[PATCH] D95070: Fix crash when emitting NullReturn guards for functions returning BOOL

[Jon Roelofs via Phabricator via cfe-commits]

jroelofs created this revision.
jroelofs added reviewers: rjmccall, arphaman.
jroelofs requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

CodeGenModule::EmitNullConstant() creates constants with their "in memory" type, not their "in vregs" type. The one place where this difference matters is when the type is _Bool, as that is an i1 when in vregs and an i8 in memory.

Fixes: rdar://73361264


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D95070

Files:
  clang/lib/CodeGen/CGObjCMac.cpp
  clang/test/CodeGenObjC/null-check-bool-ret.m


Index: clang/test/CodeGenObjC/null-check-bool-ret.m
===================================================================
--- /dev/null
+++ clang/test/CodeGenObjC/null-check-bool-ret.m
@@ -0,0 +1,38 @@
+// RUN: %clang_cc1 -triple arm64e-apple-ios15.0.0 -emit-llvm-bc -fobjc-arc -disable-llvm-passes %s -emit-llvm -o - | FileCheck %s
+
+// rdar://73361264
+
+ at protocol NSObject
+ at end
+
+ at interface NSObject <NSObject>
+ at end
+
+ at interface WidgetTester : NSObject
+ at end
+
+ at implementation WidgetTester
+
+typedef struct {
+    NSObject* impl;
+} widget_t;
+
+- (_Bool)withWidget:(widget_t)widget {
+    return 0;
+}
+
+- (_Bool)testWidget:(widget_t)widget {
+    return [self withWidget:widget];
+}
+
+ at end
+
+// CHECK-LABEL: msgSend.call:
+// CHECK: [[CALL:%[^ ]+]] = call i1 bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to
+// CHECK-NEXT: br label %msgSend.cont
+
+// CHECK-LABEL: msgSend.null-receiver:
+// CHECK: br label %msgSend.cont
+
+// CHECK-LABEL: msgSend.cont:
+// CHECK-NEXT: {{%[^ ]+}} = phi i1 [ [[CALL]], %msgSend.call ], [ false, %msgSend.null-receiver ]
Index: clang/lib/CodeGen/CGObjCMac.cpp
===================================================================
--- clang/lib/CodeGen/CGObjCMac.cpp
+++ clang/lib/CodeGen/CGObjCMac.cpp
@@ -1800,7 +1800,8 @@
     // If we've got a scalar return, build a phi.
     if (result.isScalar()) {
       // Derive the null-initialization value.
-      llvm::Constant *null = CGF.CGM.EmitNullConstant(resultType);
+      llvm::Value *null = CGF.EmitFromMemory(
+        CGF.CGM.EmitNullConstant(resultType), resultType);
 
       // If no join is necessary, just flow out.
       if (!contBB) return RValue::get(null);


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