Revert "[asan] Instrument comdat globals on COFF targets"

Causes false positive ODR violation reports on __llvm_profile_raw_version.

llvm-svn: 335681

2 files changed, 8 insertions, 79 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index c8a46087d9b..b33cc5e7c2e 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1653,6 +1653,14 @@ bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
   if (!Ty->isSized()) return false;
   if (!G->hasInitializer()) return false;
   if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
+  // Touch only those globals that will not be defined in other modules.
+  // Don't handle ODR linkage types and COMDATs since other modules may be built
+  // without ASan.
+  if (G->getLinkage() != GlobalVariable::ExternalLinkage &&
+      G->getLinkage() != GlobalVariable::PrivateLinkage &&
+      G->getLinkage() != GlobalVariable::InternalLinkage)
+    return false;
+  if (G->hasComdat()) return false;
   // Two problems with thread-locals:
   //   - The address of the main thread's copy can't be computed at link-time.
   //   - Need to poison all copies, not just the main thread's one.
@@ -1660,38 +1668,6 @@ bool AddressSanitizerModule::ShouldInstrumentGlobal(GlobalVariable *G) {
   // For now, just ignore this Global if the alignment is large.
   if (G->getAlignment() > MinRedzoneSizeForGlobal()) return false;
 
-  // If we know this global is defined only in this module (external or static),
-  // we can instrument it.
-  if (G->getLinkage() != GlobalVariable::ExternalLinkage &&
-      G->getLinkage() != GlobalVariable::PrivateLinkage &&
-      G->getLinkage() != GlobalVariable::InternalLinkage) {
-    // For targets that support comdats, we can instrument ODR globals in
-    // comdats. We simply add our global metadata to the group and hope that an
-    // instrumented global is selected.
-    // FIXME: This should work on ELF, enable it there too.
-    if (!TargetTriple.isOSBinFormatCOFF())
-      return false;
-    if (G->getLinkage() != GlobalVariable::WeakODRLinkage &&
-        G->getLinkage() != GlobalVariable::LinkOnceODRLinkage)
-      return false;
-    if (!G->hasComdat())
-      return false;
-  }
-
-  // If a comdat is present, it must have a selection kind that implies ODR
-  // semantics: no duplicates, any, or exact match.
-  if (Comdat *C = G->getComdat()) {
-    switch (C->getSelectionKind()) {
-    case Comdat::Any:
-    case Comdat::ExactMatch:
-    case Comdat::NoDuplicates:
-      break;
-    case Comdat::Largest:
-    case Comdat::SameSize:
-      return false;
-    }
-  }
-
   if (G->hasSection()) {
     StringRef Section = G->getSection();
 
@@ -2145,7 +2121,6 @@ bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool
         new GlobalVariable(M, NewTy, G->isConstant(), Linkage, NewInitializer,
                            "", G, G->getThreadLocalMode());
     NewGlobal->copyAttributesFrom(G);
-    NewGlobal->setComdat(G->getComdat());
     NewGlobal->setAlignment(MinRZ);
 
     // Move null-terminated C strings to "__asan_cstring" section on Darwin.
diff --git a/llvm/test/Instrumentation/AddressSanitizer/win-string-literal.ll b/llvm/test/Instrumentation/AddressSanitizer/win-string-literal.ll
deleted file mode 100644
index f3ea1e94a59..00000000000
--- a/llvm/test/Instrumentation/AddressSanitizer/win-string-literal.ll
+++ /dev/null
@@ -1,46 +0,0 @@
-; RUN: opt < %s -asan -asan-module -S | FileCheck %s
-
-; Generated like so:
-; $ clang -S -emit-llvm -Xclang -disable-llvm-passes -fsanitize=address -O1 t.cpp -o t.ll
-; const char *getstr() { return "asdf"; }
-
-; CHECK: $"??_C@_04JIHMPGLA@asdf?$AA@" = comdat any
-
-; CHECK: @"??_C@_04JIHMPGLA@asdf?$AA@" =
-; CHECK-SAME: linkonce_odr dso_local unnamed_addr constant { [5 x i8], [59 x i8] }
-; CHECK-SAME: { [5 x i8] c"asdf\00", [59 x i8] zeroinitializer }, comdat, align 32
-
-; CHECK: @"__asan_global_??_C@_04JIHMPGLA@asdf?$AA@" =
-; CHECK-SAME: private global { i64, i64, i64, i64, i64, i64, i64, i64 }
-; CHECK-SAME: { i64 ptrtoint ({ [5 x i8], [59 x i8] }* @"??_C@_04JIHMPGLA@asdf?$AA@" to i64),
-; CHECK-SAME:   i64 5, i64 64, i64 ptrtoint ([17 x i8]* @__asan_gen_.1 to i64),
-; CHECK-SAME:   i64 ptrtoint ([8 x i8]* @__asan_gen_ to i64), i64 0,
-; CHECK-SAME:   i64 ptrtoint ({ [6 x i8]*, i32, i32 }* @__asan_gen_.3 to i64), i64 0 },
-; CHECK-SAME:   section ".ASAN$GL", comdat($"??_C@_04JIHMPGLA@asdf?$AA@"), align 64
-
-; ModuleID = 't.cpp'
-source_filename = "t.cpp"
-target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64-pc-windows-msvc19.13.26131"
-
-$"??_C@_04JIHMPGLA@asdf?$AA@" = comdat any
-
-@"??_C@_04JIHMPGLA@asdf?$AA@" = linkonce_odr dso_local unnamed_addr constant [5 x i8] c"asdf\00", comdat, align 1
-
-; Function Attrs: nounwind sanitize_address uwtable
-define dso_local i8* @"?getstr@@YAPEBDXZ"() #0 {
-entry:
-  ret i8* getelementptr inbounds ([5 x i8], [5 x i8]* @"??_C@_04JIHMPGLA@asdf?$AA@", i32 0, i32 0)
-}
-
-attributes #0 = { nounwind sanitize_address uwtable }
-
-!llvm.asan.globals = !{!0}
-!llvm.module.flags = !{!2, !3}
-!llvm.ident = !{!4}
-
-!0 = !{[5 x i8]* @"??_C@_04JIHMPGLA@asdf?$AA@", !1, !"<string literal>", i1 false, i1 false}
-!1 = !{!"t.cpp", i32 1, i32 31}
-!2 = !{i32 1, !"wchar_size", i32 2}
-!3 = !{i32 7, !"PIC Level", i32 2}
-!4 = !{!"clang version 7.0.0 "}