Implement semantic analysis for the GNU flexible array initialization

extension. The interaction with designated initializers is a
bit... interesting... but we follow GNU's lead and don't permit too
much crazy code in this area.

Also, make the "excess initializers" error message a bit more
informative.

Addresses PR2561: http://llvm.org/bugs/show_bug.cgi?id=2561


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63785 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 38 insertions, 0 deletions

diff --git a/test/Sema/flexible-array-init.c b/test/Sema/flexible-array-init.c
new file mode 100644
index 0000000000..9ef6eb3bc0
--- /dev/null
+++ b/test/Sema/flexible-array-init.c
@@ -0,0 +1,38 @@
+// RUN: clang -fsyntax-only -verify %s
+struct one {
+  int a;
+  int values[];
+} x = {5, {1, 2, 3}};
+
+struct one x2 = { 5, 1, 2, 3 }; // expected-error{{excess elements in struct initializer}}
+
+void test() {
+  struct one x3 = {5, {1, 2, 3}};
+}
+
+struct foo { 
+  int x; 
+  int y[]; // expected-note{{initialized flexible array member 'y' is here}}
+}; 
+struct bar { struct foo z; };
+     
+struct foo a = { 1, { 2, 3, 4 } };        // Valid.
+struct bar b = { { 1, { 2, 3, 4 } } };    // expected-error{{non-empty initialization of flexible array member inside subobject}}
+struct bar c = { { 1, { } } };            // Valid.
+struct foo d[1] = { { 1, { 2, 3, 4 } } };  // expected-error{{'struct foo' may not be used as an array element due to flexible array member}}
+
+struct foo desig_foo = { .y = {2, 3, 4} };
+struct bar desig_bar = { .z.y = { } };
+struct bar desig_bar2 = { .z.y = { 2, 3, 4} }; // expected-error{{non-empty initialization of flexible array member inside subobject}}
+struct foo design_foo2 = { .y = 2 }; // expected-error{{flexible array requires brace-enclosed initializer}}
+
+struct point {
+  int x, y;
+};
+
+struct polygon {
+  int numpoints;
+  struct point points[]; // expected-note{{initialized flexible array member 'points' is here}}
+};
+struct polygon poly = { 
+  .points[2] = { 1, 2} }; // expected-error{{designator into flexible array member subobject}}