Expose the name of the checker producing each diagnostic message.

Summary:
In clang-tidy we'd like to know the name of the checker producing each
diagnostic message. PathDiagnostic has BugType and Category fields, which are
both arbitrary human-readable strings, but we need to know the exact name of the
checker in the form that can be used in the CheckersControlList option to
enable/disable the specific checker.

This patch adds the CheckName field to the CheckerBase class, and sets it in
the CheckerManager::registerChecker() method, which gets them from the
CheckerRegistry.

Checkers that implement multiple checks have to store the names of each check
in the respective registerXXXChecker method.

Reviewers: jordan_rose, krememek

Reviewed By: jordan_rose

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D2557

llvm-svn: 201186
diff --git a/clang/lib/StaticAnalyzer/Checkers/CheckSizeofPointer.cpp b/clang/lib/StaticAnalyzer/Checkers/CheckSizeofPointer.cpp
index 1207b67..5106b06 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CheckSizeofPointer.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CheckSizeofPointer.cpp
@@ -24,10 +24,12 @@
 namespace {
 class WalkAST : public StmtVisitor<WalkAST> {
   BugReporter &BR;
+  const CheckerBase *Checker;
   AnalysisDeclContext* AC;
 
 public:
-  WalkAST(BugReporter &br, AnalysisDeclContext* ac) : BR(br), AC(ac) {}
+  WalkAST(BugReporter &br, const CheckerBase *checker, AnalysisDeclContext *ac)
+      : BR(br), Checker(checker), AC(ac) {}
   void VisitUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *E);
   void VisitStmt(Stmt *S) { VisitChildren(S); }
   void VisitChildren(Stmt *S);
@@ -62,7 +64,7 @@
 
     PathDiagnosticLocation ELoc =
       PathDiagnosticLocation::createBegin(E, BR.getSourceManager(), AC);
-    BR.EmitBasicReport(AC->getDecl(),
+    BR.EmitBasicReport(AC->getDecl(), Checker,
                        "Potential unintended use of sizeof() on pointer type",
                        categories::LogicError,
                        "The code calls sizeof() on a pointer type. "
@@ -80,7 +82,7 @@
 public:
   void checkASTCodeBody(const Decl *D, AnalysisManager& mgr,
                         BugReporter &BR) const {
-    WalkAST walker(BR, mgr.getAnalysisDeclContext(D));
+    WalkAST walker(BR, this, mgr.getAnalysisDeclContext(D));
     walker.Visit(D->getBody());
   }
 };