[libclang] Fix crash in member access code completion with implicit base

If there is an unresolved member access AST node, and the base is
implicit, do not access/use it for generating candidate overloads for
code completion results.

Fixes PR31093.

llvm-svn: 298903

1 files changed, 4 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index ea4a33d..cfac3f1 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -4318,7 +4318,10 @@ void Sema::CodeCompleteCall(Scope *S, Expr *Fn, ArrayRef<Expr *> Args) {
       UME->copyTemplateArgumentsInto(TemplateArgsBuffer);
       TemplateArgs = &TemplateArgsBuffer;
     }
-    SmallVector<Expr *, 12> ArgExprs(1, UME->getBase());
+
+    // Add the base as first argument (use a nullptr if the base is implicit).
+    SmallVector<Expr *, 12> ArgExprs(
+        1, UME->isImplicitAccess() ? nullptr : UME->getBase());
     ArgExprs.append(Args.begin(), Args.end());
     UnresolvedSet<8> Decls;
     Decls.append(UME->decls_begin(), UME->decls_end());