template Magic() { void* magic = null; // remove = null; and bug disappears } struct Item { mixin Magic A; } struct Foo(alias S) { } void main() { Foo!(Item.A) bar; } Assertion failure: 'type' on line 529 in file 'todt.c'
This applies equally to D1.047. It's been present since prehistory (fails identically on DMD0.175).
Another variation gives an ICE in optimize.c. Replace void *magic = null; with void* magic = cast(void*)(0); Again, it's because no 'type' is NULL.
This is happening because in this situation, when TemplateMixin::semantic() is called, semanticRun is already 3. The members get syntax copied: // Copy the syntax trees from the TemplateDeclaration members = Dsymbol::arraySyntaxCopy(tempdecl->members); But this destroys their type info, and then since semanticRun is 3, semantic2 never gets run, hence semantic() never gets called on the members ---> they have no type. I don't think this mixin should be run at all, if it's already done the semantic3 pass. (Note: I have NOT tested this patch against the DMD test suite). PATCH: Line 4457, in template.c, TemplateMixin::semantic(Scope *sc) if (!semanticRun) semanticRun = 1; + if (semanticRun >1) return; ---------------------------- But I'm not sure if this is the correct place to do this check. Should it be being asked to do the semantic at all? It's being called from AliasDeclaration::semantic(), and I'm not sure why: if (aliassym) { if (aliassym->isTemplateInstance()) { aliassym->semantic(sc); // Is this correct?? } return; }
Fixed in SVN repository: http://www.dsource.org/projects/dmd/changeset/229
Fixed dmd 1.051 and 2.036