Bug 3374 – [tdpl] ICE(init.c): Associative array type not inferred

The error when trying to compile this snippet: auto famousNamedConstants = [ "pi" : 3.14, "e" : 2.71, "moving sofa" : 2.22 ]; is: Error: cannot infer type from this array initializer dmd: init.c:420: virtual Expression* ArrayInitializer::toExpression(): Assertion `0' failed. Changing the sample to the following works: double[string] famousNamedConstants = [ "pi" : 3.14, "e" : 2.71, "moving sofa" : 2.22 ];

The ICE only occurs if it's inside a function. BTW if you change 'auto' into enum, and 'assert' into 'static assert', it also works with the patch in place. void bug3374() { auto famousNamedConstants = [ "pi" : 3.14, "e" : 2.71, "moving sofa" : 2.22 ]; assert(famousNamedConstants["e"]==2.71); } There are two parts to this patch. The first part, in ArrayInitializer::toExpression() is just for the ICE. The ICE occurs because it's not checking for an ERROR type. (was NULL in D1). This changes it from ice-on-valid-code into rejects-valid. To completely fix the bug requires the second part. The second part, in ArrayInitializer::inferType(Scope *sc), is for the AA type inference. But, I had to do a semantic on the expression. Not sure if that's OK. This part of the patch is for D1 as well. PATCH against DMD 2.033. init.c, ArrayInitializer::toExpression(), line 407. Index: init.c =================================================================== --- init.c (revision 201) +++ init.c (working copy) @@ -404,6 +404,7 @@ Type *t = NULL; if (type) { + if (type == Type::terror) goto Lno; t = type->toBasetype(); switch (t->ty) { @@ -542,8 +543,18 @@ return type; Lno: - error(loc, "cannot infer type from this array initializer"); - return Type::terror; + Initializer *iz = (Initializer *)value.data[0]; + Expression *indexinit = (Expression *)index.data[0]; + if (iz && indexinit) + { Type *t = iz->inferType(sc); + indexinit = indexinit->semantic(sc); + Type *indext = indexinit->type; + t = new TypeAArray(t, indext); + t = t->semantic(loc, sc); + type = t; + } + return type; + }

Fixed dmd 1.049 and 2.034