PIX: Check for null HS entry point (pass-through case) (#4092)

With a null HS, just the patch constant function is present. PIX passes crash on the null, so this change suppresses that null return value.

Author: jeffnn

lib/DXIL/DxilModule.cpp

@@ -234,7 +234,9 @@ const Function *DxilModule::GetEntryFunction() const {
 llvm::SmallVector<llvm::Function *, 64> DxilModule::GetExportedFunctions() const {
     llvm::SmallVector<llvm::Function *, 64> ret;
     for (auto const& fn : m_DxilEntryPropsMap) {
+      if (fn.first != nullptr) {
         ret.push_back(const_cast<llvm::Function*>(fn.first));
+      }
     }
     return ret;
 }

lib/DxilPIXPasses/PixPassHelpers.cpp

@@ -203,10 +203,10 @@ std::vector<llvm::BasicBlock*> GetAllBlocks(hlsl::DxilModule& DM) {
     std::vector<llvm::BasicBlock*> ret;
     auto entryPoints = DM.GetExportedFunctions();
     for (auto& fn : entryPoints) {
-        auto & blocks = fn->getBasicBlockList();
-        for (auto & block : blocks) {
-            ret.push_back(&block);
-        }
+      auto& blocks = fn->getBasicBlockList();
+      for (auto& block : blocks) {
+        ret.push_back(&block);
+      }
     }
     return ret;
 }