[ASan] Collect unmangled names of global variables in Clang to print them in error reports.
Currently ASan instrumentation pass creates a string with global name
for each instrumented global (to include global names in the error report). Global
name is already mangled at this point, and we may not be able to demangle it
at runtime (e.g. there is no __cxa_demangle on Android).
Instead, create a string with fully qualified global name in Clang, and pass it
to ASan instrumentation pass in llvm.asan.globals metadata. If there is no metadata
for some global, ASan will use the original algorithm.
This fixes https://code.google.com/p/address-sanitizer/issues/detail?id=264.
llvm-svn: 212872
diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 9bd61d7..91f8041 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -345,7 +345,7 @@
DMEntry = castedAddr;
CGM.setStaticLocalDeclAddress(&D, castedAddr);
- CGM.reportGlobalToASan(var, D.getLocation());
+ CGM.reportGlobalToASan(var, D);
// Emit global variable debug descriptor for static vars.
CGDebugInfo *DI = getDebugInfo();
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 2f87392..66ac524 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1952,7 +1952,7 @@
if (NeedsGlobalCtor || NeedsGlobalDtor)
EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor);
- reportGlobalToASan(GV, D->getLocation(), NeedsGlobalCtor);
+ reportGlobalToASan(GV, *D, NeedsGlobalCtor);
// Emit global variable debug information.
if (CGDebugInfo *DI = getModuleDebugInfo())
@@ -1961,24 +1961,25 @@
}
void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV,
- SourceLocation Loc, bool IsDynInit) {
+ SourceLocation Loc, StringRef Name,
+ bool IsDynInit) {
if (!LangOpts.Sanitize.Address)
return;
IsDynInit &= !SanitizerBL.isIn(*GV, "init");
bool IsBlacklisted = SanitizerBL.isIn(*GV);
- llvm::LLVMContext &LLVMCtx = TheModule.getContext();
-
llvm::GlobalVariable *LocDescr = nullptr;
+ llvm::GlobalVariable *GlobalName = nullptr;
if (!IsBlacklisted) {
- // Don't generate source location if a global is blacklisted - it won't
- // be instrumented anyway.
+ // Don't generate source location and global name if it is blacklisted -
+ // it won't be instrumented anyway.
PresumedLoc PLoc = Context.getSourceManager().getPresumedLoc(Loc);
if (PLoc.isValid()) {
llvm::Constant *LocData[] = {
GetAddrOfConstantCString(PLoc.getFilename()),
- llvm::ConstantInt::get(llvm::Type::getInt32Ty(LLVMCtx), PLoc.getLine()),
- llvm::ConstantInt::get(llvm::Type::getInt32Ty(LLVMCtx),
+ llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
+ PLoc.getLine()),
+ llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
PLoc.getColumn()),
};
auto LocStruct = llvm::ConstantStruct::getAnon(LocData);
@@ -1990,14 +1991,17 @@
// the optimizer before the ASan instrumentation pass.
addCompilerUsedGlobal(LocDescr);
}
+ if (!Name.empty()) {
+ GlobalName = GetAddrOfConstantCString(Name);
+ // GlobalName shouldn't be removed by the optimizer.
+ addCompilerUsedGlobal(GlobalName);
+ }
}
llvm::Value *GlobalMetadata[] = {
- GV,
- LocDescr,
- llvm::ConstantInt::get(llvm::Type::getInt1Ty(LLVMCtx), IsDynInit),
- llvm::ConstantInt::get(llvm::Type::getInt1Ty(LLVMCtx), IsBlacklisted)
- };
+ GV, LocDescr, GlobalName,
+ llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsDynInit),
+ llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsBlacklisted)};
llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalMetadata);
llvm::NamedMDNode *AsanGlobals =
@@ -2005,6 +2009,16 @@
AsanGlobals->addOperand(ThisGlobal);
}
+void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV,
+ const VarDecl &D, bool IsDynInit) {
+ if (!LangOpts.Sanitize.Address)
+ return;
+ std::string QualName;
+ llvm::raw_string_ostream OS(QualName);
+ D.printQualifiedName(OS);
+ reportGlobalToASan(GV, D.getLocation(), OS.str(), IsDynInit);
+}
+
static bool isVarDeclStrongDefinition(const VarDecl *D, bool NoCommon) {
// Don't give variables common linkage if -fno-common was specified unless it
// was overridden by a NoCommon attribute.
@@ -2810,7 +2824,7 @@
if (Entry)
Entry->setValue(GV);
- reportGlobalToASan(GV, S->getStrTokenLoc(0));
+ reportGlobalToASan(GV, S->getStrTokenLoc(0), "<string literal>");
return GV;
}
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 3425469..d6b694a 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -1015,8 +1015,10 @@
return SanitizerBL;
}
- void reportGlobalToASan(llvm::GlobalVariable *GV, SourceLocation Loc,
+ void reportGlobalToASan(llvm::GlobalVariable *GV, const VarDecl &D,
bool IsDynInit = false);
+ void reportGlobalToASan(llvm::GlobalVariable *GV, SourceLocation Loc,
+ StringRef Name, bool IsDynInit = false);
void addDeferredVTable(const CXXRecordDecl *RD) {
DeferredVTables.push_back(RD);