[NewPM] Port Msan

Summary:
Keeping msan a function pass requires replacing the module level initialization:
That means, don't define a ctor function which calls __msan_init, instead just
declare the init function at the first access, and add that to the global ctors
list.

Changes:
- Pull the actual sanitizer and the wrapper pass apart.
- Add a newpm msan pass. The function pass inserts calls to runtime
  library functions, for which it inserts declarations as necessary.
- Update tests.

Caveats:
- There is one test that I dropped, because it specifically tested the
  definition of the ctor.

Reviewers: chandlerc, fedor.sergeev, leonardchan, vitalybuka

Subscribers: sdardis, nemanjai, javed.absar, hiraditya, kbarton, bollu, atanasyan, jsji

Differential Revision: https://reviews.llvm.org/D55647

llvm-svn: 350305

1 files changed, 21 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/ModuleUtils.cpp b/llvm/lib/Transforms/Utils/ModuleUtils.cpp
index ba4b7f3cc26..8040cc7d09c 100644
--- a/llvm/lib/Transforms/Utils/ModuleUtils.cpp
+++ b/llvm/lib/Transforms/Utils/ModuleUtils.cpp
@@ -174,6 +174,27 @@ std::pair<Function *, Function *> llvm::createSanitizerCtorAndInitFunctions(
   return std::make_pair(Ctor, InitFunction);
 }
 
+Function *llvm::getOrCreateInitFunction(Module &M, StringRef Name) {
+  assert(!Name.empty() && "Expected init function name");
+  if (Function *F = M.getFunction(Name)) {
+    if (F->arg_size() != 0 ||
+        F->getReturnType() != Type::getVoidTy(M.getContext())) {
+      std::string Err;
+      raw_string_ostream Stream(Err);
+      Stream << "Sanitizer interface function defined with wrong type: " << *F;
+      report_fatal_error(Err);
+    }
+    return F;
+  }
+  Function *F = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
+      Name, AttributeList(), Type::getVoidTy(M.getContext())));
+  F->setLinkage(Function::ExternalLinkage);
+
+  appendToGlobalCtors(M, F, 0);
+
+  return F;
+}
+
 void llvm::filterDeadComdatFunctions(
     Module &M, SmallVectorImpl<Function *> &DeadComdatFunctions) {
   // Build a map from the comdat to the number of entries in that comdat we