Per advice that Doug Gregor gave me several months ago, clean up the
implementation of '#pragma unused' by not constructing intermediate
DeclRefExprs, but instead do the name lookup directly. The
implementation is greatly simplified.
Along the way, degrade '#pragma unused(undeclaredvariable)' to a
warning instead of being a hard error. This implements:
<rdar://problem/6761874> [sema] allow #pragma unused to reference undefined variable (with warning)
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@78019 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaAttr.cpp b/lib/Sema/SemaAttr.cpp
index 1bf8444..6622d53 100644
--- a/lib/Sema/SemaAttr.cpp
+++ b/lib/Sema/SemaAttr.cpp
@@ -170,42 +170,35 @@
}
}
-void Sema::ActOnPragmaUnused(ExprTy **Exprs, unsigned NumExprs,
+void Sema::ActOnPragmaUnused(const Token *Identifiers, unsigned NumIdentifiers,
+ Scope *curScope,
SourceLocation PragmaLoc,
SourceLocation LParenLoc,
SourceLocation RParenLoc) {
-
- // Verify that all of the expressions are valid before
- // modifying the attributes of any referenced decl.
- Expr *ErrorExpr = 0;
-
- for (unsigned i = 0; i < NumExprs; ++i) {
- Expr *Ex = (Expr*) Exprs[i];
- if (!isa<DeclRefExpr>(Ex)) {
- ErrorExpr = Ex;
- break;
- }
- Decl *d = cast<DeclRefExpr>(Ex)->getDecl();;
+ for (unsigned i = 0; i < NumIdentifiers; ++i) {
+ const Token &Tok = Identifiers[i];
+ IdentifierInfo *Name = Tok.getIdentifierInfo();
+ const LookupResult &Lookup = LookupParsedName(curScope, NULL, Name,
+ LookupOrdinaryName,
+ false, true,
+ Tok.getLocation());
+ // FIXME: Handle Lookup.isAmbiguous?
- if (!isa<VarDecl>(d) || !cast<VarDecl>(d)->hasLocalStorage()) {
- ErrorExpr = Ex;
- break;
+ NamedDecl *ND = Lookup.getAsDecl();
+
+ if (!ND) {
+ Diag(PragmaLoc, diag::warn_pragma_unused_undeclared_var)
+ << Name << SourceRange(Tok.getLocation());
+ continue;
}
- }
-
- // Delete the expressions if we encountered any error.
- if (ErrorExpr) {
- Diag(ErrorExpr->getLocStart(), diag::warn_pragma_unused_expected_localvar);
- for (unsigned i = 0; i < NumExprs; ++i)
- ((Expr*) Exprs[i])->Destroy(Context);
- return;
- }
- // Otherwise, add the 'unused' attribute to each referenced declaration.
- for (unsigned i = 0; i < NumExprs; ++i) {
- DeclRefExpr *DR = (DeclRefExpr*) Exprs[i];
- DR->getDecl()->addAttr(::new (Context) UnusedAttr());
- DR->Destroy(Context);
+ if (!isa<VarDecl>(ND) || !cast<VarDecl>(ND)->hasLocalStorage()) {
+ Diag(PragmaLoc, diag::warn_pragma_unused_expected_localvar)
+ << Name << SourceRange(Tok.getLocation());
+ continue;
+ }
+
+ ND->addAttr(::new (Context) UnusedAttr());
}
}