[clang] [TySan] Don't report globals with external storage. (PR #120565)

[Florian Hahn via cfe-commits]

https://github.com/fhahn updated https://github.com/llvm/llvm-project/pull/120565

>From 75b6f8923dcb386d3520dbde762f3855af73aed4 Mon Sep 17 00:00:00 2001
From: Florian Hahn <flo at fhahn.com>
Date: Thu, 19 Dec 2024 11:39:20 +0000
Subject: [PATCH] [TySan] Don't report globals with external storage.

Globals with external storage should have been initialized where they
are defined.

Fixes https://github.com/llvm/llvm-project/issues/120448
---
 clang/lib/CodeGen/SanitizerMetadata.cpp      |  3 +
 clang/test/CodeGen/sanitize-type-globals.cpp | 58 ++++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 clang/test/CodeGen/sanitize-type-globals.cpp

diff --git a/clang/lib/CodeGen/SanitizerMetadata.cpp b/clang/lib/CodeGen/SanitizerMetadata.cpp
index 405124c8b87170..61fdf3399ff3c3 100644
--- a/clang/lib/CodeGen/SanitizerMetadata.cpp
+++ b/clang/lib/CodeGen/SanitizerMetadata.cpp
@@ -145,6 +145,9 @@ void SanitizerMetadata::reportGlobal(llvm::GlobalVariable *GV, const VarDecl &D,
     for (auto *Attr : D.specific_attrs<NoSanitizeAttr>())
       NoSanitizeMask |= Attr->getMask();
 
+    if (D.hasExternalStorage())
+      NoSanitizeMask |= SanitizerKind::Type;
+
     return NoSanitizeMask;
   };
 
diff --git a/clang/test/CodeGen/sanitize-type-globals.cpp b/clang/test/CodeGen/sanitize-type-globals.cpp
new file mode 100644
index 00000000000000..7cb8de8b238cc8
--- /dev/null
+++ b/clang/test/CodeGen/sanitize-type-globals.cpp
@@ -0,0 +1,58 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --check-globals all --filter-out "attributes" --filter-out "attributes #" --version 5
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s -fsanitize=type | FileCheck -check-prefix=CHECK %s
+
+//.
+// CHECK: @x = global %struct.CompleteS zeroinitializer, align 8
+// CHECK: @y = external global %struct.S, align 1
+// CHECK: @__tysan_shadow_memory_address = external global i64
+// CHECK: @__tysan_app_memory_mask = external global i64
+// CHECK: @__tysan_v1_Simple_20C_2b_2b_20TBAA = linkonce_odr constant { i64, i64, [16 x i8] } { i64 2, i64 0, [16 x i8] c"Simple C++ TBAA\00" }, comdat
+// CHECK: @__tysan_v1_omnipotent_20char = linkonce_odr constant { i64, i64, ptr, i64, [16 x i8] } { i64 2, i64 1, ptr @__tysan_v1_Simple_20C_2b_2b_20TBAA, i64 0, [16 x i8] c"omnipotent char\00" }, comdat
+// CHECK: @__tysan_v1_int = linkonce_odr constant { i64, i64, ptr, i64, [4 x i8] } { i64 2, i64 1, ptr @__tysan_v1_omnipotent_20char, i64 0, [4 x i8] c"int\00" }, comdat
+// CHECK: @__tysan_v1_any_20pointer = linkonce_odr constant { i64, i64, ptr, i64, [12 x i8] } { i64 2, i64 1, ptr @__tysan_v1_omnipotent_20char, i64 0, [12 x i8] c"any pointer\00" }, comdat
+// CHECK: @__tysan_v1_p1_20int = linkonce_odr constant { i64, i64, ptr, i64, [7 x i8] } { i64 2, i64 1, ptr @__tysan_v1_any_20pointer, i64 0, [7 x i8] c"p1 int\00" }, comdat
+// CHECK: @__tysan_v1___ZTS9CompleteS = linkonce_odr constant { i64, i64, ptr, i64, ptr, i64, [15 x i8] } { i64 2, i64 2, ptr @__tysan_v1_int, i64 0, ptr @__tysan_v1_p1_20int, i64 8, [15 x i8] c"_ZTS9CompleteS\00" }, comdat
+// CHECK: @llvm.used = appending global [7 x ptr] [ptr @tysan.module_ctor, ptr @__tysan_v1_Simple_20C_2b_2b_20TBAA, ptr @__tysan_v1_omnipotent_20char, ptr @__tysan_v1_int, ptr @__tysan_v1_any_20pointer, ptr @__tysan_v1_p1_20int, ptr @__tysan_v1___ZTS9CompleteS], section "llvm.metadata"
+// CHECK: @llvm.global_ctors = appending global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 0, ptr @tysan.module_ctor, ptr null }]
+//.
+struct CompleteS {
+  int x;
+  int *ptr;
+};
+
+void f(CompleteS *);
+CompleteS x;
+// CHECK-LABEL: define dso_local void @_Z1gv(
+// CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+// CHECK:  [[ENTRY:.*:]]
+// CHECK:    call void @_Z1fP9CompleteS(ptr noundef @x)
+// CHECK:    ret void
+//
+void g() { f(&x); }
+
+typedef struct S IncompleteS;
+void f(IncompleteS *);
+extern IncompleteS y;
+// CHECK-LABEL: define dso_local void @_Z1hv(
+// CHECK-SAME: ) #[[ATTR0]] {
+// CHECK:  [[ENTRY:.*:]]
+// CHECK:    call void @_Z1fP1S(ptr noundef @y)
+// CHECK:    ret void
+//
+void h() { f(&y); }
+//.
+// CHECK: attributes #[[ATTR0]] = { mustprogress noinline nounwind optnone sanitize_type "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+// CHECK: attributes #[[ATTR1:[0-9]+]] = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+// CHECK: attributes #[[ATTR2:[0-9]+]] = { nounwind "target-features"="+cx8,+mmx,+sse,+sse2,+x87" }
+// CHECK: attributes #[[ATTR3:[0-9]+]] = { nounwind }
+//.
+// CHECK: [[META0:![0-9]+]] = !{ptr @x, [[META1:![0-9]+]]}
+// CHECK: [[META1]] = !{!"_ZTS9CompleteS", [[META2:![0-9]+]], i64 0, [[META5:![0-9]+]], i64 8}
+// CHECK: [[META2]] = !{!"int", [[META3:![0-9]+]], i64 0}
+// CHECK: [[META3]] = !{!"omnipotent char", [[META4:![0-9]+]], i64 0}
+// CHECK: [[META4]] = !{!"Simple C++ TBAA"}
+// CHECK: [[META5]] = !{!"p1 int", [[META6:![0-9]+]], i64 0}
+// CHECK: [[META6]] = !{!"any pointer", [[META3]], i64 0}
+// CHECK: [[META7:![0-9]+]] = !{i32 1, !"wchar_size", i32 4}
+// CHECK: [[META8:![0-9]+]] = !{!"{{.*}}clang version {{.*}}"}
+//.