libpkgconf: improve API to support any number of builtin packages

libpkgconf/libpkgconf.h

@@ -158,6 +158,7 @@ const char *pkgconf_pkg_get_comparator(const pkgconf_dependency_t *pkgdep);
 int pkgconf_pkg_cflags(pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags);
 int pkgconf_pkg_libs(pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags);
 pkgconf_pkg_comparator_t pkgconf_pkg_comparator_lookup_by_name(const char *name);
+pkgconf_pkg_t *pkgconf_builtin_pkg_get(const char *name);
 
 int pkgconf_compare_version(const char *a, const char *b);
 void pkgconf_scan_all(pkgconf_pkg_iteration_func_t func);

libpkgconf/pkg.c

@@ -480,6 +480,10 @@ pkgconf_pkg_find(const char *name, unsigned int flags)
 		}
 	}
 
+	/* check builtins */
+	if ((pkg = pkgconf_builtin_pkg_get(name)) != NULL)
+		return pkg;
+
 	/* check cache */
 	if (!(flags & PKGCONF_PKG_PKGF_NO_CACHE))
 	{
@@ -660,6 +664,52 @@ static pkgconf_pkg_t pkg_config_virtual = {
 	},
 };
 
+static pkgconf_pkg_t pkgconf_virtual = {
+	.id = "pkgconf",
+	.realname = "pkgconf",
+	.description = "virtual package defining pkgconf API version supported",
+	.url = PACKAGE_BUGREPORT,
+	.version = PACKAGE_VERSION,
+	.flags = PKGCONF_PKG_PROPF_VIRTUAL,
+	.vars = {
+		.head = &(pkgconf_node_t){
+			.prev = NULL,
+			.next = NULL,
+			.data = &(pkgconf_tuple_t){
+				.key = "pc_path",
+				.value = PKG_DEFAULT_PATH,
+			},
+		},
+		.tail = NULL,
+	},
+};
+
+typedef struct {
+	const char *name;
+	pkgconf_pkg_t *pkg;
+} pkgconf_builtin_pkg_pair_t;
+
+/* keep these in alphabetical order */
+static const pkgconf_builtin_pkg_pair_t pkgconf_builtin_pkg_pair_set[] = {
+	{"pkg-config", &pkg_config_virtual},
+	{"pkgconf", &pkgconf_virtual},
+};
+
+static int pkgconf_builtin_pkg_pair_cmp(const void *key, const void *ptr)
+{
+	const pkgconf_builtin_pkg_pair_t *pair = ptr;
+	return strcasecmp(key, pair->name);
+}
+
+pkgconf_pkg_t *pkgconf_builtin_pkg_get(const char *name)
+{
+	const pkgconf_builtin_pkg_pair_t *pair = bsearch(name, pkgconf_builtin_pkg_pair_set,
+		PKGCONF_ARRAY_SIZE(pkgconf_builtin_pkg_pair_set), sizeof(pkgconf_builtin_pkg_pair_t),
+		pkgconf_builtin_pkg_pair_cmp);
+
+	return (pair != NULL) ? pair->pkg : NULL;
+}
+
 typedef bool (*pkgconf_vercmp_res_func_t)(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep);
 
 typedef struct {
@@ -786,14 +836,11 @@ pkgconf_pkg_comparator_lookup_by_name(const char *name)
 pkgconf_pkg_t *
 pkgconf_pkg_verify_dependency(pkgconf_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags)
 {
-	pkgconf_pkg_t *pkg = &pkg_config_virtual;
+	pkgconf_pkg_t *pkg = NULL;
 
 	if (eflags != NULL)
 		*eflags = PKGCONF_PKG_ERRF_OK;
 
-	/* pkg-config package name is special cased. */
-	if (strcasecmp(pkgdep->package, "pkg-config"))
-	{
 	pkg = pkgconf_pkg_find(pkgdep->package, flags);
 	if (pkg == NULL)
 	{
@@ -802,7 +849,6 @@ pkgconf_pkg_verify_dependency(pkgconf_dependency_t *pkgdep, unsigned int flags,
 
 		return NULL;
 	}
-	}
 
 	if (pkg->id == NULL)
 		pkg->id = strdup(pkgdep->package);