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kc3-lang/pkgconf/libpkgconf/pkg.c

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  • Author : William Pitcock
    Date : 2016-07-10 15:20:31
    Hash : 45d422c4
    Message : libpkgconf: implement PKG_CONFIG_LOG style auditing (closes #88)

  • libpkgconf/pkg.c
  • /*
     * pkg.c
     * higher-level dependency graph compilation, management and manipulation
     *
     * Copyright (c) 2011, 2012, 2013 pkgconf authors (see AUTHORS).
     *
     * Permission to use, copy, modify, and/or distribute this software for any
     * purpose with or without fee is hereby granted, provided that the above
     * copyright notice and this permission notice appear in all copies.
     *
     * This software is provided 'as is' and without any warranty, express or
     * implied.  In no event shall the authors be liable for any damages arising
     * from the use of this software.
     */
    
    #include <libpkgconf/libpkgconf.h>
    
    static pkgconf_error_handler_func_t pkgconf_error_handler = pkgconf_default_error_handler;
    
    bool
    pkgconf_error(const char *format, ...)
    {
    	char errbuf[PKGCONF_BUFSIZE];
    	va_list va;
    
    	va_start(va, format);
    	vsnprintf(errbuf, sizeof errbuf, format, va);
    	va_end(va);
    
    	return pkgconf_error_handler(errbuf);
    }
    
    bool
    pkgconf_default_error_handler(const char *msg)
    {
    	(void) msg;
    
    	return true;
    }
    
    void
    pkgconf_set_error_handler(pkgconf_error_handler_func_t func)
    {
    	pkgconf_error_handler = func;
    }
    
    #ifdef _WIN32
    #	define PKG_CONFIG_REG_KEY "Software\\pkgconfig\\PKG_CONFIG_PATH"
    #	undef PKG_DEFAULT_PATH
    #	define PKG_DEFAULT_PATH "../lib/pkgconfig;../share/pkgconfig"
    #endif
    
    #define PKG_CONFIG_EXT		".pc"
    #define PKG_CONFIG_PATH_SZ	(65535)
    
    /* pkg-config uses ';' on win32 as ':' is part of path */
    #ifdef _WIN32
    #define PKG_CONFIG_PATH_SEP_S	";"
    #else
    #define PKG_CONFIG_PATH_SEP_S	":"
    #endif
    
    #ifdef _WIN32
    #define PKG_DIR_SEP_S	'\\'
    #else
    #define PKG_DIR_SEP_S	'/'
    #endif
    
    typedef struct {
    	char *path;
    	pkgconf_node_t node;
    } pkg_path_t;
    
    static inline void
    path_add(const char *text, pkgconf_list_t *dirlist)
    {
    	pkg_path_t *pkg_path;
    
    	pkg_path = calloc(sizeof(pkg_path_t), 1);
    	pkg_path->path = strdup(text);
    
    	pkgconf_node_insert_tail(&pkg_path->node, pkg_path, dirlist);
    }
    
    static inline size_t
    path_split(const char *text, pkgconf_list_t *dirlist)
    {
    	size_t count = 0;
    	char *workbuf, *p, *iter;
    
    	if (text == NULL)
    		return 0;
    
    	iter = workbuf = strdup(text);
    	while ((p = strtok(iter, PKG_CONFIG_PATH_SEP_S)) != NULL)
    	{
    		path_add(p, dirlist);
    
    		count++, iter = NULL;
    	}
    	free(workbuf);
    
    	return count;
    }
    
    static inline bool
    str_has_suffix(const char *str, const char *suffix)
    {
    	size_t str_len = strlen(str);
    	size_t suf_len = strlen(suffix);
    
    	if (str_len < suf_len)
    		return false;
    
    	return !strncasecmp(str + str_len - suf_len, suffix, suf_len);
    }
    
    static inline const char *
    get_pkgconfig_path(void)
    {
    	const char *env_path;
    #ifdef _WIN32
    	static char outbuf[MAX_PATH];
    	char namebuf[MAX_PATH];
    	char *p;
    #endif
    
    	env_path = getenv("PKG_CONFIG_LIBDIR");
    	if (env_path != NULL)
    		return env_path;
    
    #ifdef _WIN32
    	int sizepath = GetModuleFileName(NULL, namebuf, sizeof namebuf);
    	char * winslash;
    	namebuf[sizepath] = '\0';
    	while ((winslash = strchr (namebuf, '\\')) != NULL)
    	{
    		*winslash = '/';
    	}
    	p = strrchr(namebuf, '/');
    	if (p == NULL)
    		return PKG_DEFAULT_PATH;
    
    	*p = '\0';
    	strlcpy(outbuf, namebuf, sizeof outbuf);
    	strlcat(outbuf, "/", sizeof outbuf);
    	strlcat(outbuf, "../lib/pkgconfig", sizeof outbuf);
    	strlcat(outbuf, ";", sizeof outbuf);
    	strlcat(outbuf, namebuf, sizeof outbuf);
    	strlcat(outbuf, "/", sizeof outbuf);
    	strlcat(outbuf, "../share/pkgconfig", sizeof outbuf);
    
    	return outbuf;
    #endif
    
    	return PKG_DEFAULT_PATH;
    }
    
    static const char *
    pkg_get_parent_dir(pkgconf_pkg_t *pkg)
    {
    	static char buf[PKGCONF_BUFSIZE];
    	char *pathbuf;
    
    	strlcpy(buf, pkg->filename, sizeof buf);
    	pathbuf = strrchr(buf, PKG_DIR_SEP_S);
    	if (pathbuf == NULL)
    		pathbuf = strrchr(buf, '/');
    	if (pathbuf != NULL)
    		pathbuf[0] = '\0';
    
    	return buf;
    }
    
    static pkgconf_list_t pkg_dir_list = PKGCONF_LIST_INITIALIZER;
    
    static void
    pkgconf_pkg_dir_list_build(unsigned int flags)
    {
    	const char *env_path;
    
    	if (pkg_dir_list.head != NULL || pkg_dir_list.tail != NULL)
    		return;
    
    	/* PKG_CONFIG_PATH has to take precedence */
    	env_path = getenv("PKG_CONFIG_PATH");
    	if (env_path)
    		path_split(env_path, &pkg_dir_list);
    
    	if (!(flags & PKGCONF_PKG_PKGF_ENV_ONLY))
    	{
    		env_path = get_pkgconfig_path();
    		path_split(env_path, &pkg_dir_list);
    	}
    }
    
    /*
     * pkgconf_pkg_new_from_file(filename, file, flags)
     *
     * Parse a .pc file into a pkgconf_pkg_t object structure.
     */
    pkgconf_pkg_t *
    pkgconf_pkg_new_from_file(const char *filename, FILE *f, unsigned int flags)
    {
    	pkgconf_pkg_t *pkg;
    	char readbuf[PKGCONF_BUFSIZE];
    	char *idptr;
    
    	pkg = calloc(sizeof(pkgconf_pkg_t), 1);
    	pkg->filename = strdup(filename);
    	pkgconf_tuple_add(&pkg->vars, "pcfiledir", pkg_get_parent_dir(pkg), true);
    
    	/* make module id */
    	if ((idptr = strrchr(pkg->filename, PKG_DIR_SEP_S)) != NULL)
    		idptr++;
    	else
    		idptr = pkg->filename;
    
    	pkg->id = strdup(idptr);
    	idptr = strrchr(pkg->id, '.');
    	if (idptr)
    		*idptr = '\0';
    
    	while (pkgconf_fgetline(readbuf, PKGCONF_BUFSIZE, f) != NULL)
    	{
    		char op, *p, *key, *value;
    
    		p = readbuf;
    		while (*p && (isalpha((unsigned int)*p) || isdigit((unsigned int)*p) || *p == '_' || *p == '.'))
    			p++;
    
    		key = readbuf;
    		if (!isalpha((unsigned int)*key) && !isdigit((unsigned int)*p))
    			continue;
    
    		while (*p && isspace((unsigned int)*p)) {
    			/* set to null to avoid trailing spaces in key */
    			*p = '\0';
    			p++;
    		}
    
    		op = *p;
    		*p = '\0';
    		p++;
    
    		while (*p && isspace((unsigned int)*p))
    			p++;
    
    		value = p;
    
    		switch (op)
    		{
    		case ':':
    			if (!strcmp(key, "Name"))
    				pkg->realname = pkgconf_tuple_parse(&pkg->vars, value);
    			else if (!strcmp(key, "Description"))
    				pkg->description = pkgconf_tuple_parse(&pkg->vars, value);
    			else if (!strcmp(key, "Version"))
    				pkg->version = pkgconf_tuple_parse(&pkg->vars, value);
    			else if (!strcasecmp(key, "CFLAGS"))
    				pkgconf_fragment_parse(&pkg->cflags, &pkg->vars, value, flags);
    			else if (!strcasecmp(key, "CFLAGS.private"))
    				pkgconf_fragment_parse(&pkg->cflags_private, &pkg->vars, value, flags);
    			else if (!strcasecmp(key, "LIBS"))
    				pkgconf_fragment_parse(&pkg->libs, &pkg->vars, value, flags);
    			else if (!strcasecmp(key, "LIBS.private"))
    				pkgconf_fragment_parse(&pkg->libs_private, &pkg->vars, value, flags);
    			else if (!strcmp(key, "Requires"))
    				pkgconf_dependency_parse(pkg, &pkg->requires, value);
    			else if (!strcmp(key, "Requires.private"))
    				pkgconf_dependency_parse(pkg, &pkg->requires_private, value);
    			else if (!strcmp(key, "Conflicts"))
    				pkgconf_dependency_parse(pkg, &pkg->conflicts, value);
    			break;
    		case '=':
    			pkgconf_tuple_add(&pkg->vars, key, value, true);
    			break;
    		default:
    			break;
    		}
    	}
    
    	fclose(f);
    	return pkgconf_pkg_ref(pkg);
    }
    
    void
    pkgconf_pkg_free(pkgconf_pkg_t *pkg)
    {
    	if (pkg == NULL || pkg->flags & PKGCONF_PKG_PROPF_VIRTUAL)
    		return;
    
    	pkgconf_cache_remove(pkg);
    
    	pkgconf_dependency_free(&pkg->requires);
    	pkgconf_dependency_free(&pkg->requires_private);
    	pkgconf_dependency_free(&pkg->conflicts);
    
    	pkgconf_fragment_free(&pkg->cflags);
    	pkgconf_fragment_free(&pkg->cflags_private);
    	pkgconf_fragment_free(&pkg->libs);
    	pkgconf_fragment_free(&pkg->libs_private);
    
    	pkgconf_tuple_free(&pkg->vars);
    
    	if (pkg->id != NULL)
    		free(pkg->id);
    
    	if (pkg->filename != NULL)
    		free(pkg->filename);
    
    	if (pkg->realname != NULL)
    		free(pkg->realname);
    
    	if (pkg->version != NULL)
    		free(pkg->version);
    
    	if (pkg->description != NULL)
    		free(pkg->description);
    
    	if (pkg->url != NULL)
    		free(pkg->url);
    
    	if (pkg->pc_filedir != NULL)
    		free(pkg->pc_filedir);
    
    	free(pkg);
    }
    
    pkgconf_pkg_t *
    pkgconf_pkg_ref(pkgconf_pkg_t *pkg)
    {
    	pkg->refcount++;
    	return pkg;
    }
    
    void
    pkgconf_pkg_unref(pkgconf_pkg_t *pkg)
    {
    	pkg->refcount--;
    	if (pkg->refcount <= 0)
    		pkgconf_pkg_free(pkg);
    }
    
    static inline pkgconf_pkg_t *
    pkgconf_pkg_try_specific_path(const char *path, const char *name, unsigned int flags)
    {
    	pkgconf_pkg_t *pkg = NULL;
    	FILE *f;
    	char locbuf[PKG_CONFIG_PATH_SZ];
    	char uninst_locbuf[PKG_CONFIG_PATH_SZ];
    
    	snprintf(locbuf, sizeof locbuf, "%s/%s" PKG_CONFIG_EXT, path, name);
    	snprintf(uninst_locbuf, sizeof uninst_locbuf, "%s/%s-uninstalled" PKG_CONFIG_EXT, path, name);
    
    	if (!(flags & PKGCONF_PKG_PKGF_NO_UNINSTALLED) && (f = fopen(uninst_locbuf, "r")) != NULL)
    	{
    		pkg = pkgconf_pkg_new_from_file(uninst_locbuf, f, flags);
    		pkg->flags |= PKGCONF_PKG_PROPF_UNINSTALLED;
    	}
    	else if ((f = fopen(locbuf, "r")) != NULL)
    		pkg = pkgconf_pkg_new_from_file(locbuf, f, flags);
    
    	return pkg;
    }
    
    static void
    pkgconf_pkg_scan_dir(const char *path, pkgconf_pkg_iteration_func_t func)
    {
    	DIR *dir;
    	struct dirent *dirent;
    
    	dir = opendir(path);
    	if (dir == NULL)
    		return;
    
    	for (dirent = readdir(dir); dirent != NULL; dirent = readdir(dir))
    	{
    		static char filebuf[PKGCONF_BUFSIZE];
    		pkgconf_pkg_t *pkg;
    		FILE *f;
    		struct stat st;
    
    		strlcpy(filebuf, path, sizeof filebuf);
    		strlcat(filebuf, "/", sizeof filebuf);
    		strlcat(filebuf, dirent->d_name, sizeof filebuf);
    
    		stat(filebuf, &st);
    		if (!(S_ISREG(st.st_mode)))
    			continue;
    
    		f = fopen(filebuf, "r");
    		if (f == NULL)
    			continue;
    
    		pkg = pkgconf_pkg_new_from_file(filebuf, f, 0);
    		if (pkg != NULL)
    		{
    			func(pkg);
    			pkgconf_pkg_unref(pkg);
    		}
    	}
    
    	closedir(dir);
    }
    
    void
    pkgconf_scan_all(pkgconf_pkg_iteration_func_t func)
    {
    	pkgconf_node_t *n;
    
    	pkgconf_pkg_dir_list_build(0);
    
    	PKGCONF_FOREACH_LIST_ENTRY(pkg_dir_list.head, n)
    	{
    		pkg_path_t *pkg_path = n->data;
    
    		pkgconf_pkg_scan_dir(pkg_path->path, func);
    	}
    }
    
    #ifdef _WIN32
    pkgconf_pkg_t *
    pkgconf_pkg_find_in_registry_key(HKEY hkey, const char *name, unsigned int flags)
    {
    	pkgconf_pkg_t *pkg = NULL;
    
    	HKEY key;
    	int i = 0;
    
    	char buf[16384]; /* per registry limits */
    	DWORD bufsize = sizeof buf;
    	if (RegOpenKeyEx(hkey, PKG_CONFIG_REG_KEY,
    				0, KEY_READ, &key) != ERROR_SUCCESS)
    		return NULL;
    
    	while (RegEnumValue(key, i++, buf, &bufsize, NULL, NULL, NULL, NULL)
    			== ERROR_SUCCESS)
    	{
    		char pathbuf[PKG_CONFIG_PATH_SZ];
    		DWORD type;
    		DWORD pathbuflen = sizeof pathbuf;
    
    		if (RegQueryValueEx(key, buf, NULL, &type, (LPBYTE) pathbuf, &pathbuflen)
    				== ERROR_SUCCESS && type == REG_SZ)
    		{
    			pkg = pkgconf_pkg_try_specific_path(pathbuf, name, flags);
    			if (pkg != NULL)
    				break;
    		}
    
    		bufsize = sizeof buf;
    	}
    
    	RegCloseKey(key);
    	return pkg;
    }
    #endif
    
    pkgconf_pkg_t *
    pkgconf_pkg_find(const char *name, unsigned int flags)
    {
    	pkgconf_pkg_t *pkg = NULL;
    	pkgconf_node_t *n;
    	FILE *f;
    
    	pkgconf_pkg_dir_list_build(flags);
    
    	/* name might actually be a filename. */
    	if (str_has_suffix(name, PKG_CONFIG_EXT))
    	{
    		if ((f = fopen(name, "r")) != NULL)
    		{
    			pkgconf_pkg_t *pkg;
    
    			pkg = pkgconf_pkg_new_from_file(name, f, flags);
    			path_add(pkg_get_parent_dir(pkg), &pkg_dir_list);
    
    			return pkg;
    		}
    	}
    
    	/* check cache */
    	if (!(flags & PKGCONF_PKG_PKGF_NO_CACHE))
    	{
    		if ((pkg = pkgconf_cache_lookup(name)) != NULL)
    		{
    			pkg->flags |= PKGCONF_PKG_PROPF_CACHED;
    			return pkg;
    		}
    	}
    
    	PKGCONF_FOREACH_LIST_ENTRY(pkg_dir_list.head, n)
    	{
    		pkg_path_t *pkg_path = n->data;
    
    		pkg = pkgconf_pkg_try_specific_path(pkg_path->path, name, flags);
    		if (pkg != NULL)
    			goto out;
    	}
    
    #ifdef _WIN32
    	/* support getting PKG_CONFIG_PATH from registry */
    	pkg = pkgconf_pkg_find_in_registry_key(HKEY_CURRENT_USER, name, flags);
    	if (!pkg)
    		pkg = pkgconf_pkg_find_in_registry_key(HKEY_LOCAL_MACHINE, name, flags);
    #endif
    
    out:
    	pkgconf_cache_add(pkg);
    
    	return pkg;
    }
    
    /*
     * pkgconf_compare_version(a, b)
     *
     * compare versions using RPM version comparison rules as described in the LSB.
     */
    int
    pkgconf_compare_version(const char *a, const char *b)
    {
    	char oldch1, oldch2;
    	char buf1[PKGCONF_BUFSIZE], buf2[PKGCONF_BUFSIZE];
    	char *str1, *str2;
    	char *one, *two;
    	int ret;
    	bool isnum;
    
    	/* optimization: if version matches then it's the same version. */
    	if (a == NULL)
    		return 1;
    
    	if (b == NULL)
    		return -1;
    
    	if (!strcasecmp(a, b))
    		return 0;
    
    	strlcpy(buf1, a, sizeof buf1);
    	strlcpy(buf2, b, sizeof buf2);
    
    	one = str1 = buf1;
    	two = str2 = buf2;
    
    	while (*one || *two)
    	{
    		while (*one && !isalnum((unsigned int)*one) && *one != '~')
    			one++;
    		while (*two && !isalnum((unsigned int)*two) && *two != '~')
    			two++;
    
    		if (*one == '~' || *two == '~')
    		{
    			if (*one != '~')
    				return -1;
    			if (*two != '~')
    				return 1;
    
    			one++;
    			two++;
    			continue;
    		}
    
    		if (!(*one && *two))
    			break;
    
    		str1 = one;
    		str2 = two;
    
    		if (isdigit((unsigned int)*str1))
    		{
    			while (*str1 && isdigit((unsigned int)*str1))
    				str1++;
    
    			while (*str2 && isdigit((unsigned int)*str2))
    				str2++;
    
    			isnum = true;
    		}
    		else
    		{
    			while (*str1 && isalpha((unsigned int)*str1))
    				str1++;
    
    			while (*str2 && isalpha((unsigned int)*str2))
    				str2++;
    
    			isnum = false;
    		}
    
    		oldch1 = *str1;
    		oldch2 = *str2;
    
    		*str1 = '\0';
    		*str2 = '\0';
    
    		if (one == str1)
    			return -1;
    
    		if (two == str2)
    			return (isnum ? 1 : -1);
    
    		if (isnum)
    		{
    			int onelen, twolen;
    
    			while (*one == '0')
    				one++;
    
    			while (*two == '0')
    				two++;
    
    			onelen = strlen(one);
    			twolen = strlen(two);
    
    			if (onelen > twolen)
    				return 1;
    			else if (twolen > onelen)
    				return -1;
    		}
    
    		ret = strcmp(one, two);
    		if (ret)
    			return ret;
    
    		*str1 = oldch1;
    		*str2 = oldch2;
    
    		one = str1;
    		two = str2;
    	}
    
    	if ((!*one) && (!*two))
    		return 0;
    
    	if (!*one)
    		return -1;
    
    	return 1;
    }
    
    static pkgconf_pkg_t pkg_config_virtual = {
    	.id = "pkg-config",
    	.realname = "pkg-config",
    	.description = "virtual package defining pkg-config 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 bool (*pkgconf_vercmp_res_func_t)(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep);
    
    typedef struct {
    	const char *name;
    	pkgconf_pkg_comparator_t compare;
    } pkgconf_pkg_comparator_name_t;
    
    static pkgconf_pkg_comparator_name_t pkgconf_pkg_comparator_names[PKGCONF_CMP_SIZE + 1] = {
    	{"<",		PKGCONF_CMP_LESS_THAN},
    	{">",		PKGCONF_CMP_GREATER_THAN},
    	{"<=",		PKGCONF_CMP_LESS_THAN_EQUAL},
    	{">=",		PKGCONF_CMP_GREATER_THAN_EQUAL},
    	{"=",		PKGCONF_CMP_EQUAL},
    	{"!=",		PKGCONF_CMP_NOT_EQUAL},
    	{"(any)",	PKGCONF_CMP_ANY},
    	{"???",		PKGCONF_CMP_SIZE},
    };
    
    static bool pkgconf_pkg_comparator_lt(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep)
    {
    	return (pkgconf_compare_version(pkg->version, pkgdep->version) < 0);
    }
    
    static bool pkgconf_pkg_comparator_gt(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep)
    {
    	return (pkgconf_compare_version(pkg->version, pkgdep->version) > 0);
    }
    
    static bool pkgconf_pkg_comparator_lte(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep)
    {
    	return (pkgconf_compare_version(pkg->version, pkgdep->version) <= 0);
    }
    
    static bool pkgconf_pkg_comparator_gte(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep)
    {
    	return (pkgconf_compare_version(pkg->version, pkgdep->version) >= 0);
    }
    
    static bool pkgconf_pkg_comparator_eq(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep)
    {
    	return (pkgconf_compare_version(pkg->version, pkgdep->version) == 0);
    }
    
    static bool pkgconf_pkg_comparator_ne(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep)
    {
    	return (pkgconf_compare_version(pkg->version, pkgdep->version) != 0);
    }
    
    static bool pkgconf_pkg_comparator_any(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep)
    {
    	(void) pkg;
    	(void) pkgdep;
    
    	return true;
    }
    
    static bool pkgconf_pkg_comparator_unimplemented(pkgconf_pkg_t *pkg, pkgconf_dependency_t *pkgdep)
    {
    	(void) pkg;
    	(void) pkgdep;
    
    	return false;
    }
    
    static pkgconf_vercmp_res_func_t pkgconf_pkg_comparator_impls[PKGCONF_CMP_SIZE + 1] = {
    	[PKGCONF_CMP_ANY]			= pkgconf_pkg_comparator_any,
    	[PKGCONF_CMP_LESS_THAN]			= pkgconf_pkg_comparator_lt,
    	[PKGCONF_CMP_GREATER_THAN]		= pkgconf_pkg_comparator_gt,
    	[PKGCONF_CMP_LESS_THAN_EQUAL]		= pkgconf_pkg_comparator_lte,
    	[PKGCONF_CMP_GREATER_THAN_EQUAL]	= pkgconf_pkg_comparator_gte,
    	[PKGCONF_CMP_EQUAL]			= pkgconf_pkg_comparator_eq,
    	[PKGCONF_CMP_NOT_EQUAL]			= pkgconf_pkg_comparator_ne,
    	[PKGCONF_CMP_SIZE]			= pkgconf_pkg_comparator_unimplemented,
    };
    
    /*
     * pkgconf_pkg_get_comparator(pkgdep)
     *
     * returns the comparator used in a depgraph dependency node as a string.
     */
    const char *
    pkgconf_pkg_get_comparator(const pkgconf_dependency_t *pkgdep)
    {
    	const pkgconf_pkg_comparator_name_t *i;
    
    	for (i = pkgconf_pkg_comparator_names; i->compare != PKGCONF_CMP_SIZE; i++)
    	{
    		if (i->compare == pkgdep->compare)
    			return i->name;
    	}
    
    	return "???";
    }
    
    /*
     * pkgconf_pkg_comparator_lookup_by_name(name)
     *
     * look up the appropriate comparator bytecode in the comparator set (defined
     * above, see pkgconf_pkg_comparator_names and pkgconf_pkg_comparator_impls).
     *
     * XXX: on error return PKGCONF_CMP_ANY or maybe we should return PKGCONF_CMP_SIZE which
     * is poisoned?
     */
    pkgconf_pkg_comparator_t
    pkgconf_pkg_comparator_lookup_by_name(const char *name)
    {
    	const pkgconf_pkg_comparator_name_t *i;
    
    	for (i = pkgconf_pkg_comparator_names; i->compare != PKGCONF_CMP_SIZE; i++)
    	{
    		if (!strcmp(i->name, name))
    			return i->compare;
    	}
    
    	return PKGCONF_CMP_ANY;
    }
    
    /*
     * pkg_verify_dependency(pkgdep, flags)
     *
     * verify a pkgconf_dependency_t node in the depgraph.  if the dependency is solvable,
     * return the appropriate pkgconf_pkg_t object, else NULL.
     */
    pkgconf_pkg_t *
    pkgconf_pkg_verify_dependency(pkgconf_dependency_t *pkgdep, unsigned int flags, unsigned int *eflags)
    {
    	pkgconf_pkg_t *pkg = &pkg_config_virtual;
    
    	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)
    		{
    			if (eflags != NULL)
    				*eflags |= PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND;
    
    			return NULL;
    		}
    	}
    
    	if (pkg->id == NULL)
    		pkg->id = strdup(pkgdep->package);
    
    	if (pkgconf_pkg_comparator_impls[pkgdep->compare](pkg, pkgdep) == true)
    		return pkg;
    
    	if (eflags != NULL)
    		*eflags |= PKGCONF_PKG_ERRF_PACKAGE_VER_MISMATCH;
    
    	return pkg;
    }
    
    /*
     * pkg_verify_graph(root, depth)
     *
     * verify the graph dependency nodes are satisfiable by walking the tree using
     * pkgconf_pkg_traverse().
     */
    unsigned int
    pkgconf_pkg_verify_graph(pkgconf_pkg_t *root, int depth, unsigned int flags)
    {
    	return pkgconf_pkg_traverse(root, NULL, NULL, depth, flags);
    }
    
    static unsigned int
    pkgconf_pkg_report_graph_error(pkgconf_pkg_t *parent, pkgconf_pkg_t *pkg, pkgconf_dependency_t *node, unsigned int eflags)
    {
    	static bool already_sent_notice = false;
    
    	if (eflags & PKGCONF_PKG_ERRF_PACKAGE_NOT_FOUND)
    	{
    		if (!already_sent_notice)
    		{
    			pkgconf_error("Package %s was not found in the pkg-config search path.\n", node->package);
    			pkgconf_error("Perhaps you should add the directory containing `%s.pc'\n", node->package);
    			pkgconf_error("to the PKG_CONFIG_PATH environment variable\n");
    			already_sent_notice = true;
    		}
    
    		pkgconf_error("Package '%s', required by '%s', not found\n", node->package, parent->id);
    		pkgconf_audit_log("%s NOT-FOUND\n", node->package);
    	}
    	else if (eflags & PKGCONF_PKG_ERRF_PACKAGE_VER_MISMATCH)
    	{
    		pkgconf_error("Package dependency requirement '%s %s %s' could not be satisfied.\n",
    			node->package, pkgconf_pkg_get_comparator(node), node->version);
    
    		if (pkg != NULL)
    			pkgconf_error("Package '%s' has version '%s', required version is '%s %s'\n",
    				node->package, pkg->version, pkgconf_pkg_get_comparator(node), node->version);
    	}
    
    	if (pkg != NULL)
    		pkgconf_pkg_unref(pkg);
    
    	return eflags;
    }
    
    static inline unsigned int
    pkgconf_pkg_walk_list(pkgconf_pkg_t *parent,
    	pkgconf_list_t *deplist,
    	pkgconf_pkg_traverse_func_t func,
    	void *data,
    	int depth,
    	unsigned int flags)
    {
    	unsigned int eflags = PKGCONF_PKG_ERRF_OK;
    	pkgconf_node_t *node;
    
    	PKGCONF_FOREACH_LIST_ENTRY(deplist->head, node)
    	{
    		unsigned int eflags_local = PKGCONF_PKG_ERRF_OK;
    		pkgconf_dependency_t *depnode = node->data;
    		pkgconf_pkg_t *pkgdep;
    
    		if (*depnode->package == '\0')
    			continue;
    
    		pkgdep = pkgconf_pkg_verify_dependency(depnode, flags, &eflags_local);
    
    		eflags |= eflags_local;
    		if (eflags_local != PKGCONF_PKG_ERRF_OK && !(flags & PKGCONF_PKG_PKGF_SKIP_ERRORS))
    		{
    			pkgconf_pkg_report_graph_error(parent, pkgdep, depnode, eflags_local);
    			continue;
    		}
    		if (pkgdep == NULL)
    			continue;
    
    		if (pkgdep->flags & PKGCONF_PKG_PROPF_SEEN)
    		{
    			pkgconf_pkg_unref(pkgdep);
    			continue;
    		}
    
    		pkgconf_audit_log_dependency(pkgdep, depnode);
    
    		pkgdep->flags |= PKGCONF_PKG_PROPF_SEEN;
    		eflags |= pkgconf_pkg_traverse(pkgdep, func, data, depth - 1, flags);
    		pkgdep->flags &= ~PKGCONF_PKG_PROPF_SEEN;
    		pkgconf_pkg_unref(pkgdep);
    	}
    
    	return eflags;
    }
    
    static inline unsigned int
    pkgconf_pkg_walk_conflicts_list(pkgconf_pkg_t *root, pkgconf_list_t *deplist, unsigned int flags)
    {
    	unsigned int eflags;
    	pkgconf_node_t *node, *childnode;
    
    	PKGCONF_FOREACH_LIST_ENTRY(deplist->head, node)
    	{
    		pkgconf_dependency_t *parentnode = node->data;
    
    		if (*parentnode->package == '\0')
    			continue;
    
    		PKGCONF_FOREACH_LIST_ENTRY(root->requires.head, childnode)
    		{
    			pkgconf_pkg_t *pkgdep;
    			pkgconf_dependency_t *depnode = childnode->data;
    
    			if (*depnode->package == '\0' || strcmp(depnode->package, parentnode->package))
    				continue;
    
    			pkgdep = pkgconf_pkg_verify_dependency(parentnode, flags, &eflags);
    			if (eflags == PKGCONF_PKG_ERRF_OK)
    			{
    				pkgconf_error("Version '%s' of '%s' conflicts with '%s' due to satisfying conflict rule '%s %s%s%s'.\n",
    					pkgdep->version, pkgdep->realname, root->realname, parentnode->package, pkgconf_pkg_get_comparator(parentnode),
    					parentnode->version != NULL ? " " : "", parentnode->version != NULL ? parentnode->version : "");
    				pkgconf_error("It may be possible to ignore this conflict and continue, try the\n");
    				pkgconf_error("PKG_CONFIG_IGNORE_CONFLICTS environment variable.\n");
    
    				pkgconf_pkg_unref(pkgdep);
    
    				return PKGCONF_PKG_ERRF_PACKAGE_CONFLICT;
    			}
    
    			pkgconf_pkg_unref(pkgdep);
    		}
    	}
    
    	return PKGCONF_PKG_ERRF_OK;
    }
    
    /*
     * pkgconf_pkg_traverse(root, func, data, maxdepth, flags)
     *
     * walk the dependency graph up to maxdepth levels.  -1 means infinite recursion.
     */
    unsigned int
    pkgconf_pkg_traverse(pkgconf_pkg_t *root,
    	pkgconf_pkg_traverse_func_t func,
    	void *data,
    	int maxdepth,
    	unsigned int flags)
    {
    	unsigned int rflags = flags & ~PKGCONF_PKG_PKGF_SKIP_ROOT_VIRTUAL;
    	unsigned int eflags = PKGCONF_PKG_ERRF_OK;
    
    	if (maxdepth == 0)
    		return eflags;
    
    	if ((root->flags & PKGCONF_PKG_PROPF_VIRTUAL) != PKGCONF_PKG_PROPF_VIRTUAL || (flags & PKGCONF_PKG_PKGF_SKIP_ROOT_VIRTUAL) != PKGCONF_PKG_PKGF_SKIP_ROOT_VIRTUAL)
    	{
    		if (func != NULL)
    			func(root, data, flags);
    	}
    
    	if (!(flags & PKGCONF_PKG_PKGF_SKIP_CONFLICTS))
    	{
    		eflags = pkgconf_pkg_walk_conflicts_list(root, &root->conflicts, rflags);
    		if (eflags != PKGCONF_PKG_ERRF_OK)
    			return eflags;
    	}
    
    	eflags = pkgconf_pkg_walk_list(root, &root->requires, func, data, maxdepth, rflags);
    	if (eflags != PKGCONF_PKG_ERRF_OK)
    		return eflags;
    
    	if (flags & PKGCONF_PKG_PKGF_SEARCH_PRIVATE)
    	{
    		eflags = pkgconf_pkg_walk_list(root, &root->requires_private, func, data, maxdepth, rflags | PKGCONF_PKG_PKGF_ITER_PKG_IS_PRIVATE);
    		if (eflags != PKGCONF_PKG_ERRF_OK)
    			return eflags;
    	}
    
    	return eflags;
    }
    
    static void
    pkgconf_pkg_cflags_collect(pkgconf_pkg_t *pkg, void *data, unsigned int flags)
    {
    	pkgconf_list_t *list = data;
    	pkgconf_node_t *node;
    	(void) flags;
    
    	PKGCONF_FOREACH_LIST_ENTRY(pkg->cflags.head, node)
    	{
    		pkgconf_fragment_t *frag = node->data;
    		pkgconf_fragment_copy(list, frag, flags, false);
    	}
    }
    
    static void
    pkgconf_pkg_cflags_private_collect(pkgconf_pkg_t *pkg, void *data, unsigned int flags)
    {
    	pkgconf_list_t *list = data;
    	pkgconf_node_t *node;
    	(void) flags;
    
    	PKGCONF_FOREACH_LIST_ENTRY(pkg->cflags_private.head, node)
    	{
    		pkgconf_fragment_t *frag = node->data;
    
    		pkgconf_fragment_copy(list, frag, flags, true);
    	}
    }
    
    int
    pkgconf_pkg_cflags(pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags)
    {
    	int eflag;
    
    	eflag = pkgconf_pkg_traverse(root, pkgconf_pkg_cflags_collect, list, maxdepth, flags);
    	if (eflag != PKGCONF_PKG_ERRF_OK)
    		pkgconf_fragment_free(list);
    
    	if (flags & PKGCONF_PKG_PKGF_MERGE_PRIVATE_FRAGMENTS)
    	{
    		eflag = pkgconf_pkg_traverse(root, pkgconf_pkg_cflags_private_collect, list, maxdepth, flags);
    		if (eflag != PKGCONF_PKG_ERRF_OK)
    			pkgconf_fragment_free(list);
    	}
    
    	return eflag;
    }
    
    static void
    pkgconf_pkg_libs_collect(pkgconf_pkg_t *pkg, void *data, unsigned int flags)
    {
    	pkgconf_list_t *list = data;
    	pkgconf_node_t *node;
    	(void) flags;
    
    	PKGCONF_FOREACH_LIST_ENTRY(pkg->libs.head, node)
    	{
    		pkgconf_fragment_t *frag = node->data;
    		pkgconf_fragment_copy(list, frag, flags, (flags & PKGCONF_PKG_PKGF_ITER_PKG_IS_PRIVATE) != 0);
    	}
    
    	if (flags & PKGCONF_PKG_PKGF_MERGE_PRIVATE_FRAGMENTS)
    	{
    		PKGCONF_FOREACH_LIST_ENTRY(pkg->libs_private.head, node)
    		{
    			pkgconf_fragment_t *frag = node->data;
    			pkgconf_fragment_copy(list, frag, flags, true);
    		}
    	}
    }
    
    int
    pkgconf_pkg_libs(pkgconf_pkg_t *root, pkgconf_list_t *list, int maxdepth, unsigned int flags)
    {
    	int eflag;
    
    	eflag = pkgconf_pkg_traverse(root, pkgconf_pkg_libs_collect, list, maxdepth, flags);
    
    	if (eflag != PKGCONF_PKG_ERRF_OK)
    	{
    		pkgconf_fragment_free(list);
    		return eflag;
    	}
    
    	return eflag;
    }