[include-fixer] Use scope contexts information to improve query.

[bkramer]

This needs more tests (check that using stuff from a different namespace in namespace scope still works). It's also better written as a unit test against the in-memory database, that way we don't have to create a file for every test.

[hokein]

Improvement and use unittest.

[bkramer]

Tests look much better now, thanks!

[hokein]

Rebase.

include-fixer/IncludeFixer.cpp

clang::TypoCorrection CorrectTypo(const DeclarationNameInfo &Typo,
                                     CorrectionCandidateCallback &CCC,
                                     DeclContext *MemberContext,
                                     bool EnteringContext,
                                     const ObjCObjectPointerType *OPT) override {
     // Ignore spurious callbacks from SFINAE contexts.
     if (getCompilerInstance().getSema().isSFINAEContext())
       return clang::TypoCorrection();
 
+    std::string TypoScopeString;
+    if (S) {
+      // FIXME: Currently we only use namespace contexts.
+      // Use other context types for query.
+      for (const auto *Context = S->getEntity(); Context;
+           Context = Context->getParent()) {
+        if (const auto *ND = dyn_cast<NamespaceDecl>(Context)) {
+          if (!ND->getName().empty())
+            TypoScopeString = ND->getNameAsString() + "::" + TypoScopeString;
+        }
+        else
+          break;
+      }
+    }
+
     /// If we have a scope specification, use that to get more precise results.
     std::string QueryString;
     if (SS && SS->getRange().isValid()) {
       auto Range = CharSourceRange::getTokenRange(SS->getRange().getBegin(),
                                                   Typo.getLoc());
       StringRef Source =
           Lexer::getSourceText(Range, getCompilerInstance().getSourceManager(),
                                getCompilerInstance().getLangOpts());
if (SS && SS->getRange().isValid()) {
       //
       // With the extension we get the full nested name specifier including
       // parent_path.
       // FIXME: Don't rely on source text.
       const char *End = Source.end();
       while (isIdentifierBody(*End) || *End == ':')
         ++End;
 
-      QueryString = std::string(Source.begin(), End);
+      QueryString = TypoScopeString + std::string(Source.begin(), End);
     } else {
-      QueryString = Typo.getAsString();
+      QueryString = TypoScopeString + Typo.getAsString();
     }
 
     return query(QueryString, Typo.getLoc());
   }
 
   StringRef filename() const { return Filename; }
 
   /// Called for each include file we discover is in the file.

include-fixer/XrefsDBManager.cpp

DEBUG(llvm::dbgs() << "Searching " << Names.back() << "... got "
                      << Symbols.size() << " results...\n");
 
   std::vector<std::string> Results;
   for (const auto &Symbol : Symbols) {
     // Match the identifier name without qualifier.
     if (Symbol.getName() == Names.back()) {
       bool IsMatched = true;
       auto SymbolContext = Symbol.getContexts().begin();
+      auto IdentiferContext = Names.rbegin() + 1; // Skip the name;
       // Match the remaining context names.
-      for (auto IdentiferContext = Names.rbegin() + 1;
-           IdentiferContext != Names.rend() &&
+      for (; IdentiferContext != Names.rend() &&
              SymbolContext != Symbol.getContexts().end();
            ++IdentiferContext, ++SymbolContext) {
         if (SymbolContext->second != *IdentiferContext) {
           IsMatched = false;
           break;
         }
       }
 
-      if (IsMatched) {
+      if (IsMatched && IdentiferContext == Names.rend()) {
         // FIXME: file path should never be in the form of <...> or "...", but
         // the unit test with fixed database use <...> file path, which might
         // need to be changed.
         // FIXME: if the file path is a system header name, we want to use angle
         // brackets.
         std::string FilePath = Symbol.getFilePath().str();
         Results.push_back((FilePath[0] == '"' || FilePath[0] == '<')
                               ? FilePath

test/include-fixer/scoped_namespace.cpp

+// REQUIRES: shell
+// RUN: sed -e 's#//.*$##' %s > %t.cpp
+// RUN: clang-include-fixer -db=yaml -input=%p/Inputs/fake_yaml_db.yaml %t.cpp --
+// RUN: FileCheck %s -input-file=%t.cpp
+
+// CHECK: namespace B {
+// CHECK: a::foo f;
+// CHECK: }
+
+namespace B {
+a::foo f;
+}