Bug#846214: gcc-6: wrong code generation in protobuf-c testsuite, adding printf works around

[Thorsten Glaser <t.glaser@tarent.de>]

tags 846214 - moreinfo
thanks

On Thu, 1 Dec 2016, Matthias Klose wrote:

>  - please could you reduce the test case to just run the failing test?

I’ll try…

>  - please add the preprocessed source

Attached from the following command:

gcc -DHAVE_CONFIG_H -I.  -include ./config.h -I./protobuf-c -I. -I. -Wdate-time -D_FORTIFY_SOURCE=2   -g -O2 -fdebug-prefix-map=/tmp/buildd/protobuf-c-1.2.1=. -specs=/usr/share/dpkg/pie-compile.specs -fstack-protector-strong -Wformat -Werror=format-security -E -o /tmp/x1.i t/generated-code2/test-generated-code2.c

The diff to the working version boils down to:

(pbuild15677)root@tglase:/tmp/buildd/protobuf-c-1.2.1 # diff -u /tmp/x?.i
--- /tmp/x1.i   2016-12-01 21:21:12.804468216 +0000
+++ /tmp/x2.i   2016-12-01 21:21:46.620862123 +0000
@@ -6429,7 +6429,7 @@
   if (memcmp (a.data, b.data, a.len) == 0) {
     return 1;
   } else {
-    printf("E: memcmp unequal\n");
+    printf("E: memcmp len=%zd unequal\n", a.len);
     return 0;
   }
 }

So, nothing changed in the preprocessed output.

>  - does this work with GCC 7?

I fail to see how this is relevant for a bugreport against GCC 6,
but… as it’s in experimental, I can try (7-20161125-1, as today’s
upload is still not built).

Compile commands are:

gcc-7 -DHAVE_CONFIG_H -I.  -include ./config.h -I./protobuf-c -I. -I. -Wdate-time -D_FORTIFY_SOURCE=2   -g -O2 -fdebug-prefix-map=/tmp/buildd/protobuf-c-1.2.1=. -specs=/usr/share/dpkg/pie-compile.specs -fstack-protector-strong -Wformat -Werror=format-security -c -o t/generated-code2/test-generated-code2.o t/generated-code2/test-generated-code2.c
gcc-7 -g -O2 -fdebug-prefix-map=/tmp/buildd/protobuf-c-1.2.1=. -specs=/usr/share/dpkg/pie-compile.specs -fstack-protector-strong -Wformat -Werror=format-security -specs=/usr/share/dpkg/pie-link.specs -Wl,-z -Wl,relro -o t/generated-code2/.libs/test-generated-code2 t/generated-code2/test-generated-code2.o t/test-full.pb-c.o t/test-optimized.pb-c.o  protobuf-c/.libs/libprotobuf-c.so

Yes, this fails just the same.

bye,
//mirabilos
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