Fix overloaded static functions in SemaCodeComplete

https://bugs.llvm.org/show_bug.cgi?id=33904
Happens when static function is accessed via the class variable. That leads to incorrect overloads number because the variable is considered as the first argument.

struct Bar {
  static void foo(); static void foo(int);
};

int main() {
  Bar b;
  b.foo(/*complete here*/); // did not work before
  Bar::foo(/*complete here*/); // worked fine
}

Patch by Ivan Donchevskii!

Differential Revision: https://reviews.llvm.org/D36390

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@316646 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 23 insertions, 9 deletions

diff --git a/lib/Sema/SemaCodeComplete.cpp b/lib/Sema/SemaCodeComplete.cpp
index 06246d469f..a0d8c9941e 100644
--- a/lib/Sema/SemaCodeComplete.cpp
+++ b/lib/Sema/SemaCodeComplete.cpp
@@ -4396,9 +4396,11 @@ void Sema::CodeCompleteCall(Scope *S, Expr *Fn, ArrayRef<Expr *> Args) {
     ArgExprs.append(Args.begin(), Args.end());
     UnresolvedSet<8> Decls;
     Decls.append(UME->decls_begin(), UME->decls_end());
+    const bool FirstArgumentIsBase = !UME->isImplicitAccess() && UME->getBase();
     AddFunctionCandidates(Decls, ArgExprs, CandidateSet, TemplateArgs,
                           /*SuppressUsedConversions=*/false,
-                          /*PartialOverloading=*/true);
+                          /*PartialOverloading=*/true,
+                          FirstArgumentIsBase);
   } else {
     FunctionDecl *FD = nullptr;
     if (auto MCE = dyn_cast<MemberExpr>(NakedFn))
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 49e9126afc..8efb7c69d3 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -6343,24 +6343,36 @@ void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
                                  OverloadCandidateSet& CandidateSet,
                                  TemplateArgumentListInfo *ExplicitTemplateArgs,
                                  bool SuppressUserConversions,
-                                 bool PartialOverloading) {
+                                 bool PartialOverloading,
+                                 bool FirstArgumentIsBase) {
   for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
     NamedDecl *D = F.getDecl()->getUnderlyingDecl();
     if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+      ArrayRef<Expr *> FunctionArgs = Args;
       if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) {
         QualType ObjectType;
         Expr::Classification ObjectClassification;
-        if (Expr *E = Args[0]) {
-          // Use the explit base to restrict the lookup:
-          ObjectType = E->getType();
-          ObjectClassification = E->Classify(Context);
-        } // .. else there is an implit base.
+        if (Args.size() > 0) {
+          if (Expr *E = Args[0]) {
+            // Use the explit base to restrict the lookup:
+            ObjectType = E->getType();
+            ObjectClassification = E->Classify(Context);
+          } // .. else there is an implit base.
+          FunctionArgs = Args.slice(1);
+        }
         AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
                            cast<CXXMethodDecl>(FD)->getParent(), ObjectType,
-                           ObjectClassification, Args.slice(1), CandidateSet,
+                           ObjectClassification, FunctionArgs, CandidateSet,
                            SuppressUserConversions, PartialOverloading);
       } else {
-        AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet,
+        // Slice the first argument (which is the base) when we access
+        // static method as non-static
+        if (Args.size() > 0 && (!Args[0] || (FirstArgumentIsBase && isa<CXXMethodDecl>(FD) &&
+                                             !isa<CXXConstructorDecl>(FD)))) {
+          assert(cast<CXXMethodDecl>(FD)->isStatic());
+          FunctionArgs = Args.slice(1);
+        }
+        AddOverloadCandidate(FD, F.getPair(), FunctionArgs, CandidateSet,
                              SuppressUserConversions, PartialOverloading);
       }
     } else {