Rework the ConstStructBuilder code to emit missing initializer

elements with explicit zero values instead of with tail padding.
On an example like this:

struct foo { int a; int b; };

struct foo fooarray[] = {
    {1, 2},
    {4},
};

We now lay this out as:

@fooarray = global [2 x %struct.foo] [%struct.foo { i32 1, i32 2 }, %struct.foo { i32 4, i32 0 }]

instead of as:

@fooarray = global %0 <{ %struct.foo { i32 1, i32 2 }, %1 { i32 4, [4 x i8] zeroinitializer } }>

Preserving both the struct type of the second element, but also the array type of the entire thing.

llvm-svn: 101155

1 files changed, 11 insertions, 1 deletions

diff --git a/clang/test/CodeGen/decl.c b/clang/test/CodeGen/decl.c
index 2b07be24fbb..0c7ef5fc97f 100644
--- a/clang/test/CodeGen/decl.c
+++ b/clang/test/CodeGen/decl.c
@@ -5,7 +5,10 @@
 // CHECK: @test5w = global %0 { i32 2, [4 x i8] zeroinitializer }
 // CHECK: @test5y = global %union.test5u { double 7.300000e+0{{[0]*}}1 }
 
-// CHECK: @test6.x = internal constant %1 { i8 1, i8 2, i32 3, [4 x i8] zeroinitializer }
+// CHECK: @test6.x = internal constant %struct.SelectDest { i8 1, i8 2, i32 3, i32 0 }
+
+// CHECK: @test7 = global [2 x %struct.test7s] [%struct.test7s { i32 1, i32 2 }, %struct.test7s { i32 4, i32 0 }]
+
 void test1() {
   // This should codegen as a "@test1.x" global.
   const int x[] = { 1, 2, 3, 4, 6, 8, 9, 10, 123, 231, 123,23 };
@@ -74,3 +77,10 @@ void test6() {
   struct SelectDest x = {1, 2, 3};
   test6f(&x);
 }
+
+// rdar://7657600
+struct test7s { int a; int b; } test7[] = {
+  {1, 2},
+  {4},
+};
+