This was because at the point at which exit is called, we can only free a
t_simple_cmd, but not the whole t_cmd tree. This commit introduces a convention
of returning a t_subprocess enum from each function in exec. If the current
thread is a subprocess, SUBPROCESS is returned, else PARENTPROCESS. We also no
longer call exit in subproceses. This way, all processes bubble up to main,
where if SUBPROCESS is returned, all memory is freed and the program exits.
This also removes the previous should_exit convention.
Still TODO: handling of the exit builtin, which should also bubble up in the
same way.
$ touch cat
$ unset PATH
$ cat
m==75845== Memcheck, a memory error detector
==75845== Copyright (C) 2002-2024, and GNU GPL'd, by Julian Seward et al.
==75845== Using Valgrind-3.23.0 and LibVEX; rerun with -h for copyright info
==75845== Command: ./minishell
==75845==
==75846== Memcheck, a memory error detector
==75846== Copyright (C) 2002-2024, and GNU GPL'd, by Julian Seward et al.
==75846== Using Valgrind-3.23.0 and LibVEX; rerun with -h for copyright info
==75846== Command: /nix/store/6wgd8c9vq93mqxzc7jhkl86mv6qbc360-coreutils-9.5/bin/touch cat
==75846==
==75846==
==75846== FILE DESCRIPTORS: 0 open (0 std) at exit.
==75846==
==75846== HEAP SUMMARY:
==75846== in use at exit: 0 bytes in 0 blocks
==75846== total heap usage: 46 allocs, 46 frees, 8,126 bytes allocated
==75846==
==75846== All heap blocks were freed -- no leaks are possible
==75846==
==75846== For lists of detected and suppressed errors, rerun with: -s
==75846== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
minishell: cat: Permission denied
==75849==
==75849== FILE DESCRIPTORS: 3 open (3 std) at exit.
==75849==
==75849== HEAP SUMMARY:
==75849== in use at exit: 4,181 bytes in 12 blocks
==75849== total heap usage: 982 allocs, 970 frees, 122,299 bytes allocated
==75849==
==75849== 8 bytes in 1 blocks are definitely lost in loss record 1 of 9
==75849== at 0x48467D9: malloc (in /nix/store/phbnjdfmy3v4ak9xf211y2336mv5kx9s-valgrind-3.23.0/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==75849== by 0x113C22: ft_calloc (ft_calloc.c:28)
==75849== by 0x112399: get_paths_array (src/subst/simple_filename_exp.c:37)
==75849== by 0x1121EE: filepath_from_env (src/subst/simple_filename_exp.c:144)
==75849== by 0x1121C0: get_cmdpath (src/subst/simple_filename_exp.c:184)
==75849== by 0x10CD97: exec_external_cmd (src/executing/simple_cmd/simple_cmd_execute.c:67)
==75849== by 0x10CC58: simple_cmd_execute (src/executing/simple_cmd/simple_cmd_execute.c:94)
==75849== by 0x10B12C: cmd_execute (src/executing/cmd/cmd_execute.c:23)
==75849== by 0x10A4FD: execute_command (src/minishell.c:37)
==75849== by 0x10A3B2: main (src/minishell.c:90)
==75849==
==75849== 24 bytes in 1 blocks are still reachable in loss record 6 of 9
==75849== at 0x48467D9: malloc (in /nix/store/phbnjdfmy3v4ak9xf211y2336mv5kx9s-valgrind-3.23.0/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==75849== by 0x113C22: ft_calloc (ft_calloc.c:28)
==75849== by 0x10D4A9: cmd_create (src/parser/cmd/cmd.c:20)
==75849== by 0x10F6A1: simple_cmd_create (src/parser/simple_cmd/simple_cmd_parse.c:24)
==75849== by 0x10F4E4: minishell_simple_cmd_parse (src/parser/simple_cmd/simple_cmd_parse.c:38)
==75849== by 0x10E078: minishell_group_or_simple_parse (src/parser/group_cmd/group_cmd_parse.c:53)
==75849== by 0x10E4AC: minishell_pipeline_parse (src/parser/pipeline/pipeline_parse.c:26)
==75849== by 0x10D93C: minishell_cmds_parse (src/parser/cmd/cmds_parse.c:30)
==75849== by 0x1139D5: minishell_parse (src/parser/cmd_parsing.c:67)
==75849== by 0x10A38B: main (src/minishell.c:87)
==75849==
==75849== LEAK SUMMARY:
==75849== definitely lost: 8 bytes in 1 blocks
==75849== indirectly lost: 0 bytes in 0 blocks
==75849== possibly lost: 0 bytes in 0 blocks
==75849== still reachable: 24 bytes in 1 blocks
==75849== suppressed: 4,149 bytes in 10 blocks
==75849==
==75849== For lists of detected and suppressed errors, rerun with: -s
==75849== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
126
==75845==
==75845== FILE DESCRIPTORS: 3 open (3 std) at exit.
==75845==
==75845== HEAP SUMMARY:
==75845== in use at exit: 4,201 bytes in 14 blocks
==75845== total heap usage: 844 allocs, 830 frees, 72,248 bytes allocated
==75845==
==75845== 8 bytes in 1 blocks are definitely lost in loss record 1 of 8
==75845== at 0x48467D9: malloc (in /nix/store/phbnjdfmy3v4ak9xf211y2336mv5kx9s-valgrind-3.23.0/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==75845== by 0x113C22: ft_calloc (ft_calloc.c:28)
==75845== by 0x112399: get_paths_array (src/subst/simple_filename_exp.c:37)
==75845== by 0x1121EE: filepath_from_env (src/subst/simple_filename_exp.c:144)
==75845== by 0x1121C0: get_cmdpath (src/subst/simple_filename_exp.c:184)
==75845== by 0x10CD97: exec_external_cmd (src/executing/simple_cmd/simple_cmd_execute.c:67)
==75845== by 0x10CC58: simple_cmd_execute (src/executing/simple_cmd/simple_cmd_execute.c:94)
==75845== by 0x10B12C: cmd_execute (src/executing/cmd/cmd_execute.c:23)
==75845== by 0x10A4FD: execute_command (src/minishell.c:37)
==75845== by 0x10A3B2: main (src/minishell.c:90)
==75845==
==75845== LEAK SUMMARY:
==75845== definitely lost: 8 bytes in 1 blocks
==75845== indirectly lost: 0 bytes in 0 blocks
==75845== possibly lost: 0 bytes in 0 blocks
==75845== still reachable: 0 bytes in 0 blocks
==75845== suppressed: 4,193 bytes in 13 blocks
==75845==
==75845== For lists of detected and suppressed errors, rerun with: -s
==75845== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)inishell: cat: Permission denied
debug notes:
$ cat << eof > /root/outfile
hello
eof
minishell: open: Permission denied
minishell: hello: command not found
==42382==
==42382== FILE DESCRIPTORS: 9 open (3 std) at exit.
==42382== Open file descriptor 8: /dev/pts/3
==42382== at 0x49A8C1B: dup (in /nix/store/nqb2ns2d1lahnd5ncwmn6k84qfd7vx2k-glibc-2.40-36/lib/libc.so.6)
==42382== by 0x10C9CC: handle_redirections (src/executing/simple_cmd/handle_redirections.c:65)
==42382== by 0x10CBF6: simple_cmd_execute (src/executing/simple_cmd/simple_cmd_execute.c:91)
==42382== by 0x10B10C: cmd_execute (src/executing/cmd/cmd_execute.c:23)
==42382== by 0x10A4DD: execute_command (src/minishell.c:37)
==42382== by 0x10A3A2: main (src/minishell.c:89)
==42382==
==42382== Open file descriptor 7: /dev/pts/3
==42382== at 0x49A8C1B: dup (in /nix/store/nqb2ns2d1lahnd5ncwmn6k84qfd7vx2k-glibc-2.40-36/lib/libc.so.6)
==42382== by 0x10C9B9: handle_redirections (src/executing/simple_cmd/handle_redirections.c:64)
==42382== by 0x10CBF6: simple_cmd_execute (src/executing/simple_cmd/simple_cmd_execute.c:91)
==42382== by 0x10B10C: cmd_execute (src/executing/cmd/cmd_execute.c:23)
==42382== by 0x10A4DD: execute_command (src/minishell.c:37)
==42382== by 0x10A3A2: main (src/minishell.c:89)
==42382==
==42382== Open file descriptor 6: /dev/pts/3
==42382== at 0x49A8C1B: dup (in /nix/store/nqb2ns2d1lahnd5ncwmn6k84qfd7vx2k-glibc-2.40-36/lib/libc.so.6)
==42382== by 0x10C9CC: handle_redirections (src/executing/simple_cmd/handle_redirections.c:65)
==42382== by 0x10CBF6: simple_cmd_execute (src/executing/simple_cmd/simple_cmd_execute.c:91)
==42382== by 0x10B10C: cmd_execute (src/executing/cmd/cmd_execute.c:23)
==42382== by 0x10A4DD: execute_command (src/minishell.c:37)
==42382== by 0x10A3A2: main (src/minishell.c:89)
==42382==
==42382== Open file descriptor 5: /dev/pts/3
==42382== at 0x49A8C1B: dup (in /nix/store/nqb2ns2d1lahnd5ncwmn6k84qfd7vx2k-glibc-2.40-36/lib/libc.so.6)
==42382== by 0x10C9B9: handle_redirections (src/executing/simple_cmd/handle_redirections.c:64)
==42382== by 0x10CBF6: simple_cmd_execute (src/executing/simple_cmd/simple_cmd_execute.c:91)
==42382== by 0x10B10C: cmd_execute (src/executing/cmd/cmd_execute.c:23)
==42382== by 0x10A4DD: execute_command (src/minishell.c:37)
==42382== by 0x10A3A2: main (src/minishell.c:89)
==42382==
==42382== Open file descriptor 4: /dev/pts/3
==42382== at 0x49A8C1B: dup (in /nix/store/nqb2ns2d1lahnd5ncwmn6k84qfd7vx2k-glibc-2.40-36/lib/libc.so.6)
==42382== by 0x10C9A6: handle_redirections (src/executing/simple_cmd/handle_redirections.c:63)
==42382== by 0x10CBF6: simple_cmd_execute (src/executing/simple_cmd/simple_cmd_execute.c:91)
==42382== by 0x10B10C: cmd_execute (src/executing/cmd/cmd_execute.c:23)
==42382== by 0x10A4DD: execute_command (src/minishell.c:37)
==42382== by 0x10A3A2: main (src/minishell.c:89)
==42382==
==42382== Open file descriptor 3: /tmp/minishell_here_doc_78Ak8J9TeVu (deleted)
==42382== at 0x49A8C1B: dup (in /nix/store/nqb2ns2d1lahnd5ncwmn6k84qfd7vx2k-glibc-2.40-36/lib/libc.so.6)
==42382== by 0x10C9A6: handle_redirections (src/executing/simple_cmd/handle_redirections.c:63)
==42382== by 0x10CBF6: simple_cmd_execute (src/executing/simple_cmd/simple_cmd_execute.c:91)
==42382== by 0x10B10C: cmd_execute (src/executing/cmd/cmd_execute.c:23)
==42382== by 0x10A4DD: execute_command (src/minishell.c:37)
==42382== by 0x10A3A2: main (src/minishell.c:89)
