Subzero: Replace pointers to allocation functions in loads

src/IceASanInstrumentation.cpp

Index: src/IceASanInstrumentation.cpp
diff --git a/src/IceASanInstrumentation.cpp b/src/IceASanInstrumentation.cpp
index e7c531bdec2030f062926a6246affa827c8a5d0b..e245e299bc4606484eac82ab51d83ff8839c1398 100644
--- a/src/IceASanInstrumentation.cpp
+++ b/src/IceASanInstrumentation.cpp
@@ -363,6 +363,26 @@ void ASanInstrumentation::instrumentCall(LoweringContext &Context,
 
 void ASanInstrumentation::instrumentLoad(LoweringContext &Context,
                                          InstLoad *Instr) {
+  Operand *Src = Instr->getSourceAddress();
+  auto *Reloc = llvm::dyn_cast<ConstantRelocatable>(Src);
+  if (Reloc != nullptr) {

[Jim Stichnoth, 2016/08/16 21:36:46]

if (auto *Reloc = llvm::dyn_cast<ConstantRelocatable>(Src)) {

[tlively, 2016/08/16 21:55:38]

Done.

+    std::string SrcName = Reloc->getName().toStringOrEmpty();
+    assert(!SrcName.empty());
+    StringMap::const_iterator SrcSub = FuncSubstitutions.find(SrcName);
+    if (SrcSub != FuncSubstitutions.end()) {
+      auto *NewSrc = ConstantRelocatable::create(
+          Ctx, Reloc->getType(),
+          RelocatableTuple(Reloc->getOffset(), RelocOffsetArray(0),
+                           Ctx->getGlobalString(SrcSub->second),
+                           Reloc->getEmitString()));
+      auto *NewLoad = InstLoad::create(Context.getNode()->getCfg(),
+                                       Instr->getDest(), NewSrc);
+      Instr->setDeleted();
+      Context.insert(NewLoad);
+      instrumentLoad(Context, NewLoad);

[Karl, 2016/08/16 21:38:43]

Do you need to recurse here? It looks like you just need to set Inst to NewLoad
and continue.

[tlively, 2016/08/16 21:55:38]

Done.

+      return;
+    }
+  }
   Constant *Func =
       Ctx->getConstantExternSym(Ctx->getGlobalString("__asan_check_load"));
   instrumentAccess(Context, Instr->getSourceAddress(),
@@ -417,7 +437,8 @@ void ASanInstrumentation::instrumentAccess(LoweringContext &Context,
   Context.setNext(Next);
 }
 
-// TODO(tlively): Trace back load and store addresses to find their real offsets
+// TODO(tlively): Trace back load and store addresses to find their real

[Jim Stichnoth, 2016/08/16 21:36:46]

Why did this line change?

[tlively, 2016/08/16 21:55:38]

Done.

+// offsets
 bool ASanInstrumentation::isOkGlobalAccess(Operand *Op, SizeT Size) {
   auto *Reloc = llvm::dyn_cast<ConstantRelocatable>(Op);
   if (Reloc == nullptr)