(playdate support) delimcc.c is compiled even if Continuations isn't used

[kubukoz]

To reproduce:

1. Add this line to delimcc.c, just to make it clear that the code is being included

diff --git a/nativelib/src/main/resources/scala-native/delimcc.c b/nativelib/src/main/resources/scala-native/delimcc.c
index bd00eb6aa..dd0597d1e 100644
--- a/nativelib/src/main/resources/scala-native/delimcc.c
+++ b/nativelib/src/main/resources/scala-native/delimcc.c
@@ -1,4 +1,6 @@
 #if defined(SCALANATIVE_COMPILE_ALWAYS) || defined(__SCALANATIVE_DELIMCC)
+
+#error "this shouldn't happen!"
 #include "delimcc.h"
 #include <stddef.h>
 #include <stdio.h>

2. Publish a snapshot
3. Try to link an app/library, even a "hello world" or a no-op main.

Output:

[info] Linking (multithreadingEnabled=true, disable if not used) (322 ms)
[info] Discovered 907 classes and 5623 methods after classloading
[info] Checking intermediate code (quick) (4 ms)
[info] Multithreading was not explicitly enabled - initial class loading has not detected any usage of system threads. Multithreading support will be disabled to improve performance.
[info] Linking (multithreadingEnabled=false) (277 ms)
[info] Discovered 774 classes and 4690 methods after classloading
[info] Checking intermediate code (quick) (2 ms)
[info] Discovered 749 classes and 3668 methods after optimization
[info] Optimizing (debug mode) (156 ms)
[info] Produced 43 LLVM IR files
[info] Generating intermediate code (413 ms)
[error] /Users/kubukoz/projects/demos/target/scala-3.3.3/native/dependencies/nativelib_native0.5_3-0/scala-native/delimcc.c:3:2: error: "this shouldn't happen!"
[error] #error "this shouldn't happen!"
[error]  ^
[error] 1 error generated.
[info] Compiling to native code (1524 ms)
[error] stack trace is suppressed; run last Compile / nativeLink for the full output
[error] stack trace is suppressed; run last Compile / nativeLink for the full output
[error] stack trace is suppressed; run last Compile / nativeLink for the full output
[error] stack trace is suppressed; run last Compile / nativeLink for the full output
[error] stack trace is suppressed; run last Compile / nativeLink for the full output
[error] stack trace is suppressed; run last Compile / nativeLink for the full output
[info] Total (2502 ms)
[error] Failed to compile /Users/kubukoz/projects/demos/target/scala-3.3.3/native/dependencies/nativelib_native0.5_3-0/scala-native/delimcc.c
[error] (Compile / nativeLink) Failed to compile /Users/kubukoz/projects/demos/target/scala-3.3.3/native/dependencies/nativelib_native0.5_3-0/scala-native/delimcc.c

Example app setup (requires a publish of 0.5.1-SNAPSHOT): https://github.com/kubukoz/demos/compare/sn-continuations-repro?expand=1

[ekrich]

Won't argue that but if you look how SCALANATIVE_COMPILE_ALWAYS is used it is always like the following on the whole file:

#if defined(SCALANATIVE_COMPILE_ALWAYS) || defined(__SCALANATIVE_POSIX_PTHREAD)
#include <pthread.h>

Our glue code pthread.c has that code. Then here on the Scala side - https://github.com/scala-native/scala-native/blob/main/posixlib/src/main/scala/scala/scalanative/posix/pthread.scala#L12-L15

So if that Scala code is optimized away then no define.

[kubukoz]

right, there's a lot of this pattern in the codebase, and it seems to work correctly for my needs most of the time - the only offender I've found so far is delimcc.

[ekrich]

That is not really the one you want to use because that is for the glue code. I put a note on this issue which might be better.
#3877

[ekrich]

The delimcc is another factor - that should be a feature option somehow.