[MSVC Compat] Correctly handle finallys nested within finallys

We'd lose track of the parent CodeGenFunction, leading us to get
confused with regard to which function a nested finally belonged to.

Differential Revision: http://reviews.llvm.org/D17752

llvm-svn: 262379

4 files changed, 36 insertions, 9 deletions

diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index bf52152237d..3c730008326 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -1625,14 +1625,13 @@ void CodeGenFunction::startOutlinedSEHHelper(CodeGenFunction &ParentCGF,
   SmallString<128> Name;
   {
     llvm::raw_svector_ostream OS(Name);
-    const Decl *ParentCodeDecl = ParentCGF.CurCodeDecl;
-    const NamedDecl *Parent = dyn_cast_or_null<NamedDecl>(ParentCodeDecl);
-    assert(Parent && "FIXME: handle unnamed decls (lambdas, blocks) with SEH");
+    const FunctionDecl *ParentSEHFn = ParentCGF.CurSEHParent;
+    assert(ParentSEHFn && "No CurSEHParent!");
     MangleContext &Mangler = CGM.getCXXABI().getMangleContext();
     if (IsFilter)
-      Mangler.mangleSEHFilterExpression(Parent, OS);
+      Mangler.mangleSEHFilterExpression(ParentSEHFn, OS);
     else
-      Mangler.mangleSEHFinallyBlock(Parent, OS);
+      Mangler.mangleSEHFinallyBlock(ParentSEHFn, OS);
   }
 
   FunctionArgList Args;
@@ -1679,6 +1678,7 @@ void CodeGenFunction::startOutlinedSEHHelper(CodeGenFunction &ParentCGF,
 
   StartFunction(GlobalDecl(), RetTy, Fn, FnInfo, Args,
                 OutlinedStmt->getLocStart(), OutlinedStmt->getLocStart());
+  CurSEHParent = ParentCGF.CurSEHParent;
 
   CGM.SetLLVMFunctionAttributes(nullptr, FnInfo, CurFn);
   EmitCapturedLocals(ParentCGF, OutlinedStmt, IsFilter);
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 8e327c2bc4e..0e118b8f6f7 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -669,6 +669,9 @@ void CodeGenFunction::StartFunction(GlobalDecl GD,
 
   DidCallStackSave = false;
   CurCodeDecl = D;
+  if (const auto *FD = dyn_cast_or_null<FunctionDecl>(D))
+    if (FD->usesSEHTry())
+      CurSEHParent = FD;
   CurFuncDecl = (D ? D->getNonClosureContext() : nullptr);
   FnRetTy = RetTy;
   CurFn = Fn;
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 9a31c8f78b5..b9421fc0128 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -276,6 +276,8 @@ public:
   /// potentially set the return value.
   bool SawAsmBlock;
 
+  const FunctionDecl *CurSEHParent = nullptr;
+
   /// True if the current function is an outlined SEH helper. This can be a
   /// finally block or filter expression.
   bool IsOutlinedSEHHelper;
@@ -1150,10 +1152,7 @@ public:
     return getInvokeDestImpl();
   }
 
-  bool currentFunctionUsesSEHTry() const {
-    const auto *FD = dyn_cast_or_null<FunctionDecl>(CurCodeDecl);
-    return FD && FD->usesSEHTry();
-  }
+  bool currentFunctionUsesSEHTry() const { return CurSEHParent != nullptr; }
 
   const TargetInfo &getTarget() const { return Target; }
   llvm::LLVMContext &getLLVMContext() { return CGM.getLLVMContext(); }
diff --git a/clang/test/CodeGen/exceptions-seh-finally.c b/clang/test/CodeGen/exceptions-seh-finally.c
index f0ed2230640..be1501f9e9d 100644
--- a/clang/test/CodeGen/exceptions-seh-finally.c
+++ b/clang/test/CodeGen/exceptions-seh-finally.c
@@ -230,3 +230,28 @@ int nested___finally___finally_with_eh_edge() {
 
 // CHECK-LABEL: define internal void @"\01?fin$1@0@nested___finally___finally_with_eh_edge@@"({{.*}})
 // CHECK: unreachable
+
+void finally_within_finally() {
+  __try {
+    might_crash();
+  } __finally {
+    __try {
+      might_crash();
+    } __finally {
+    }
+  }
+}
+
+// CHECK-LABEL: define void @finally_within_finally(
+// CHECK: invoke void @might_crash(
+
+// CHECK: call void @"\01?fin$0@0@finally_within_finally@@"(
+// CHECK: call void @"\01?fin$0@0@finally_within_finally@@"({{.*}}) [ "funclet"(
+
+// CHECK-LABEL: define internal void @"\01?fin$0@0@finally_within_finally@@"(
+// CHECK: invoke void @might_crash(
+
+// CHECK: call void @"\01?fin$1@0@finally_within_finally@@"(
+// CHECK: call void @"\01?fin$1@0@finally_within_finally@@"({{.*}}) [ "funclet"(
+
+// CHECK-LABEL: define internal void @"\01?fin$1@0@finally_within_finally@@"(