Explicitly use and check for FD_CLOEXEC.

This may break places which have the FD_CLOEXEC functionality
but do not have the FD_CLOEXEC define.

In any case, using a boolean for the F_SETFD flag is icky.
Using an explicit 1 is also dubious.

4 files changed, 20 insertions, 16 deletions

diff --git a/perl.c b/perl.c
index 303e1f2c5c..64cc3957ff 100644
--- a/perl.c
+++ b/perl.c
@@ -3796,10 +3796,10 @@ S_open_script(pTHX_ const char *scriptname, bool dosearch, bool *suidscript)
 		    CopFILE(PL_curcop), Strerror(errno));
     }
     fd = PerlIO_fileno(rsfp);
-#if defined(HAS_FCNTL) && defined(F_SETFD)
+#if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
     if (fd >= 0) {
         /* ensure close-on-exec */
-        if (fcntl(fd, F_SETFD, 1) < 0) {
+        if (fcntl(fd, F_SETFD, FD_CLOEXEC) < 0) {
             Perl_croak(aTHX_ "Can't open perl script \"%s\": %s\n",
                        CopFILE(PL_curcop), Strerror(errno));
         }
diff --git a/pp_sys.c b/pp_sys.c
index dc1b3cec1a..658dee19fa 100644
--- a/pp_sys.c
+++ b/pp_sys.c
@@ -708,10 +708,10 @@ PP(pp_pipe_op)
 	    PerlLIO_close(fd[1]);
 	goto badexit;
     }
-#if defined(HAS_FCNTL) && defined(F_SETFD)
+#if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
     /* ensure close-on-exec */
-    if ((fcntl(fd[0], F_SETFD,fd[0] > PL_maxsysfd) < 0) ||
-        (fcntl(fd[1], F_SETFD,fd[1] > PL_maxsysfd) < 0))
+    if ((fd[0] > PL_maxsysfd && fcntl(fd[0], F_SETFD, FD_CLOEXEC) < 0) ||
+        (fd[1] > PL_maxsysfd && fcntl(fd[1], F_SETFD, FD_CLOEXEC) < 0))
         goto badexit;
 #endif
     RETPUSHYES;
@@ -2496,8 +2496,9 @@ PP(pp_socket)
 	if (!IoIFP(io) && !IoOFP(io)) PerlLIO_close(fd);
 	RETPUSHUNDEF;
     }
-#if defined(HAS_FCNTL) && defined(F_SETFD)
-    if (fcntl(fd, F_SETFD, fd > PL_maxsysfd) < 0)	/* ensure close-on-exec */
+#if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
+    /* ensure close-on-exec */
+    if (fd > PL_maxsysfd && fcntl(fd, F_SETFD, FD_CLOEXEC) < 0)
 	RETPUSHUNDEF;
 #endif
 
@@ -2542,10 +2543,10 @@ PP(pp_sockpair)
 	if (!IoIFP(io2) && !IoOFP(io2)) PerlLIO_close(fd[1]);
 	RETPUSHUNDEF;
     }
-#if defined(HAS_FCNTL) && defined(F_SETFD)
+#if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
     /* ensure close-on-exec */
-    if ((fcntl(fd[0],F_SETFD,fd[0] > PL_maxsysfd) < 0) ||
-        (fcntl(fd[1],F_SETFD,fd[1] > PL_maxsysfd) < 0))
+    if ((fd[0] > PL_maxsysfd && fcntl(fd[0], F_SETFD, FD_CLOEXEC) < 0) ||
+        (fd[1] > PL_maxsysfd && fcntl(fd[1], F_SETFD, FD_CLOEXEC) < 0))
 	RETPUSHUNDEF;
 #endif
 
@@ -2659,8 +2660,9 @@ PP(pp_accept)
 	if (!IoIFP(nstio) && !IoOFP(nstio)) PerlLIO_close(fd);
 	goto badexit;
     }
-#if defined(HAS_FCNTL) && defined(F_SETFD)
-    if (fcntl(fd, F_SETFD, fd > PL_maxsysfd) < 0)	/* ensure close-on-exec */
+#if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
+    /* ensure close-on-exec */
+    if (fd > PL_maxsysfd && fcntl(fd, F_SETFD, FD_CLOEXEC) < 0)
         goto badexit;
 #endif
 
@@ -4386,7 +4388,7 @@ PP(pp_system)
 #endif
 	if (did_pipes) {
 	    PerlLIO_close(pp[0]);
-#if defined(HAS_FCNTL) && defined(F_SETFD)
+#if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
 	    if (fcntl(pp[1], F_SETFD, FD_CLOEXEC) < 0)
                 RETPUSHUNDEF;
 #endif
diff --git a/toke.c b/toke.c
index 7a0f1b6c55..d30bfe69da 100644
--- a/toke.c
+++ b/toke.c
@@ -7039,10 +7039,12 @@ Perl_yylex(pTHX)
 		if (!GvIO(gv))
 		    GvIOp(gv) = newIO();
 		IoIFP(GvIOp(gv)) = PL_rsfp;
-#if defined(HAS_FCNTL) && defined(F_SETFD)
+#if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
 		{
 		    const int fd = PerlIO_fileno(PL_rsfp);
-		    fcntl(fd,F_SETFD,fd >= 3);
+                    if (fd >= 3) {
+                        fcntl(fd,F_SETFD, FD_CLOEXEC);
+                    }
 		}
 #endif
 		/* Mark this internal pseudo-handle as clean */
diff --git a/util.c b/util.c
index e357379197..98c2cd9952 100644
--- a/util.c
+++ b/util.c
@@ -2373,7 +2373,7 @@ Perl_my_popen_list(pTHX_ const char *mode, int n, SV **args)
 	/* Close parent's end of error status pipe (if any) */
 	if (did_pipes) {
 	    PerlLIO_close(pp[0]);
-#if defined(HAS_FCNTL) && defined(F_SETFD)
+#if defined(HAS_FCNTL) && defined(F_SETFD) && defined(FD_CLOEXEC)
 	    /* Close error pipe automatically if exec works */
 	    if (fcntl(pp[1], F_SETFD, FD_CLOEXEC) < 0)
                 return NULL;