implement the alias attirbute (in both Sema and Codegen)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@52092 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index b56622ceb9..ed34f9fe00 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2250,6 +2250,9 @@ void Sema::HandleDeclAttribute(Decl *New, AttributeList *Attr) {
     }
     // FIXME: Diagnostic?
     break;
+  case AttributeList::AT_alias:
+    HandleAliasAttribute(New, Attr);
+    break;
   case AttributeList::AT_deprecated:
     HandleDeprecatedAttribute(New, Attr);
     break;
@@ -2438,6 +2441,32 @@ void Sema::HandlePackedAttribute(Decl *d, AttributeList *rawAttr) {
          rawAttr->getName()->getName());
 }
 
+void Sema::HandleAliasAttribute(Decl *d, AttributeList *rawAttr) {
+  // check the attribute arguments.
+  if (rawAttr->getNumArgs() != 1) {
+    Diag(rawAttr->getLoc(), diag::err_attribute_wrong_number_arguments,
+         std::string("1"));
+    return;
+  }
+
+  Expr *Arg = static_cast<Expr*>(rawAttr->getArg(0));
+  Arg = Arg->IgnoreParenCasts();
+  StringLiteral *Str = dyn_cast<StringLiteral>(Arg);
+
+  if (Str == 0 || Str->isWide()) {
+    Diag(rawAttr->getLoc(), diag::err_attribute_argument_n_not_string,
+         "alias", std::string("1"));
+    return;
+  }
+
+  const char *Alias = Str->getStrData();
+  unsigned AliasLen = Str->getByteLength();
+
+  // FIXME: check if target symbol exists in current file
+
+  d->addAttr(new AliasAttr(std::string(Alias, AliasLen)));
+}
+
 void Sema::HandleNoReturnAttribute(Decl *d, AttributeList *rawAttr) {
   // check the attribute arguments.
   if (rawAttr->getNumArgs() != 0) {