* c-typeck.c (comptypes): Handle zero-length arrays properly.

From-SVN: r45641

1 files changed, 42 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/array-5.c b/gcc/testsuite/gcc.dg/array-5.c
new file mode 100644
index 0000000..f5321e4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/array-5.c
@@ -0,0 +1,42 @@
+/* { dg-do compile } */
+/* { dg-options "" } */
+
+/* Check compatibility of array declarations.  */
+
+/* Incomplete decl matches.  */
+extern char arr0[];
+char arr0[1];
+
+/* Two integral expressions must be the same.  Note that 0 is
+   a gcc extension, but it should work like any other constant.  */
+extern char arr1[1];
+char arr1[1];
+extern char arr2[0];
+char arr2[0];
+extern char arr3[0];            /* { dg-error "previous declaration" } */
+char arr3[1];                   /* { dg-error "conflicting types" } */
+
+/* Variable size matches.  */
+void func(int n, int m)
+{
+  /* The next two are from the example in c99 6.7.5.2/9.  */
+  {
+    /* Invalid: not compatible because 4 != 6.  */
+    int a[n][6][m];
+    int (*p)[4][n+1];
+    p = a;			/* { dg-error "incompatible" } */
+  }
+  {
+    /* Compatible, but defined behavior only if n == 6 and m == n+1.  */
+    int c[n][n][6][m];
+    int (*r)[n][n][n+1];
+    r = c;
+  }
+  {
+    /* Compatible, but undefined behavior; (2, 2) is not a constant
+       expression, and thus A is a VLA.  */
+    int a[(2, 2)];
+    int (*p)[3];
+    p = a; /* { dg-bogus "incompatible" "bad vla handling" { xfail *-*-* } } */
+  }
+}