Improve "assignment to cast" diagnostic.
- Strip off extra parens when looking for casts.
- Change the location info to point at the cast (instead of the
assignment).
For example, on
int *b;
#define a ((void*) b)
void f0() {
a = 10;
}
we now emit:
/tmp/t.c:4:3: error: assignment to cast is illegal, lvalue casts are not supported
a = 10;
^ ~
/tmp/t.c:2:12: note: instantiated from:
#define a ((void*) b)
~^~~~~~~~~~
instead of:
/tmp/t.c:4:5: error: expression is not assignable
a = 10;
~ ^
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69114 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 973e662..dd34617 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -756,7 +756,8 @@
/// if it is a structure or union, does not have any member (including,
/// recursively, any member or element of all contained aggregates or unions)
/// with a const-qualified type.
-Expr::isModifiableLvalueResult Expr::isModifiableLvalue(ASTContext &Ctx) const {
+Expr::isModifiableLvalueResult
+Expr::isModifiableLvalue(ASTContext &Ctx, SourceLocation *Loc) const {
isLvalueResult lvalResult = isLvalue(Ctx);
switch (lvalResult) {
@@ -775,9 +776,13 @@
// lvalue, then this is probably a use of the old-school "cast as lvalue"
// GCC extension. We don't support it, but we want to produce good
// diagnostics when it happens so that the user knows why.
- if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(IgnoreParens()))
- if (CE->getSubExpr()->isLvalue(Ctx) == LV_Valid)
+ if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(IgnoreParens())) {
+ if (CE->getSubExpr()->isLvalue(Ctx) == LV_Valid) {
+ if (Loc)
+ *Loc = CE->getLParenLoc();
return MLV_LValueCast;
+ }
+ }
return MLV_InvalidExpression;
case LV_MemberFunction: return MLV_MemberFunction;
}