fix: real argv[0] via SYS_GETEXECPATH - GCC driver finds its backends

The GCC driver relocates its install prefix from argv[0]. crt1 hardcoded argv[0] as "prog", so make_relative_prefix cwd-joined it and computed exec prefixes relative to the current directory (0:/users/admin/../libexec/gcc/...), and because the computed gcc_exec_prefix is non-NULL the standard /sdk prefixes were never searched. cc1plus was unreachable from anywhere except (by accident of the path arithmetic) 0:/sdk/bin. sdk-diag proved the kernel and libc layers all worked; only the driver's self-relocation was lost. New SYS_GETEXECPATH (151) returns the absolute path the process was spawned from (Process::name); crt1 uses it for argv[0] with a "prog" fallback. With a real argv[0], make_relative_prefix computes 0:/sdk/bin/../libexec/gcc/ from any cwd. Native GCC relinked against the new crt1; sdk-diag ships in the SDK as a permanent probe; the montauk.h TCC mirror gains the wrapper (checker enforced it). Co-Authored-By: Claude Fable 5 <[email protected]>
2026-07-17 10:43:59 +02:00
parent 2f1010b02e
commit 1c851a3627
12 changed files with 83 additions and 6 deletions
@@ -0,0 +1,44 @@
+/*
+    * sdk-diag.c
+    * Probes the exact libc/kernel layers the GCC driver depends on:
+    * access/stat on the compiler backends, and a direct posix_spawn
+    * of cc1plus. Prints one line per probe.
+*/
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <spawn.h>
+#include <sys/wait.h>
+
+#define CC1PLUS "/sdk/libexec/gcc/x86_64-montauk/14.2.0/cc1plus"
+
+static void probe(const char *p) {
+    struct stat st;
+    int a = access(p, X_OK);
+    int s = stat(p, &st);
+    printf("%-52s access=%d stat=%d", p, a, s);
+    if (s == 0) {
+        printf(" mode=%o size=%ld", (unsigned)st.st_mode, (long)st.st_size);
+    }
+    printf("\n");
+}
+
+int main(void) {
+    probe(CC1PLUS);
+    probe("/sdk/libexec/gcc/x86_64-montauk/14.2.0");
+    probe("/sdk/libexec/gcc");
+    probe("/sdk/bin/as.elf");
+    probe("/tmp");
+
+    pid_t pid = -1;
+    char *argv[] = { (char *)"cc1plus", (char *)"--version", 0 };
+    int r = posix_spawn(&pid, CC1PLUS, 0, 0, argv, 0);
+    printf("posix_spawn(cc1plus --version) = %d pid=%d\n", r, (int)pid);
+    if (r == 0) {
+        int st = -1;
+        waitpid(pid, &st, 0);
+        printf("cc1plus wait status = %d (exit %d)\n", st, (st >> 8) & 0xFF);
+    }
+    return 0;
+}