assert (crtl->parm_stack_boundary <= INCOMING_STACK_BOUNDARY);
> > + if (crtl->parm_stack_boundary > INCOMING_STACK_BOUNDARY)
> > + {
> > + /* The incoming stack frame has to be aligned at least at
> > + parm_stack_boundary. NB: The incoming stack frame alignment
> > + for main is fixed. */
> > + if (expanding_main)
> > + warning_at (DECL_SOURCE_LOCATION (current_function_decl),
> > + OPT_Wmain, "argument alignment of %q+D is too large",
> > + current_function_decl);
> > + else
> > + gcc_unreachable ();
> > + }
>
> Could you do this instead in ix86_minimum_incoming_stack_boundary
Fixed.
> /* The incoming stack frame has to be aligned at least at
> parm_stack_boundary. */
> if (incoming_stack_boundary < crtl->parm_stack_boundary)
> incoming_stack_boundary = crtl->parm_stack_boundary;
>
> /* Stack at entrance of main is aligned by runtime. We use the
> smallest incoming stack boundary. */
> if (incoming_stack_boundary > MAIN_STACK_BOUNDARY
> && DECL_NAME (current_function_decl)
> && MAIN_NAME_P (DECL_NAME (current_function_decl))
> && DECL_FILE_SCOPE_P (current_function_decl))
> incoming_stack_boundary = MAIN_STACK_BOUNDARY;
>
>
> maybe just repeat this after incoming_stack_boundary is set to
> MAIN_STACK_BOUNDARY:
>
> /* The incoming stack frame has to be aligned at least at
> parm_stack_boundary. */
> if (incoming_stack_boundary < crtl->parm_stack_boundary)
> incoming_stack_boundary = crtl->parm_stack_boundary;
>
> and print the warning here?
>
Here is the v2 patch to issue a warning in
ix86_minimum_incoming_stack_boundary.
OK for master?
Thanks.
--
H.J.
From c28fb9d5c6f6d68ac137e461aada23f8e10352bb Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Thu, 13 May 2021 06:31:04 -0700
Subject: [PATCH v2] x86: Warn for excessive argument alignment in main
Warn for excessive argument alignment in main instead of ICE.
gcc/
PR c/100575
* config/i386/i386.c (ix86_minimum_incoming_stack_boundary):
Warn for excessive argument alignment in main.
gcc/testsuite/
PR c/100575
* gcc.target/i386/pr100575.c: New test.
---
gcc/config/i386/i386.c | 12 +++++++++++-
gcc/testsuite/gcc.target/i386/pr100575.c | 11 +++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr100575.c
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index befe69e5eeb..85283d23bd3 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -7272,7 +7272,17 @@ ix86_minimum_incoming_stack_boundary (bool sibcall)
&& DECL_NAME (current_function_decl)
&& MAIN_NAME_P (DECL_NAME (current_function_decl))
&& DECL_FILE_SCOPE_P (current_function_decl))
- incoming_stack_boundary = MAIN_STACK_BOUNDARY;
+ {
+ incoming_stack_boundary = MAIN_STACK_BOUNDARY;
+ if (crtl->parm_stack_boundary > incoming_stack_boundary)
+ {
+ warning_at (DECL_SOURCE_LOCATION (current_function_decl),
+ OPT_Wmain,
+ "argument alignment of %q+D is too large",
+ current_function_decl);
+ incoming_stack_boundary = crtl->parm_stack_boundary;
+ }
+ }
return incoming_stack_boundary;
}
diff --git a/gcc/testsuite/gcc.target/i386/pr100575.c b/gcc/testsuite/gcc.target/i386/pr100575.c
new file mode 100644
index 00000000000..e7366a8fe7f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr100575.c
@@ -0,0 +1,11 @@
+/* { dg-do run } */
+/* { dg-options "-Wall -Wno-psabi" } */
+
+int
+main (int __attribute__((vector_size(1 << 29))) argc,
+ char **argv)
+/* { dg-warning "first argument of" "" { target *-*-* } .-2 } */
+/* { dg-warning "argument alignment of" "" { target *-*-* } .-3 } */
+{
+ return 0;
+}
--
2.31.1
