feat: process exit codes, posix_spawn, 4 KiB command lines

Groundwork for the GCC driver: a compiler driver must spawn cc1/as/ld and know whether each stage succeeded. Kernel: the scheduler keeps an exit-code ledger (pid -> code; pids are monotonic so entries never alias), published during teardown right before waiters wake. SYS_EXIT records main()'s return value, SYS_KILL records 256+SIGKILL, and the exception handler records 256+signal mapped from the fault vector (#PF/#GP -> SIGSEGV, #DE/FP -> SIGFPE, #UD -> SIGILL). SYS_WAITPID now returns the code: 0..255 for a normal exit, 256+signal for a violent death. Process args grow from 256 bytes to 4 KiB (cc1 invocations do not fit in 256), with crt1 now parsing up to 255 argv entries from a static buffer. libc: new spawn.h with posix_spawn/posix_spawnp over SYS_SPAWN - libiberty's pex layer has a posix_spawn backend, so GCC's driver works without fork. argv is joined into the kernel args string (spaces in arguments rejected; no kernel quoting), envp is not transferred, and non-empty file actions fail loudly with ENOTSUP until the kernel can redirect stdio on spawn. waitpid() now decodes real POSIX status and the sys/wait.h macros distinguish exited from signaled children. Shell: prints [exit code N] after nonzero exits and [terminated by signal N] for killed or crashed children. Verified on the OS: cat on a missing file reports exit code 1; a window-close (clean exit 0) stays silent as it should. Co-Authored-By: Claude Fable 5 <[email protected]>
2026-07-16 16:59:17 +02:00
parent 54c0584b85
commit 75184e0651
19 changed files with 326 additions and 23 deletions
@@ -0,0 +1,60 @@
+#ifndef _LIBC_SPAWN_H
+#define _LIBC_SPAWN_H
+
+#pragma once
+
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+    * posix_spawn for MontaukOS, layered on SYS_SPAWN.
+    *
+    * Limitations (kernel spawn model):
+    *  - argv is joined into a single args string; arguments containing
+    *    spaces are rejected with EINVAL (no quoting in the kernel).
+    *  - envp is ignored (no environment transfer on spawn).
+    *  - file actions must be empty: stdio redirection needs kernel
+    *    support that does not exist yet, so any recorded action makes
+    *    posix_spawn fail with ENOTSUP rather than misbehave silently.
+*/
+
+typedef struct {
+    short flags;
+} posix_spawnattr_t;
+
+typedef struct {
+    int action_count;
+} posix_spawn_file_actions_t;
+
+int posix_spawnattr_init(posix_spawnattr_t *attr);
+int posix_spawnattr_destroy(posix_spawnattr_t *attr);
+int posix_spawnattr_setflags(posix_spawnattr_t *attr, short flags);
+int posix_spawnattr_getflags(const posix_spawnattr_t *attr, short *flags);
+
+int posix_spawn_file_actions_init(posix_spawn_file_actions_t *actions);
+int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *actions);
+int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *actions,
+                                     int fd, int newfd);
+int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *actions,
+                                      int fd);
+int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *actions,
+                                     int fd, const char *path, int oflag,
+                                     mode_t mode);
+
+int posix_spawn(pid_t *pid, const char *path,
+                const posix_spawn_file_actions_t *actions,
+                const posix_spawnattr_t *attr,
+                char *const argv[], char *const envp[]);
+int posix_spawnp(pid_t *pid, const char *file,
+                 const posix_spawn_file_actions_t *actions,
+                 const posix_spawnattr_t *attr,
+                 char *const argv[], char *const envp[]);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _LIBC_SPAWN_H */