[PATCH] Fix Cilk+ #pragma cilk grainsize preprocessing (PR c++/69826)

[Jakub Jelinek]

Hi!

The following testcase works unless -save-temps or ccache is used
(or manually performing -E and compilation separately).  The problem
is that #pragma cilk grainsize is supposed to have macro expansion
(except for the grainsize keyword), but we weren't enabling that for -E.

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

2016-02-17  Jakub Jelinek  <ja...@redhat.com>

        PR c++/69826
        * c-pragma.c (c_pp_lookup_pragma): Handle PRAGMA_CILK_GRAINSIZE.
        (init_pragma): Register PRAGMA_CILK_GRAINSIZE even for
        flag_preprocess_only.

        * c-c++-common/cilk-plus/CK/pr69826-1.c: New test.
        * c-c++-common/cilk-plus/CK/pr69826-2.c: New test.

--- gcc/c-family/c-pragma.c.jj  2016-02-01 23:35:05.000000000 +0100
+++ gcc/c-family/c-pragma.c     2016-02-17 14:48:37.489399494 +0100
@@ -1336,6 +1336,13 @@ c_pp_lookup_pragma (unsigned int id, con
       return;
     }
 
+  if (id == PRAGMA_CILK_GRAINSIZE)
+    {
+      *space = "cilk";
+      *name = "grainsize";
+      return;
+    }
+
   if (id >= PRAGMA_FIRST_EXTERNAL
       && (id < PRAGMA_FIRST_EXTERNAL + registered_pp_pragmas.length ()))
     {
@@ -1523,7 +1530,7 @@ init_pragma (void)
     cpp_register_deferred_pragma (parse_in, "GCC", "ivdep", PRAGMA_IVDEP, 
false,
                                  false);
 
-  if (flag_cilkplus && !flag_preprocess_only)
+  if (flag_cilkplus)
     cpp_register_deferred_pragma (parse_in, "cilk", "grainsize",
                                  PRAGMA_CILK_GRAINSIZE, true, false);
 
--- gcc/testsuite/c-c++-common/cilk-plus/CK/pr69826-1.c.jj      2016-02-17 
15:09:10.685152534 +0100
+++ gcc/testsuite/c-c++-common/cilk-plus/CK/pr69826-1.c 2016-02-17 
15:11:39.518070410 +0100
@@ -0,0 +1,25 @@
+/* { dg-do run { target { i?86-*-* x86_64-*-* } } } */
+/* { dg-options "-fcilkplus" } */
+/* { dg-additional-options "-std=gnu99" { target c } } */
+/* { dg-additional-options "-lcilkrts" { target { i?86-*-* x86_64-*-* } } } */
+
+#define GRAINSIZE 2
+
+int
+main ()
+{
+  int a[64];
+  #pragma cilk grainsize=GRAINSIZE
+  _Cilk_for (int i = 0; i < 64; i++)
+    a[i] = 0;
+  #pragma cilk grainsize =GRAINSIZE
+  _Cilk_for (int i = 0; i < 64; i++)
+    a[i]++;
+  #pragma cilk grainsize = GRAINSIZE
+  _Cilk_for (int i = 0; i < 64; i++)
+    a[i]++;
+  for (int i = 0; i < 64; i++)
+    if (a[i] != 2)
+      __builtin_abort ();
+  return 0;
+}
--- gcc/testsuite/c-c++-common/cilk-plus/CK/pr69826-2.c.jj      2016-02-17 
15:11:57.073824810 +0100
+++ gcc/testsuite/c-c++-common/cilk-plus/CK/pr69826-2.c 2016-02-17 
15:12:12.409610268 +0100
@@ -0,0 +1,6 @@
+/* { dg-do run { target { i?86-*-* x86_64-*-* } } } */
+/* { dg-options "-fcilkplus -save-temps" } */
+/* { dg-additional-options "-std=gnu99" { target c } } */
+/* { dg-additional-options "-lcilkrts" { target { i?86-*-* x86_64-*-* } } } */
+
+#include "pr69826-1.c"

        Jakub