On Friday, 14 July 2017 at 23:51:24 UTC, Walter Bright wrote:
On 7/14/2017 9:53 AM, Johan Engelen wrote:
What happens in that in one kind of compilation, @nogc is
deduced for a function. But in another compilation, it isn't.
Thus references to the function will have the wrong mangling,
and linker errors happen:
https://issues.dlang.org/show_bug.cgi?id=17541
At the moment you can work around it by explicitly adding the
annotation.
Cannot add something to a compiler internal function (e.g.
__fieldPostblit), @nogc and pure are infectious, the templates
are instantiated with different types where some instantiations
require deducing @nogc/pure/..., others require @gc/impure/...,
annotations cannot be applied conditionally (at least I don't
know how), cannot add @gc, cannot add @impure, etc.
My current workarounds force deduction one way or another, but
it's definitely not nice and it is very time consuming to figure
out what tricks the compiler into doing the right thing. Each
error needs it's own special work around.
For example, working around the __fieldPostblit deduction problem
involved searching all member fields (and their members, etc.) to
try to find which this(this) should be annotated to fix things.
Not so nice to do for a somewhat complex struct in a 9MB D-code
base, sprinkled with conditional compilation, templates, CTFE...
Each trial build (incremental) takes approx a minute. Fun times.
Fortunately, it looks like I've "fixed" all issues and we can now
link; kicked of the testing, let's hope there are not too many
regression bugs at runtime.
-Johan
