Add the 'noinline' attribute to call sites within __try bodies

LLVM doesn't support non-call exceptions, so inlining makes it harder to
catch such asynchronous exceptions.

llvm-svn: 228876

clang/lib/CodeGen/CGCall.cpp

@@ -3325,6 +3325,12 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
         Attrs.addAttribute(getLLVMContext(), llvm::AttributeSet::FunctionIndex,
                            llvm::Attribute::AlwaysInline);
 
+  // Disable inlining inside SEH __try blocks.
+  if (IsSEHTryScope)
+    Attrs =
+        Attrs.addAttribute(getLLVMContext(), llvm::AttributeSet::FunctionIndex,
+                           llvm::Attribute::NoInline);
+
   CS.setAttributes(Attrs);
   CS.setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
 

clang/lib/CodeGen/CGException.cpp

@@ -21,6 +21,7 @@
 #include "clang/AST/StmtObjC.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Intrinsics.h"
+#include "llvm/Support/SaveAndRestore.h"
 
 using namespace clang;
 using namespace CodeGen;
@@ -1703,7 +1704,11 @@ void CodeGenFunction::EmitSEHTryStmt(const SEHTryStmt &S) {
 
   SEHFinallyInfo FI;
   EnterSEHTryStmt(S, FI);
-  EmitStmt(S.getTryBlock());
+  {
+    // Disable inlining inside SEH __try scopes.
+    SaveAndRestore<bool> Saver(IsSEHTryScope, true);
+    EmitStmt(S.getTryBlock());
+  }
   ExitSEHTryStmt(S, FI);
 }
 

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -40,7 +40,7 @@ CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
       CurFn(nullptr), CapturedStmtInfo(nullptr),
       SanOpts(CGM.getLangOpts().Sanitize), IsSanitizerScope(false),
       CurFuncIsThunk(false), AutoreleaseResult(false), SawAsmBlock(false),
-      BlockInfo(nullptr), BlockPointer(nullptr),
+      IsSEHTryScope(false), BlockInfo(nullptr), BlockPointer(nullptr),
       LambdaThisCaptureField(nullptr), NormalCleanupDest(nullptr),
       NextCleanupDestIndex(1), FirstBlockInfo(nullptr), EHResumeBlock(nullptr),
       ExceptionSlot(nullptr), EHSelectorSlot(nullptr),

clang/lib/CodeGen/CodeGenFunction.h

@@ -263,6 +263,9 @@ public:
   /// potentially set the return value.
   bool SawAsmBlock;
 
+  /// Codegen is currently inside an SEH try block.
+  bool IsSEHTryScope;
+
   const CodeGen::CGBlockInfo *BlockInfo;
   llvm::Value *BlockPointer;
 

clang/test/CodeGen/exceptions-seh.c

@@ -21,7 +21,7 @@ int safe_div(int numerator, int denominator, int *res) {
   return success;
 }
 // CHECK-LABEL: define i32 @safe_div(i32 %numerator, i32 %denominator, i32* %res)
-// CHECK: invoke void @try_body(i32 %{{.*}}, i32 %{{.*}}, i32* %{{.*}})
+// CHECK: invoke void @try_body(i32 %{{.*}}, i32 %{{.*}}, i32* %{{.*}}) #[[NOINLINE:[0-9]+]]
 // CHECK:       to label %{{.*}} unwind label %[[lpad:[^ ]*]]
 //
 // CHECK: [[lpad]]
@@ -51,7 +51,7 @@ int filter_expr_capture(void) {
 // CHECK-LABEL: define i32 @filter_expr_capture()
 // FIXMECHECK: %[[captures]] = call i8* @llvm.frameallocate(i32 4)
 // CHECK: store i32 42, i32* %[[r:[^ ,]*]]
-// CHECK: invoke void @j()
+// CHECK: invoke void @j() #[[NOINLINE]]
 //
 // CHECK: landingpad
 // CHECK-NEXT: catch i8* bitcast (i32 (i8*, i8*)* @"\01?filt$0@0@filter_expr_capture@@" to i8*)
@@ -81,7 +81,7 @@ int nested_try(void) {
 }
 // CHECK-LABEL: define i32 @nested_try()
 // CHECK: store i32 42, i32* %[[r:[^ ,]*]]
-// CHECK: invoke void @j()
+// CHECK: invoke void @j() #[[NOINLINE]]
 // CHECK:       to label %[[cont:[^ ]*]] unwind label %[[lpad:[^ ]*]]
 //
 // CHECK: [[cont]]
@@ -179,3 +179,5 @@ int except_return(void) {
 // CHECK: [[retbb]]
 // CHECK: %[[r:[^ ]*]] = load i32* %[[rv]]
 // CHECK: ret i32 %[[r]]
+
+// CHECK: attributes #[[NOINLINE]] = { {{.*noinline.*}} }

clang/test/CodeGenCXX/exceptions-seh.cpp

@@ -58,7 +58,7 @@ extern "C" void use_seh() {
 // Make sure we use __C_specific_handler for SEH.
 
 // CHECK-LABEL: define void @use_seh()
-// CHECK: invoke void @might_throw()
+// CHECK: invoke void @might_throw() #[[NOINLINE:[0-9]+]]
 // CHECK:       to label %[[cont:[^ ]*]] unwind label %[[lpad:[^ ]*]]
 //
 // CHECK: [[cont]]
@@ -92,4 +92,7 @@ void use_seh_in_lambda() {
 // NOCXX: ret void
 
 // CHECK-LABEL: define internal void @"\01??R<lambda_0>@?use_seh_in_lambda@@YAXXZ@QEBAXXZ"(%class.anon* %this)
+// CHECK: invoke void @might_throw() #[[NOINLINE]]
 // CHECK: landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__C_specific_handler to i8*)
+
+// CHECK: attributes #[[NOINLINE]] = { {{.*noinline.*}} }