[analyzer] Improve Nullability checker diagnostics

- Include the position of the argument on which the nullability is violated
- Differentiate between a 'method' and a 'function' in the message wording
- Test for the error message text in the tests
- Fix a bug with setting 'IsDirectDereference' which resulted in regular dereferences assumed to have call context.

llvm-svn: 259221

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp b/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp
index 5ec8bfa8007..548b06ef91f 100644
--- a/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CheckerContext.cpp
@@ -35,6 +35,13 @@ StringRef CheckerContext::getCalleeName(const FunctionDecl *FunDecl) const {
   return funI->getName();
 }
 
+StringRef CheckerContext::getDeclDescription(const Decl *D) {
+  if (isa<ObjCMethodDecl>(D) || isa<CXXMethodDecl>(D))
+    return "method";
+  if (isa<BlockDecl>(D))
+    return "anonymous block";
+  return "function";
+}
 
 bool CheckerContext::isCLibraryFunction(const FunctionDecl *FD,
                                         StringRef Name) {