commit 6acdc6465eb2000dee877ee1b06bb1036b689af7
author Googler <no-reply@google.com> Thu Oct 19 08:03:40 2023 -0700
committer Copybara-Service <copybara-worker@google.com> Thu Oct 19 08:04:26 2023 -0700
tree 5b8ce26c0f9f4dd6fe4de3fe03a641684eb65703
parent f1f793d61054277cf26b4076a753945839dd515d

Store USR cache outside of EvidenceEmitter so that it can be shared in more places.

For example, the current function decl's USR is needed to look up whether inferable slots' nullabilities were inferred in previous rounds.

PiperOrigin-RevId: 574873175
Change-Id: Id96d5cb082e7d61464bcc2bdd6825858eac16015

nullability/inference/collect_evidence.cc

diff --git a/nullability/inference/collect_evidence.cc b/nullability/inference/collect_evidence.cc
index 8ddc113..f2964cf 100644
--- a/nullability/inference/collect_evidence.cc
+++ b/nullability/inference/collect_evidence.cc
@@ -7,6 +7,7 @@
 #include <memory>
 #include <optional>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
@@ -40,7 +41,6 @@
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/Specifiers.h"
 #include "clang/Index/USRGeneration.h"
-#include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/FunctionExtras.h"
 #include "llvm/ADT/STLFunctionalExtras.h"
@@ -51,13 +51,24 @@
 using ::clang::dataflow::DataflowAnalysisContext;
 using ::clang::dataflow::Environment;
 
+std::string_view getOrGenerateUSR(USRCache &Cache, const Decl &Decl) {
+  auto [It, Inserted] = Cache.try_emplace(&Decl);
+  if (Inserted) {
+    llvm::SmallString<128> USR;
+    if (!index::generateUSRForDecl(&Decl, USR)) It->second = USR.str();
+  }
+  return It->second;
+}
+
 llvm::unique_function<EvidenceEmitter> evidenceEmitter(
-    llvm::unique_function<void(const Evidence &) const> Emit) {
+    llvm::unique_function<void(const Evidence &) const> Emit,
+    nullability::USRCache &USRCache) {
   class EvidenceEmitterImpl {
    public:
     EvidenceEmitterImpl(
-        llvm::unique_function<void(const Evidence &) const> Emit)
-        : Emit(std::move(Emit)) {}
+        llvm::unique_function<void(const Evidence &) const> Emit,
+        nullability::USRCache &USRCache)
+        : Emit(std::move(Emit)), USRCache(USRCache) {}
 
     void operator()(const Decl &Target, Slot S, Evidence::Kind Kind,
                     SourceLocation Loc) const {
@@ -68,13 +79,9 @@
       E.set_slot(S);
       E.set_kind(Kind);
 
-      auto [It, Inserted] = USRCache.try_emplace(&Target);
-      if (Inserted) {
-        llvm::SmallString<128> USR;
-        if (!index::generateUSRForDecl(&Target, USR)) It->second = USR.str();
-      }
-      if (It->second.empty()) return;  // Can't emit without a USR
-      E.mutable_symbol()->set_usr(It->second);
+      std::string_view USR = getOrGenerateUSR(USRCache, Target);
+      if (USR.empty()) return;  // Can't emit without a USR
+      E.mutable_symbol()->set_usr(USR);
 
       // TODO: make collecting and propagating location information optional?
       auto &SM =
@@ -88,10 +95,10 @@
     }
 
    private:
-    mutable llvm::DenseMap<const Decl *, std::string> USRCache;
     llvm::unique_function<void(const Evidence &) const> Emit;
+    nullability::USRCache &USRCache;
   };
-  return EvidenceEmitterImpl(std::move(Emit));
+  return EvidenceEmitterImpl(std::move(Emit), USRCache);
 }
 
 namespace {
@@ -336,6 +343,7 @@
 
 llvm::Error collectEvidenceFromImplementation(
     const Decl &Decl, llvm::function_ref<EvidenceEmitter> Emit,
+    USRCache &USRCache,
     const llvm::DenseSet<SlotFingerprint> &PreviouslyInferredNullable,
     const llvm::DenseSet<SlotFingerprint> &PreviouslyInferredNonnull) {
   const FunctionDecl *Func = dyn_cast<FunctionDecl>(&Decl);