Remove more useless if tests before "free"-like functions.

* build-aux/useless-if-before-free: Rename from ...
* build-aux/find-unnecessary-if-before-free: ... this.  Remove file.
Also changed it so that new names are no longer hard-coded in the
script.  Instead, they're supplied via options:
* Makefile.cfg (useless_free_options): Define.
Add xmlXPathFreeObject to the list of free-like functions it detects.
* Makefile.maint (sc_avoid_if_before_free): Reflect script renaming.
* .x-sc_avoid_if_before_free: Likewise.
* src/openvz_conf.c (openvzParseXML): Remove useless "if"-before-free.
* src/qemu_conf.c (qemudParseXML, qemudParseNetworkXML): Likewise.
* src/virsh.c (cmdVNCDisplay, cmdTTYConsole, cmdDetachInterface):
(cmdDetachDisk): Likewise.
* src/xm_internal.c (xenXMConfigSetIntFromXPath): Likewise.
(xenXMConfigSetStringFromXPath, xenXMParseXMLToConfig): Likewise.
(xenXMDomainAttachDevice, xenXMAttachDisk, xenXMAttachInterface):
(xenXMDomainDetachDevice): Likewise.
* src/xml.c (virXPathString): Likewise.
* tests/xmlrpctest.c (checkRequestValue): Likewise.

.x-sc_avoid_if_before_free

@@ -1,5 +1,5 @@
 ^gnulib/lib/getaddrinfo\.c$
 ^gnulib/lib/printf-parse\.c$
 ^gnulib/lib/vasnprintf\.c$
-^build-aux/find-unnecessary-if-before-free$
+^build-aux/useless-if-before-free$
 ^ChangeLog$

ChangeLog

@@ -1,4 +1,24 @@
-2008-02-07  Jim Meyering  <meyering@redhat.com>
+Thu Feb  7 17:48:30 CET 2008 Jim Meyering  <meyering@redhat.com>
+
+	Remove more useless if tests before "free"-like functions.
+	* build-aux/useless-if-before-free: Rename from ...
+	* build-aux/find-unnecessary-if-before-free: ... this.  Remove file.
+	Also changed it so that new names are no longer hard-coded in the
+	script.  Instead, they're supplied via options:
+	* Makefile.cfg (useless_free_options): Define.
+	Add xmlXPathFreeObject to the list of free-like functions it detects.
+	* Makefile.maint (sc_avoid_if_before_free): Reflect script renaming.
+	* .x-sc_avoid_if_before_free: Likewise.
+	* src/openvz_conf.c (openvzParseXML): Remove useless "if"-before-free.
+	* src/qemu_conf.c (qemudParseXML, qemudParseNetworkXML): Likewise.
+	* src/virsh.c (cmdVNCDisplay, cmdTTYConsole, cmdDetachInterface):
+	(cmdDetachDisk): Likewise.
+	* src/xm_internal.c (xenXMConfigSetIntFromXPath): Likewise.
+	(xenXMConfigSetStringFromXPath, xenXMParseXMLToConfig): Likewise.
+	(xenXMDomainAttachDevice, xenXMAttachDisk, xenXMAttachInterface):
+	(xenXMDomainDetachDevice): Likewise.
+	* src/xml.c (virXPathString): Likewise.
+	* tests/xmlrpctest.c (checkRequestValue): Likewise.
 
 	* src/xm_internal.c: Remove trailing blanks
 	* NEWS, ChangeLog: Likewise.

Makefile.cfg

@@ -52,3 +52,8 @@ local-checks-to-skip =			\
   patch-check				\
   check-AUTHORS				\
   changelog-check
+
+useless_free_options =		\
+  --name=sexpr_free		\
+  --name=xmlXPathFreeContext	\
+  --name=xmlXPathFreeObject

Makefile.maint

@@ -40,7 +40,8 @@ syntax-check: $(local-check)
 ## --------------- ##
 
 sc_avoid_if_before_free:
-	@$(srcdir)/build-aux/find-unnecessary-if-before-free		\
+	@$(srcdir)/build-aux/useless-if-before-free			\
+		$(useless_free_options)					\
 	    $$($(CVS_LIST_EXCEPT)) &&					\
 	  { echo '$(ME): found useless "if" before "free" above' 1>&2;	\
 	    exit 1; } || :

build-aux/find-unnecessary-if-before-free

@@ -1,42 +0,0 @@
-#!/usr/bin/perl
-# Detect instances of "if (p) free (p);".
-# Likewise for "if (p != NULL) free (p);".
-# Exit status is like grep: 0 for no match. 1 for any number.
-
-# Note: giving line numbers isn't practical, since I've reset the
-# input record separator.
-use strict;
-use warnings;
-(my $ME = $0) =~ s|.*/||;
-
-{
-  # Use ';' as the input record separator.
-  $/ = ';';
-
-  my $found_match = 0;
-  foreach my $file (@ARGV)
-    {
-      open FH, '<', $file
-	or die "$ME: can't open `$file' for reading: $!\n";
-      while (defined (my $line = <FH>))
-	{
-	  if ($line =~
-	      /\b(if\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)
-	       \s+(?:xmlXPathFreeContext|(?:sexpr_)?free)\s*\(\s*\2\s*\))/sx)
-	    {
-	      print "$file: $1\n";
-	      $found_match = 1;
-	    }
-	}
-      close FH;
-    }
-  exit !$found_match;
-}
-
-my $foo = <<'EOF';
-# The above is to *find* them.
-# This adjusts them, removing the unnecessary "if (p)" part.
-
-git ls-files -z --exclude=find-unnecessary-if-before-free |xargs -0 \
-perl -0x3b -pi -e 's/\bif\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)\s+((?:xmlXPathFreeContext|(?:sexpr_)?free)\s*\(\s*\1\s*\))/$2/s'
-EOF

build-aux/useless-if-before-free

@@ -0,0 +1,118 @@
+#!/usr/bin/perl -T
+# Detect instances of "if (p) free (p);".
+# Likewise for "if (p != NULL) free (p);".
+
+my $VERSION = '2008-02-04 22:25'; # UTC
+# The definition above must lie within the first 8 lines in order
+# for the Emacs time-stamp write hook (at end) to update it.
+# If you change this file with Emacs, please let the write hook
+# do its job.  Otherwise, update this string manually.
+
+# Exit status is like grep: 0 for no match. 1 for any number.
+# Note: giving line numbers isn't practical, since I've reset the
+# input record separator.
+use strict;
+use warnings;
+use Getopt::Long;
+
+(my $ME = $0) =~ s|.*/||;
+
+my $debug = 0;
+my $verbose = 0;
+
+sub usage ($)
+{
+  my ($exit_code) = @_;
+  my $STREAM = ($exit_code == 0 ? *STDOUT : *STDERR);
+  if ($exit_code != 0)
+    {
+      print $STREAM "Try `$ME --help' for more information.\n";
+    }
+  else
+    {
+      print $STREAM <<EOF;
+Usage: $ME [OPTIONS] FILE...
+
+OPTIONS:
+
+   --name=N     add name N to the list of `free'-like functions to detect;
+                  may be repeated
+
+   --help       display this help and exit
+   --version    output version information and exit
+   --verbose    generate verbose output
+
+EXAMPLE:
+
+    git ls-files -z |xargs -0 $ME
+
+EOF
+    }
+  exit $exit_code;
+}
+
+{
+  my @name = qw(free);
+  GetOptions
+    (
+     debug => \$debug,
+     verbose => \$verbose,
+     help => sub { usage 0 },
+     version => sub { print "$ME version $VERSION\n"; exit },
+     'name=s@' => \@name,
+    ) or usage 1;
+
+  # Make sure we have the right number of non-option arguments.
+  # Always tell the user why we fail.
+  @ARGV < 1
+    and (warn "$ME: missing FILE argument\n"), usage 1;
+
+  my $or = join '|', @name;
+  my $regexp = qr/(?:$or)/;
+
+  # Set the input record separator.
+  $/ = '"';
+
+  my $found_match = 0;
+  foreach my $file (@ARGV)
+    {
+      open FH, '<', $file
+        or die "$ME: can't open `$file' for reading: $!\n";
+      while (defined (my $line = <FH>))
+        {
+          if ($line =~
+              /\b(if\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)
+               (?:   \s*$regexp\s*\(\s*\2\s*\)|
+                \s*\{\s*$regexp\s*\(\s*\2\s*\)\s*;\s*\}))/sx)
+            {
+              print "$file: $1\n";
+              $found_match = 1;
+            }
+        }
+      close FH;
+    }
+  exit !$found_match;
+}
+
+my $foo = <<'EOF';
+# The above is to *find* them.
+# This adjusts them, removing the unnecessary "if (p)" part.
+
+# FIXME: do something like this as an option.
+git ls-files -z --exclude=$ME |xargs -0 \
+perl -0x3b -pi -e 's/\bif\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)\s+((?:sexpr_)?free\s*\(\s*\1\s*\))/$2/s'
+
+When modifying files, refuse to process anything other than a regular file.
+
+# Or this one-liner to detect them:
+git ls-files -z |xargs -0 perl -00 -ne '/\b(if\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)(?:\s*(?:sexpr_)?free\s*\(\s*\2\s*\)|\s*\{\s*(?:sexpr_)?free\s*\(\s*\2\s*\)\s*;\s*\}))/sx and print "$1\n"'
+EOF
+
+## Local Variables:
+## indent-tabs-mode: nil
+## eval: (add-hook 'write-file-hooks 'time-stamp)
+## time-stamp-start: "my $VERSION = '"
+## time-stamp-format: "%:y-%02m-%02d %02H:%02M"
+## time-stamp-time-zone: "UTC"
+## time-stamp-end: "'; # UTC"
+## End:

src/openvz_conf.c

@@ -495,7 +495,6 @@ static struct openvz_vm_def
 
  bail_out:
     free(prop);
-    if (obj)
     xmlXPathFreeObject(obj);
     xmlXPathFreeContext(ctxt);
     openvzFreeVMDef(def);

src/qemu_conf.c

@@ -1,7 +1,7 @@
 /*
  * config.c: VM configuration management
  *
- * Copyright (C) 2006, 2007 Red Hat, Inc.
+ * Copyright (C) 2006, 2007, 2008 Red Hat, Inc.
  * Copyright (C) 2006 Daniel P. Berrange
  *
  * This library is free software; you can redistribute it and/or
@@ -1004,7 +1004,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
             goto error;
         }
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
 
@@ -1023,7 +1022,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
             goto error;
         }
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
     /* Extract domain vcpu info */
@@ -1039,7 +1037,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
             goto error;
         }
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
     /* See if ACPI feature is requested */
@@ -1062,7 +1059,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
         else
             def->noReboot = 0;
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
     /* See if we set clock to localtime */
@@ -1076,7 +1072,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
         else
             def->localtime = 0;
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
 
@@ -1111,7 +1106,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
         }
         strcpy(def->os.arch, (const char *)obj->stringval);
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
     obj = xmlXPathEval(BAD_CAST "string(/domain/os/type[1]/@machine)", ctxt);
@@ -1134,7 +1128,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
         }
         strcpy(def->os.machine, (const char *)obj->stringval);
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
 
@@ -1147,7 +1140,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
         }
         strcpy(def->os.kernel, (const char *)obj->stringval);
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
 
@@ -1160,7 +1152,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
         }
         strcpy(def->os.initrd, (const char *)obj->stringval);
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
 
@@ -1173,7 +1164,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
         }
         strcpy(def->os.cmdline, (const char *)obj->stringval);
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
 
@@ -1224,7 +1214,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
         }
         strcpy(def->os.binary, (const char *)obj->stringval);
     }
-    if (obj)
     xmlXPathFreeObject(obj);
 
     obj = xmlXPathEval(BAD_CAST "/domain/devices/graphics", ctxt);
@@ -1382,7 +1371,6 @@ static struct qemud_vm_def *qemudParseXML(virConnectPtr conn,
 
  error:
     free(prop);
-    if (obj)
     xmlXPathFreeObject(obj);
     xmlXPathFreeContext(ctxt);
     qemudFreeVMDef(def);
@@ -2389,9 +2377,7 @@ static struct qemud_network_def *qemudParseNetworkXML(virConnectPtr conn,
  error:
     /* XXX free all the stuff in the qemud_network struct, or leave it upto
        the caller ? */
-    if (obj)
     xmlXPathFreeObject(obj);
-    if (tmp)
     xmlXPathFreeObject(tmp);
     xmlXPathFreeContext(ctxt);
     qemudFreeNetworkDef(def);

src/virsh.c

@@ -2931,7 +2931,6 @@ cmdVNCDisplay(vshControl * ctl, vshCmd * cmd)
     ret = TRUE;
 
  cleanup:
-    if (obj)
     xmlXPathFreeObject(obj);
     xmlXPathFreeContext(ctxt);
     if (xml)
@@ -2993,7 +2992,6 @@ cmdTTYConsole(vshControl * ctl, vshCmd * cmd)
     vshPrint(ctl, "%s\n", (const char *)obj->stringval);
 
  cleanup:
-    if (obj)
     xmlXPathFreeObject(obj);
     xmlXPathFreeContext(ctxt);
     if (xml)
@@ -3338,7 +3336,6 @@ cmdDetachInterface(vshControl * ctl, vshCmd * cmd)
  cleanup:
     if (dom)
         virDomainFree(dom);
-    if (obj)
     xmlXPathFreeObject(obj);
     xmlXPathFreeContext(ctxt);
     if (xml)
@@ -3611,7 +3608,6 @@ cmdDetachDisk(vshControl * ctl, vshCmd * cmd)
         ret = TRUE;
 
  cleanup:
-    if (obj)
     xmlXPathFreeObject(obj);
     xmlXPathFreeContext(ctxt);
     if (xml)

src/xm_internal.c

@@ -1558,7 +1558,6 @@ int xenXMConfigSetIntFromXPath(virConnectPtr conn,
     ret = 0;
 
  error:
-    if (obj)
     xmlXPathFreeObject(obj);
 
     return ret;
@@ -1593,7 +1592,6 @@ int xenXMConfigSetStringFromXPath(virConnectPtr conn,
     ret = 0;
 
  error:
-    if (obj)
     xmlXPathFreeObject(obj);
 
     return ret;
@@ -2280,7 +2278,6 @@ virConfPtr xenXMParseXMLToConfig(virConnectPtr conn, const char *xml) {
         virConfFree(conf);
     if (prop != NULL)
         xmlFree(prop);
-    if (obj != NULL)
     xmlXPathFreeObject(obj);
     xmlXPathFreeContext(ctxt);
     if (doc != NULL)
@@ -2580,7 +2577,6 @@ xenXMDomainAttachDevice(virDomainPtr domain, const char *xml) {
         (obj->stringval) && (STREQ((char *)obj->stringval, "hvm")))
         hvm = 1;
 
-    if (ctxt)
     xmlXPathFreeContext(ctxt);
     ctxt = NULL;
     if (doc)
@@ -2619,11 +2615,8 @@ xenXMDomainAttachDevice(virDomainPtr domain, const char *xml) {
     ret = 0;
 
  cleanup:
-    if (domxml)
     free(domxml);
-    if (obj)
     xmlXPathFreeObject(obj);
-    if (ctxt)
     xmlXPathFreeContext(ctxt);
     if (doc)
         xmlFreeDoc(doc);
@@ -2738,7 +2731,6 @@ xenXMAttachDisk(virDomainPtr domain, xmlXPathContextPtr ctxt, int hvm,
             prev->next = list_val;
     } else {
         /* configure */
-        if (list_val->str)
         free(list_val->str);
         list_val->str = dev;
     }
@@ -2747,11 +2739,8 @@ xenXMAttachDisk(virDomainPtr domain, xmlXPathContextPtr ctxt, int hvm,
     goto cleanup;
 
  cleanup:
-    if (type)
     free(type);
-    if (source)
     free(source);
-    if (target)
     free(target);
 
     return (ret);
@@ -2825,7 +2814,6 @@ xenXMAttachInterface(virDomainPtr domain, xmlXPathContextPtr ctxt, int hvm,
 
             if (!(strcmp(dommac, (const char *) mac))) {
                 if (autoassign) {
-                    if (mac)
                     free(mac);
                     mac = NULL;
                     if (!(mac = (xmlChar *)xenXMAutoAssignMac()))
@@ -2914,7 +2902,6 @@ xenXMAttachInterface(virDomainPtr domain, xmlXPathContextPtr ctxt, int hvm,
             prev->next = list_val;
     } else {
         /* configure */
-        if (list_val->str)
         free(list_val->str);
         list_val->str = dev;
     }
@@ -2930,11 +2917,8 @@ xenXMAttachInterface(virDomainPtr domain, xmlXPathContextPtr ctxt, int hvm,
     if (text_node)
         xmlFree(text_node);
  cleanup:
-    if (type)
     free(type);
-    if (source)
     free(source);
-    if (mac)
     free(mac);
 
     return (ret);
@@ -3139,15 +3123,11 @@ xenXMDomainDetachDevice(virDomainPtr domain, const char *xml) {
     ret = 0;
 
  cleanup:
-    if (ctxt)
     xmlXPathFreeContext(ctxt);
     if (doc)
         xmlFreeDoc(doc);
-    if (domdevice)
     free(domdevice);
-    if (key)
     free(key);
-    if (list_val)
     free(list_val);
 
     return (ret);

src/xml.c

@@ -479,7 +479,6 @@ virXPathString(const char *xpath, xmlXPathContextPtr ctxt)
     obj = xmlXPathEval(BAD_CAST xpath, ctxt);
     if ((obj == NULL) || (obj->type != XPATH_STRING) ||
         (obj->stringval == NULL) || (obj->stringval[0] == 0)) {
-        if (obj)
         xmlXPathFreeObject(obj);
         return (NULL);
     }

tests/xmlrpctest.c

@@ -1,7 +1,7 @@
 /*
  * xmlrpctest.c: simple client for XML-RPC tests
  *
- * Copyright (C) 2005 Red Hat, Inc.
+ * Copyright (C) 2005, 2008 Red Hat, Inc.
  *
  * See COPYING.LIB for the License of this software
  *
@@ -119,7 +119,6 @@ checkRequestValue(const char *xmlstr, const char *xpath, int type, void *expecte
     ret = 0;
 
 error:
-    if (obj)
     xmlXPathFreeObject(obj);
     xmlXPathFreeContext(ctxt);
     if (xml)