Implement dependent alignment attribute support. This is a bit gross given the

current attribute system, but it is enough to handle class templates which
specify parts of their alignment in terms of their template parameters.

This also replaces the attributes test in SemaTemplate with one that actually
tests working attributes instead of broken ones. I plan to add more tests here
for non-dependent attributes in a subsequent patch.

Thanks to John for walking me through some of this. =D

llvm-svn: 106818

1 files changed, 18 insertions, 12 deletions

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 527b469fed8..0f53fb92ef6 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -1458,7 +1458,7 @@ static void HandleAnnotateAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   d->addAttr(::new (S.Context) AnnotateAttr(S.Context, SE->getString()));
 }
 
-static void HandleAlignedAttr(Decl *d, const AttributeList &Attr, Sema &S) {
+static void HandleAlignedAttr(Decl *D, const AttributeList &Attr, Sema &S) {
   // check the attribute arguments.
   if (Attr.getNumArgs() > 1) {
     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
@@ -1469,30 +1469,36 @@ static void HandleAlignedAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   //       than GNU's, and should error out when it is used to specify a
   //       weaker alignment, rather than being silently ignored.
 
-  unsigned Align = 0;
   if (Attr.getNumArgs() == 0) {
     // FIXME: This should be the target specific maximum alignment.
     // (For now we just use 128 bits which is the maximum on X86).
-    Align = 128;
-    d->addAttr(::new (S.Context) AlignedAttr(Align));
+    D->addAttr(::new (S.Context) AlignedAttr(128));
+    return;
+  }
+
+  S.AddAlignedAttr(Attr.getLoc(), D, static_cast<Expr *>(Attr.getArg(0)));
+}
+
+void Sema::AddAlignedAttr(SourceLocation AttrLoc, Decl *D, Expr *E) {
+  if (E->isTypeDependent() || E->isValueDependent()) {
+    // Save dependent expressions in the AST to be instantiated.
+    D->addAttr(::new (Context) AlignedAttr(E));
     return;
   }
 
-  Expr *alignmentExpr = static_cast<Expr *>(Attr.getArg(0));
   llvm::APSInt Alignment(32);
-  if (alignmentExpr->isTypeDependent() || alignmentExpr->isValueDependent() ||
-      !alignmentExpr->isIntegerConstantExpr(Alignment, S.Context)) {
-    S.Diag(Attr.getLoc(), diag::err_attribute_argument_not_int)
-      << "aligned" << alignmentExpr->getSourceRange();
+  if (!E->isIntegerConstantExpr(Alignment, Context)) {
+    Diag(AttrLoc, diag::err_attribute_argument_not_int)
+      << "aligned" << E->getSourceRange();
     return;
   }
   if (!llvm::isPowerOf2_64(Alignment.getZExtValue())) {
-    S.Diag(Attr.getLoc(), diag::err_attribute_aligned_not_power_of_two)
-      << alignmentExpr->getSourceRange();
+    Diag(AttrLoc, diag::err_attribute_aligned_not_power_of_two)
+      << E->getSourceRange();
     return;
   }
 
-  d->addAttr(::new (S.Context) AlignedAttr(Alignment.getZExtValue() * 8));
+  D->addAttr(::new (Context) AlignedAttr(Alignment.getZExtValue() * 8));
 }
 
 /// HandleModeAttr - This attribute modifies the width of a decl with primitive