Remove fake signal-handling code

Microsoft Windows has only limited support for signals.  busybox-w32
initially papered over this fact by adding definitions for unsupported
signals and signal-handling functions.

Remove this fake code and deal with the consequences by excluding
anything that fails to compile as a result.

8 files changed, 39 insertions, 32 deletions

diff --git a/archival/tar.c b/archival/tar.c
index 990755429..fbe5e3be8 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -1117,7 +1117,9 @@ int tar_main(int argc UNUSED_PARAM, char **argv)
 
         if (opt & OPT_2COMMAND) {
                 putenv((char*)"TAR_FILETYPE=f");
+#ifdef SIGPIPE
                 signal(SIGPIPE, SIG_IGN);
+#endif
                 tar_handle->action_data = data_extract_to_command;
                 IF_FEATURE_TAR_TO_COMMAND(tar_handle->tar__to_command_shell = xstrdup(get_shell_name());)
         }
diff --git a/coreutils/tee.c b/coreutils/tee.c
index f0ec791bb..d0ded58c4 100644
--- a/coreutils/tee.c
+++ b/coreutils/tee.c
@@ -69,9 +69,11 @@ int tee_main(int argc, char **argv)
                 signal(SIGINT, SIG_IGN); /* TODO - switch to sigaction. (why?) */
         }
         retval = EXIT_SUCCESS;
+#ifdef SIGPIPE
         /* gnu tee ignores SIGPIPE in case one of the output files is a pipe
          * that doesn't consume all its input.  Good idea... */
         signal(SIGPIPE, SIG_IGN);
+#endif
 
         /* Allocate an array of FILE *'s, with one extra for a sentinel. */
         fp = files = xzalloc(sizeof(FILE *) * (argc + 2));
diff --git a/include/libbb.h b/include/libbb.h
index 761370111..4a59ee7d8 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -526,18 +526,36 @@ enum {
          * Dance around with long long to guard against that...
          */
         BB_FATAL_SIGS = (int)(0
+#ifdef SIGHUP
                 + (1LL << SIGHUP)
+#endif
                 + (1LL << SIGINT)
                 + (1LL << SIGTERM)
+#ifdef SIGPIPE
                 + (1LL << SIGPIPE)   // Write to pipe with no readers
+#endif
+#ifdef SIGQUIT
                 + (1LL << SIGQUIT)   // Quit from keyboard
+#endif
                 + (1LL << SIGABRT)   // Abort signal from abort(3)
+#ifdef SIGALRM
                 + (1LL << SIGALRM)   // Timer signal from alarm(2)
+#endif
+#ifdef SIGVTALRM
                 + (1LL << SIGVTALRM) // Virtual alarm clock
+#endif
+#ifdef SIGXCPU
                 + (1LL << SIGXCPU)   // CPU time limit exceeded
+#endif
+#ifdef SIGXFSZ
                 + (1LL << SIGXFSZ)   // File size limit exceeded
+#endif
+#ifdef SIGUSR1
                 + (1LL << SIGUSR1)   // Yes kids, these are also fatal!
+#endif
+#ifdef SIGUSR1
                 + (1LL << SIGUSR2)
+#endif
                 + 0),
 };
 #if !ENABLE_PLATFORM_MINGW32
diff --git a/include/mingw.h b/include/mingw.h
index c662f4baf..1bb2032cd 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -90,39 +90,11 @@ IMPL(getpwent,struct passwd *,NULL,void)
 /*
  * signal.h
  */
-#define SIGHUP 1
-#define SIGQUIT 3
 #define SIGKILL 9
-#define SIGUSR1 10
-#define SIGUSR2 12
-#define SIGPIPE 13
-#define SIGALRM 14
-#define SIGCHLD 17
-#define SIGCONT 18
-#define SIGSTOP 19
-#define SIGTSTP 20
-#define SIGTTIN 21
-#define SIGTTOU 22
-#define SIGXCPU 24
-#define SIGXFSZ 25
-#define SIGVTALRM 26
-#define SIGWINCH 28
 
 #define SIG_UNBLOCK 1
 
-typedef void (__cdecl *sighandler_t)(int);
-struct sigaction {
-        sighandler_t sa_handler;
-        unsigned sa_flags;
-        int sa_mask;
-};
-#define sigemptyset(x) (void)0
-#define SA_RESTART 0
-
-NOIMPL(sigaction,int sig UNUSED_PARAM, struct sigaction *in UNUSED_PARAM, struct sigaction *out UNUSED_PARAM);
-NOIMPL(sigfillset,int *mask UNUSED_PARAM);
 NOIMPL(FAST_FUNC sigprocmask_allsigs, int how UNUSED_PARAM);
-NOIMPL(FAST_FUNC sigaction_set,int signo UNUSED_PARAM, const struct sigaction *sa UNUSED_PARAM);
 
 /*
  * stdio.h
diff --git a/libbb/Kbuild.src b/libbb/Kbuild.src
index c0cc2baf5..4b838ab7a 100644
--- a/libbb/Kbuild.src
+++ b/libbb/Kbuild.src
@@ -12,7 +12,6 @@ INSERT
 
 lib-y += appletlib.o
 lib-y += ask_confirmation.o
-lib-y += bb_askpass.o
 lib-y += bb_bswap_64.o
 lib-y += bb_do_delay.o
 lib-y += bb_pwd.o
@@ -105,6 +104,7 @@ lib-y += xgetcwd.o
 lib-y += xreadlink.o
 lib-y += xrealloc_vector.o
 
+lib-$(CONFIG_PLATFORM_POSIX) += bb_askpass.o
 lib-$(CONFIG_PLATFORM_POSIX) += get_console.o
 lib-$(CONFIG_PLATFORM_POSIX) += getpty.o
 lib-$(CONFIG_PLATFORM_POSIX) += inet_common.o
diff --git a/networking/nc.c b/networking/nc.c
index de02ccc9d..3e122b787 100644
--- a/networking/nc.c
+++ b/networking/nc.c
@@ -110,10 +110,12 @@
  * when compared to "standard" nc
  */
 
+#if ENABLE_NC_EXTRA
 static void timeout(int signum UNUSED_PARAM)
 {
         bb_error_msg_and_die("timed out");
 }
+#endif
 
 int nc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int nc_main(int argc, char **argv)
@@ -187,10 +189,12 @@ int nc_main(int argc, char **argv)
                 argv++;
         }
 
+#if ENABLE_NC_EXTRA
         if (wsecs) {
                 signal(SIGALRM, timeout);
                 alarm(wsecs);
         }
+#endif
 
         if (!cfd) {
                 if (do_listen) {
diff --git a/procps/kill.c b/procps/kill.c
index c95afb8b3..4477dedb7 100644
--- a/procps/kill.c
+++ b/procps/kill.c
@@ -207,6 +207,7 @@ int kill_main(int argc UNUSED_PARAM, char **argv)
  do_it_now:
         pid = getpid();
 
+#if ENABLE_KILLALL5
         if (is_killall5) {
                 pid_t sid;
                 procps_status_t* p = NULL;
@@ -264,6 +265,7 @@ int kill_main(int argc UNUSED_PARAM, char **argv)
                         kill(-1, SIGCONT);
                 return errors;
         }
+#endif
 
 #if ENABLE_KILL || ENABLE_KILLALL
         /* Pid or name is required for kill/killall */
diff --git a/shell/ash.c b/shell/ash.c
index fa71bd84d..88834f49a 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -3747,6 +3747,7 @@ static smallint doing_jobctl; //references:8
 static void setjobctl(int);
 #endif
 
+#if !ENABLE_PLATFORM_MINGW32
 /*
  * Ignore a signal.
  */
@@ -3761,7 +3762,6 @@ ignoresig(int signo)
         sigmode[signo - 1] = S_HARD_IGN;
 }
 
-#if !ENABLE_PLATFORM_MINGW32
 /*
  * Only one usage site - in setsignal()
  */
@@ -3896,6 +3896,7 @@ setsignal(int signo)
 }
 #else
 #define setsignal(s)
+#define ignoresig(s)
 #endif
 
 /* mode flags for set_curjob */
@@ -4372,7 +4373,11 @@ sprint_status48(char *s, int status, int sigonly)
 #endif
                         st = WTERMSIG(status);
                 if (sigonly) {
+#ifdef SIGPIPE
                         if (st == SIGINT || st == SIGPIPE)
+#else
+                        if (st == SIGINT)
+#endif
                                 goto out;
 #if JOBS
                         if (WIFSTOPPED(status))
@@ -10633,7 +10638,7 @@ evalcommand(union node *cmd, int flags)
                  * we can just exec it.
                  */
 #if ENABLE_PLATFORM_MINGW32
-                if (!(flags & EV_EXIT) || trap[0]) {
+                if (!(flags & EV_EXIT) || may_have_traps) {
                         /* No, forking off a child is necessary */
                         struct forkshell fs;
 
@@ -14394,6 +14399,7 @@ init(void)
         basepf.next_to_pgetc = basepf.buf = ckmalloc(IBUFSIZ);
         basepf.linno = 1;
 
+#if !ENABLE_PLATFORM_MINGW32
         sigmode[SIGCHLD - 1] = S_DFL; /* ensure we install handler even if it is SIG_IGNed */
         setsignal(SIGCHLD);
 
@@ -14401,6 +14407,7 @@ init(void)
          * Try: "trap '' HUP; bash; echo RET" and type "kill -HUP $$"
          */
         signal(SIGHUP, SIG_DFL);
+#endif
 
         {
                 char **envp;
@@ -14838,7 +14845,7 @@ forkshell_openhere(struct forkshell *fs)
         ignoresig(SIGQUIT); //signal(SIGQUIT, SIG_IGN);
         ignoresig(SIGHUP);  //signal(SIGHUP, SIG_IGN);
         ignoresig(SIGTSTP); //signal(SIGTSTP, SIG_IGN);
-        signal(SIGPIPE, SIG_DFL);
+        //signal(SIGPIPE, SIG_DFL);
         if (redir->type == NHERE) {
                 size_t len = strlen(redir->nhere.doc->narg.text);
                 full_write(pip[1], redir->nhere.doc->narg.text, len);