#include "m4.h"
struct includes
{
struct includes *next;
const char *dir;
int len;
};
typedef struct includes includes;
static includes *dir_list;
static includes *dir_list_end;
static int dir_max_length;
void
include_init (void)
{
dir_list = NULL;
dir_list_end = NULL;
dir_max_length = 0;
}
void
include_env_init (void)
{
char *path;
char *path_end;
if (no_gnu_extensions)
return;
path = getenv ("M4PATH");
if (path == NULL)
return;
do
{
path_end = strchr (path, ':');
if (path_end)
*path_end = '\0';
add_include_directory (path);
path = path_end + 1;
}
while (path_end);
}
void
add_include_directory (const char *dir)
{
includes *incl;
if (no_gnu_extensions)
return;
if (*dir == '\0')
dir = ".";
incl = (includes *) xmalloc (sizeof (struct includes));
incl->next = NULL;
incl->len = strlen (dir);
incl->dir = xstrdup (dir);
if (incl->len > dir_max_length)
dir_max_length = incl->len;
if (dir_list_end == NULL)
dir_list = incl;
else
dir_list_end->next = incl;
dir_list_end = incl;
#ifdef DEBUG_INCL
fprintf (stderr, "add_include_directory (%s);\n", dir);
#endif
}
FILE *
path_search (const char *file, const char **result)
{
FILE *fp;
includes *incl;
char *name;
int e;
if (result)
*result = NULL;
if (!*file)
{
errno = ENOENT;
return NULL;
}
fp = fopen (file, "r");
if (fp != NULL)
{
if (set_cloexec_flag (fileno (fp), true) != 0)
M4ERROR ((warning_status, errno,
"Warning: cannot protect input file across forks"));
if (result)
*result = xstrdup (file);
return fp;
}
if (*file == '/' || no_gnu_extensions)
return NULL;
e = errno;
name = (char *) xmalloc (dir_max_length + 1 + strlen (file) + 1);
for (incl = dir_list; incl != NULL; incl = incl->next)
{
strncpy (name, incl->dir, incl->len);
name[incl->len] = '/';
strcpy (name + incl->len + 1, file);
#ifdef DEBUG_INCL
fprintf (stderr, "path_search (%s) -- trying %s\n", file, name);
#endif
fp = fopen (name, "r");
if (fp != NULL)
{
if (debug_level & DEBUG_TRACE_PATH)
DEBUG_MESSAGE2 ("path search for `%s' found `%s'", file, name);
if (set_cloexec_flag (fileno (fp), true) != 0)
M4ERROR ((warning_status, errno,
"Warning: cannot protect input file across forks"));
if (result)
*result = name;
else
free (name);
errno = e;
return fp;
}
}
free (name);
errno = e;
return fp;
}
#ifdef DEBUG_INCL
static void M4_GNUC_UNUSED
include_dump (void)
{
includes *incl;
fprintf (stderr, "include_dump:\n");
for (incl = dir_list; incl != NULL; incl = incl->next)
fprintf (stderr, "\t%s\n", incl->dir);
}
#endif