Commit08672e86Recorded9 Jul 2026Repositorysigil-audio

Gate native audio C out of wasm builds

Message

sigil-audio's native C (sokol_audio, vendored libogg/libvorbis) has no wasm32-wasi backend, so a wasm app depending on sigil-audio for the (sigil audio sink) facade failed to compile it ("unsupported platform").

Wrap the C-compilation build steps in skip-on-wasm so they are a no-op on wasm/wasi targets; compile-sigil-modules still runs, producing the facade + module bytecode. On wasm the facade delegates to the WebAudio bridge, so none of this C is needed. Native builds are byte-identical (the guard is false), and test-streaming-sink.sgl stays green.

Note: run-steps threads each step's return value as the next step's ctx, so a skipped step must return ctx unchanged.

Changed
 package.sgl | 37 ++++++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 9 deletions(-)
Diff
package.sglmodified
@@ -4,7 +4,21 @@
4
;;; Sound effects are loaded into memory, music is streamed via stb_vorbis.
5
;;; OGG Vorbis encoding ships in-tree via vendored libogg + libvorbis.
6
−7
(package
+7
;; skip-on-wasm wraps a build step so it is a no-op on wasm/wasi targets.
+8
;; The native audio C (sokol_audio, vendored libogg/libvorbis) has no
+9
;; wasm32-wasi backend; on wasm the (sigil audio sink) facade delegates to
+10
;; the WebAudio bridge, so none of this C is needed. Only compile-sigil-modules
+11
;; runs on wasm, producing the facade + module bytecode. Native builds are
+12
;; unaffected (the guard is false), so behavior there is byte-identical.
+13
;; run-steps threads each step's return value as the ctx for the next step
+14
;; (fold-left over steps), so a skipped step must return ctx UNCHANGED.
+15
(let ((skip-on-wasm
+16
(lambda (step)
+17
(lambda (ctx)
+18
(if (memq (target-os ctx) '(wasm wasi))
+19
ctx
+20
(step ctx))))))
+21
(package
22
name: "sigil-audio"
23
version: "0.11.0"
24
sigil: "^0.17"
@@ -83,7 +97,12 @@
97
;; vendor/ogg/README.md); keeping warnings off avoids polluting
98
;; sigil-audio's own strict-flag set when upstream's style
99
;; trips -Wparentheses / -Wunused-* / -Wsign-compare.
−86
(compile-c-sources
+100
;;
+101
;; The C steps are wrapped in skip-on-wasm: none of this native audio
+102
;; C cross-compiles to wasm32-wasi, and the (sigil audio sink) facade's
+103
;; wasm arm uses the WebAudio bridge instead. compile-sigil-modules is
+104
;; NOT wrapped: the facade + module bytecode must still build on wasm.
+105
(skip-on-wasm (compile-c-sources
106
sources: '("vendor/ogg/src/bitwise.c"
107
"vendor/ogg/src/framing.c")
108
include-dirs: '("vendor/ogg/include")
@@ -92,13 +111,13 @@
111
"-Wno-unused-function"
112
"-Wno-unused-but-set-variable"
113
"-Wno-sign-compare"
−95
"-Wno-strict-aliasing"))
+114
"-Wno-strict-aliasing")))
115
116
;; Compile vendored libvorbis (full library + encoder + file
117
;; I/O). Upstream sources are byte-identical to the 1.3.7
118
;; tarball (see vendor/vorbis/README.md). Same relaxed-warning
119
;; rationale as libogg above.
−101
(compile-c-sources
+120
(skip-on-wasm (compile-c-sources
121
sources: '("vendor/vorbis/lib/analysis.c"
122
"vendor/vorbis/lib/bitrate.c"
123
"vendor/vorbis/lib/block.c"
@@ -143,16 +162,16 @@
162
"-Wno-unused-function"
163
"-Wno-unused-but-set-variable"
164
"-Wno-sign-compare"
−146
"-Wno-strict-aliasing")))
+165
"-Wno-strict-aliasing"))))
166
167
;; sigil-audio's own C sources.
−149
(compile-c-sources
+168
(skip-on-wasm (compile-c-sources
169
sources: '("src/c/sokol-audio.c" "src/c/audio.c" "src/c/audio-stream.c" "src/c/ogg-encode.c")
170
include-dirs: '("vendor/sokol" "vendor/stb"
171
"vendor/ogg/include"
172
"vendor/vorbis/include")
173
flags: (with-sigil-c-flags '("-std=c11" "-D_GNU_SOURCE"
−155
"-Wno-unused-parameter" "-Wno-unused-function" "-Wno-sign-compare")))
−156
(create-static-library name: "sigil-audio")
+174
"-Wno-unused-parameter" "-Wno-unused-function" "-Wno-sign-compare"))))
+175
(skip-on-wasm (create-static-library name: "sigil-audio"))
176
(compile-sigil-modules sources: "src/**/*.sgl"
−158
output-dir: (config-output-subdir "lib"))))))
+177
output-dir: (config-output-subdir "lib")))))))