ash: improve signal handling

Allow waitpid() to detect SIGTERM/SIGKILL by checking the (Windows)
status returned by GetExitCodeProcess() and updating the Unix
status to suit.  This allows ash to detect when a process has been
'signalled'.

Provide our own implementation of strsignal(3) which returns
expanded text for SIGTERM/SIGKILL.

Costs 192 bytes.

4 files changed, 12 insertions, 1 deletions

diff --git a/include/mingw.h b/include/mingw.h
index d48ad3814..74a65116c 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -210,6 +210,7 @@ int unsetenv(const char *env);
  */
 char *strndup(char const *s, size_t n);
 char *mingw_strerror(int errnum);
+char *strsignal(int sig);
 
 #define strerror mingw_strerror
 
diff --git a/include/platform.h b/include/platform.h
index 37e48dcc5..7bb39fd93 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -473,7 +473,6 @@ typedef unsigned smalluint;
 # undef HAVE_STRCASESTR
 # undef HAVE_STRCHRNUL
 # undef HAVE_STRSEP
-# undef HAVE_STRSIGNAL
 # undef HAVE_STRVERSCMP
 #if !defined(__MINGW64_VERSION_MAJOR)
 # undef HAVE_VASPRINTF
diff --git a/shell/ash.c b/shell/ash.c
index f91cd7e1f..613bb97a0 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -4835,6 +4835,8 @@ waitpid_child(int *status, int wait_flags)
         if (idx < pid_nr) {
                 GetExitCodeProcess(proclist[idx], &win_status);
                 *status = (int)win_status << 8;
+                if (win_status == 128 + SIGTERM || win_status == 128 + SIGKILL)
+                        *status += win_status - 128;
                 pid = pidlist[idx];
         }
  done:
diff --git a/win32/mingw.c b/win32/mingw.c
index 40714296f..b8dd6a511 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -171,6 +171,15 @@ char *mingw_strerror(int errnum)
         return strerror(errnum);
 }
 
+char *strsignal(int sig)
+{
+        if (sig == SIGTERM)
+                return (char *)"Terminated";
+        else if (sig == SIGKILL)
+                return (char *)"Killed";
+        return (char *)get_signame(sig);
+}
+
 static int zero_fd = -1;
 static int rand_fd = -1;