[PATCH] D29884: [analyzer] Proper caching in CallDescription objects.

[Gábor Horváth via Phabricator via cfe-commits]

xazax.hun created this revision.

During the review of https://reviews.llvm.org/D29567 it turned out the caching in CallDescription is not implemented properly. In case an identifier does not exist in a translation unit, repeated identifier lookups will be done which might have bad impact on the performance. This patch guarantees that the lookup is only executed once. Moreover this patch fixes a corner case when the identifier of CallDescription does not exist in the translation unit and the called function does not have an identifier (e.g.: overloaded operator in C++).


https://reviews.llvm.org/D29884

Files:
  include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
  lib/StaticAnalyzer/Core/CallEvent.cpp


Index: lib/StaticAnalyzer/Core/CallEvent.cpp
===================================================================
--- lib/StaticAnalyzer/Core/CallEvent.cpp
+++ lib/StaticAnalyzer/Core/CallEvent.cpp
@@ -212,9 +212,12 @@
 
 bool CallEvent::isCalled(const CallDescription &CD) const {
   assert(getKind() != CE_ObjCMessage && "Obj-C methods are not supported");
-  if (!CD.II)
+  if (!CD.IsLookupDone) {
+    CD.IsLookupDone = true;
     CD.II = &getState()->getStateManager().getContext().Idents.get(CD.FuncName);
-  if (getCalleeIdentifier() != CD.II)
+  }
+  const IdentifierInfo *II = getCalleeIdentifier();
+  if (!II || II != CD.II)
     return false;
   return (CD.RequiredArgs == CallDescription::NoArgRequirement ||
           CD.RequiredArgs == getNumArgs());
Index: include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
===================================================================
--- include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
+++ include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
@@ -55,6 +55,7 @@
 class CallDescription {
   friend CallEvent;
   mutable IdentifierInfo *II;
+  mutable bool IsLookupDone;
   StringRef FuncName;
   unsigned RequiredArgs;
 
@@ -68,7 +69,8 @@
   /// call. Omit this parameter to match every occurance of call with a given
   /// name regardless the number of arguments.
   CallDescription(StringRef FuncName, unsigned RequiredArgs = NoArgRequirement)
-      : II(nullptr), FuncName(FuncName), RequiredArgs(RequiredArgs) {}
+      : II(nullptr), IsLookupDone(false), FuncName(FuncName),
+        RequiredArgs(RequiredArgs) {}
 
   /// \brief Get the name of the function that this object matches.
   StringRef getFunctionName() const { return FuncName; }


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