Improve the error message for attempting to build a for range loop using a
function parameter that has array type. Such a parameter will be treated as
a pointer type instead, resulting in a missing begin function error is a
suggestion to dereference the pointer. This provides a different,
more informative diagnostic as well as point to the parameter declaration.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192512 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 2977404..9bd8678 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -2131,10 +2131,25 @@
BeginVar, EndVar, ColonLoc, &CandidateSet,
&BeginExpr, &EndExpr, &BEFFailure);
- // If building the range failed, try dereferencing the range expression
- // unless a diagnostic was issued or the end function is problematic.
if (Kind == BFRK_Build && RangeStatus == FRS_NoViableFunction &&
BEFFailure == BEF_begin) {
+ // If the range is being built from an array parameter, emit a
+ // a diagnostic that it is being treated as a pointer.
+ if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Range)) {
+ if (ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
+ QualType ArrayTy = PVD->getOriginalType();
+ QualType PointerTy = PVD->getType();
+ if (PointerTy->isPointerType() && ArrayTy->isArrayType()) {
+ Diag(Range->getLocStart(), diag::err_range_on_array_parameter)
+ << RangeLoc << PVD << ArrayTy << PointerTy;
+ Diag(PVD->getLocation(), diag::note_declared_at);
+ return StmtError();
+ }
+ }
+ }
+
+ // If building the range failed, try dereferencing the range expression
+ // unless a diagnostic was issued or the end function is problematic.
StmtResult SR = RebuildForRangeWithDereference(*this, S, ForLoc,
LoopVarDecl, ColonLoc,
Range, RangeLoc,