Don't crash when generating code for __attribute__((naked)) member functions.

Summary:
Previously this crashed inside EmitThisParam().  There should be no
prelude for naked functions, so just skip the whole thing.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D22715

llvm-svn: 276925

3 files changed, 21 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 6051594fb00..36eb40ef09c 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -1390,6 +1390,10 @@ void ItaniumCXXABI::addImplicitStructorParams(CodeGenFunction &CGF,
 }
 
 void ItaniumCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
+  // Naked functions have no prolog.
+  if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
+    return;
+
   /// Initialize the 'this' slot.
   EmitThisParam(CGF);
 
diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index 6b919d16881..28312fce774 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -1417,6 +1417,10 @@ llvm::Value *MicrosoftCXXABI::adjustThisParameterInVirtualFunctionPrologue(
 }
 
 void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
+  // Naked functions have no prolog.
+  if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
+    return;
+
   EmitThisParam(CGF);
 
   /// If this is a function that the ABI specifies returns 'this', initialize
diff --git a/clang/test/CodeGenCXX/naked.cpp b/clang/test/CodeGenCXX/naked.cpp
new file mode 100644
index 00000000000..7032823e44b
--- /dev/null
+++ b/clang/test/CodeGenCXX/naked.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-windows -emit-llvm %s -o - | FileCheck %s
+
+class TestNaked {
+public:
+  void NakedFunction();
+};
+
+__attribute__((naked)) void TestNaked::NakedFunction() {
+  // CHECK-LABEL: define void @
+  // CHECK: call void asm sideeffect
+  asm("");
+}