re PR c/58346 (ICE with SIGFPE at -O1 and above on x86_64-linux-gnu (affecting trunk...

	PR c/58346
c-family/
	* c-common.c (pointer_to_zero_sized_aggr_p): New function.
	* c-common.h: Declare it.
cp/
	* typeck.c (pointer_diff): Give an error on arithmetic on pointer to
	an empty aggregate.
c/
	* c-typeck.c (pointer_diff): Give an error on arithmetic on pointer to
	an empty aggregate.
testsuite/
	* c-c++-common/pr58346-1.c: New test.
	* c-c++-common/pr58346-2.c: New test.
	* c-c++-common/pr58346-3.c: New test.

From-SVN: r207004

diff --git a/gcc/c-family/ChangeLog b/gcc/c-family/ChangeLog
index 31985585b5964d5a67c0c0f9e383facc04f6d614..cba9f4e1484c63dde2192f9accf7e92e1b7f9b43 100644 (file)
--- a/gcc/c-family/ChangeLog
+++ b/gcc/c-family/ChangeLog
@@ -1,3 +1,9 @@
+2014-01-23  Marek Polacek  <polacek@redhat.com>
+
+       PR c/58346
+       * c-common.c (pointer_to_zero_sized_aggr_p): New function.
+       * c-common.h: Declare it.
+
 2014-01-20  Eric Botcazou  <ebotcazou@adacore.com>
 
        * c-ada-spec.h (dump_ada_specs): Revert prototype change.

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 35958ea41f07c8e373dd48759cf9866d99833d89..09128016ba46b85cc0b1443115c10a9bf0619451 100644 (file)
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -11823,4 +11823,15 @@ cxx_fundamental_alignment_p  (unsigned align)
                         TYPE_ALIGN (long_double_type_node)));
 }
 
+/* Return true if T is a pointer to a zero-sized aggregate.  */
+
+bool
+pointer_to_zero_sized_aggr_p (tree t)
+{
+  if (!POINTER_TYPE_P (t))
+    return false;
+  t = TREE_TYPE (t);
+  return (TYPE_SIZE (t) && integer_zerop (TYPE_SIZE (t)));
+}
+
 #include "gt-c-family-c-common.h"

diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 7e3ece6a691d2579011572b68955caf827d3097e..dab0b8cd82147c52bed08fec48befa750792176b 100644 (file)
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -789,6 +789,7 @@ extern bool keyword_is_storage_class_specifier (enum rid);
 extern bool keyword_is_type_qualifier (enum rid);
 extern bool keyword_is_decl_specifier (enum rid);
 extern bool cxx_fundamental_alignment_p (unsigned);
+extern bool pointer_to_zero_sized_aggr_p (tree);
 
 #define c_sizeof(LOC, T)  c_sizeof_or_alignof_type (LOC, T, true, false, 1)
 #define c_alignof(LOC, T) c_sizeof_or_alignof_type (LOC, T, false, false, 1)

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index 237ac1a959c3368b8b14a0c6a4d7a9ba6324a720..4088912db61662cb9faf1f20fab4067b971dcb27 100644 (file)
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,9 @@
+2014-01-23  Marek Polacek  <polacek@redhat.com>
+
+       PR c/58346
+       * c-typeck.c (pointer_diff): Give an error on arithmetic on pointer to
+       an empty aggregate.
+
 2014-01-23  Marek Polacek  <polacek@redhat.com>
 
        PR c/59871

diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
index 781d4df246ddc94745a1711d2b1b806d8b0a3c9e..77f3bddc469816cae6bb34db9c9be4adce315284 100644 (file)
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -3536,6 +3536,9 @@ pointer_diff (location_t loc, tree op0, tree op1)
   /* This generates an error if op0 is pointer to incomplete type.  */
   op1 = c_size_in_bytes (target_type);
 
+  if (pointer_to_zero_sized_aggr_p (TREE_TYPE (orig_op1)))
+    error_at (loc, "arithmetic on pointer to an empty aggregate");
+
   /* Divide by the size, in easiest possible way.  */
   result = fold_build2_loc (loc, EXACT_DIV_EXPR, inttype,
                            op0, convert (inttype, op1));

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 24282044fee1e2966bcf27ae7473c95e1fcecf8c..aee3fcf8a988128ebb681f53ed9f5a527d14b983 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2014-01-23  Marek Polacek  <polacek@redhat.com>
+
+       PR c/58346
+       * typeck.c (pointer_diff): Give an error on arithmetic on pointer to
+       an empty aggregate.
+
 2014-01-23  Jason Merrill  <jason@redhat.com>
 
        PR c++/55189

diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 84e287e56bc71fa6b8a4e5a1b183700afceaec38..9cd6a95a7f11cdc7f1201075e62f3f579334d20b 100644 (file)
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -5043,6 +5043,14 @@ pointer_diff (tree op0, tree op1, tree ptrtype, tsubst_flags_t complain)
        return error_mark_node;
     }
 
+  if (pointer_to_zero_sized_aggr_p (TREE_TYPE (op1)))
+    {
+      if (complain & tf_error)
+       error ("arithmetic on pointer to an empty aggregate");
+      else
+       return error_mark_node;
+    }
+
   op1 = (TYPE_PTROB_P (ptrtype)
         ? size_in_bytes (target_type)
         : integer_one_node);

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3857078b1db5684395ce00e3e4aea873cbcf42b1..f3d8d3a7caaeceb247a84a1365b3e1676d142136 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2014-01-23  Marek Polacek  <polacek@redhat.com>
+
+       PR c/58346
+       * c-c++-common/pr58346-1.c: New test.
+       * c-c++-common/pr58346-2.c: New test.
+       * c-c++-common/pr58346-3.c: New test.
+
 2014-01-23  Marek Polacek  <polacek@redhat.com>
 
        PR c/59871

diff --git a/gcc/testsuite/c-c++-common/pr58346-1.c b/gcc/testsuite/c-c++-common/pr58346-1.c
new file mode 100644 (file)
index 0000000..371fcf4
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr58346-1.c
@@ -0,0 +1,24 @@
+/* PR c/58346 */
+/* { dg-do compile } */
+
+struct U {
+#ifdef __cplusplus
+  char a[0];
+#endif
+};
+static struct U b[6];
+static struct U *u1, *u2;
+
+int
+foo (struct U *p, struct U *q)
+{
+  return q - p; /* { dg-error "arithmetic on pointer to an empty aggregate" } */
+}
+
+void
+bar (void)
+{
+  __PTRDIFF_TYPE__ d = u1 - u2; /* { dg-error "arithmetic on pointer to an empty aggregate" } */
+  __asm volatile ("" : "+g" (d));
+  foo (&b[0], &b[4]);
+}

diff --git a/gcc/testsuite/c-c++-common/pr58346-2.c b/gcc/testsuite/c-c++-common/pr58346-2.c
new file mode 100644 (file)
index 0000000..195060e
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr58346-2.c
@@ -0,0 +1,8 @@
+/* PR c/58346 */
+/* { dg-do compile } */
+
+__PTRDIFF_TYPE__
+foo (int p[3][0], int q[3][0])
+{
+  return p - q; /* { dg-error "arithmetic on pointer to an empty aggregate" } */
+}

diff --git a/gcc/testsuite/c-c++-common/pr58346-3.c b/gcc/testsuite/c-c++-common/pr58346-3.c
new file mode 100644 (file)
index 0000000..41627ed
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr58346-3.c
@@ -0,0 +1,16 @@
+/* PR c/58346 */
+/* { dg-do compile } */
+
+void
+foo (void)
+{
+  __PTRDIFF_TYPE__ d;
+  const int i = 0;
+  int a1[2][0], a2[2][0];
+  int b1[3][i], b2[4][i];
+  d = a1 - a2; /* { dg-error "arithmetic on pointer to an empty aggregate" } */
+  __asm volatile ("" : "+g" (d));
+  /* No error here for C.  */
+  d = b1 - b2; /* { dg-error "arithmetic on pointer to an empty aggregate" "" { target c++ } } */
+  __asm volatile ("" : "+g" (d));
+}