[PATCH] D53459: Ensure sanitizer check function calls have a !dbg location

[Adrian Prantl via Phabricator via cfe-commits]

aprantl added inline comments.


================
Comment at: lib/CodeGen/CGExpr.cpp:2871
+  auto *DI = CGF.getDebugInfo();
+  SourceLocation Loc = DI ? DI->getLocation() : SourceLocation();
+  auto DL = ApplyDebugLocation::CreateDefaultArtificial(CGF, Loc);
----------------
vsk wrote:
> Why shouldn't this always be line 0? A call to a check handler is always auto-generated.
I was thinking that it might be nice to have the source location of the expression with the UB in the backtrace, too — not just in the error message. (Which is the current behavior by accident, since no location means carry over the previous instruction's location). But I'm fine with just setting line 0, too.


================
Comment at: test/CodeGenCXX/ubsan-check-debuglocs.cpp:2
+// RUN: %clang_cc1 -emit-llvm -debug-info-kind=limited \
+// RUN:   -fsanitize=null,object-size,return -fsanitize-recover=null \
+// RUN:   %s -o - | FileCheck %s
----------------
vsk wrote:
> Are all three sanitizers needed here to reproduce the bug? Seems like a simpler test would be:
> 
> ```
> // RUN: ... -fsanitize=null ...
> 
> int deref(int *p) { return *p; }
> // CHECK-LABEL: @deref
> // CHECK: __ubsan_handle_type_mismatch_v1{{.*}} !dbg [[ubsan_handler_loc:![0-9]+]]
> // CHECK: [[ubsan_handler_loc]] = !DILocation(line: 0
> ```
Probably not for the testcase; only to trigger the subsequent crash.


https://reviews.llvm.org/D53459