Re: [PING] [test case, patch] ICE in Cilk Plus structured block checker

[Thomas Schwinge]

Hi!

On Tue, 11 Feb 2014 13:43:46 +0100, I wrote:
> Ping again for test case and rather trivial patch to cure a GCC trunk ICE
> in the Cilk Plus structured block checker if both -fcilkplus and -fopenmp
> are specified.

Jakub asked me to »please repost just the (hopefully small) trunk patch
alone«, so here we go:

Consider the following code:

    void baz()
    {
      bad1:
      #pragma omp parallel
        goto bad1;
    }

Then, if both -fcilkplus and -fopenmp are specified, that will run into a
SIGSEGV/ICE because of label_ctx == NULL in omp-low.c:diagnose_sb_0.

The testcase is basically a concatenation of gcc.dg/cilk-plus/jump.c and
gcc.dg/gomp/block-1.c -- should this be done differently/better?

Fix potential ICE (null pointer dereference) in omp-low.c:diagnose_sb_0.

        gcc/
        * omp-low.c (diagnose_sb_0): Make sure label_ctx is valid to
        dereference.
        gcc/testsuite/
        * gcc.dg/cilk-plus/jump-openmp.c: New file.

diff --git gcc/omp-low.c gcc/omp-low.c
index e0f7d1d..91221c0 100644
--- gcc/omp-low.c
+++ gcc/omp-low.c
@@ -10865,7 +10865,8 @@ diagnose_sb_0 (gimple_stmt_iterator *gsi_p,
       if ((branch_ctx
           && gimple_code (branch_ctx) == GIMPLE_OMP_FOR
           && gimple_omp_for_kind (branch_ctx) == GF_OMP_FOR_KIND_CILKSIMD)
-         || (gimple_code (label_ctx) == GIMPLE_OMP_FOR
+         || (label_ctx
+             && gimple_code (label_ctx) == GIMPLE_OMP_FOR
              && gimple_omp_for_kind (label_ctx) == GF_OMP_FOR_KIND_CILKSIMD))
        cilkplus_block = true;
     }
diff --git gcc/testsuite/gcc.dg/cilk-plus/jump-openmp.c 
gcc/testsuite/gcc.dg/cilk-plus/jump-openmp.c
new file mode 100644
index 0000000..95e6b2d
--- /dev/null
+++ gcc/testsuite/gcc.dg/cilk-plus/jump-openmp.c
@@ -0,0 +1,49 @@
+/* { dg-do compile } */
+/* { dg-options "-fcilkplus -fopenmp" } */
+/* { dg-require-effective-target fopenmp } */
+
+int *a, *b, c;
+
+void foo()
+{
+#pragma simd
+  for (int i=0; i < 1000; ++i)
+    {
+      a[i] = b[i];
+      if (c == 5)
+       return; /* { dg-error "invalid branch to/from a Cilk Plus structured 
block" } */
+    }
+}
+
+void bar()
+{
+#pragma simd
+  for (int i=0; i < 1000; ++i)
+    {
+    lab:
+      a[i] = b[i];
+    }
+  if (c == 6)
+    goto lab; /* { dg-error "invalid entry to Cilk Plus structured block" } */
+}
+
+void baz()
+{
+  bad1:
+  #pragma omp parallel
+    goto bad1; /* { dg-error "invalid branch to/from an OpenMP structured 
block" } */
+
+  goto bad2; /* { dg-error "invalid entry to OpenMP structured block" } */
+  #pragma omp parallel
+    {
+      bad2: ;
+    }
+
+  #pragma omp parallel
+    {
+      int i;
+      goto ok1;
+      for (i = 0; i < 10; ++i)
+       { ok1: break; }
+    }
+}


Grüße,
 Thomas

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