Merge dmd-1.074 into ldc.

dmd/cond.c

@@ -1,6 +1,6 @@
 
 // Compiler implementation of the D programming language
-// Copyright (c) 1999-2011 by Digital Mars
+// Copyright (c) 1999-2012 by Digital Mars
 // All Rights Reserved
 // written by Walter Bright
 // http://www.digitalmars.com
@@ -225,6 +225,7 @@ StaticIfCondition::StaticIfCondition(Loc loc, Expression *exp)
     : Condition(loc)
 {
     this->exp = exp;
+    this->nest = 0;
 }
 
 Condition *StaticIfCondition::syntaxCopy()
@@ -235,7 +236,7 @@ Condition *StaticIfCondition::syntaxCopy()
 int StaticIfCondition::include(Scope *sc, ScopeDsymbol *s)
 {
 #if 0
-    printf("StaticIfCondition::include(sc = %p, s = %p)\n", sc, s);
+    printf("StaticIfCondition::include(sc = %p, s = %p) this=%p inc = %d\n", sc, s, this, inc);
     if (s)
     {
         printf("\ts = '%s', kind = %s\n", s->toChars(), s->kind());
@@ -243,6 +244,15 @@ int StaticIfCondition::include(Scope *sc, ScopeDsymbol *s)
 #endif
     if (inc == 0)
     {
+        if (exp->op == TOKerror || nest > 100)
+        {
+            error(loc, (nest > 1000) ? "unresolvable circular static if expression"
+                                     : "error evaluating static if expression");
+            if (!global.gag)
+                inc = 2;                // so we don't see the error message again
+            return 0;
+        }
+
         if (!sc)
         {
             error(loc, "static if conditional cannot be at global scope");
@@ -250,13 +260,19 @@ int StaticIfCondition::include(Scope *sc, ScopeDsymbol *s)
             return 0;
         }
 
+        ++nest;
         sc = sc->push(sc->scopesym);
         sc->sd = s;                     // s gets any addMember()
         sc->flags |= SCOPEstaticif;
         Expression *e = exp->semantic(sc);
         sc->pop();
         e = e->optimize(WANTvalue | WANTinterpret);
-        if (e->isBool(TRUE))
+        --nest;
+        if (e->op == TOKerror)
+        {   exp = e;
+            inc = 0;
+        }
+        else if (e->isBool(TRUE))
             inc = 1;
         else if (e->isBool(FALSE))
             inc = 2;