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[ubsan] Null-check and adjust TypeLoc before using it
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Authored by vsk on Feb 10 2020, 1:38 PM.

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Details

Reviewers

erik.pilkington
delcypher

Commits

rG025b47d49987: [ubsan] Null-check and adjust TypeLoc before using it
rG8b81ebfe7eba: [ubsan] Null-check and adjust TypeLoc before using it

Summary

Null-check and adjut a TypeLoc before casting it to a FunctionTypeLoc.
This fixes a crash in -fsanitize=nullability-return, and also makes the
location of the nonnull type available when the return type is adjusted.

rdar://59263039

Diff Detail

Repository: rG LLVM Github Monorepo

Event Timeline

vsk created this revision.Feb 10 2020, 1:38 PM

Herald added a subscriber: dexonsmith. · View Herald TranscriptFeb 10 2020, 1:38 PM

Check adjusted return type per Erik's offline feedback.

LGTM!

This revision is now accepted and ready to land.Feb 10 2020, 2:06 PM

Closed by commit rG8b81ebfe7eba: [ubsan] Null-check and adjust TypeLoc before using it (authored by vsk). · Explain WhyFeb 10 2020, 2:15 PM

This revision was automatically updated to reflect the committed changes.

Herald added a project: Restricted Project. · View Herald TranscriptFeb 10 2020, 2:15 PM

Revision Contents

Path

Size

clang/

lib/

CodeGen/

CGCall.cpp

2 lines

test/

CodeGenObjCXX/

ubsan-nullability-return-notypeloc.mm

19 lines

Diff 243673

clang/lib/CodeGen/CGCall.cpp

Show First 20 Lines • Show All 3,054 Lines • ▼ Show 20 Lines	if (RetNNAttr) {
assert(!requiresReturnValueNullabilityCheck() &&		assert(!requiresReturnValueNullabilityCheck() &&
"Cannot check nullability and the nonnull attribute");		"Cannot check nullability and the nonnull attribute");
AttrLoc = RetNNAttr->getLocation();		AttrLoc = RetNNAttr->getLocation();
CheckKind = SanitizerKind::ReturnsNonnullAttribute;		CheckKind = SanitizerKind::ReturnsNonnullAttribute;
Handler = SanitizerHandler::NonnullReturn;		Handler = SanitizerHandler::NonnullReturn;
} else {		} else {
if (auto *DD = dyn_cast<DeclaratorDecl>(CurCodeDecl))		if (auto *DD = dyn_cast<DeclaratorDecl>(CurCodeDecl))
if (auto *TSI = DD->getTypeSourceInfo())		if (auto *TSI = DD->getTypeSourceInfo())
if (auto FTL = TSI->getTypeLoc().castAs<FunctionTypeLoc>())		if (auto FTL = TSI->getTypeLoc().getAsAdjusted<FunctionTypeLoc>())
AttrLoc = FTL.getReturnLoc().findNullabilityLoc();		AttrLoc = FTL.getReturnLoc().findNullabilityLoc();
CheckKind = SanitizerKind::NullabilityReturn;		CheckKind = SanitizerKind::NullabilityReturn;
Handler = SanitizerHandler::NullabilityReturn;		Handler = SanitizerHandler::NullabilityReturn;
}		}

SanitizerScope SanScope(this);		SanitizerScope SanScope(this);

// Make sure the "return" source location is valid. If we're checking a		// Make sure the "return" source location is valid. If we're checking a
▲ Show 20 Lines • Show All 1,745 Lines • Show Last 20 Lines

clang/test/CodeGenObjCXX/ubsan-nullability-return-notypeloc.mm

This file was added.

				// RUN: %clang_cc1 -fsanitize=nullability-return -emit-llvm %s -o - -triple x86_64-apple-macosx10.10.0 \| FileCheck %s

				// CHECK: [[ATTR_LOC:@[0-9]+]] = {{.}} global { {{.}} i32 15, i32 38

				// CHECK-LABEL: define i8* @_Z3foov()
				// CHECK: [[CALL:%.]] = call i8 @_Z6helperv()
				// CHECK: icmp ne i8* [[CALL]]
				// CHECK: call void @__ubsan_handle_nullability_return_v1_abort({{.*}}[[ATTR_LOC]]

				struct S {
				using PtrTy = id;
				};

				#pragma clang assume_nonnull begin
				__attribute__((ns_returns_retained)) S::PtrTy foo(void) {
				extern S::PtrTy helper(void);
				return helper();
				}
				#pragma clang assume_nonnull end