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copy with-c-layout to mem namespace

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Kristin Rutenkolk 2024-10-11 14:53:09 +02:00
parent cf6dff3b52
commit d04a9f6286
1 changed files with 27 additions and 0 deletions
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27
src/clj/coffi/mem.clj
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@ -1546,6 +1546,33 @@
:args (s/cat :new-type qualified-keyword?
:aliased-type any?))
(defn- with-c-layout
"Forces a struct specification to C layout rules.
This will add padding fields between fields to match C alignment
requirements."
[struct-spec]
(let [aligned-fields
(loop [offset 0
aligned-fields []
fields (nth struct-spec 1)]
(if (seq fields)
(let [[[_ type :as field] & fields] fields
size (mem/size-of type)
align (mem/align-of type)
r (rem offset align)]
(recur (cond-> (+ offset size)
(pos? r) (+ (- align r)))
(cond-> aligned-fields
(pos? r) (conj [::padding [::mem/padding (- align r)]])
:always (conj field))
fields))
(let [strongest-alignment (reduce max (map (comp mem/align-of second) (nth struct-spec 1)))
r (rem offset strongest-alignment)]
(cond-> aligned-fields
(pos? r) (conj [::padding [::mem/padding (- strongest-alignment r)]])))))]
(assoc struct-spec 1 aligned-fields)))
(defn- typename->coffi-typename [_type]
(get
{'byte ::byte