Implement name mangling for lambda expressions that occur within the

default arguments of function parameters. This simple-sounding task is
complicated greatly by two issues:

  (1) Default arguments aren't actually a real context, so we need to
  maintain extra state within lambda expressions to track when a
  lambda was actually in a default argument.
  (2) At the time that we parse a default argument, the FunctionDecl
  doesn't exist yet, so lambda closure types end up in the enclosing
  context. It's not clear that we ever want to change that, so instead
  we introduce the notion of the "effective" context of a declaration
  for the purposes of name mangling.

llvm-svn: 151011

1 files changed, 56 insertions, 1 deletions

diff --git a/clang/test/CodeGenCXX/mangle-lambdas.cpp b/clang/test/CodeGenCXX/mangle-lambdas.cpp
index b2376648c20..de8360d730e 100644
--- a/clang/test/CodeGenCXX/mangle-lambdas.cpp
+++ b/clang/test/CodeGenCXX/mangle-lambdas.cpp
@@ -14,9 +14,64 @@ inline void inline_func(int n) {
   // CHECK: call i32 @_ZZ11inline_funciENKUliE_clEi
   int l = [=] (int x) -> int { return x + i; }(n);
 
-  // CHECK: ret void
+  int inner(int i = []{ return 1; }());
+  // CHECK: call i32 @_ZZ11inline_funciENKUlvE2_clEv
+  // CHECK-NEXT: call i32 @_Z5inneri
+  inner();
+
+  // CHECK-NEXT: ret void
 }
 
 void call_inline_func() {
   inline_func(17);
 }
+
+struct S {
+  void f(int = []{return 1;}()
+             + []{return 2;}(),
+         int = []{return 3;}());
+  void g(int, int);
+};
+
+void S::g(int i = []{return 1;}(),
+          int j = []{return 2; }()) {}
+
+// CHECK: define void @_Z6test_S1S
+void test_S(S s) {
+  // CHECK: call i32 @_ZZN1S1fEiiEd0_NKUlvE_clEv
+  // CHECK-NEXT: call i32 @_ZZN1S1fEiiEd0_NKUlvE0_clEv
+  // CHECK-NEXT: add nsw i32
+  // CHECK-NEXT: call i32 @_ZZN1S1fEiiEd_NKUlvE_clEv
+  // CHECK-NEXT: call void @_ZN1S1fEii
+  s.f();
+
+  // NOTE: These manglings don't actually matter that much, because
+  // the lambdas in the default arguments of g() won't be seen by
+  // multiple translation units. We check them mainly to ensure that they don't 
+  // get the special mangling for lambdas in in-class default arguments.
+  // CHECK: call i32 @_ZNK1SUlvE_clEv
+  // CHECK-NEXT: call i32 @_ZNK1SUlvE0_clEv
+  // CHECK-NEXT: call void @_ZN1S1gEi
+  s.g();
+
+  // CHECK-NEXT: ret void
+}
+
+template<typename T>
+struct ST {
+  void f(T = []{return T() + 1;}()
+           + []{return T() + 2;}(),
+         T = []{return T(3);}());
+};
+
+// CHECK: define void @_Z7test_ST2STIdE
+void test_ST(ST<double> st) {
+  // CHECK: call double @_ZZN2ST1fET_S0_Ed0_NKUlvE_clEv
+  // CHECK-NEXT: call double @_ZZN2ST1fET_S0_Ed0_NKUlvE0_clEv
+  // CHECK-NEXT: fadd double
+  // CHECK-NEXT: call double @_ZZN2ST1fET_S0_Ed_NKUlvE_clEv
+  // CHECK-NEXT: call void @_ZN2STIdE1fEdd
+  st.f();
+
+  // CHECK-NEXT: ret void
+}