[Analyzer] Remove inclusion of uniqueing decl from diagnostic profile.

[balazske]

Summary

The uniqueing decl in PathDiagnostic is the declaration with the
uniqueing loc, as stated by documentation comments.
It is enough to include the uniqueing loc in the profile. It is possible
to have objects with different uniqueing decl but same location, at
least with templates. These belong to the same class and should have
same profile.

[vsavchenko]

LGTM! Thanks for the fast fix!

[NoQ]

Aha, ok, yeah, so that's what caused it!

I guess if we want a uniqueing decl for this case, we should use the original template decl rather than the instantiation.

clang/lib/Analysis/PathDiagnostic.cpp

 
 void PathDiagnosticPopUpPiece::Profile(llvm::FoldingSetNodeID &ID) const {
   PathDiagnosticSpotPiece::Profile(ID);
 }
 
 void PathDiagnostic::Profile(llvm::FoldingSetNodeID &ID) const {
   ID.Add(getLocation());
   ID.Add(getUniqueingLoc());
-  ID.AddPointer(getUniqueingLoc().isValid() ? getUniqueingDecl() : nullptr);
   ID.AddString(BugType);
   ID.AddString(VerboseDesc);
   ID.AddString(Category);
 }
 
 void PathDiagnostic::FullProfile(llvm::FoldingSetNodeID &ID) const {
   Profile(ID);
   for (const auto &I : path)

clang/test/Analysis/report-uniqueing.cpp

+// RUN: %clang_analyze_cc1 -verify %s \
+// RUN:   -analyzer-checker=security
+
+void bzero(void *, unsigned long);
+
+template <typename T> void foo(T l) {
+  // The warning comes from multiple instances and with
+  // different declarations that have same source location.
+  // One instance should be shown.
+  bzero(l, 1); // expected-warning{{The bzero() function is obsoleted}}
+}
+
+void p(int *p, unsigned *q) {
+  foo(p);
+  foo(q);
+}