changing buffering behavior of stdout

[drapl0n]

Force a flush of the stdout buffer, ensuring that any buffered output is immediately written to the terminal without waiting for the buffer to fill or for the program to exit.

This resolves issue #526, which caused test failures due to output mismatches when executed in Lind.

Results:

printing getgid:
1000
printing getuid:
1000
printing getegid:
1000
printing geteuid:
1000

[rennergade]

This probably works as a quick fix. What happens if the fp gets changed from stdout? (like during dup) Does it change in libc as well?

If thats true this might just be everything we need but let's make sure.

[github-actions]

End-to-End Test Report

Test Preview

Test Report

Deterministic Tests

Summary

Metric	Count
Total Test Cases	81
Number of Successes	81
Number of Failures	0
Number of Compilation Failure Native	0
Number of Runtime Failure Native	0
Number of Segmentation Fault Native	0
Number of Timeout During Native	0
Number of Lind Wasm Compile Failure	0
Number of Lind Wasm Runtime Failure	0
Number of Lind Wasm Segmentation Failure	0
Number of Timeout During Lind Wasm run	0
Number of Unknown Failure	0
Number of C Compiler and Wasm Output mismatch	0
Number of Fail Test: Native Succeeded (Should Fail)	0
Number of Fail Test: Wasm Succeeded (Should Fail)	0
Number of Fail Test: Both Native and Wasm Succeeded (Should Fail)	0
Number of Fail Test: Native Compilation Failure (Should Succeed)	0
Number of Fail Test: Wasm Compilation Failure (Should Succeed)	0

Test Results by Category

Test Case	Status	Error Type	Output
File Tests
chmod.c	Success	None	Success
close.c	Success	None	Success
doubleclose.c	Success	None	Success
dupwrite.c	Success	None	Success
fchmod.c	Success	None	Success
fcntl.c	Success	None	Success
fdatasync.c	Success	None	Success
filetest.c	Success	None	Success
filetest1000.c	Success	None	Success
fstat.c	Success	None	Success
fsync.c	Success	None	Success
ftruncate.c	Success	None	Success
ioctl.c	Success	None	Success
link.c	Success	None	Success
lseek.c	Success	None	Success
mkdir_rmdir.c	Success	None	Success
open.c	Success	None	Success
pread_pwrite.c	Success	None	Success
printf.c	Success	None	Success
readbytes.c	Success	None	Success
readlink.c	Success	None	Success
rename.c	Success	None	Success
stat.c	Success	None	Success
sync_file_range.c	Success	None	Success
truncate.c	Success	None	Success
unlink.c	Success	None	Success
unlinkat.c	Success	None	Success
write.c	Success	None	Success
writeloop.c	Success	None	Success
writepartial.c	Success	None	Success
writev.c	Success	None	Success
Memory Tests
brk.c	Success	None	Success
malloc.c	Success	None	Success
memcpy.c	Success	None	Success
memory_error_test.c	Success	None	Success
mmap.c	Success	None	Success
mmap_aligned.c	Success	None	Success
mmap_file.c	Success	None	Success
mprotect.c	Success	None	Success
mprotect_boundary.c	Success	None	Success
mprotect_end_region.c	Success	None	Success
mprotect_middle_region.c	Success	None	Success
mprotect_multiple_times.c	Success	None	Success
mprotect_same_value.c	Success	None	Success
mprotect_spanning_regions.c	Success	None	Success
sbrk.c	Success	None	Success
shmtest.c	Success	None	Success
Networking Tests
gethostname.c	Success	None	Success
makepipe.c	Success	None	Success
pipepong.c	Success	None	Success
poll.c	Success	None	Success
recvfrom-sendto.c	Success	None	Success
simple_epoll.c	Success	None	Success
socket.c	Success	None	Success
socket_cloexec.c	Success	None	Success
socketpair.c	Success	None	Success
tcp_connect_single.c	Success	None	Success
Process Tests
chain_thread.c	Success	None	Success
exit.c	Success	None	Success
forkexecv-arg.c	Success	None	Success
forkexecv.c	Success	None	Success
function-ptr.c	Success	None	Success
getppid.c	Success	None	Success
hello-arg.c	Success	None	Success
hello.c	Success	None	Success
longjmp.c	Success	None	Success
mutex.c	Success	None	Success
noforkfiles.c	Success	None	Success
sem_forks.c	Success	None	Success
setsid.c	Success	None	Success
thread-test.c	Success	None	Success
thread.c	Success	None	Success
wait.c	Success	None	Success
waitpid_wnohang.c	Success	None	Success
Signal Tests
alarm.c	Success	None	Success
setitimer.c	Success	None	Success
sigalrm.c	Success	None	Success
sigchld.c	Success	None	Success
signal-fork.c	Success	None	Success
signal-simple.c	Success	None	Success
sigprocmask.c	Success	None	Success

Non Deterministic Tests

Summary

Metric	Count
Total Test Cases	40
Number of Successes	39
Number of Failures	1
Number of Compilation Failure Native	0
Number of Runtime Failure Native	0
Number of Segmentation Fault Native	0
Number of Timeout During Native	0
Number of Lind Wasm Compile Failure	0
Number of Lind Wasm Runtime Failure	0
Number of Lind Wasm Segmentation Failure	0
Number of Timeout During Lind Wasm run	1
Number of Unknown Failure	0
Number of C Compiler and Wasm Output mismatch	0
Number of Fail Test: Native Succeeded (Should Fail)	0
Number of Fail Test: Wasm Succeeded (Should Fail)	0
Number of Fail Test: Both Native and Wasm Succeeded (Should Fail)	0
Number of Fail Test: Native Compilation Failure (Should Succeed)	0
Number of Fail Test: Wasm Compilation Failure (Should Succeed)	0

Test Results by Category

Test Case	Status	Error Type	Output
File Tests
chdir_getcwd.c	Success	None	Success
clock_gettime_highlevel.c	Success	None	Success
clock_gettime_simple.c	Success	None	Success
dup.c	Success	None	Success
fchdir.c	Success	None	Success
fstatfs.c	Success	None	Success
getcwd.c	Success	None	Success
read.c	Success	None	Success
statfs.c	Success	None	Success
Memory Tests
malloc_large.c	Success	None	Success
mmap_complicated.c	Success	None	Success
mmap_shared.c	Success	None	Success
segfault.c	Failure	Lind_wasm_Timeout	Timed Out (timeout: 10s)
shm.c	Success	None	Success
vtable.c	Success	None	Success
Networking Tests
dnstest.c	Success	None	Success
getifaddrs.c	Success	None	Success
pipe.c	Success	None	Success
pipe2.c	Success	None	Success
pipeinput.c	Success	None	Success
pipeinput2.c	Success	None	Success
pipeonestring.c	Success	None	Success
pipewrite.c	Success	None	Success
shutdown_fork.c	Success	None	Success
simple-select.c	Success	None	Success
Process Tests
fork2malloc.c	Success	None	Success
fork_simple.c	Success	None	Success
forkandopen.c	Success	None	Success
forkfiles.c	Success	None	Success
forkmalloc.c	Success	None	Success
forknodup.c	Success	None	Success
getpid.c	Success	None	Success
Signal Tests
signal.c	Success	None	Success
signal_SIGCHLD.c	Success	None	Success
signal_fork.c	Success	None	Success
signal_int_thread.c	Success	None	Success
signal_longjmp.c	Success	None	Success
signal_nodefer.c	Success	None	Success
signal_procmask.c	Success	None	Success
signal_sa_mask.c	Success	None	Success

Fail Tests

Summary

Metric	Count
Total Test Cases	1
Number of Successes	1
Number of Failures	0
Number of Compilation Failure Native	0
Number of Runtime Failure Native	0
Number of Segmentation Fault Native	0
Number of Timeout During Native	0
Number of Lind Wasm Compile Failure	0
Number of Lind Wasm Runtime Failure	0
Number of Lind Wasm Segmentation Failure	0
Number of Timeout During Lind Wasm run	0
Number of Unknown Failure	0
Number of C Compiler and Wasm Output mismatch	0
Number of Fail Test: Native Succeeded (Should Fail)	0
Number of Fail Test: Wasm Succeeded (Should Fail)	0
Number of Fail Test: Both Native and Wasm Succeeded (Should Fail)	0
Number of Fail Test: Native Compilation Failure (Should Succeed)	0
Number of Fail Test: Wasm Compilation Failure (Should Succeed)	0

Test Results by Category

Test Case	Status	Error Type	Output
Memory Tests
mmap-negative1.c	Success	None	Success

[rennergade]

Also lets re-enable the tests it fixes in this PR too so they can pass CI.

[github-actions]

End-to-End Test Report

Test Preview

Test Report

Deterministic Tests

Summary

Metric	Count
Total Test Cases	81
Number of Successes	81
Number of Failures	0
Number of Compilation Failure Native	0
Number of Runtime Failure Native	0
Number of Segmentation Fault Native	0
Number of Timeout During Native	0
Number of Lind Wasm Compile Failure	0
Number of Lind Wasm Runtime Failure	0
Number of Lind Wasm Segmentation Failure	0
Number of Timeout During Lind Wasm run	0
Number of Unknown Failure	0
Number of C Compiler and Wasm Output mismatch	0
Number of Fail Test: Native Succeeded (Should Fail)	0
Number of Fail Test: Wasm Succeeded (Should Fail)	0
Number of Fail Test: Both Native and Wasm Succeeded (Should Fail)	0
Number of Fail Test: Native Compilation Failure (Should Succeed)	0
Number of Fail Test: Wasm Compilation Failure (Should Succeed)	0

Test Results by Category

Test Case	Status	Error Type	Output
File Tests
chmod.c	Success	None	Success
close.c	Success	None	Success
doubleclose.c	Success	None	Success
dupwrite.c	Success	None	Success
fchmod.c	Success	None	Success
fcntl.c	Success	None	Success
fdatasync.c	Success	None	Success
filetest.c	Success	None	Success
filetest1000.c	Success	None	Success
fstat.c	Success	None	Success
fsync.c	Success	None	Success
ftruncate.c	Success	None	Success
ioctl.c	Success	None	Success
link.c	Success	None	Success
lseek.c	Success	None	Success
mkdir_rmdir.c	Success	None	Success
open.c	Success	None	Success
pread_pwrite.c	Success	None	Success
printf.c	Success	None	Success
readbytes.c	Success	None	Success
readlink.c	Success	None	Success
rename.c	Success	None	Success
stat.c	Success	None	Success
sync_file_range.c	Success	None	Success
truncate.c	Success	None	Success
unlink.c	Success	None	Success
unlinkat.c	Success	None	Success
write.c	Success	None	Success
writeloop.c	Success	None	Success
writepartial.c	Success	None	Success
writev.c	Success	None	Success
Memory Tests
brk.c	Success	None	Success
malloc.c	Success	None	Success
memcpy.c	Success	None	Success
memory_error_test.c	Success	None	Success
mmap.c	Success	None	Success
mmap_aligned.c	Success	None	Success
mmap_file.c	Success	None	Success
mprotect.c	Success	None	Success
mprotect_boundary.c	Success	None	Success
mprotect_end_region.c	Success	None	Success
mprotect_middle_region.c	Success	None	Success
mprotect_multiple_times.c	Success	None	Success
mprotect_same_value.c	Success	None	Success
mprotect_spanning_regions.c	Success	None	Success
sbrk.c	Success	None	Success
shmtest.c	Success	None	Success
Networking Tests
gethostname.c	Success	None	Success
makepipe.c	Success	None	Success
pipepong.c	Success	None	Success
poll.c	Success	None	Success
recvfrom-sendto.c	Success	None	Success
simple_epoll.c	Success	None	Success
socket.c	Success	None	Success
socket_cloexec.c	Success	None	Success
socketpair.c	Success	None	Success
tcp_connect_single.c	Success	None	Success
Process Tests
chain_thread.c	Success	None	Success
exit.c	Success	None	Success
forkexecv-arg.c	Success	None	Success
forkexecv.c	Success	None	Success
function-ptr.c	Success	None	Success
getppid.c	Success	None	Success
hello-arg.c	Success	None	Success
hello.c	Success	None	Success
longjmp.c	Success	None	Success
mutex.c	Success	None	Success
noforkfiles.c	Success	None	Success
sem_forks.c	Success	None	Success
setsid.c	Success	None	Success
thread-test.c	Success	None	Success
thread.c	Success	None	Success
wait.c	Success	None	Success
waitpid_wnohang.c	Success	None	Success
Signal Tests
alarm.c	Success	None	Success
setitimer.c	Success	None	Success
sigalrm.c	Success	None	Success
sigchld.c	Success	None	Success
signal-fork.c	Success	None	Success
signal-simple.c	Success	None	Success
sigprocmask.c	Success	None	Success

Non Deterministic Tests

Summary

Metric	Count
Total Test Cases	40
Number of Successes	40
Number of Failures	0
Number of Compilation Failure Native	0
Number of Runtime Failure Native	0
Number of Segmentation Fault Native	0
Number of Timeout During Native	0
Number of Lind Wasm Compile Failure	0
Number of Lind Wasm Runtime Failure	0
Number of Lind Wasm Segmentation Failure	0
Number of Timeout During Lind Wasm run	0
Number of Unknown Failure	0
Number of C Compiler and Wasm Output mismatch	0
Number of Fail Test: Native Succeeded (Should Fail)	0
Number of Fail Test: Wasm Succeeded (Should Fail)	0
Number of Fail Test: Both Native and Wasm Succeeded (Should Fail)	0
Number of Fail Test: Native Compilation Failure (Should Succeed)	0
Number of Fail Test: Wasm Compilation Failure (Should Succeed)	0

Test Results by Category

Test Case	Status	Error Type	Output
File Tests
chdir_getcwd.c	Success	None	Success
clock_gettime_highlevel.c	Success	None	Success
clock_gettime_simple.c	Success	None	Success
dup.c	Success	None	Success
fchdir.c	Success	None	Success
fstatfs.c	Success	None	Success
getcwd.c	Success	None	Success
read.c	Success	None	Success
statfs.c	Success	None	Success
Memory Tests
malloc_large.c	Success	None	Success
mmap_complicated.c	Success	None	Success
mmap_shared.c	Success	None	Success
segfault.c	Success	None	Success
shm.c	Success	None	Success
vtable.c	Success	None	Success
Networking Tests
dnstest.c	Success	None	Success
getifaddrs.c	Success	None	Success
pipe.c	Success	None	Success
pipe2.c	Success	None	Success
pipeinput.c	Success	None	Success
pipeinput2.c	Success	None	Success
pipeonestring.c	Success	None	Success
pipewrite.c	Success	None	Success
shutdown_fork.c	Success	None	Success
simple-select.c	Success	None	Success
Process Tests
fork2malloc.c	Success	None	Success
fork_simple.c	Success	None	Success
forkandopen.c	Success	None	Success
forkfiles.c	Success	None	Success
forkmalloc.c	Success	None	Success
forknodup.c	Success	None	Success
getpid.c	Success	None	Success
Signal Tests
signal.c	Success	None	Success
signal_SIGCHLD.c	Success	None	Success
signal_fork.c	Success	None	Success
signal_int_thread.c	Success	None	Success
signal_longjmp.c	Success	None	Success
signal_nodefer.c	Success	None	Success
signal_procmask.c	Success	None	Success
signal_sa_mask.c	Success	None	Success

Fail Tests

Summary

Metric	Count
Total Test Cases	1
Number of Successes	1
Number of Failures	0
Number of Compilation Failure Native	0
Number of Runtime Failure Native	0
Number of Segmentation Fault Native	0
Number of Timeout During Native	0
Number of Lind Wasm Compile Failure	0
Number of Lind Wasm Runtime Failure	0
Number of Lind Wasm Segmentation Failure	0
Number of Timeout During Lind Wasm run	0
Number of Unknown Failure	0
Number of C Compiler and Wasm Output mismatch	0
Number of Fail Test: Native Succeeded (Should Fail)	0
Number of Fail Test: Wasm Succeeded (Should Fail)	0
Number of Fail Test: Both Native and Wasm Succeeded (Should Fail)	0
Number of Fail Test: Native Compilation Failure (Should Succeed)	0
Number of Fail Test: Wasm Compilation Failure (Should Succeed)	0

Test Results by Category

Test Case	Status	Error Type	Output
Memory Tests
mmap-negative1.c	Success	None	Success

[drapl0n]

This probably works as a quick fix. What happens if the fp gets changed from stdout? (like during dup) Does it change in libc as well?

I changed the logic. It now flushes only when stdout is not connected to a terminal device, avoiding unnecessary forced flush operations in interactive contexts and eliminating edge cases.

[github-actions]

End-to-End Test Report

Test Preview

Test Report

Deterministic Tests

Summary

Metric	Count
Total Test Cases	81
Number of Successes	81
Number of Failures	0
Number of Compilation Failure Native	0
Number of Runtime Failure Native	0
Number of Segmentation Fault Native	0
Number of Timeout During Native	0
Number of Lind Wasm Compile Failure	0
Number of Lind Wasm Runtime Failure	0
Number of Lind Wasm Segmentation Failure	0
Number of Timeout During Lind Wasm run	0
Number of Unknown Failure	0
Number of C Compiler and Wasm Output mismatch	0
Number of Fail Test: Native Succeeded (Should Fail)	0
Number of Fail Test: Wasm Succeeded (Should Fail)	0
Number of Fail Test: Both Native and Wasm Succeeded (Should Fail)	0
Number of Fail Test: Native Compilation Failure (Should Succeed)	0
Number of Fail Test: Wasm Compilation Failure (Should Succeed)	0

Test Results by Category

Test Case	Status	Error Type	Output
File Tests
chmod.c	Success	None	Success
close.c	Success	None	Success
doubleclose.c	Success	None	Success
dupwrite.c	Success	None	Success
fchmod.c	Success	None	Success
fcntl.c	Success	None	Success
fdatasync.c	Success	None	Success
filetest.c	Success	None	Success
filetest1000.c	Success	None	Success
fstat.c	Success	None	Success
fsync.c	Success	None	Success
ftruncate.c	Success	None	Success
ioctl.c	Success	None	Success
link.c	Success	None	Success
lseek.c	Success	None	Success
mkdir_rmdir.c	Success	None	Success
open.c	Success	None	Success
pread_pwrite.c	Success	None	Success
printf.c	Success	None	Success
readbytes.c	Success	None	Success
readlink.c	Success	None	Success
rename.c	Success	None	Success
stat.c	Success	None	Success
sync_file_range.c	Success	None	Success
truncate.c	Success	None	Success
unlink.c	Success	None	Success
unlinkat.c	Success	None	Success
write.c	Success	None	Success
writeloop.c	Success	None	Success
writepartial.c	Success	None	Success
writev.c	Success	None	Success
Memory Tests
brk.c	Success	None	Success
malloc.c	Success	None	Success
memcpy.c	Success	None	Success
memory_error_test.c	Success	None	Success
mmap.c	Success	None	Success
mmap_aligned.c	Success	None	Success
mmap_file.c	Success	None	Success
mprotect.c	Success	None	Success
mprotect_boundary.c	Success	None	Success
mprotect_end_region.c	Success	None	Success
mprotect_middle_region.c	Success	None	Success
mprotect_multiple_times.c	Success	None	Success
mprotect_same_value.c	Success	None	Success
mprotect_spanning_regions.c	Success	None	Success
sbrk.c	Success	None	Success
shmtest.c	Success	None	Success
Networking Tests
gethostname.c	Success	None	Success
makepipe.c	Success	None	Success
pipepong.c	Success	None	Success
poll.c	Success	None	Success
recvfrom-sendto.c	Success	None	Success
simple_epoll.c	Success	None	Success
socket.c	Success	None	Success
socket_cloexec.c	Success	None	Success
socketpair.c	Success	None	Success
tcp_connect_single.c	Success	None	Success
Process Tests
chain_thread.c	Success	None	Success
exit.c	Success	None	Success
forkexecv-arg.c	Success	None	Success
forkexecv.c	Success	None	Success
function-ptr.c	Success	None	Success
getppid.c	Success	None	Success
hello-arg.c	Success	None	Success
hello.c	Success	None	Success
longjmp.c	Success	None	Success
mutex.c	Success	None	Success
noforkfiles.c	Success	None	Success
sem_forks.c	Success	None	Success
setsid.c	Success	None	Success
thread-test.c	Success	None	Success
thread.c	Success	None	Success
wait.c	Success	None	Success
waitpid_wnohang.c	Success	None	Success
Signal Tests
alarm.c	Success	None	Success
setitimer.c	Success	None	Success
sigalrm.c	Success	None	Success
sigchld.c	Success	None	Success
signal-fork.c	Success	None	Success
signal-simple.c	Success	None	Success
sigprocmask.c	Success	None	Success

Non Deterministic Tests

Summary

Metric	Count
Total Test Cases	40
Number of Successes	40
Number of Failures	0
Number of Compilation Failure Native	0
Number of Runtime Failure Native	0
Number of Segmentation Fault Native	0
Number of Timeout During Native	0
Number of Lind Wasm Compile Failure	0
Number of Lind Wasm Runtime Failure	0
Number of Lind Wasm Segmentation Failure	0
Number of Timeout During Lind Wasm run	0
Number of Unknown Failure	0
Number of C Compiler and Wasm Output mismatch	0
Number of Fail Test: Native Succeeded (Should Fail)	0
Number of Fail Test: Wasm Succeeded (Should Fail)	0
Number of Fail Test: Both Native and Wasm Succeeded (Should Fail)	0
Number of Fail Test: Native Compilation Failure (Should Succeed)	0
Number of Fail Test: Wasm Compilation Failure (Should Succeed)	0

Test Results by Category

Test Case	Status	Error Type	Output
File Tests
chdir_getcwd.c	Success	None	Success
clock_gettime_highlevel.c	Success	None	Success
clock_gettime_simple.c	Success	None	Success
dup.c	Success	None	Success
fchdir.c	Success	None	Success
fstatfs.c	Success	None	Success
getcwd.c	Success	None	Success
read.c	Success	None	Success
statfs.c	Success	None	Success
Memory Tests
malloc_large.c	Success	None	Success
mmap_complicated.c	Success	None	Success
mmap_shared.c	Success	None	Success
segfault.c	Success	None	Success
shm.c	Success	None	Success
vtable.c	Success	None	Success
Networking Tests
dnstest.c	Success	None	Success
getifaddrs.c	Success	None	Success
pipe.c	Success	None	Success
pipe2.c	Success	None	Success
pipeinput.c	Success	None	Success
pipeinput2.c	Success	None	Success
pipeonestring.c	Success	None	Success
pipewrite.c	Success	None	Success
shutdown_fork.c	Success	None	Success
simple-select.c	Success	None	Success
Process Tests
fork2malloc.c	Success	None	Success
fork_simple.c	Success	None	Success
forkandopen.c	Success	None	Success
forkfiles.c	Success	None	Success
forkmalloc.c	Success	None	Success
forknodup.c	Success	None	Success
getpid.c	Success	None	Success
Signal Tests
signal.c	Success	None	Success
signal_SIGCHLD.c	Success	None	Success
signal_fork.c	Success	None	Success
signal_int_thread.c	Success	None	Success
signal_longjmp.c	Success	None	Success
signal_nodefer.c	Success	None	Success
signal_procmask.c	Success	None	Success
signal_sa_mask.c	Success	None	Success

Fail Tests

Summary

Metric	Count
Total Test Cases	1
Number of Successes	1
Number of Failures	0
Number of Compilation Failure Native	0
Number of Runtime Failure Native	0
Number of Segmentation Fault Native	0
Number of Timeout During Native	0
Number of Lind Wasm Compile Failure	0
Number of Lind Wasm Runtime Failure	0
Number of Lind Wasm Segmentation Failure	0
Number of Timeout During Lind Wasm run	0
Number of Unknown Failure	0
Number of C Compiler and Wasm Output mismatch	0
Number of Fail Test: Native Succeeded (Should Fail)	0
Number of Fail Test: Wasm Succeeded (Should Fail)	0
Number of Fail Test: Both Native and Wasm Succeeded (Should Fail)	0
Number of Fail Test: Native Compilation Failure (Should Succeed)	0
Number of Fail Test: Wasm Compilation Failure (Should Succeed)	0

Test Results by Category

Test Case	Status	Error Type	Output
Memory Tests
mmap-negative1.c	Success	None	Success