testsuite: Add compat.exp testcase for most common zero width bitfld ABI passing [PR102024]

On Tue, Mar 22, 2022 at 05:51:58PM +0100, Jakub Jelinek via Gcc wrote:
> I guess it would be nice to include the testcases we are talking about,
> like { float x; int : 0; float y; } and { float x; int : 0; } and
> { int : 0; float x; } into compat.exp testsuite so that we see ABI
> differences in compat testing.

Here is a patch that does that.  It uses the struct-layout-1* framework,
but isn't generated because we don't want in this case pseudo-random
structure layouts, but particular ones we know cause or could cause problems
on some targets.  If other problematic cases are discovered, we can add
further ones.

Tested on x86_64-linux with:
make check-gcc check-g++ RUNTESTFLAGS='ALT_CC_UNDER_TEST=gcc ALT_CXX_UNDER_TEST=g++ compat.exp=pr102*'
and with
make check-gcc check-g++ RUNTESTFLAGS='compat.exp=pr102*'
The former as expected has:
FAIL: gcc.dg/compat/pr102024 c_compat_x_tst.o-c_compat_y_alt.o execute
FAIL: gcc.dg/compat/pr102024 c_compat_x_alt.o-c_compat_y_tst.o execute
fails because on x86_64 we've changed the C ABI but kept the C++ ABI here.
E.g. on rs6000 it should be the g++.dg such tests to fail (all assuming
the alt gcc/g++ is GCC 4.5 through 11).

2022-03-24  Jakub Jelinek  <jakub@redhat.com>

	PR target/102024
	* gcc.dg/compat/pr102024_main.c: New test.
	* gcc.dg/compat/pr102024_test.h: New test.
	* gcc.dg/compat/pr102024_x.c: New test.
	* gcc.dg/compat/pr102024_y.c: New test.
	* g++.dg/compat/pr102024_main.C: New test.
	* g++.dg/compat/pr102024_test.h: New test.
	* g++.dg/compat/pr102024_x.C: New test.
	* g++.dg/compat/pr102024_y.C: New test.

gcc/testsuite/g++.dg/compat/pr102024_main.C

@@ -0,0 +1,26 @@
+/* { dg-require-effective-target int32plus } */
+/* { dg-options "-Wno-abi" } */
+/* { dg-options "-mno-mmx -Wno-abi" { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-fno-common" { target hppa*-*-hpux* powerpc*-*-darwin* } } */
+/* { dg-options "-mno-mmx -fno-common -Wno-abi" { target i?86-*-darwin* x86_64-*-darwin* } } */
+/* { dg-options "-mno-base-addresses" { target mmix-*-* } } */
+/* { dg-options "-mlongcalls -mtext-section-literals" { target xtensa*-*-* } } */
+
+#include "struct-layout-1.h"
+
+#define TX(n, type, attrs, fields, ops) extern void test##n (void);
+#include "pr102024_test.h"
+#undef TX
+
+int main (void)
+{
+#define TX(n, type, attrs, fields, ops)   test##n ();
+#include "pr102024_test.h"
+#undef TX
+  if (fails)
+    {
+      fflush (stdout);
+      abort ();
+    }
+  exit (0);
+}

gcc/testsuite/g++.dg/compat/pr102024_test.h

@@ -0,0 +1,6 @@
+T(0,float a;int:0;float b;,F(0,a,42.0f,43.125f)F(0,b,-17.5f,35.75f))
+T(1,float a;int:0;,F(1,a,1.0f,17.125f))
+T(2,int:0;float a;,F(2,a,2.25f,16.5f))
+T(3,double a;long long:0;double b;,F(3,a,42.0,43.125)F(3,b,-17.5,35.75))
+T(4,double a;long long:0;,F(4,a,1.0,17.125))
+T(5,long long:0;double a;,F(5,a,2.25,16.5))

gcc/testsuite/g++.dg/compat/pr102024_x.C

@@ -0,0 +1,11 @@
+/* { dg-options "-w -Wno-abi" } */
+/* { dg-options "-w -mno-mmx -Wno-abi" { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-w -fno-common" { target hppa*-*-hpux* powerpc*-*-darwin* } } */
+/* { dg-options "-w -mno-mmx -fno-common -Wno-abi" { target i?86-*-darwin* x86_64-*-darwin* } } */
+/* { dg-options "-w -mno-base-addresses" { target mmix-*-* } } */
+/* { dg-options "-w -mlongcalls -mtext-section-literals" { target xtensa*-*-* } } */
+
+#include "struct-layout-1_x1.h"
+#include "pr102024_test.h"
+#include "struct-layout-1_x2.h"
+#include "pr102024_test.h"

gcc/testsuite/g++.dg/compat/pr102024_y.C

@@ -0,0 +1,11 @@
+/* { dg-options "-w -Wno-abi" } */
+/* { dg-options "-w -mno-mmx -Wno-abi" { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-w -fno-common" { target hppa*-*-hpux* powerpc*-*-darwin* } } */
+/* { dg-options "-w -mno-mmx -fno-common -Wno-abi" { target i?86-*-darwin* x86_64-*-darwin* } } */
+/* { dg-options "-w -mno-base-addresses" { target mmix-*-* } } */
+/* { dg-options "-w -mlongcalls -mtext-section-literals" { target xtensa*-*-* } } */
+
+#include "struct-layout-1_y1.h"
+#include "pr102024_test.h"
+#include "struct-layout-1_y2.h"
+#include "pr102024_test.h"

gcc/testsuite/gcc.dg/compat/pr102024_main.c

@@ -0,0 +1,22 @@
+/* { dg-require-effective-target int32plus } */
+/* { dg-options "-Wno-abi" } */
+/* { dg-options "-mno-mmx -Wno-abi" { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-fno-common" { target hppa*-*-hpux* powerpc*-*-darwin* } } */
+/* { dg-options "-mno-mmx -fno-common -Wno-abi" { target i?86-*-darwin* x86_64-*-darwin* } } */
+/* { dg-options "-mno-base-addresses" { target mmix-*-* } } */
+/* { dg-options "-mlongcalls -mtext-section-literals" { target xtensa*-*-* } } */
+/* { dg-prune-output ".*-Wno-abi.*" } */
+/* { dg-prune-output ".*Offset of packed bit-field.*" } */
+#include "struct-layout-1.h"
+
+#define TX(n, type, attrs, fields, ops) extern void test##n (void);
+#include "pr102024_test.h"
+#undef TX
+
+int main (void)
+{
+#define TX(n, type, attrs, fields, ops)   test##n ();
+#include "pr102024_test.h"
+#undef TX
+  exit (fails != 0);
+}

gcc/testsuite/gcc.dg/compat/pr102024_test.h

@@ -0,0 +1,6 @@
+T(0,float a;int:0;float b;,F(0,a,42.0f,43.125f)F(0,b,-17.5f,35.75f))
+T(1,float a;int:0;,F(1,a,1.0f,17.125f))
+T(2,int:0;float a;,F(2,a,2.25f,16.5f))
+T(3,double a;long long:0;double b;,F(3,a,42.0,43.125)F(3,b,-17.5,35.75))
+T(4,double a;long long:0;,F(4,a,1.0,17.125))
+T(5,long long:0;double a;,F(5,a,2.25,16.5))

gcc/testsuite/gcc.dg/compat/pr102024_x.c

@@ -0,0 +1,10 @@
+/* { dg-options "-w -Wno-abi" } */
+/* { dg-options "-w -mno-mmx -Wno-abi" { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-w -fno-common" { target hppa*-*-hpux* powerpc*-*-darwin* } } */
+/* { dg-options "-w -mno-mmx -fno-common -Wno-abi" { target i?86-*-darwin* x86_64-*-darwin* } } */
+/* { dg-options "-w -mno-base-addresses" { target mmix-*-* } } */
+/* { dg-options "-w -mlongcalls -mtext-section-literals" { target xtensa*-*-* } } */
+#include "struct-layout-1_x1.h"
+#include "pr102024_test.h"
+#include "struct-layout-1_x2.h"
+#include "pr102024_test.h"

gcc/testsuite/gcc.dg/compat/pr102024_y.c

@@ -0,0 +1,10 @@
+/* { dg-options "-w -Wno-abi" } */
+/* { dg-options "-w -mno-mmx -Wno-abi" { target i?86-*-* x86_64-*-* } } */
+/* { dg-options "-w -fno-common" { target hppa*-*-hpux* powerpc*-*-darwin* } } */
+/* { dg-options "-w -mno-mmx -fno-common -Wno-abi" { target i?86-*-darwin* x86_64-*-darwin* } } */
+/* { dg-options "-w -mno-base-addresses" { target mmix-*-* } } */
+/* { dg-options "-w -mlongcalls -mtext-section-literals" { target xtensa*-*-* } } */
+#include "struct-layout-1_y1.h"
+#include "pr102024_test.h"
+#include "struct-layout-1_y2.h"
+#include "pr102024_test.h"