PATCH: Fix SSP on amd64 for ports gcc 4.9

"As Shmuel reported in
<https://gcc.gnu.org/ml/gcc-help/2017-03/msg00009.html>,
on x86-64 small structures in automatic storage are aligned to 16 bytes.
This seems to be because of a mix-up between bits and bytes in the i386
target code.

* config/i386/i386.c (ix86_local_alignment): Align most aggregates
of 16 bytes and more to 16 bytes, not those of 16 bits and more."

https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=b44e9be23d38be8997ae64d7509ac22cb4c556d6

It might be worth fixing this in ports gcc 4.9, found by tedu@ in 2014
and committed by martynas@ to base gcc4 shortly later.

http://www.tedunangst.com/flak/post/my-stack-protector-wasnt-working
http://marc.info/?l=openbsd-cvs&m=139895377300712&w=2
http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/gnu/gcc/gcc/config/i386/i386.c.diff?r1=1.3&r2=1.4&f=h

-Bryan.

Index: Makefile
===================================================================
RCS file: /cvs/ports/lang/gcc/4.9/Makefile,v
retrieving revision 1.47
diff -u -p -u -r1.47 Makefile
--- Makefile 4 Mar 2017 21:59:55 -0000 1.47
+++ Makefile 4 Jun 2017 08:36:12 -0000
@@ -4,7 +4,7 @@ ONLY_FOR_ARCHS = amd64 arm hppa i386 mip
DPB_PROPERTIES = parallel

V = 4.9.4
-REVISION = 4
+REVISION = 5
FULL_VERSION = $V
FULL_PKGVERSION = $V

Index: patches/patch-gcc_config_i386_i386_c
===================================================================
RCS file: /cvs/ports/lang/gcc/4.9/patches/patch-gcc_config_i386_i386_c,v
retrieving revision 1.4
diff -u -p -u -r1.4 patch-gcc_config_i386_i386_c
--- patches/patch-gcc_config_i386_i386_c 1 Sep 2016 17:30:33 -0000 1.4
+++ patches/patch-gcc_config_i386_i386_c 4 Jun 2017 08:36:12 -0000
@@ -1,6 +1,6 @@
$OpenBSD: patch-gcc_config_i386_i386_c,v 1.4 2016/09/01 17:30:33 pascal Exp $
---- gcc/config/i386/i386.c.orig Mon Aug 1 18:03:41 2016
-+++ gcc/config/i386/i386.c Sat Aug 6 19:19:04 2016
+--- gcc/config/i386/i386.c.orig Mon Aug 1 12:03:41 2016
++++ gcc/config/i386/i386.c Sun Jun 4 04:30:01 2017
@@ -2307,6 +2307,8 @@ struct ix86_frame
HOST_WIDE_INT reg_save_offset;
HOST_WIDE_INT sse_reg_save_offset;
@@ -18,13 +18,22 @@ $OpenBSD: patch-gcc_config_i386_i386_c,v
frame->nregs = ix86_nsaved_regs ();
frame->nsseregs = ix86_nsaved_sseregs ();

-@@ -10903,6 +10906,9 @@ ix86_expand_prologue (void)
- m->fs.sp_offset = INCOMING_FRAME_SP_OFFSET;
+@@ -10904,6 +10907,9 @@ ix86_expand_prologue (void)
m->fs.realigned = true;
}
-+
+
+ if (warn_stack_larger_than && frame.local_size > stack_larger_than_size)
+ warning (OPT_Wstack_larger_than_, "stack usage is %ld bytes", frame.local_size);
-
++
int_registers_saved = (frame.nregs == 0);
sse_registers_saved = (frame.nsseregs == 0);
+
+@@ -26860,7 +26866,7 @@ ix86_local_alignment (tree exp, enum machine_mode mode
+ != TYPE_MAIN_VARIANT (va_list_type_node)))
+ && TYPE_SIZE (type)
+ && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
+- && (TREE_INT_CST_LOW (TYPE_SIZE (type)) >= 16
++ && (TREE_INT_CST_LOW (TYPE_SIZE (type)) >= 128
+ || TREE_INT_CST_HIGH (TYPE_SIZE (type))) && align < 128)
+ return 128;
+ }