[ubsan] Improve diagnostics for return value checks (clang)
This patch makes ubsan's nonnull return value diagnostics more precise,
which makes the diagnostics more useful when there are multiple return
statements in a function. Example:
1 |__attribute__((returns_nonnull)) char *foo() {
2 | if (...) {
3 | return expr_which_might_evaluate_to_null();
4 | } else {
5 | return another_expr_which_might_evaluate_to_null();
6 | }
7 |} // <- The current diagnostic always points here!
runtime error: Null returned from Line 7, Column 2!
With this patch, the diagnostic would point to either Line 3, Column 5
or Line 5, Column 5.
This is done by emitting source location metadata for each return
statement in a sanitized function. The runtime is passed a pointer to
the appropriate metadata so that it can prepare and deduplicate reports.
Compiler-rt patch (with more tests): https://reviews.llvm.org/D34298
Differential Revision: https://reviews.llvm.org/D34299
llvm-svn: 306163
diff --git a/clang/test/CodeGenObjC/ubsan-nullability.m b/clang/test/CodeGenObjC/ubsan-nullability.m
index 7f53ea62..eeb24b0 100644
--- a/clang/test/CodeGenObjC/ubsan-nullability.m
+++ b/clang/test/CodeGenObjC/ubsan-nullability.m
@@ -2,7 +2,7 @@
// RUN: %clang_cc1 -x objective-c -emit-llvm -triple x86_64-apple-macosx10.10.0 -fsanitize=nullability-arg,nullability-assign,nullability-return -w %s -o - | FileCheck %s
// RUN: %clang_cc1 -x objective-c++ -emit-llvm -triple x86_64-apple-macosx10.10.0 -fsanitize=nullability-arg,nullability-assign,nullability-return -w %s -o - | FileCheck %s
-// CHECK: [[NONNULL_RV_LOC1:@.*]] = private unnamed_addr global {{.*}} i32 109, i32 1 {{.*}} i32 100, i32 6
+// CHECK: [[NONNULL_RV_LOC1:@.*]] = private unnamed_addr global {{.*}} i32 100, i32 6
// CHECK: [[NONNULL_ARG_LOC:@.*]] = private unnamed_addr global {{.*}} i32 204, i32 15 {{.*}} i32 190, i32 23
// CHECK: [[NONNULL_ASSIGN1_LOC:@.*]] = private unnamed_addr global {{.*}} i32 305, i32 9
// CHECK: [[NONNULL_ASSIGN2_LOC:@.*]] = private unnamed_addr global {{.*}} i32 405, i32 10
@@ -10,7 +10,7 @@
// CHECK: [[NONNULL_INIT1_LOC:@.*]] = private unnamed_addr global {{.*}} i32 604, i32 25
// CHECK: [[NONNULL_INIT2_LOC1:@.*]] = private unnamed_addr global {{.*}} i32 707, i32 26
// CHECK: [[NONNULL_INIT2_LOC2:@.*]] = private unnamed_addr global {{.*}} i32 707, i32 29
-// CHECK: [[NONNULL_RV_LOC2:@.*]] = private unnamed_addr global {{.*}} i32 817, i32 1 {{.*}} i32 800, i32 6
+// CHECK: [[NONNULL_RV_LOC2:@.*]] = private unnamed_addr global {{.*}} i32 800, i32 6
#define NULL ((void *)0)
#define INULL ((int *)NULL)
@@ -19,14 +19,11 @@
// CHECK-LABEL: define i32* @{{.*}}nonnull_retval1
#line 100
int *_Nonnull nonnull_retval1(int *p) {
- // CHECK: br i1 true, label %[[NULL:.*]], label %[[NONULL:.*]], !nosanitize
- // CHECK: [[NULL]]:
// CHECK: [[ICMP:%.*]] = icmp ne i32* {{.*}}, null, !nosanitize
- // CHECK-NEXT: br i1 [[ICMP]], {{.*}}, !nosanitize
+ // CHECK: br i1 [[ICMP]], {{.*}}, !nosanitize
// CHECK: call void @__ubsan_handle_nullability_return{{.*}}[[NONNULL_RV_LOC1]]
return p;
- // CHECK: [[NONULL]]:
- // CHECK-NEXT: ret i32*
+ // CHECK: ret i32*
}
#line 190
@@ -108,10 +105,13 @@
// CHECK-NEXT: [[DO_RV_CHECK_1:%.*]] = and i1 true, [[ARG1CMP]], !nosanitize
// CHECK: [[ARG2CMP:%.*]] = icmp ne i32* %arg2, null, !nosanitize
// CHECK-NEXT: [[DO_RV_CHECK_2:%.*]] = and i1 [[DO_RV_CHECK_1]], [[ARG2CMP]]
- // CHECK: br i1 [[DO_RV_CHECK_2]], label %[[NULL:.*]], label %[[NONULL:.*]], !nosanitize
+ // CHECK: [[SLOC_PTR:%.*]] = load i8*, i8** %return.sloc.ptr
+ // CHECK-NEXT: [[SLOC_NONNULL:%.*]] = icmp ne i8* [[SLOC_PTR]], null
+ // CHECK-NEXT: [[DO_RV_CHECK_3:%.*]] = and i1 [[SLOC_NONNULL]], [[DO_RV_CHECK_2]]
+ // CHECK: br i1 [[DO_RV_CHECK_3]], label %[[NULL:.*]], label %[[NONULL:.*]], !nosanitize
// CHECK: [[NULL]]:
// CHECK-NEXT: [[ICMP:%.*]] = icmp ne i32* {{.*}}, null, !nosanitize
- // CHECK-NEXT: br i1 [[ICMP]], {{.*}}, !nosanitize
+ // CHECK: br i1 [[ICMP]], {{.*}}, !nosanitize
// CHECK: call void @__ubsan_handle_nullability_return{{.*}}[[NONNULL_RV_LOC2]]
return arg1;
// CHECK: [[NONULL]]:
@@ -129,10 +129,13 @@
+(int *_Nonnull) objc_clsmethod: (int *_Nonnull) arg1 {
// CHECK: [[ARG1CMP:%.*]] = icmp ne i32* %arg1, null, !nosanitize
// CHECK-NEXT: [[DO_RV_CHECK:%.*]] = and i1 true, [[ARG1CMP]]
- // CHECK: br i1 [[DO_RV_CHECK]], label %[[NULL:.*]], label %[[NONULL:.*]], !nosanitize
+ // CHECK: [[SLOC_PTR:%.*]] = load i8*, i8** %return.sloc.ptr
+ // CHECK-NEXT: [[SLOC_NONNULL:%.*]] = icmp ne i8* [[SLOC_PTR]], null
+ // CHECK-NEXT: [[DO_RV_CHECK_2:%.*]] = and i1 [[SLOC_NONNULL]], [[DO_RV_CHECK]]
+ // CHECK: br i1 [[DO_RV_CHECK_2]], label %[[NULL:.*]], label %[[NONULL:.*]], !nosanitize
// CHECK: [[NULL]]:
// CHECK-NEXT: [[ICMP:%.*]] = icmp ne i32* {{.*}}, null, !nosanitize
- // CHECK-NEXT: br i1 [[ICMP]], {{.*}}, !nosanitize
+ // CHECK: br i1 [[ICMP]], {{.*}}, !nosanitize
// CHECK: call void @__ubsan_handle_nullability_return{{.*}}
return arg1;
// CHECK: [[NONULL]]:
@@ -143,10 +146,13 @@
-(int *_Nonnull) objc_method: (int *_Nonnull) arg1 {
// CHECK: [[ARG1CMP:%.*]] = icmp ne i32* %arg1, null, !nosanitize
// CHECK-NEXT: [[DO_RV_CHECK:%.*]] = and i1 true, [[ARG1CMP]]
- // CHECK: br i1 [[DO_RV_CHECK]], label %[[NULL:.*]], label %[[NONULL:.*]], !nosanitize
+ // CHECK: [[SLOC_PTR:%.*]] = load i8*, i8** %return.sloc.ptr
+ // CHECK-NEXT: [[SLOC_NONNULL:%.*]] = icmp ne i8* [[SLOC_PTR]], null
+ // CHECK-NEXT: [[DO_RV_CHECK_2:%.*]] = and i1 [[SLOC_NONNULL]], [[DO_RV_CHECK]]
+ // CHECK: br i1 [[DO_RV_CHECK_2]], label %[[NULL:.*]], label %[[NONULL:.*]], !nosanitize
// CHECK: [[NULL]]:
// CHECK-NEXT: [[ICMP:%.*]] = icmp ne i32* {{.*}}, null, !nosanitize
- // CHECK-NEXT: br i1 [[ICMP]], {{.*}}, !nosanitize
+ // CHECK: br i1 [[ICMP]], {{.*}}, !nosanitize
// CHECK: call void @__ubsan_handle_nullability_return{{.*}}
return arg1;
// CHECK: [[NONULL]]: