Re: [PATCH] Fix up -fsanitize=undefined (PR sanitizer/69278)

[Richard Biener]

On November 23, 2016 8:33:54 PM GMT+01:00, Jakub Jelinek  
wrote:
>Hi!
>
>As mentioned in the PR, the r240491 change broke -fsanitize=undefined,
>which no longer enables -fsanitize=unreachable or -fsanitize=return.
>That is undesirable change, we only want not to enable
>-fsanitize-recover=unreachable,return on -fsanitize-recover=undefined.
>
>Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok
>for
>trunk?

OK.

Richard.

>2016-11-23  Jakub Jelinek  
>
>   PR sanitizer/69278
>   * opts.c (parse_sanitizer_options): For -fsanitize=undefined,
>   restore enabling also SANITIZE_UNREACHABLE and SANITIZE_RETURN.
>
>   * g++.dg/ubsan/return-7.C: New test.
>   * c-c++-common/ubsan/unreachable-4.c: New test.
>
>--- gcc/opts.c.jj  2016-11-23 16:47:34.0 +0100
>+++ gcc/opts.c 2016-11-23 18:25:05.400325912 +0100
>@@ -1558,7 +1558,8 @@ parse_sanitizer_options (const char *p,
>   /* Do not enable -fsanitize-recover=unreachable and
>  -fsanitize-recover=return if -fsanitize-recover=undefined
>  is selected.  */
>-  if (sanitizer_opts[i].flag == SANITIZE_UNDEFINED)
>+  if (code == OPT_fsanitize_recover_
>+  && sanitizer_opts[i].flag == SANITIZE_UNDEFINED)
> flags |= (SANITIZE_UNDEFINED
>   & ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN));
>   else
>--- gcc/testsuite/g++.dg/ubsan/return-7.C.jj   2016-11-23
>18:27:16.525687072 +0100
>+++ gcc/testsuite/g++.dg/ubsan/return-7.C  2016-11-23 18:27:21.854620469
>+0100
>@@ -0,0 +1,27 @@
>+// { dg-do run }
>+// { dg-options "-fsanitize=undefined" }
>+// { dg-shouldfail "ubsan" }
>+
>+struct S { S (); ~S (); };
>+
>+S::S () {}
>+S::~S () {}
>+
>+int
>+foo (int x)
>+{
>+  S a;
>+  {
>+S b;
>+if (x)
>+  return 1;
>+  }
>+}
>+
>+int
>+main ()
>+{
>+  foo (0);
>+}
>+
>+// { dg-output "execution reached the end of a value-returning
>function without returning a value" }
>--- gcc/testsuite/c-c++-common/ubsan/unreachable-4.c.jj2016-11-23
>18:25:57.692672348 +0100
>+++ gcc/testsuite/c-c++-common/ubsan/unreachable-4.c   2016-11-23
>18:26:05.961569001 +0100
>@@ -0,0 +1,10 @@
>+/* { dg-do run } */
>+/* { dg-options "-fsanitize=undefined" } */
>+/* { dg-shouldfail "ubsan" } */
>+
>+int
>+main (void)
>+{
>+  __builtin_unreachable ();
>+}
>+ /* { dg-output "execution reached a __builtin_unreachable\\(\\) call"
>} */
>
>   Jakub

[PATCH] Fix up -fsanitize=undefined (PR sanitizer/69278)

[Jakub Jelinek]

Hi!

As mentioned in the PR, the r240491 change broke -fsanitize=undefined,
which no longer enables -fsanitize=unreachable or -fsanitize=return.
That is undesirable change, we only want not to enable
-fsanitize-recover=unreachable,return on -fsanitize-recover=undefined.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?

2016-11-23  Jakub Jelinek  

PR sanitizer/69278
* opts.c (parse_sanitizer_options): For -fsanitize=undefined,
restore enabling also SANITIZE_UNREACHABLE and SANITIZE_RETURN.

* g++.dg/ubsan/return-7.C: New test.
* c-c++-common/ubsan/unreachable-4.c: New test.

--- gcc/opts.c.jj   2016-11-23 16:47:34.0 +0100
+++ gcc/opts.c  2016-11-23 18:25:05.400325912 +0100
@@ -1558,7 +1558,8 @@ parse_sanitizer_options (const char *p,
/* Do not enable -fsanitize-recover=unreachable and
   -fsanitize-recover=return if -fsanitize-recover=undefined
   is selected.  */
-   if (sanitizer_opts[i].flag == SANITIZE_UNDEFINED)
+   if (code == OPT_fsanitize_recover_
+   && sanitizer_opts[i].flag == SANITIZE_UNDEFINED)
  flags |= (SANITIZE_UNDEFINED
& ~(SANITIZE_UNREACHABLE | SANITIZE_RETURN));
else
--- gcc/testsuite/g++.dg/ubsan/return-7.C.jj2016-11-23 18:27:16.525687072 
+0100
+++ gcc/testsuite/g++.dg/ubsan/return-7.C   2016-11-23 18:27:21.854620469 
+0100
@@ -0,0 +1,27 @@
+// { dg-do run }
+// { dg-options "-fsanitize=undefined" }
+// { dg-shouldfail "ubsan" }
+
+struct S { S (); ~S (); };
+
+S::S () {}
+S::~S () {}
+
+int
+foo (int x)
+{
+  S a;
+  {
+S b;
+if (x)
+  return 1;
+  }
+}
+
+int
+main ()
+{
+  foo (0);
+}
+
+// { dg-output "execution reached the end of a value-returning function 
without returning a value" }
--- gcc/testsuite/c-c++-common/ubsan/unreachable-4.c.jj 2016-11-23 
18:25:57.692672348 +0100
+++ gcc/testsuite/c-c++-common/ubsan/unreachable-4.c2016-11-23 
18:26:05.961569001 +0100
@@ -0,0 +1,10 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=undefined" } */
+/* { dg-shouldfail "ubsan" } */
+
+int
+main (void)
+{
+  __builtin_unreachable ();
+}
+ /* { dg-output "execution reached a __builtin_unreachable\\(\\) call" } */

Jakub