d: Fix qualifier ignored in alias definition if parentheses are not present

Fixes regression where the qualifier was ignored in an alias definition
if parentheses were not present.

gcc/d/ChangeLog:

	* dmd/dsymbolsem.c (aliasInstanceSemantic): Merge storage class of old
	alias into new symbol.

gcc/testsuite/ChangeLog:

	* gdc.test/compilable/test21898.d: New test.

(cherry picked from commit a30ee3aa8210f14fa3b4ee84fd3974c6b6a93047)

diff --git a/gcc/d/dmd/dsymbolsem.c b/gcc/d/dmd/dsymbolsem.c
index 33f74edf6ba8e6b0e1f22753a6800a1d7b8b8100..7a44ed2c41d859d64192431e6929d5be83001682 100644 (file)
--- a/gcc/d/dmd/dsymbolsem.c
+++ b/gcc/d/dmd/dsymbolsem.c
@@ -4880,8 +4880,11 @@ static void aliasInstanceSemantic(TemplateInstance *tempinst, Scope *sc, Templat
 
     TemplateTypeParameter *ttp = (*tempdecl->parameters)[0]->isTemplateTypeParameter();
     Type *ta = isType(tempinst->tdtypes[0]);
-    Declaration *d = new AliasDeclaration(tempinst->loc, ttp->ident, ta->addMod(tempdecl->onemember->isAliasDeclaration()->type->mod));
-    d->storage_class |= STCtemplateparameter;
+    AliasDeclaration *ad = tempdecl->onemember->isAliasDeclaration();
+
+    // Note: qualifiers can be in both 'ad.type.mod' and 'ad.storage_class'
+    Declaration *d = new AliasDeclaration(tempinst->loc, ttp->ident, ta->addMod(ad->type->mod));
+    d->storage_class |= STCtemplateparameter | ad->storage_class;
     dsymbolSemantic(d, sc);
 
     paramscope->pop();

diff --git a/gcc/testsuite/gdc.test/compilable/test21898.d b/gcc/testsuite/gdc.test/compilable/test21898.d
new file mode 100644 (file)
index 0000000..9ac18b8
--- /dev/null
+++ b/gcc/testsuite/gdc.test/compilable/test21898.d
@@ -0,0 +1,7 @@
+// https://issues.dlang.org/show_bug.cgi?id=21898
+
+alias Works(T) = immutable(T);
+alias Fails(T) = immutable T;
+
+static assert(is(Works!int == immutable int));
+static assert(is(Fails!int == immutable int));