[CodeGen] Add additional mangling for struct members of non trivial structs

In https://bugs.llvm.org/show_bug.cgi?id=41206 we observe bad codegen
when embedding a non-trivial C struct within a C struct. This is due to
the fact that name mangling for non-trivial structs marks the two
structs as identical. This diff contains a fix for this issue.

Patch by Dan Zimmerman <daniel.zimmerman@me.com>.

Differential Revision: https://reviews.llvm.org/D59873

llvm-svn: 357184

3 files changed, 63 insertions, 18 deletions

diff --git a/clang/lib/CodeGen/CGNonTrivialStruct.cpp b/clang/lib/CodeGen/CGNonTrivialStruct.cpp
index a1649e4fb7b..f2b59f8bc50 100644
--- a/clang/lib/CodeGen/CGNonTrivialStruct.cpp
+++ b/clang/lib/CodeGen/CGNonTrivialStruct.cpp
@@ -139,8 +139,8 @@ struct CopyStructVisitor : StructVisitor<Derived>,
 // <alignment-info> ::= <dst-alignment> ["_" <src-alignment>]
 // <struct-field-info> ::= <field-info>+
 // <field-info> ::= <struct-or-scalar-field-info> | <array-field-info>
-// <struct-or-scalar-field-info> ::= <struct-field-info> | <strong-field-info> |
-//                                   <trivial-field-info>
+// <struct-or-scalar-field-info> ::= "_S" <struct-field-info> |
+//                                   <strong-field-info> | <trivial-field-info>
 // <array-field-info> ::= "_AB" <array-offset> "s" <element-size> "n"
 //                        <num-elements> <innermost-element-info> "_AE"
 // <innermost-element-info> ::= <struct-or-scalar-field-info>
@@ -175,6 +175,7 @@ template <class Derived> struct GenFuncNameBase {
   void visitStruct(QualType QT, const FieldDecl *FD,
                    CharUnits CurStructOffset) {
     CharUnits FieldOffset = CurStructOffset + asDerived().getFieldOffset(FD);
+    appendStr("_S");
     asDerived().visitStructFields(QT, FieldOffset);
   }
 
diff --git a/clang/test/CodeGenObjC/nontrivial-c-struct-within-struct-name.m b/clang/test/CodeGenObjC/nontrivial-c-struct-within-struct-name.m
new file mode 100644
index 00000000000..854c097c0ea
--- /dev/null
+++ b/clang/test/CodeGenObjC/nontrivial-c-struct-within-struct-name.m
@@ -0,0 +1,44 @@
+// RUN: %clang_cc1 -triple arm64-apple-ios11 -fobjc-arc -emit-llvm -o - %s | FileCheck %s
+
+@class I;
+
+typedef struct {
+  I *name;
+} Foo;
+
+typedef struct {
+  Foo foo;
+} Bar;
+
+typedef struct {
+  Bar bar;
+} Baz;
+
+I *getI();
+
+void f() {
+  Foo foo = {getI()};
+  Bar bar = {foo};
+  Baz baz = {bar};
+}
+
+// CHECK: define linkonce_odr hidden void @__destructor_8_S_S_s0(i8** %[[DST:.*]])
+// CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
+// CHECK: store i8** %[[DST]], i8*** %[[DST_ADDR]], align 8
+// CHECK: %[[V0:.*]] = load i8**, i8*** %[[DST_ADDR]], align 8
+// CHECK: call void @__destructor_8_S_s0(i8** %[[V0]])
+// CHECK: ret void
+
+// CHECK: define linkonce_odr hidden void @__destructor_8_S_s0(i8** %[[DST:.*]])
+// CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
+// CHECK: store i8** %[[DST]], i8*** %[[DST_ADDR]], align 8
+// CHECK: %[[V0:.*]] = load i8**, i8*** %[[DST_ADDR]], align 8
+// CHECK: call void @__destructor_8_s0(i8** %[[V0]])
+// CHECK: ret void
+
+// CHECK: define linkonce_odr hidden void @__destructor_8_s0(i8** %dst)
+// CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
+// CHECK: store i8** %[[DST]], i8*** %[[DST_ADDR]], align 8
+// CHECK: %[[V0:.*]] = load i8**, i8*** %[[DST_ADDR]], align 8
+// CHECK: call void @llvm.objc.storeStrong(i8** %[[V0]], i8* null)
+// CHECK: ret void
diff --git a/clang/test/CodeGenObjC/strong-in-c-struct.m b/clang/test/CodeGenObjC/strong-in-c-struct.m
index 999b89dd60f..17587f7d62d 100644
--- a/clang/test/CodeGenObjC/strong-in-c-struct.m
+++ b/clang/test/CodeGenObjC/strong-in-c-struct.m
@@ -89,12 +89,12 @@ void func(Strong *);
 // CHECK: define void @test_constructor_destructor_StrongOuter()
 // CHECK: %[[T:.*]] = alloca %[[STRUCT_STRONGOUTER:.*]], align 8
 // CHECK: %[[V0:.*]] = bitcast %[[STRUCT_STRONGOUTER]]* %[[T]] to i8**
-// CHECK: call void @__default_constructor_8_s16_s24(i8** %[[V0]])
+// CHECK: call void @__default_constructor_8_S_s16_s24(i8** %[[V0]])
 // CHECK: %[[V1:.*]] = bitcast %[[STRUCT_STRONGOUTER]]* %[[T]] to i8**
-// CHECK: call void @__destructor_8_s16_s24(i8** %[[V1]])
+// CHECK: call void @__destructor_8_S_s16_s24(i8** %[[V1]])
 // CHECK: ret void
 
-// CHECK: define linkonce_odr hidden void @__default_constructor_8_s16_s24(i8** %[[DST:.*]])
+// CHECK: define linkonce_odr hidden void @__default_constructor_8_S_s16_s24(i8** %[[DST:.*]])
 // CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
 // CHECK: store i8** %[[DST]], i8*** %[[DST_ADDR]], align 8
 // CHECK: %[[V0:.*]] = load i8**, i8*** %[[DST_ADDR]], align 8
@@ -117,7 +117,7 @@ void func(Strong *);
 // CHECK: call void @llvm.memset.p0i8.i64(i8* align 8 %[[V4]], i8 0, i64 8, i1 false)
 // CHECK: ret void
 
-// CHECK: define linkonce_odr hidden void @__destructor_8_s16_s24(i8** %[[DST:.*]])
+// CHECK: define linkonce_odr hidden void @__destructor_8_S_s16_s24(i8** %[[DST:.*]])
 // CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
 // CHECK: store i8** %[[DST]], i8*** %[[DST_ADDR]], align 8
 // CHECK: %[[V0:.*]] = load i8**, i8*** %[[DST_ADDR]], align 8
@@ -149,12 +149,12 @@ void test_constructor_destructor_StrongOuter(void) {
 // CHECK: %[[V0:.*]] = load %[[STRUCT_STRONGOUTER]]*, %[[STRUCT_STRONGOUTER]]** %[[S_ADDR]], align 8
 // CHECK: %[[V1:.*]] = bitcast %[[STRUCT_STRONGOUTER]]* %[[T]] to i8**
 // CHECK: %[[V2:.*]] = bitcast %[[STRUCT_STRONGOUTER]]* %[[V0]] to i8**
-// CHECK: call void @__copy_constructor_8_8_t0w16_s16_s24_t32w8(i8** %[[V1]], i8** %[[V2]])
+// CHECK: call void @__copy_constructor_8_8_S_t0w16_s16_s24_t32w8(i8** %[[V1]], i8** %[[V2]])
 // CHECK: %[[V3:.*]] = bitcast %[[STRUCT_STRONGOUTER]]* %[[T]] to i8**
-// CHECK: call void @__destructor_8_s16_s24(i8** %[[V3]])
+// CHECK: call void @__destructor_8_S_s16_s24(i8** %[[V3]])
 // CHECK: ret void
 
-// CHECK: define linkonce_odr hidden void @__copy_constructor_8_8_t0w16_s16_s24_t32w8(i8** %[[DST:.*]], i8** %[[SRC:.*]])
+// CHECK: define linkonce_odr hidden void @__copy_constructor_8_8_S_t0w16_s16_s24_t32w8(i8** %[[DST:.*]], i8** %[[SRC:.*]])
 // CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
 // CHECK: %[[SRC_ADDR:.*]] = alloca i8**, align 8
 // CHECK: store i8** %[[DST]], i8*** %[[DST_ADDR]], align 8
@@ -208,7 +208,7 @@ void test_copy_constructor_StrongOuter(StrongOuter *s) {
   StrongOuter t = *s;
 }
 
-/// CHECK: define linkonce_odr hidden void @__copy_assignment_8_8_t0w16_s16_s24_t32w8(i8** %[[DST:.*]], i8** %[[SRC:.*]])
+/// CHECK: define linkonce_odr hidden void @__copy_assignment_8_8_S_t0w16_s16_s24_t32w8(i8** %[[DST:.*]], i8** %[[SRC:.*]])
 // CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
 // CHECK: %[[SRC_ADDR:.*]] = alloca i8**, align 8
 // CHECK: store i8** %[[DST]], i8*** %[[DST_ADDR]], align 8
@@ -231,15 +231,15 @@ void test_copy_assignment_StrongOuter(StrongOuter *d, StrongOuter *s) {
 // CHECK: define void @test_move_constructor_StrongOuter()
 // CHECK: %[[T1:.*]] = getelementptr inbounds %[[STRUCT_BLOCK_BYREF_T:.*]], %[[STRUCT_BLOCK_BYREF_T]]* %{{.*}}, i32 0, i32 7
 // CHECK: %[[V1:.*]] = bitcast %[[STRUCT_STRONGOUTER]]* %[[T1]] to i8**
-// CHECK: call void @__default_constructor_8_s16_s24(i8** %[[V1]])
+// CHECK: call void @__default_constructor_8_S_s16_s24(i8** %[[V1]])
 // CHECK: %[[T2:.*]] = getelementptr inbounds %[[STRUCT_BLOCK_BYREF_T]], %[[STRUCT_BLOCK_BYREF_T]]* %{{.*}}, i32 0, i32 7
 // CHECK: %[[V9:.*]] = bitcast %[[STRUCT_STRONGOUTER]]* %[[T2]] to i8**
-// CHECK: call void @__destructor_8_s16_s24(i8** %[[V9]])
+// CHECK: call void @__destructor_8_S_s16_s24(i8** %[[V9]])
 
 // CHECK: define internal void @__Block_byref_object_copy_(i8*, i8*)
-// CHECK: call void @__move_constructor_8_8_t0w16_s16_s24_t32w8(
+// CHECK: call void @__move_constructor_8_8_S_t0w16_s16_s24_t32w8(
 
-// CHECK: define linkonce_odr hidden void @__move_constructor_8_8_t0w16_s16_s24_t32w8(i8** %[[DST:.*]], i8** %[[SRC:.*]])
+// CHECK: define linkonce_odr hidden void @__move_constructor_8_8_S_t0w16_s16_s24_t32w8(i8** %[[DST:.*]], i8** %[[SRC:.*]])
 // CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
 // CHECK: %[[SRC_ADDR:.*]] = alloca i8**, align 8
 // CHECK: store i8** %[[DST]], i8*** %[[DST_ADDR]], align 8
@@ -258,14 +258,14 @@ void test_copy_assignment_StrongOuter(StrongOuter *d, StrongOuter *s) {
 // CHECK: store i8* %[[V8]], i8** %[[V4]], align 8
 
 // CHECK: define internal void @__Block_byref_object_dispose_(i8*)
-// CHECK: call void @__destructor_8_s16_s24(
+// CHECK: call void @__destructor_8_S_s16_s24(
 
 void test_move_constructor_StrongOuter(void) {
   __block StrongOuter t;
   BlockTy b = ^{ (void)t; };
 }
 
-// CHECK: define linkonce_odr hidden void @__move_assignment_8_8_t0w16_s16_s24_t32w8(i8** %[[DST:.*]], i8** %[[SRC:.*]])
+// CHECK: define linkonce_odr hidden void @__move_assignment_8_8_S_t0w16_s16_s24_t32w8(i8** %[[DST:.*]], i8** %[[SRC:.*]])
 // CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
 // CHECK: %[[SRC_ADDR:.*]] = alloca i8**, align 8
 // CHECK: store i8** %[[DST]], i8*** %[[DST_ADDR]], align 8
@@ -480,14 +480,14 @@ void test_constructor_destructor_IDArray(void) {
   IDArray t;
 }
 
-// CHECK: define linkonce_odr hidden void @__default_constructor_8_AB8s24n4_s24_AE(
+// CHECK: define linkonce_odr hidden void @__default_constructor_8_AB8s24n4_S_s24_AE(
 void test_constructor_destructor_StructArray(void) {
   StructArray t;
 }
 
 // Test that StructArray's field 'd' is copied before entering the loop.
 
-// CHECK: define linkonce_odr hidden void @__copy_constructor_8_8_t0w8_AB8s24n4_t8w16_s24_AE(i8** %[[DST:.*]], i8** %[[SRC:.*]])
+// CHECK: define linkonce_odr hidden void @__copy_constructor_8_8_t0w8_AB8s24n4_S_t8w16_s24_AE(i8** %[[DST:.*]], i8** %[[SRC:.*]])
 // CHECK: entry:
 // CHECK: %[[DST_ADDR:.*]] = alloca i8**, align 8
 // CHECK: %[[SRC_ADDR:.*]] = alloca i8**, align 8