Make improvements

- Fix unused local variable errors
- Remove yoinks from sigaction() header
- Add nox87 and aarch64 to github actions
- Fix cosmocc -fportcosmo in linking mode
- It's now possible to build `make m=llvm o/llvm/libc`

libc/log/checkfail.c

@@ -46,14 +46,12 @@ relegated void __check_fail(const char *suffix,   //
                             int line,             //
                             const char *fmt,      //
                             ...) {
-  int e;
   char *p;
   size_t i;
   va_list va;
   char hostname[32];
   strace_enabled(-1);
   ftrace_enabled(-1);
-  e = errno;
   __start_fatal(file, line);
   __stpcpy(hostname, "unknown");
   gethostname(hostname, sizeof(hostname));

libc/log/gdbexec.c

@@ -31,7 +31,6 @@
 relegated int(gdbexec)(const char *cmd) {
   struct StackFrame *bp;
   int pid, ttyin, ttyout;
-  intptr_t continuetoaddr;
   const char *se, *elf, *gdb;
   char pidstr[11], breakcmd[40];
   if (!(gdb = GetGdbPath())) return -1;
@@ -43,7 +42,6 @@ relegated int(gdbexec)(const char *cmd) {
     elf = "-q";
   }
   bp = __builtin_frame_address(0);
-  continuetoaddr = bp->addr;
   sprintf(breakcmd, "%s *%#p", "break", bp->addr);
   if (!(pid = vfork())) {
     execv(gdb, (char *const[]){

libc/log/memlog.c

@@ -17,6 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
+#include "libc/atomic.h"
 #include "libc/intrin/atomic.h"
 #include "libc/intrin/kprintf.h"
 #include "libc/log/backtrace.internal.h"
@@ -67,7 +68,7 @@ static struct Memlog {
       long size;
     } * p;
   } allocs;
-  long usage;
+  atomic_long usage;
 } __memlog;
 
 static pthread_mutex_t __memlog_lock_obj;

libc/log/oncrash_amd64.c

@@ -23,6 +23,7 @@
 #include "libc/calls/struct/sigaction.h"
 #include "libc/calls/struct/utsname.h"
 #include "libc/calls/syscall-sysv.internal.h"
+#include "libc/calls/ucontext.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
 #include "libc/fmt/itoa.h"
@@ -44,6 +45,7 @@
 #include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
+#include "libc/sysv/consts/sig.h"
 #include "libc/thread/thread.h"
 #include "libc/thread/tls.h"
 #ifdef __x86_64__
@@ -292,7 +294,9 @@ static wontreturn relegated dontinstrument void __minicrash(int sig,
  */
 relegated void __oncrash_amd64(int sig, struct siginfo *si, void *arg) {
   int bZero;
+#ifdef ATTACH_GDB_ON_CRASH
   intptr_t rip;
+#endif
   int me, owner;
   int gdbpid, err;
   ucontext_t *ctx = arg;
@@ -307,13 +311,15 @@ relegated void __oncrash_amd64(int sig, struct siginfo *si, void *arg) {
   if (atomic_compare_exchange_strong_explicit(
           &once, &owner, me, memory_order_relaxed, memory_order_relaxed)) {
     if (!__vforked) {
+#ifdef ATTACH_GDB_ON_CRASH
       rip = ctx ? ctx->uc_mcontext.rip : 0;
+#endif
       err = errno;
       if ((gdbpid = IsDebuggerPresent(true))) {
         DebugBreak();
       } else if (__nocolor || g_isrunningundermake) {
         gdbpid = -1;
-#if 0
+#if ATTACH_GDB_ON_CRASH
       } else if (!IsTiny() && IsLinux() && FindDebugBinary() && !__isworker) {
         // RestoreDefaultCrashSignalHandlers();
         gdbpid = AttachDebugger(