sysinfo: Make libpci an optional dependency

plugins/sysinfo/meson.build

@@ -19,14 +19,17 @@ if system == 'linux' or system == 'darwin'
   ]
 
   if system == 'linux'
-    libpci = dependency('libpci')
+    libpci = dependency('libpci', required: false)
+    if libpci.found()
       sysinfo_deps += libpci
+      sysinfo_cargs += '-DHAVE_LIBPCI'
+      sysinfo_sources += 'unix/pci.c'
+    endif
     sysinfo_includes += 'unix'
     sysinfo_sources += [
       'unix/backend.c',
       'unix/match.c',
       'unix/parse.c',
-      'unix/pci.c',
     ]
 
     picidsdir = libpci.get_pkgconfig_variable('idsdir')

plugins/sysinfo/unix/parse.c

@@ -140,6 +140,9 @@ gint64 xs_parse_uptime(void)
 
 int xs_parse_sound(char *snd_card)
 {
+#ifndef HAVE_LIBPCI
+	return 1;
+#else
 	char buffer[bsize], cards[bsize] = "\0", vendor[7] = "\0", device[7] = "\0", *pos;
 	u16 class = PCI_CLASS_MULTIMEDIA_AUDIO;
 
@@ -178,10 +181,14 @@ int xs_parse_sound(char *snd_card)
 
 	fclose(fp);
 	return 0;
+#endif
 }
 
 int xs_parse_video(char *vid_card)
 {
+#ifndef HAVE_LIBPCI
+	return 1;
+#else
 	char vendor[7] = "\0", device[7] = "\0";
 	u16 class = PCI_CLASS_DISPLAY_VGA;
 	if (pci_find_by_class(&class, vendor, device))
@@ -189,10 +196,14 @@ int xs_parse_video(char *vid_card)
 	else
 		pci_find_fullname(vid_card, vendor, device);
 	return 0;
+#endif
 }
 
 int xs_parse_ether(char *ethernet_card)
 {
+#ifndef HAVE_LIBPCI
+	return 1;
+#else
 	char vendor[7] = "\0", device[7] = "\0";
 	u16 class = PCI_CLASS_NETWORK_ETHERNET;
 	if (pci_find_by_class(&class, vendor, device))
@@ -200,10 +211,14 @@ int xs_parse_ether(char *ethernet_card)
 	else
 		pci_find_fullname(ethernet_card, vendor, device);
 	return 0;
+#endif
 }
 
 int xs_parse_agpbridge(char *agp_bridge)
 {
+#ifndef HAVE_LIBPCI
+	return 1;
+#else
 	char vendor[7] = "\0", device[7] = "\0";
 	u16 class = PCI_CLASS_BRIDGE_HOST;
 	if (pci_find_by_class(&class, vendor, device))
@@ -211,6 +226,7 @@ int xs_parse_agpbridge(char *agp_bridge)
 	else
 		pci_find_fullname(agp_bridge, vendor, device);
 	return 0;
+#endif
 }
 
 int xs_parse_meminfo(unsigned long long *mem_tot, unsigned long long *mem_free, int swap)