[MS ABI] Don't crash while mangling recursive lambdas

We might get into bad situations where we try to embed the signature of
an inner lambda into an outer lambda which cannot work: the inner lambda
wants to embed the name of the outer lambda!

Instead, omit the return type for lambdas.

This fixes PR26105.

N.B.  While we are here, make lambdas nested within functions use an
artificial scope so that they can get demangled.

llvm-svn: 258003

5 files changed, 25 insertions, 18 deletions

diff --git a/clang/test/CodeGenCXX/exceptions-seh-filter-captures.cpp b/clang/test/CodeGenCXX/exceptions-seh-filter-captures.cpp
index 4e8be72089d..ab75a87698a 100644
--- a/clang/test/CodeGenCXX/exceptions-seh-filter-captures.cpp
+++ b/clang/test/CodeGenCXX/exceptions-seh-filter-captures.cpp
@@ -70,14 +70,14 @@ void test_lambda() {
   lambda();
 }
 
-// CHECK-LABEL: define internal void @"\01??R<lambda_0>@?test_lambda@@YAXXZ@QEBAXXZ"(%class.anon* %this)
+// CHECK-LABEL: define internal void @"\01??R<lambda_0>@?0??test_lambda@@YAXXZ@QEBA@XZ"(%class.anon* %this)
 // CHECK: @llvm.localescape(i32* %[[l2_addr:[^, ]*]])
 // CHECK: store i32 42, i32* %[[l2_addr]], align 4
 // CHECK: invoke void @might_crash()
 
-// CHECK-LABEL: define internal i32 @"\01?filt$0@0@?R<lambda_0>@?test_lambda@@YAXXZ@"(i8* %exception_pointers, i8* %frame_pointer)
-// CHECK: %[[fp:[^ ]*]] = call i8* @llvm.x86.seh.recoverfp(i8* bitcast (void (%class.anon*)* @"\01??R<lambda_0>@?test_lambda@@YAXXZ@QEBAXXZ" to i8*), i8* %frame_pointer)
-// CHECK: %[[l2_i8:[^ ]*]] = call i8* @llvm.localrecover(i8* bitcast (void (%class.anon*)* @"\01??R<lambda_0>@?test_lambda@@YAXXZ@QEBAXXZ" to i8*), i8* %[[fp]], i32 0)
+// CHECK-LABEL: define internal i32 @"\01?filt$0@0@?R<lambda_0>@?0??test_lambda@@YAXXZ@"(i8* %exception_pointers, i8* %frame_pointer)
+// CHECK: %[[fp:[^ ]*]] = call i8* @llvm.x86.seh.recoverfp(i8* bitcast (void (%class.anon*)* @"\01??R<lambda_0>@?0??test_lambda@@YAXXZ@QEBA@XZ" to i8*), i8* %frame_pointer)
+// CHECK: %[[l2_i8:[^ ]*]] = call i8* @llvm.localrecover(i8* bitcast (void (%class.anon*)* @"\01??R<lambda_0>@?0??test_lambda@@YAXXZ@QEBA@XZ" to i8*), i8* %[[fp]], i32 0)
 // CHECK: %[[l2_ptr:[^ ]*]] = bitcast i8* %[[l2_i8]] to i32*
 // CHECK: %[[l2:[^ ]*]] = load i32, i32* %[[l2_ptr]]
 // CHECK: call i32 (i32, ...) @basic_filter(i32 %[[l2]])
diff --git a/clang/test/CodeGenCXX/exceptions-seh.cpp b/clang/test/CodeGenCXX/exceptions-seh.cpp
index abbe95be340..589bc226576 100644
--- a/clang/test/CodeGenCXX/exceptions-seh.cpp
+++ b/clang/test/CodeGenCXX/exceptions-seh.cpp
@@ -95,7 +95,7 @@ void use_seh_in_lambda() {
 // NOCXX-NOT: invoke
 // NOCXX: ret void
 
-// CHECK-LABEL: define internal void @"\01??R<lambda_0>@?use_seh_in_lambda@@YAXXZ@QEBAXXZ"(%class.anon* %this)
+// CHECK-LABEL: define internal void @"\01??R<lambda_0>@?0??use_seh_in_lambda@@YAXXZ@QEBA@XZ"(%class.anon* %this)
 // CXXEH-SAME:  personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*)
 // CHECK: invoke void @might_throw() #[[NOINLINE]]
 // CHECK: catchpad
diff --git a/clang/test/CodeGenCXX/mangle-ms-cxx11.cpp b/clang/test/CodeGenCXX/mangle-ms-cxx11.cpp
index 999def87fc5..99384440a18 100644
--- a/clang/test/CodeGenCXX/mangle-ms-cxx11.cpp
+++ b/clang/test/CodeGenCXX/mangle-ms-cxx11.cpp
@@ -166,14 +166,14 @@ inline int define_lambda() {
   static auto lambda = [] { static int local; ++local; return local; };
 // First, we have the static local variable of type "<lambda_1>" inside of
 // "define_lambda".
-// CHECK-DAG: @"\01?lambda@?1??define_lambda@@YAHXZ@4V<lambda_1>@?1@YAHXZ@A"
+// CHECK-DAG: @"\01?lambda@?1??define_lambda@@YAHXZ@4V<lambda_1>@?0??1@YAHXZ@A"
 // Next, we have the "operator()" for "<lambda_1>" which is inside of
 // "define_lambda".
-// CHECK-DAG: @"\01??R<lambda_1>@?define_lambda@@YAHXZ@QBEHXZ"
+// CHECK-DAG: @"\01??R<lambda_1>@?0??define_lambda@@YAHXZ@QBE@XZ"
 // Finally, we have the local which is inside of "<lambda_1>" which is inside of
 // "define_lambda". Hooray.
-// MSVC2013-DAG: @"\01?local@?2???R<lambda_1>@?define_lambda@@YAHXZ@QBEHXZ@4HA"
-// MSVC2015-DAG: @"\01?local@?1???R<lambda_1>@?define_lambda@@YAHXZ@QBEHXZ@4HA"
+// MSVC2013-DAG: @"\01?local@?2???R<lambda_1>@?0??define_lambda@@YAHXZ@QBE@XZ@4HA"
+// MSVC2015-DAG: @"\01?local@?1???R<lambda_1>@?0??define_lambda@@YAHXZ@QBE@XZ@4HA"
   return lambda();
 }
 
@@ -182,12 +182,12 @@ void use_lambda_arg(T) {}
 
 inline void call_with_lambda_arg1() {
   use_lambda_arg([]{});
-  // CHECK-DAG: @"\01??$use_lambda_arg@V<lambda_1>@?call_with_lambda_arg1@@YAXXZ@@@YAXV<lambda_1>@?call_with_lambda_arg1@@YAXXZ@@Z"
+  // CHECK-DAG: @"\01??$use_lambda_arg@V<lambda_1>@?0??call_with_lambda_arg1@@YAXXZ@@@YAXV<lambda_1>@?0??call_with_lambda_arg1@@YAXXZ@@Z"
 }
 
 inline void call_with_lambda_arg2() {
   use_lambda_arg([]{});
-  // CHECK-DAG: @"\01??$use_lambda_arg@V<lambda_1>@?call_with_lambda_arg2@@YAXXZ@@@YAXV<lambda_1>@?call_with_lambda_arg2@@YAXXZ@@Z"
+  // CHECK-DAG: @"\01??$use_lambda_arg@V<lambda_1>@?0??call_with_lambda_arg2@@YAXXZ@@@YAXV<lambda_1>@?0??call_with_lambda_arg2@@YAXXZ@@Z"
 }
 
 int call_lambda() {
@@ -286,3 +286,10 @@ static union {
 };
 // CHECK-DAG: @"\01??$f@T<unnamed-type-$S1>@PR18204@@@PR18204@@YAHPAT<unnamed-type-$S1>@0@@Z"
 }
+
+int PR26105() {
+  auto add = [](int x) { return ([x](int y) { return x + y; }); };
+  return add(3)(4);
+}
+// CHECK-DAG: @"\01??R<lambda_0>@?0??PR26105@@YAHXZ@QBE@H@Z"
+// CHECK-DAG: @"\01??R<lambda_1>@?0???R<lambda_0>@?0??PR26105@@YAHXZ@QBE@H@Z@QBE@H@Z"
diff --git a/clang/test/CodeGenCXX/mangle-ms-cxx14.cpp b/clang/test/CodeGenCXX/mangle-ms-cxx14.cpp
index 9d30c406c8c..084eb7ddf12 100644
--- a/clang/test/CodeGenCXX/mangle-ms-cxx14.cpp
+++ b/clang/test/CodeGenCXX/mangle-ms-cxx14.cpp
@@ -35,12 +35,12 @@ auto TemplateFuncionWithLocalLambda(T) {
   return LocalLambdaWithLocalType();
 }
 
-// MSVC2013-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?2???R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?3@XZ@A"
-// MSVC2013-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?2???R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?3@XZ@A"
-// MSVC2015-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?1???R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?3@XZ@A"
-// MSVC2015-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?1???R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?3@XZ@A"
+// MSVC2013-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?2???R<lambda_1>@?0???$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?3@XZ@A"
+// MSVC2013-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?2???R<lambda_1>@?0???$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?3@XZ@A"
+// MSVC2015-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?1???R<lambda_1>@?0???$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?3@XZ@A"
+// MSVC2015-DAG: "\01?ValueFromTemplateFuncionWithLocalLambda@@3ULocalType@?1???R<lambda_1>@?0???$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?3@XZ@A"
 // CHECK-DAG: "\01??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z"
-// CHECK-DAG: "\01??R<lambda_1>@??$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?1@XZ"
+// CHECK-DAG: "\01??R<lambda_1>@?0???$TemplateFuncionWithLocalLambda@H@@YA?A?<auto>@@H@Z@QBE?A?1@XZ"
 auto ValueFromTemplateFuncionWithLocalLambda = TemplateFuncionWithLocalLambda(0);
 
 struct S;
diff --git a/clang/test/CodeGenCXX/pr20719.cpp b/clang/test/CodeGenCXX/pr20719.cpp
index 208d1113584..1c3b21b0b84 100644
--- a/clang/test/CodeGenCXX/pr20719.cpp
+++ b/clang/test/CodeGenCXX/pr20719.cpp
@@ -2,8 +2,8 @@
 
 // Make sure that we emit H's constructor twice: once with the first lambda
 // inside of 'lep' and again with the second lambda inside of 'lep'.
-// CHECK-DAG: @"\01??0?$H@V<lambda_1>@??$lep@X@@YAXXZ@@@QAE@XZ"
-// CHECK-DAG: @"\01??0?$H@V<lambda_2>@??$lep@X@@YAXXZ@@@QAE@XZ"
+// CHECK-DAG: @"\01??0?$H@V<lambda_1>@?0???$lep@X@@YAXXZ@@@QAE@XZ"
+// CHECK-DAG: @"\01??0?$H@V<lambda_2>@?0???$lep@X@@YAXXZ@@@QAE@XZ"
 
 template <typename>
 struct H {