re PR c/64417 ([SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors))

	PR c/64417
c/
	* c-typeck.c (process_init_element): Disallow initialization of
	a flexible array member with a string constant if the structure
	is in an array.
testsuite/
	* gcc.c-torture/compile/pr28865.c: Add dg-errors.
	* gcc.dg/pr64417.c: New test.

From-SVN: r219278

5 files changed, 62 insertions, 6 deletions

diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog
index d6b2289..357d2c4 100644
--- a/gcc/c/ChangeLog
+++ b/gcc/c/ChangeLog
@@ -1,3 +1,10 @@
+2015-01-07  Marek Polacek  <polacek@redhat.com>
+
+	PR c/64417
+	* c-typeck.c (process_init_element): Disallow initialization of
+	a flexible array member with a string constant if the structure
+	is in an array.
+
 2015-01-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR sanitizer/64344
diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c
index 0db43cc..38ba9b8 100644
--- a/gcc/c/c-typeck.c
+++ b/gcc/c/c-typeck.c
@@ -8809,6 +8809,33 @@ process_init_element (location_t loc, struct c_expr value, bool implicit,
 	      break;
 	    }
 
+	  /* Error for initialization of a flexible array member with
+	     a string constant if the structure is in an array.  E.g.:
+	     struct S { int x; char y[]; };
+	     struct S s[] = { { 1, "foo" } };
+	     is invalid.  */
+	  if (string_flag
+	      && fieldcode == ARRAY_TYPE
+	      && constructor_depth > 1
+	      && TYPE_SIZE (fieldtype) == NULL_TREE
+	      && DECL_CHAIN (constructor_fields) == NULL_TREE)
+	    {
+	      bool in_array_p = false;
+	      for (struct constructor_stack *p = constructor_stack;
+		   p && p->type; p = p->next)
+		if (TREE_CODE (p->type) == ARRAY_TYPE)
+		  {
+		    in_array_p = true;
+		    break;
+		  }
+	      if (in_array_p)
+		{
+		  error_init (loc, "initialization of flexible array "
+			      "member in a nested context");
+		  break;
+		}
+	    }
+
 	  /* Accept a string constant to initialize a subarray.  */
 	  if (value.value != 0
 	      && fieldcode == ARRAY_TYPE
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5e0d7d5..214cfd6 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-01-07  Marek Polacek  <polacek@redhat.com>
+
+	PR c/64417
+	* gcc.c-torture/compile/pr28865.c: Add dg-errors.
+	* gcc.dg/pr64417.c: New test.
+
 2015-01-06  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	PR target/64505
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr28865.c b/gcc/testsuite/gcc.c-torture/compile/pr28865.c
index aa6ae07..ef0eba54 100644
--- a/gcc/testsuite/gcc.c-torture/compile/pr28865.c
+++ b/gcc/testsuite/gcc.c-torture/compile/pr28865.c
@@ -5,12 +5,12 @@ struct var_len
 };
 
 /* Note - strictly speaking this array declaration is illegal
-   since each element has a variable length.  GCC allows it
-   (for the moment) because it is used in existing code, such
-   as glibc.  */
+   since each element has a variable length.  We used to allow
+   this because it was used in existing code.
+   Since PR64417 we reject this code.  */
 static const struct var_len var_array[] = 
 {
-  { 1, "Long exposure noise reduction" },
-  { 2, "Shutter/AE lock buttons" },
-  { 3, "Mirror lockup" }
+  { 1, "Long exposure noise reduction" }, /* { dg-error "initialization of flexible array member" } */
+  { 2, "Shutter/AE lock buttons" }, /* { dg-error "initialization of flexible array member" } */
+  { 3, "Mirror lockup" } /* { dg-error "initialization of flexible array member" } */
 };
diff --git a/gcc/testsuite/gcc.dg/pr64417.c b/gcc/testsuite/gcc.dg/pr64417.c
new file mode 100644
index 0000000..1e98b22
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr64417.c
@@ -0,0 +1,16 @@
+/* PR c/64417 */
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+struct foo { int x; char y[]; };
+struct bar { struct foo f; };
+struct baz { struct bar b; };
+
+struct foo a1 = { 1, "abc" };
+struct foo a2 = { 1, { "abc" } };
+struct foo b1[] = { { 1, "abc" } }; /* { dg-error "initialization of flexible array member" } */
+struct foo b2[] = { { 1, { "abc" } } }; /* { dg-error "initialization of flexible array member" } */
+struct bar c1[] = { { { 1, "abc" } } }; /* { dg-error "initialization of flexible array member" } */
+struct bar c2[] = { { { 1, { "abc" } } } }; /* { dg-error "initialization of flexible array member" } */
+struct baz d1[] = { { { { 1, "abc" } } } }; /* { dg-error "initialization of flexible array member" } */
+struct baz d2[] = { { { { 1, { "abc" } } } } }; /* { dg-error "initialization of flexible array member" } */