3 files changed, 70 insertions, 3 deletions
diff --git a/test/ASTMerge/Inputs/struct1.c b/test/ASTMerge/Inputs/struct1.c
index 381f00a0a6..5743fe0f48 100644
--- a/test/ASTMerge/Inputs/struct1.c
+++ b/test/ASTMerge/Inputs/struct1.c
@@ -1,6 +1,7 @@
 typedef int Int;
 typedef float Float;
 
+// Matches
 struct S0 {
   Int field1;
   Float field2;
@@ -8,9 +9,28 @@ struct S0 {
 
 struct S0 x0;
 
+// Mismatch in field type
 struct S1 {
   Int field1;
   int field2;
 };
 
 struct S1 x1;
+
+// Mismatch in tag kind.
+struct S2 { int i; float f; } x2;
+
+// Missing fields
+struct S3 { int i; float f; double d; } x3;
+
+// Extra fields
+struct S4 { int i; } x4;
+
+// Bit-field matches
+struct S5 { int i : 8; unsigned j : 8; } x5;
+
+// Bit-field mismatch
+struct S6 { int i : 8; unsigned j : 8; } x6;
+
+// Bit-field mismatch
+struct S7 { int i : 8; unsigned j : 8; } x7;
diff --git a/test/ASTMerge/Inputs/struct2.c b/test/ASTMerge/Inputs/struct2.c
index 0a90609006..a707ed2a5b 100644
--- a/test/ASTMerge/Inputs/struct2.c
+++ b/test/ASTMerge/Inputs/struct2.c
@@ -1,3 +1,4 @@
+// Matches
 struct S0 {
   int field1;
   float field2;
@@ -5,9 +6,28 @@ struct S0 {
 
 struct S0 x0;
 
+// Mismatch in field type
 struct S1 {
   int field1;
   float field2;
 };
 
 struct S1 x1;
+
+// Mismatch in tag kind.
+union S2 { int i; float f; } x2;
+
+// Missing fields
+struct S3 { int i; float f; } x3;
+
+// Extra fields
+struct S4 { int i; float f; } x4;
+
+// Bit-field matches
+struct S5 { int i : 8; unsigned j : 8; } x5;
+
+// Bit-field mismatch
+struct S6 { int i : 8; unsigned j; } x6;
+
+// Bit-field mismatch
+struct S7 { int i : 8; unsigned j : 16; } x7;
diff --git a/test/ASTMerge/struct.c b/test/ASTMerge/struct.c
index 99fa74b10d..c6e57185ab 100644
--- a/test/ASTMerge/struct.c
+++ b/test/ASTMerge/struct.c
@@ -2,6 +2,33 @@
 // RUN: %clang_cc1 -emit-pch -o %t.2.ast %S/Inputs/struct2.c
 // RUN: %clang_cc1 -ast-merge %t.1.ast -ast-merge %t.2.ast -fsyntax-only %s 2>&1 | FileCheck %s
 
-// CHECK: struct2.c:13:11: error: external variable 'x1' declared with incompatible types in different translation units ('struct S1' vs. 'struct S1')
-// CHECK: struct1.c:16:11: note: declared here with type 'struct S1'
-// CHECK: 2 diagnostics
+// CHECK: struct1.c:13:8: warning: type 'struct S1' has incompatible definitions in different translation units
+// CHECK: struct1.c:15:7: note: field 'field2' has type 'int' here
+// CHECK: struct2.c:12:9: note: field 'field2' has type 'float' here
+// CHECK: struct2.c:15:11: error: external variable 'x1' declared with incompatible types in different translation units ('struct S1' vs. 'struct S1')
+// CHECK: struct1.c:18:11: note: declared here with type 'struct S1'
+// CHECK: struct1.c:21:8: warning: type 'struct S2' has incompatible definitions in different translation units
+// CHECK: struct2.c:18:7: note: 'S2' is a union here
+// CHECK: struct2.c:18:30: error: external variable 'x2' declared with incompatible types in different translation units ('union S2' vs. 'struct S2')
+// CHECK: struct1.c:21:31: note: declared here with type 'struct S2'
+// CHECK: struct1.c:24:8: warning: type 'struct S3' has incompatible definitions in different translation units
+// CHECK: struct1.c:24:36: note: field 'd' has type 'double' here
+// CHECK: struct2.c:21:8: note: no corresponding field here
+// CHECK: struct2.c:21:31: error: external variable 'x3' declared with incompatible types in different translation units ('struct S3' vs. 'struct S3')
+// CHECK: struct1.c:24:41: note: declared here with type 'struct S3'
+// CHECK: struct1.c:27:8: warning: type 'struct S4' has incompatible definitions in different translation units
+// CHECK: struct2.c:24:26: note: field 'f' has type 'float' here
+// CHECK: struct1.c:27:8: note: no corresponding field here
+// CHECK: struct2.c:24:31: error: external variable 'x4' declared with incompatible types in different translation units ('struct S4' vs. 'struct S4')
+// CHECK: struct1.c:27:22: note: declared here with type 'struct S4'
+// CHECK: struct1.c:33:8: warning: type 'struct S6' has incompatible definitions in different translation units
+// CHECK: struct1.c:33:33: note: bit-field 'j' with type 'unsigned int' and length 8 here
+// CHECK: struct2.c:30:33: note: field 'j' is not a bit-field
+// CHECK: struct2.c:30:38: error: external variable 'x6' declared with incompatible types in different translation units ('struct S6' vs. 'struct S6')
+// CHECK: struct1.c:33:42: note: declared here with type 'struct S6'
+// CHECK: struct1.c:36:8: warning: type 'struct S7' has incompatible definitions in different translation units
+// CHECK: struct1.c:36:33: note: bit-field 'j' with type 'unsigned int' and length 8 here
+// CHECK: struct2.c:33:33: note: bit-field 'j' with type 'unsigned int' and length 16 here
+// CHECK: struct2.c:33:43: error: external variable 'x7' declared with incompatible types in different translation units ('struct S7' vs. 'struct S7')
+// CHECK: struct1.c:36:42: note: declared here with type 'struct S7'
+// CHECK: 29 diagnostics