Don't crash in IRGen if a conditional with 'throw' in one of its branches is
used as a branch condition.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181368 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGException.cpp b/lib/CodeGen/CGException.cpp
index 36642bc..a088d78 100644
--- a/lib/CodeGen/CGException.cpp
+++ b/lib/CodeGen/CGException.cpp
@@ -419,14 +419,16 @@
return Builder.CreateLoad(getEHSelectorSlot(), "sel");
}
-void CodeGenFunction::EmitCXXThrowExpr(const CXXThrowExpr *E) {
+void CodeGenFunction::EmitCXXThrowExpr(const CXXThrowExpr *E,
+ bool KeepInsertionPoint) {
if (!E->getSubExpr()) {
EmitNoreturnRuntimeCallOrInvoke(getReThrowFn(CGM),
ArrayRef<llvm::Value*>());
// throw is an expression, and the expression emitters expect us
// to leave ourselves at a valid insertion point.
- EmitBlock(createBasicBlock("throw.cont"));
+ if (KeepInsertionPoint)
+ EmitBlock(createBasicBlock("throw.cont"));
return;
}
@@ -440,7 +442,8 @@
CGM.getObjCRuntime().EmitThrowStmt(*this, S, false);
// This will clear insertion point which was not cleared in
// call to EmitThrowStmt.
- EmitBlock(createBasicBlock("throw.cont"));
+ if (KeepInsertionPoint)
+ EmitBlock(createBasicBlock("throw.cont"));
return;
}
@@ -478,7 +481,8 @@
// throw is an expression, and the expression emitters expect us
// to leave ourselves at a valid insertion point.
- EmitBlock(createBasicBlock("throw.cont"));
+ if (KeepInsertionPoint)
+ EmitBlock(createBasicBlock("throw.cont"));
}
void CodeGenFunction::EmitStartEHSpec(const Decl *D) {
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 791c1a8..75c60ed 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -928,6 +928,16 @@
return;
}
+ if (const CXXThrowExpr *Throw = dyn_cast<CXXThrowExpr>(Cond)) {
+ // Conditional operator handling can give us a throw expression as a
+ // condition for a case like:
+ // br(c ? throw x : y, t, f) -> br(c, br(throw x, t, f), br(y, t, f)
+ // Fold this to:
+ // br(c, throw x, br(y, t, f))
+ EmitCXXThrowExpr(Throw, /*KeepInsertionPoint*/false);
+ return;
+ }
+
// Emit the code with the fully general case.
llvm::Value *CondV = EvaluateExprAsBool(Cond);
Builder.CreateCondBr(CondV, TrueBlock, FalseBlock);
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 08e60c4..ff74c15 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -2708,7 +2708,7 @@
}
void enterNonTrivialFullExpression(const ExprWithCleanups *E);
- void EmitCXXThrowExpr(const CXXThrowExpr *E);
+ void EmitCXXThrowExpr(const CXXThrowExpr *E, bool KeepInsertionPoint = true);
void EmitLambdaExpr(const LambdaExpr *E, AggValueSlot Dest);
diff --git a/test/CodeGenCXX/throw-expressions.cpp b/test/CodeGenCXX/throw-expressions.cpp
index f04185b..22d7841 100644
--- a/test/CodeGenCXX/throw-expressions.cpp
+++ b/test/CodeGenCXX/throw-expressions.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -emit-llvm-only -verify %s -Wno-unreachable-code
+// RUN: %clang_cc1 -fcxx-exceptions -fexceptions -Wno-unreachable-code -Werror -emit-llvm -o - %s | FileCheck %s
// expected-no-diagnostics
int val = 42;
@@ -19,3 +19,28 @@
int test4() {
return 1 ? throw val : val;
}
+
+// PR15923
+int test5(bool x, bool y, int z) {
+ return (x ? throw 1 : y) ? z : throw 2;
+}
+// CHECK: define i32 @_Z5test5bbi(
+// CHECK: br i1
+//
+// x.true:
+// CHECK: call void @__cxa_throw(
+// CHECK-NEXT: unreachable
+//
+// x.false:
+// CHECK: br i1
+//
+// y.true:
+// CHECK: load i32*
+// CHECK: br label
+//
+// y.false:
+// CHECK: call void @__cxa_throw(
+// CHECK-NEXT: unreachable
+//
+// end:
+// CHECK: ret i32
