[ASan] Improve blacklisting of global variables.

This commit changes the way we blacklist global variables in ASan.
Now the global is excluded from instrumentation (either regular
bounds checking, or initialization-order checking) if:

1) Global is explicitly blacklisted by its mangled name.
This part is left unchanged.

2) SourceLocation of a global is in blacklisted source file.
This changes the old behavior, where instead of looking at the
SourceLocation of a variable we simply considered llvm::Module
identifier. This was wrong, as identifier may not correspond to
the file name, and we incorrectly disabled instrumentation
for globals coming from #include'd files.

3) Global is blacklisted by type.
Now we build the type of a global variable using Clang machinery
(QualType::getAsString()), instead of llvm::StructType::getName().

After this commit, the active users of ASan blacklist files
may have to revisit them (this is a backwards-incompatible change).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220097 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 18 deletions

diff --git a/lib/Basic/SanitizerBlacklist.cpp b/lib/Basic/SanitizerBlacklist.cpp
index 2f4bdb5113..9b2cdfd4f5 100644
--- a/lib/Basic/SanitizerBlacklist.cpp
+++ b/lib/Basic/SanitizerBlacklist.cpp
@@ -12,31 +12,16 @@
 //
 //===----------------------------------------------------------------------===//
 #include "clang/Basic/SanitizerBlacklist.h"
-#include "llvm/IR/GlobalValue.h"
-#include "llvm/IR/Module.h"
 
 using namespace clang;
 
-static StringRef GetGlobalTypeString(const llvm::GlobalValue &G) {
-  // Types of GlobalVariables are always pointer types.
-  llvm::Type *GType = G.getType()->getElementType();
-  // For now we support blacklisting struct types only.
-  if (llvm::StructType *SGType = dyn_cast<llvm::StructType>(GType)) {
-    if (!SGType->isLiteral())
-      return SGType->getName();
-  }
-  return "<unknown type>";
-}
-
 SanitizerBlacklist::SanitizerBlacklist(StringRef BlacklistPath,
                                        SourceManager &SM)
     : SCL(llvm::SpecialCaseList::createOrDie(BlacklistPath)), SM(SM) {}
 
-bool SanitizerBlacklist::isIn(const llvm::GlobalVariable &G,
-                              StringRef Category) const {
-  return isBlacklistedFile(G.getParent()->getModuleIdentifier(), Category) ||
-         SCL->inSection("global", G.getName(), Category) ||
-         SCL->inSection("type", GetGlobalTypeString(G), Category);
+bool SanitizerBlacklist::isBlacklistedGlobal(StringRef GlobalName,
+                                             StringRef Category) const {
+  return SCL->inSection("global", GlobalName, Category);
 }
 
 bool SanitizerBlacklist::isBlacklistedType(StringRef MangledTypeName,