musl support

- disable utterly useless "bitwise arithmetic instead of logic" compile
  Clang warning
- deps.sh: add linux-headers Alpine package
- fdctl: switch between GCC-internal __rlimit_resource_t type and
  POSIX-compatible int for RLIMIT_{...}
- quic: remove accidental execinfo.h import
- log: only export backtraces when execinfo.h found
- shmem: replace non-standard PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
  with portable PTHREAD_MUTEX_RECURSIVE initializer
- tile: skip non-standard pthread_attr_setaffinity_np on non-glibc

config/x86-64-clang-flags.mk

@@ -1 +1,2 @@
+CPPFLAGS+=-Wno-bitwise-instead-of-logical
 LDFLAGS+=-lrt

deps.sh

@@ -178,7 +178,7 @@ check_debian_pkgs () {
 }
 
 check_alpine_pkgs () {
-  local REQUIRED_APKS=( perl autoconf gettext automake flex bison build-base )
+  local REQUIRED_APKS=( perl autoconf gettext automake flex bison build-base linux-headers )
 
   echo "[~] Checking for required APK packages"
 

src/app/fdctl/security.c

@@ -44,11 +44,11 @@ check_cap( security_t * security,
 }
 
 void
-check_res( security_t *        security,
-           const char *        name,
-           __rlimit_resource_t resource,
-           ulong               limit,
-           const char *        reason ) {
+check_res( security_t *    security,
+           const char *    name,
+           fd_rlimit_res_t resource,
+           ulong           limit,
+           const char *    reason ) {
   struct rlimit rlim;
   if( FD_UNLIKELY( getrlimit( resource, &rlim ) ) )
     FD_LOG_ERR(( "getrlimit failed (%i-%s)", errno, strerror( errno ) ));

src/app/fdctl/security.h

@@ -22,6 +22,18 @@ typedef struct security {
   char  errors[ MAX_SECURITY_ERRORS ][ 256 ];
 } security_t;
 
+/* fd_rlimit_res_t is the appropriate type for RLIMIT_{...} for the
+   libc flavor in use.  glibc with GNU_SOURCE redefines the type of
+   the first arg to {get,set}rlimit(2), sigh ... */
+
+#ifdef __GLIBC__
+typedef __rlimit_resource_t fd_rlimit_res_t;
+#else /* non-glibc */
+typedef int fd_rlimit_res_t;
+#endif /* __GLIBC__ */
+
+FD_PROTOTYPES_BEGIN
+
 /* check_root() checks if the current process is running as the root
    user (uid 0). If it's not, an error entry is added to the security
    context with the given reason. */
@@ -44,10 +56,12 @@ check_cap( security_t * security,
    increase the resource itself (which it will do). If it cannot, an
    error entry is added to the security context with the given reason. */
 void
-check_res( security_t *        security,
-           const char *        name,
-           __rlimit_resource_t resource,
-           ulong               limit,
-           const char *        reason );
+check_res( security_t *    security,
+           const char *    name,
+           fd_rlimit_res_t resource,
+           ulong           limit,
+           const char *    reason );
+
+FD_PROTOTYPES_END
 
 #endif /* HEADER_fd_src_app_fdctl_security_h */

src/tango/quic/fd_quic.c

@@ -9,7 +9,6 @@
 #include "tls/fd_quic_tls.h"
 
 #include <errno.h>
-#include <execinfo.h>
 #include <string.h>
 #include <fcntl.h>   /* for keylog open(2)  */
 #include <unistd.h>  /* for keylog close(2) */

src/util/log/fd_log.c

@@ -25,7 +25,13 @@
 #include <sched.h>
 #include <time.h>
 #include <syscall.h>
+
+#if __has_include( <execinfo.h> )
+#define FD_HAS_BACKTRACE 1
 #include <execinfo.h>
+#else
+#define FD_HAS_BACKTRACE 0
+#endif /* __has_include( <execinfo.h> ) */
 
 /* TEXT_* are quick-and-dirty color terminal hacks.  Probably should
    do something more robust longer term. */
@@ -918,6 +924,8 @@ fd_log_private_sig_abort( int         sig,
   /* Hopefully all out streams are idle now and we have flushed out
      all non-logging activity ... log a backtrace */
 
+# if FD_HAS_BACKTRACE
+
   void * btrace[128];
   int btrace_cnt = backtrace( btrace, 128 );
 
@@ -940,6 +948,23 @@ fd_log_private_sig_abort( int         sig,
   backtrace_symbols_fd( btrace, btrace_cnt, fd );
   fsync( fd );
 
+# else /* !FD_HAS_BACKTRACE */
+
+  FILE * log_file = FD_VOLATILE_CONST( fd_log_private_file );
+  if( log_file ) {
+    fprintf( log_file, "Caught signal %i.\n", sig );
+#   if FD_LOG_FFLUSH_LOG_FILE
+    fflush( log_file );
+#   endif
+  }
+
+  fprintf( stderr, "\nCaught signal %i.\n", sig );
+# if FD_LOG_FFLUSH_STDERR
+  fflush( stderr );
+# endif
+
+# endif /* FD_HAS_BACKTRACE */
+
   /* Do final log cleanup */
 
   fd_log_private_cleanup();
@@ -1053,6 +1078,7 @@ fd_log_private_boot( int  *   pargc,
   int log_backtrace = fd_env_strip_cmdline_int( pargc, pargv, "--log-backtrace", "FD_LOG_BACKTRACE", 1 );
   if( log_backtrace ) {
 
+#   if FD_HAS_BACKTRACE
     /* If libgcc isn't already linked into the program when a trapped
        signal is received by an application, calls to backtrace and
        backtrace_symbols_fd within the signal handler can silently
@@ -1072,6 +1098,7 @@ fd_log_private_boot( int  *   pargc,
       if( FD_UNLIKELY( close( fd ) ) )
         fprintf( stderr, "close( \"/dev/null\" ) failed (%i-%s); attempting to continue\n", errno, strerror( errno ) );
     }
+#   endif /* FD_HAS_BACKTRACE */
 
     /* This is all overridable POSIX sigs whose default behavior is to
        abort the program.  It will backtrace and then fallback to the

src/util/shmem/fd_shmem_admin.c

@@ -16,7 +16,7 @@
 #include <linux/mman.h>
 
 #if FD_HAS_THREADS
-pthread_mutex_t fd_shmem_private_lock[1] = { PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP };
+pthread_mutex_t fd_shmem_private_lock[1];
 #endif
 
 char  fd_shmem_private_base[ FD_SHMEM_PRIVATE_BASE_MAX ]; /* ""  at thread group start, initialized at boot */
@@ -652,6 +652,16 @@ fd_shmem_private_boot( int *    pargc,
                        char *** pargv ) {
   FD_LOG_INFO(( "fd_shmem: booting" ));
 
+  /* Initialize the phtread mutex */
+
+# if FD_HAS_THREADS
+  pthread_mutexattr_t lockattr[1];
+  pthread_mutexattr_init( lockattr );
+  pthread_mutexattr_settype( lockattr, PTHREAD_MUTEX_RECURSIVE );
+  pthread_mutex_init( fd_shmem_private_lock, lockattr );
+  pthread_mutexattr_destroy( lockattr );
+# endif /* FD_HAS_THREADS */
+
   /* Cache the numa topology for this thread group's host for
      subsequent fast use by the application. */
 

src/util/tile/fd_tile_threads.cxx

@@ -572,6 +572,11 @@ fd_tile_private_boot( int *    pargc,
     if( FD_UNLIKELY( err ) ) FD_LOG_ERR(( "fd_tile: pthread_attr_init failed (%i-%s) for tile %lu.\n\t",
                                           err, strerror( err ), tile_idx ));
 
+    /* Set affinity ahead of time.  This is a GNU-specific extension
+       that is not available on musl.  On musl, we just skip this
+       step as we call sched_setaffinity(2) later on regardless. */
+
+#   if __GLIBC__
     if( fixed ) {
       cpu_set_t cpu_set[1];
       CPU_ZERO( cpu_set );
@@ -586,6 +591,7 @@ fd_tile_private_boot( int *    pargc,
                                                 "to eliminate this warning.",
                                                 err, strerror( err ), tile_idx, cpu_idx ));
     }
+#   endif /* __GLIBC__ */
 
     /* Create an optimized stack with guard regions if the build target
        is x86 (e.g. supports huge pages necessary to optimize TLB usage)