Refactor subprocess signal setup

ChangeLog

@@ -1,3 +1,16 @@
+2008-05-12  Guillem Jover  <guillem@debian.org>
+
+	* dselect/method.cc: Include <dpkg-priv.h>. Use setup_subproc_signals
+	and cu_subproc_signals instead of cu_restoresignals and duped code
+	in falliblesubprocess.
+	* lib/Makefile.am (libdpkg_a_SOURCES): Add 'subproc.c'.
+	* ib/dpkg-priv.h (setup_subproc_signals): New prototype.
+	(cu_subproc_signals): Likewise.
+	* src/help.c: Include <dpkg-priv.h> and stop including <signal.h>.
+	(cu_restorescriptsignals, script_catchsignals): Move to ...
+	* lib/subproc.c (cu_subproc_signals, setup_subproc_signals): ... here.
+	New file.
+
 2008-05-12  Guillem Jover  <guillem@debian.org>
 
 	* lib/Makefile.am (libdpkg_a_SOURCES): Add 'dpkg-priv.h' and 'path.c'.

debian/changelog

@@ -3,6 +3,7 @@ dpkg (1.15.0) UNRELEASED; urgency=low
   [ Guillem Jover ]
   * Do not suggest manually changing the alternative symlinks on
     update-alternative's verbose mode. Closes: #412487
+  * Refactor subprocess signal setup.
 
   [ Raphael Hertzog ]
   * Enhance dpkg-shlibdeps's error message when a library can't be found to

dselect/method.cc

@@ -44,6 +44,7 @@ extern "C" {
 #include <dpkg.h>
 #include <dpkg-db.h>
 }
+#include <dpkg-priv.h>
 #include "dselect.h"
 #include "method.h"
 
@@ -133,38 +134,17 @@ static enum urqresult lockmethod(void) {
   return urqr_normal;
 }
 
-static int catchsignals[]= { SIGQUIT, SIGINT, 0 };
-#define NCATCHSIGNALS ((signed)(sizeof(catchsignals)/sizeof(int))-1)
-static struct sigaction uncatchsignal[NCATCHSIGNALS];
-
-void cu_restoresignals(int, void**) {
-  int i;
-  for (i=0; i<NCATCHSIGNALS; i++)
-    if (sigaction(catchsignals[i],&uncatchsignal[i],0))
-      fprintf(stderr,_("error un-catching signal %d: %s\n"),
-              catchsignals[i],strerror(errno));
-}
-
 urqresult falliblesubprocess(const char *exepath, const char *name,
                              const char *const *args) {
   pid_t c1, cr;
   int status, i, c;
-  struct sigaction catchsig;
   
   cursesoff();
 
-  memset(&catchsig,0,sizeof(catchsig));
-  catchsig.sa_handler= SIG_IGN;
-  sigemptyset(&catchsig.sa_mask);
-  catchsig.sa_flags= 0;
-  for (i=0; i<NCATCHSIGNALS; i++)
-    if (sigaction(catchsignals[i],&catchsig,&uncatchsignal[i]))
-      ohshite(_("unable to ignore signal %d before running %.250s"),
-              catchsignals[i], name);
-  push_cleanup(cu_restoresignals,~0, 0,0, 0);
+  setup_subproc_signals(name);
 
   if (!(c1= m_fork())) {
-    cu_restoresignals(0,0);
+    cu_subproc_signals(0, 0);
     execvp(exepath,(char* const*) args);
     ohshite(_("unable to run %.250s process `%.250s'"),name,exepath);
   }

lib/Makefile.am

@@ -38,6 +38,7 @@ libdpkg_a_SOURCES = \
 	parsedump.h \
 	path.c \
 	showpkg.c \
+	subproc.c \
 	tarfn.c tarfn.h \
 	triglib.c \
 	trigdeferred.l \

lib/dpkg-priv.h

@@ -30,6 +30,11 @@ extern "C" {
 
 void rtrim_slash_slashdot(char *path);
 
+/* Subprocess handling. */
+
+void setup_subproc_signals(const char *name);
+void cu_subproc_signals(int argc, void **argv);
+
 #ifdef __cplusplus
 }
 #endif

lib/subproc.c

@@ -0,0 +1,68 @@
+/*
+ * libdpkg - Debian packaging suite library routines
+ * subproc.c - subprocess helper routines
+ *
+ * Copyright (C) 1995 Ian Jackson <ian@chiark.greenend.org.uk>
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with dpkg; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <signal.h>
+
+#include <dpkg.h>
+#include <dpkg-priv.h>
+
+#define NCATCHSIGNALS (int)(sizeof(catch_signals) / sizeof(int) - 1)
+static int catch_signals[] = { SIGQUIT, SIGINT, 0 };
+static struct sigaction uncatch_signals[NCATCHSIGNALS];
+
+void
+setup_subproc_signals(const char *name)
+{
+	int i;
+	struct sigaction catchsig;
+
+	onerr_abort++;
+	memset(&catchsig, 0, sizeof(catchsig));
+	catchsig.sa_handler = SIG_IGN;
+	sigemptyset(&catchsig.sa_mask);
+	catchsig.sa_flags = 0;
+	for (i = 0; i < NCATCHSIGNALS; i++)
+	if (sigaction(catch_signals[i], &catchsig, &uncatch_signals[i]))
+		ohshite(_("unable to ignore signal %s before running %.250s"),
+		        strsignal(catch_signals[i]), name);
+	push_cleanup(cu_subproc_signals, ~0, NULL, 0, 0);
+	onerr_abort--;
+}
+
+void
+cu_subproc_signals(int argc, void **argv)
+{
+	int i;
+
+	for (i = 0; i < NCATCHSIGNALS; i++) {
+		if (sigaction(catch_signals[i], &uncatch_signals[i], NULL)) {
+			fprintf(stderr, _("error un-catching signal %s: %s\n"),
+			        strsignal(catch_signals[i]), strerror(errno));
+			onerr_abort++;
+		}
+	}
+}
+

src/help.c

@@ -28,11 +28,11 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <signal.h>
 #include <time.h>
 
 #include <dpkg.h>
 #include <dpkg-db.h>
+#include <dpkg-priv.h>
 
 #include "filesdb.h"
 #include "main.h"
@@ -193,38 +193,6 @@ static char *const *buildarglist(const char *scriptname, ...) {
   return arglist;
 }
 
-#define NSCRIPTCATCHSIGNALS (int)(sizeof(script_catchsignallist)/sizeof(int)-1)
-static int script_catchsignallist[]= { SIGQUIT, SIGINT, 0 };
-static struct sigaction script_uncatchsignal[NSCRIPTCATCHSIGNALS];
-
-static void cu_restorescriptsignals(int argc, void **argv) {
-  int i;
-  for (i=0; i<NSCRIPTCATCHSIGNALS; i++) {
-    if (sigaction(script_catchsignallist[i], &script_uncatchsignal[i], NULL)) {
-      fprintf(stderr,_("error un-catching signal %s: %s\n"),
-              strsignal(script_catchsignallist[i]),strerror(errno));
-      onerr_abort++;
-    }
-  }
-}
-
-static void script_catchsignals(void) {
-  int i;
-  struct sigaction catchsig;
-  
-  onerr_abort++;
-  memset(&catchsig,0,sizeof(catchsig));
-  catchsig.sa_handler= SIG_IGN;
-  sigemptyset(&catchsig.sa_mask);
-  catchsig.sa_flags= 0;
-  for (i=0; i<NSCRIPTCATCHSIGNALS; i++)
-    if (sigaction(script_catchsignallist[i],&catchsig,&script_uncatchsignal[i]))
-      ohshite(_("unable to ignore signal %s before running script"),
-              strsignal(script_catchsignallist[i]));
-  push_cleanup(cu_restorescriptsignals, ~0, NULL, 0, 0);
-  onerr_abort--;
-}
-
 void
 post_postinst_tasks(struct pkginfo *pkg, enum pkgstatus new_status)
 {
@@ -286,7 +254,7 @@ static int do_script(const char *pkg, const char *scriptname, const char *script
     execv(scriptexec,(char * const *)narglist);
     ohshite(desc,name);
   }
-  script_catchsignals(); /* This does a push_cleanup() */
+  setup_subproc_signals(name); /* This does a push_cleanup() */
   r= waitsubproc(c1,name,warn);
   pop_cleanup(ehflag_normaltidy);