1 files changed, 16 insertions, 1 deletions
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index b93a568ebee..93b5ff9c996 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -5044,6 +5044,14 @@ static FunctionDecl *rewriteBuiltinFunctionDecl(Sema *Sema, ASTContext &Context,
   return OverloadDecl;
 }
 
+static bool isNumberOfArgsValidForCall(Sema &S, const FunctionDecl *Callee,
+                                       std::size_t NumArgs) {
+  if (S.TooManyArguments(Callee->getNumParams(), NumArgs,
+                         /*PartialOverloading=*/false))
+    return Callee->isVariadic();
+  return Callee->getMinRequiredArguments() <= NumArgs;
+}
+
 /// ActOnCallExpr - Handle a call to Fn with the specified array of arguments.
 /// This provides the location of the left/right parens and a list of comma
 /// locations.
@@ -5175,7 +5183,14 @@ Sema::ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc,
                                            Fn->getLocStart()))
       return ExprError();
 
-    if (FD->hasAttr<EnableIfAttr>()) {
+    // CheckEnableIf assumes that the we're passing in a sane number of args for
+    // FD, but that doesn't always hold true here. This is because, in some
+    // cases, we'll emit a diag about an ill-formed function call, but then
+    // we'll continue on as if the function call wasn't ill-formed. So, if the
+    // number of args looks incorrect, don't do enable_if checks; we should've
+    // already emitted an error about the bad call.
+    if (FD->hasAttr<EnableIfAttr>() &&
+        isNumberOfArgsValidForCall(*this, FD, ArgExprs.size())) {
       if (const EnableIfAttr *Attr = CheckEnableIf(FD, ArgExprs, true)) {
         Diag(Fn->getLocStart(),
              isa<CXXMethodDecl>(FD) ?