Optimize LF test compilation with CMake

[sbgaia]

This PR reworks how LF and unit tests are built and executed. Instead of compiling reactor-uc from scratch for each LF test via the Makefile, we now use CMake to share a single reactor-uc build across all tests and compile them in parallel.

I also added a batch processing function in lfc.cmake so we can invoke LFC once for multiple test files instead of calling it repeatedly, and added coverage support for LF tests (previously we only had it for unit tests).

Minor changes:

• Moved federated LF tests into test/lf/src/federated/ with a dedicated runner script;
• Improved runtime symlink handling in UcPlatformGenerator.kt;
• Fixed a couple of ASAN errors in connection logging and the event payload pool test;
• Cleaned up the build config so unit tests and LF tests are properly decoupled.

Closes #275 and #136.

Benchmark

This is the improvement I got on my laptop:

Approach	Time
Makefile (compiles reactor-uc per test, sequential)	1210s
CMake (shared reactor-uc, -j16)	182s
Speedup	6.6x

CMake breakdown:

• LFC generation (cmake configure): ~101s
• Compilation: ~18s
• Test execution (ctest): ~63s

We can squeeze more out of this:

1. Batch generation in LFC for federates: LFC reports an error if the batch contains more than one main federate. Currently, we still must process each federate individually, adding a lot of overhead.
2. Move re-generation checks inside LFC: Currently, when a .lf file has already been built, LFC re-executes the entire generation pipeline and checks for each file whether the output it wants to write matches what's already on disk. Instead, we could take the same approach as make and check whether the output directory was modified more recently than the .lf file and its imports. This would allow us to cache the generated output in the CI pipeline and skip the generation step entirely when the tests haven't changed.

[github-actions]

Memory usage after merging this PR will be:

Memory Report

action_buffer_full_defer_test_c

	from	to	increase (%)
text	78247	78281	0.04
data	752	752	0.00
bss	12448	12448	0.00
dec	91447	91481	0.04

action_buffer_full_drop_test_c

	from	to	increase (%)
text	78247	78281	0.04
data	752	752	0.00
bss	12448	12448	0.00
dec	91447	91481	0.04

action_buffer_full_replace_test_c

	from	to	increase (%)
text	78247	78281	0.04
data	752	752	0.00
bss	12448	12448	0.00
dec	91447	91481	0.04

action_buffer_full_update_test_c

	from	to	increase (%)
text	78247	78281	0.04
data	752	752	0.00
bss	12448	12448	0.00
dec	91447	91481	0.04

action_defer_test_c

	from	to	increase (%)
text	78361	78395	0.04
data	752	752	0.00
bss	12512	12512	0.00
dec	91625	91659	0.04

action_drop_test_c

	from	to	increase (%)
text	78185	78219	0.04
data	752	752	0.00
bss	12512	12512	0.00
dec	91449	91483	0.04

action_empty_test_c

	from	to	increase (%)
text	77866	77900	0.04
data	752	752	0.00
bss	12448	12448	0.00
dec	91066	91100	0.04

action_microstep_test_c

	from	to	increase (%)
text	78396	78430	0.04
data	760	760	0.00
bss	12512	12512	0.00
dec	91668	91702	0.04

action_overwrite_test_c

	from	to	increase (%)
text	78079	78113	0.04
data	752	752	0.00
bss	12512	12512	0.00
dec	91343	91377	0.04

action_replace_test_c

	from	to	increase (%)
text	78185	78219	0.04
data	752	752	0.00
bss	12512	12512	0.00
dec	91449	91483	0.04

action_test_c

	from	to	increase (%)
text	78173	78207	0.04
data	760	760	0.00
bss	12512	12512	0.00
dec	91445	91479	0.04

action_update_test_c

	from	to	increase (%)
text	78282	78316	0.04
data	752	752	0.00
bss	12512	12512	0.00
dec	91546	91580	0.04

deadline_test_c

	from	to	increase (%)
text	72475	72509	0.05
data	768	768	0.00
bss	11808	11808	0.00
dec	85051	85085	0.04

delayed_conn_test_c

	from	to	increase (%)
text	76671	76705	0.04
data	752	752	0.00
bss	13280	13280	0.00
dec	90703	90737	0.04

event_payload_pool_test_c

	from	to	increase (%)
text	24314	24314	0.00
data	720	720	0.00
bss	480	480	0.00
dec	25514	25514	0.00

event_queue_test_c

	from	to	increase (%)
text	36107	36107	0.00
data	728	728	0.00
bss	640	640	0.00
dec	37475	37475	0.00

nanopb_test_c

	from	to	increase (%)
text	44218	44218	0.00
data	1928	1928	0.00
bss	320	320	0.00
dec	46466	46466	0.00

physical_clock_test_c

	from	to	increase (%)
text	54308	54342	0.06
data	832	832	0.00
bss	640	640	0.00
dec	55780	55814	0.06

port_test_c

	from	to	increase (%)
text	76574	76608	0.04
data	752	752	0.00
bss	13088	13088	0.00
dec	90414	90448	0.04

reaction_queue_test_c

	from	to	increase (%)
text	30420	30420	0.00
data	728	728	0.00
bss	480	480	0.00
dec	31628	31628	0.00

request_shutdown_test_c

	from	to	increase (%)
text	78210	78244	0.04
data	752	752	0.00
bss	12512	12512	0.00
dec	91474	91508	0.04

startup_test_c

	from	to	increase (%)
text	72104	72138	0.05
data	760	760	0.00
bss	11808	11808	0.00
dec	84672	84706	0.04

tcp_channel_test_c

	from	to	increase (%)
text	96862	96896	0.04
data	2288	2288	0.00
bss	14720	14720	0.00
dec	113870	113904	0.03

timer_test_c

	from	to	increase (%)
text	72076	72110	0.05
data	752	752	0.00
bss	11808	11808	0.00
dec	84636	84670	0.04

[github-actions]

Benchmark results after merging this PR:

Benchmark results

Performance:

PingPongUc:
Best Time: 594.642 msec
Worst Time: 765.766 msec
Median Time: 693.478 msec

PingPongC:
Best Time: 175.908 msec
Worst Time: 176.074 msec
Median Time: 175.686 msec

ReactionLatencyUc:
Best latency: 31871 nsec
Median latency: 66555 nsec
Worst latency: 337964 nsec

ReactionLatencyC:
Best latency: 61262 nsec
Median latency: 66739 nsec
Worst latency: 127535 nsec

Memory usage:

PingPongUc:
text data bss dec hex filename
41026 760 8536 50322 c492 bin/PingPongUc

PingPongC:
text data bss dec hex filename
52194 934 424 53552 d130 bin/PingPongC

ReactionLatencyUc:
text data bss dec hex filename
26151 744 2552 29447 7307 bin/ReactionLatencyUc

ReactionLatencyC:
text data bss dec hex filename
47736 902 424 49062 bfa6 bin/ReactionLatencyC

[edwardalee]

LGTM, but I did not check it carefully. I would say, if it works, and you are sure all tests are running, go for it. I would be curious to know how much it speeds up the CI tests.

[tanneberger]

so this function basically adds an executable to cmake and links all the libraries?

Maybe can put this function actually into the generic cmake function file and reuse it here:
https://github.com/lf-lang/reactor-uc/blob/main/lfc/core/src/main/kotlin/org/lflang/generator/uc/UcCmakeGenerator.kt#L55

And I think we need a better name: e.g. lf_add_executable or something like this.

[github-actions]

Coverage after merging opt-lftests into main will be

84.95%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
include/reactor-uc
event.h	48.78%	37.50%	66.67%	52.63%	101, 101–102, 115–116, 116, 116, 116, 116–117, 119–121, 140–141, 141, 141, 141, 141
src
action.c	94.35%	84%	100%	98.32%	106, 145, 25, 42, 42, 60, 75, 97–99
builtin_triggers.c	90.91%	70%	100%	96.77%	14, 18, 40, 43
clock_synchronization.c	75.45%	62.16%	92.31%	78.54%	106–109, 116–118, 143, 149–151, 154, 158, 160–161, 161, 161–163, 163, 163, 166, 166, 166–167, 170–175, 175, 175–176, 180, 182–188, 188, 188–189, 192, 214–215, 224–225, 238–239, 241, 254–256, 26, 264–266, 27, 30, 310–311, 323, 323–326, 33–35, 49–52, 79–80, 95–97
connection.c	90.45%	76.60%	100%	96.04%	106, 112, 14, 140–141, 147, 149–150, 152, 27–28, 35, 50, 56, 99
environment.c	94.12%	83.33%	100%	100%	16, 29
event.c	100%	100%	100%	100%
federated.c	80.50%	57.29%	100%	90%	120, 123–124, 148–149, 17, 176, 18–20, 202–203, 21, 210, 214, 214, 214, 214–217, 224–225, 228–230, 233–234, 236–239, 243, 246, 256, 275–277, 285–287, 30, 301–302, 304–307, 310–313, 33–34, 40–41, 45, 58, 58, 58–59, 65
logging.c	88.52%	83.33%	100%	89.36%	25, 38–40, 47, 60–61
network_channel.c	80.77%	75%	100%	82.35%	40, 40, 45–46, 57
physical_clock.c	97.40%	83.33%	100%	100%	26, 41
port.c	92.50%	78.57%	100%	100%	10, 15, 22, 26, 46–47
queues.c	91.90%	84.21%	100%	94.15%	128, 132, 132, 132–133, 181, 188–191, 217–219, 221, 234, 250, 255, 261, 55, 62–65
reaction.c	95.90%	89.13%	100%	100%	21, 30, 32, 56, 72
reactor.c	86%	69.70%	100%	98.73%	10, 101–102, 14–19, 22, 28, 32–34, 37–38, 43, 60, 77, 83, 91
serialization.c	75%	50%	100%	80%	16–17, 26–27, 34–35, 42–43
startup_coordinator.c	57.34%	48.78%	71.43%	60.88%	104–106, 116, 122, 124–125, 128, 138, 144, 149, 153–154, 174, 177–178, 188, 188, 188–189, 191, 193, 196, 21, 222, 226–227, 227, 227–228, 232, 235, 237, 242–243, 264, 273, 276, 293–294, 303, 303–304, 308, 316, 32, 362–364, 364, 364–365, 365, 365–368, 371–372, 372, 372, 375, 380, 380, 380–390, 393, 395, 398, 400–401, 401, 401–402, 405, 405, 405–407, 407, 407–408, 408, 408–410, 414, 414, 414–416, 420–423, 423, 423, 425–426, 429, 429, 429–430, 430, 430, 430, 430–431, 436–437, 437, 437–438, 438, 438–439, 443–444, 446, 448, 448, 448–457, 457, 457–465, 467, 471, 473, 473, 473, 475–476, 476, 476–477, 477, 477, 480–481, 481, 481–483, 488, 494, 494, 494, 494, 510–513, 515–518, 520–523, 525–527, 544, 544, 544, 544, 64, 67, 67, 67–69, 69, 69–76, 76, 76, 79, 79, 79–80, 82, 91–92, 94
tag.c	45.79%	37.04%	60%	54.17%	14, 17, 23–24, 24, 24, 24, 24–25, 27, 27, 27, 27, 27–28, 30, 30, 30–31, 33–34, 34, 34–35, 37, 37, 37, 37, 37–38, 40, 40, 40, 40, 40–41, 43, 63, 67–68, 83–85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85–87, 89
timer.c	97.50%	83.33%	100%	100%	14
trigger.c	100%	100%	100%	100%
util.c	56.41%	33.33%	75%	65.22%	12–13, 13, 13–14, 14, 14–15, 15, 15–16, 18–19, 21, 24, 5
src/environments
federated_environment.c	85.11%	70%	100%	90.22%	113–116, 116, 116–119, 119, 119–121, 147–149, 25, 31, 43, 52, 55
unfederated_environment.c	93.41%	71.43%	100%	96.88%	13, 42, 42–43, 59–60
src/platform/posix
posix.c	84.87%	63.64%	86.67%	90.24%	114, 121, 126, 133, 17, 19, 21–23, 36–37, 59, 63, 77, 81, 95
tcp_ip_channel.c	70.56%	57.31%	100%	79.38%	102–103, 103, 103–104, 107–108, 108, 108–109, 112–113, 113, 113–114, 125–126, 128, 130, 134–135, 143, 146–147, 147, 147–148, 153–154, 154, 154–155, 161–162, 162, 162–163, 179, 182, 186, 186, 186, 186, 186–187, 187, 187–188, 188, 188–189, 191, 193, 193, 193–194, 203, 210–211, 216, 220–222, 222, 222–223, 226, 235, 235, 235–236, 269–270, 270, 270–271, 277, 282–283, 283, 283–284, 284, 284–285, 287–288, 288, 288–289, 289, 289, 291–292,