From 5fed9e61acaca03822dd871372ebf6cfe19df989 Mon Sep 17 00:00:00 2001
From: Walter Bright <walter@walterbright.com>
Date: Thu, 14 Aug 2014 18:39:32 -0700
Subject: [PATCH] Merge pull request #3822 from 9rnsr/fix13204

Issue 13204 - recursive alias declaration
---
 src/declaration.c         | 34 ++++++++++++++++++++++++----------
 src/declaration.h         |  2 +-
 src/mtype.c               |  9 +++++----
 test/runnable/template9.d | 32 ++++++++++++++++++++++++++++++++
 4 files changed, 62 insertions(+), 15 deletions(-)

diff --git a/src/declaration.c b/src/declaration.c
index a8d935460c86..078e34fe5088 100644
--- a/src/declaration.c
+++ b/src/declaration.c
@@ -429,7 +429,7 @@ AliasDeclaration::AliasDeclaration(Loc loc, Identifier *id, Type *type)
     this->htype = NULL;
     this->haliassym = NULL;
     this->overnext = NULL;
-    this->inSemantic = false;
+    this->inSemantic = 0;
     assert(type);
 }
 
@@ -445,7 +445,7 @@ AliasDeclaration::AliasDeclaration(Loc loc, Identifier *id, Dsymbol *s)
     this->htype = NULL;
     this->haliassym = NULL;
     this->overnext = NULL;
-    this->inSemantic = false;
+    this->inSemantic = 0;
     assert(s);
 }
 
@@ -490,7 +490,7 @@ void AliasDeclaration::semantic(Scope *sc)
             aliassym->semantic(sc);
         return;
     }
-    this->inSemantic = true;
+    this->inSemantic = 1;
 
     storage_class |= sc->stc & STCdeprecated;
     protection = sc->protection;
@@ -570,7 +570,7 @@ void AliasDeclaration::semantic(Scope *sc)
     }
     if (overnext)
         ScopeDsymbol::multiplyDefined(Loc(), overnext, this);
-    this->inSemantic = false;
+    this->inSemantic = 0;
 
     if (global.gag && errors != global.errors)
         type = savedtype;
@@ -646,14 +646,12 @@ void AliasDeclaration::semantic(Scope *sc)
         {
             type = savedtype;
             overnext = savedovernext;
-            aliassym = NULL;
-            inSemantic = false;
-            return;
+            s = NULL;
         }
     }
     //printf("setting aliassym %s to %s %s\n", toChars(), s->kind(), s->toChars());
     aliassym = s;
-    this->inSemantic = false;
+    this->inSemantic = 0;
 }
 
 bool AliasDeclaration::overloadInsert(Dsymbol *s)
@@ -712,10 +710,26 @@ Dsymbol *AliasDeclaration::toAlias()
     //printf("AliasDeclaration::toAlias('%s', this = %p, aliassym = %p, kind = '%s')\n", toChars(), this, aliassym, aliassym ? aliassym->kind() : "");
     assert(this != aliassym);
     //static int count; if (++count == 10) *(char*)0=0;
+    if (inSemantic == 1 && type && scope)
+    {
+        inSemantic = 2;
+        unsigned olderrors = global.errors;
+        Dsymbol *s = type->toDsymbol(scope);
+        //printf("[%s] %s, s = %p, this = %p\n", loc.toChars(), type->toChars(), s, this);
+        if (!s || global.errors != olderrors)
+            goto Lerr;
+        s = s->toAlias();
+        if (global.errors != olderrors)
+            goto Lerr;
+
+        aliassym = s;
+        inSemantic = 0;
+    }
     if (inSemantic)
     {
         error("recursive alias declaration");
 
+    Lerr:
         // Avoid breaking "recursive alias" state during errors gagged
         if (global.isSpeculativeGagging())
             return this;
@@ -736,9 +750,9 @@ Dsymbol *AliasDeclaration::toAlias()
     }
     else if (scope)
         semantic(scope);
-    inSemantic = true;
+    inSemantic = 1;
     Dsymbol *s = aliassym ? aliassym->toAlias() : this;
-    inSemantic = false;
+    inSemantic = 0;
     return s;
 }
 
diff --git a/src/declaration.h b/src/declaration.h
index 150c7143367b..f899d498a2ed 100644
--- a/src/declaration.h
+++ b/src/declaration.h
@@ -223,7 +223,7 @@ class AliasDeclaration : public Declaration
     Dsymbol *aliassym;
     Dsymbol *overnext;          // next in overload list
     Dsymbol *import;            // !=NULL if unresolved internal alias for selective import
-    bool inSemantic;
+    int inSemantic;
 
     AliasDeclaration(Loc loc, Identifier *ident, Type *type);
     AliasDeclaration(Loc loc, Identifier *ident, Dsymbol *s);
diff --git a/src/mtype.c b/src/mtype.c
index 40e009414b13..edafa663d6b8 100644
--- a/src/mtype.c
+++ b/src/mtype.c
@@ -6842,7 +6842,8 @@ Dsymbol *TypeIdentifier::toDsymbol(Scope *sc)
             RootObject *id = idents[i];
             s = s->searchX(loc, sc, id);
             if (!s)                 // failed to find a symbol
-            {   //printf("\tdidn't find a symbol\n");
+            {
+                //printf("\tdidn't find a symbol\n");
                 break;
             }
         }
@@ -7001,6 +7002,8 @@ Dsymbol *TypeInstance::toDsymbol(Scope *sc)
 
     //printf("TypeInstance::semantic(%s)\n", toChars());
     resolve(loc, sc, &e, &t, &s);
+    if (t && t->ty != Tinstance)
+        s = t->toDsymbol(sc);
 
     return s;
 }
@@ -7055,9 +7058,7 @@ Type *TypeTypeof::syntaxCopy()
 
 Dsymbol *TypeTypeof::toDsymbol(Scope *sc)
 {
-    Type *t;
-
-    t = semantic(loc, sc);
+    Type *t = semantic(loc, sc);
     if (t == this)
         return NULL;
     return t->toDsymbol(sc);
diff --git a/test/runnable/template9.d b/test/runnable/template9.d
index 2ce8019ad8f4..a53a64b20671 100644
--- a/test/runnable/template9.d
+++ b/test/runnable/template9.d
@@ -3766,6 +3766,38 @@ void test13180()
     string s2b = get2b(def, aa);
 }
 
+/******************************************/
+// 13204
+
+struct A13204(uint v)
+{
+    alias whatever = A13204y;
+    static assert(is(whatever == A13204));
+}
+alias A13204x = A13204!1;
+alias A13204y = A13204x;
+
+struct B13204(uint v)
+{
+    alias whatever = B13204z;
+    static assert(is(whatever == B13204));
+}
+alias B13204x = B13204!1;
+alias B13204y = B13204x;
+alias B13204z = B13204y;
+
+void test13204()
+{
+    static assert(is(A13204x == A13204!1));
+    static assert(is(A13204x == A13204!1.whatever));
+    static assert(is(A13204x == A13204y));
+
+    static assert(is(B13204x == B13204!1));
+    static assert(is(B13204x == B13204!1.whatever));
+    static assert(is(B13204x == B13204y));
+    static assert(is(B13204x == B13204z));
+}
+
 /******************************************/
 // 13218