#include <string.h>
#include <ctype.h>
#include <assert.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
#include "macros.h"
#include "mem.h"
#include "vector.h"
#include "log.h"
+#include "hash.h"
+#include "sink.h"
+#include "syscalls.h"
VECTOR_TYPE(mx_node_vector, const struct mx_node *, xrealloc);
+/** @brief Definition of an expansion */
+struct expansion {
+ /** @brief Minimum permitted arguments */
+ int min;
+
+ /** @brief Maximum permitted arguments */
+ int max;
+
+ /** @brief Flags */
+ unsigned flags;
+
+ /** @brief Callback (cast to appropriate type) */
+ void (*callback)();
+};
+
+/** @brief Expansion takes parsed templates, not strings */
+#define EXP_MAGIC 0x0001
+
+static hash *expansions;
+
+/* Parsing ------------------------------------------------------------------ */
+
/** @brief Parse a template
* @param filename Input filename (for diagnostics)
* @param line Line number (use 1 on initial call)
return d->vec;
}
+/* Expansion registration --------------------------------------------------- */
+
+static void mx__register(unsigned flags,
+ const char *name,
+ int min,
+ int max,
+ void (*callback)()) {
+ struct expansion e[1];
+
+ if(!expansions)
+ expansions = hash_new(sizeof(struct expansion));
+ e->min = min;
+ e->max = max;
+ e->flags = flags;
+ e->callback = callback;
+ hash_add(expansions, name, &e, HASH_INSERT_OR_REPLACE);
+}
+
+/** @brief Register a simple expansion rule
+ * @param name Name
+ * @param min Minimum number of arguments
+ * @param max Maximum number of arguments
+ * @param callback Callback to write output
+ */
+void mx_register(const char *name,
+ int min,
+ int max,
+ mx_simple_callback *callback) {
+ mx__register(0, name, min, max, (void (*)())callback);
+}
+
+/** @brief Register a magic expansion rule
+ * @param name Name
+ * @param min Minimum number of arguments
+ * @param max Maximum number of arguments
+ * @param callback Callback to write output
+ */
+void mx_magic_register(const char *name,
+ int min,
+ int max,
+ mx_magic_callback *callback) {
+ mx__register(EXP_MAGIC, name, min, max, (void (*)())callback);
+}
+
+/* Expansion ---------------------------------------------------------------- */
+
+/** @brief Expand a template
+ * @param m Where to start
+ * @param output Where to send output
+ * @param u User data
+ * @return 0 on success, non-0 on error∑
+ *
+ * If a sink write fails then -1 is returned. If any callback returns non-zero
+ * then that value is returned. It is suggested that callbacks adopt this
+ * policy too and use positive values to mean other kinds of fatal error.
+ */
+int mx_expand(const struct mx_node *m,
+ struct sink *output,
+ void *u) {
+ const struct expansion *e;
+ int rc;
+
+ if(!m)
+ return 0;
+ switch(m->type) {
+ case MX_TEXT:
+ if(sink_writes(output, m->text) < 0)
+ return -1;
+ break;
+ case MX_EXPANSION:
+ if(!(e = hash_find(expansions, m->name))) {
+ error(0, "%s:%d: unknown expansion name '%s'",
+ m->filename, m->line, m->name);
+ if(sink_printf(output, "[[%s unknown]]", m->name) < 0)
+ return -1;
+ } else if(m->nargs < e->min) {
+ error(0, "%s:%d: expansion '%s' requires %d args, only %d given",
+ m->filename, m->line, m->name, e->min, m->nargs);
+ if(sink_printf(output, "[[%s too few args]]", m->name) < 0)
+ return -1;
+ } else if(m->nargs > e->max) {
+ error(0, "%s:%d: expansion '%s' takes at most %d args, but %d given",
+ m->filename, m->line, m->name, e->max, m->nargs);
+ if(sink_printf(output, "[[%s too many args]]", m->name) < 0)
+ return -1;
+ } else if(e->flags & EXP_MAGIC) {
+ /* Magic callbacks we can call directly */
+ if((rc = ((mx_magic_callback *)e->callback)(m->nargs,
+ m->args,
+ output,
+ u)))
+ return rc;
+ } else {
+ /* For simple callbacks we expand their arguments for them */
+ char **args = xcalloc(1 + m->nargs, sizeof (char *));
+ int n;
+
+ for(n = 0; n < m->nargs; ++n)
+ if((rc = mx_expandstr(m->args[n], &args[n], u)))
+ return rc;
+ args[n] = NULL;
+ if((rc = ((mx_simple_callback *)e->callback)(m->nargs,
+ args,
+ output,
+ u)))
+ return rc;
+ }
+ break;
+ default:
+ assert(!"invalid m->type");
+ }
+ return mx_expand(m, output, u);
+}
+
+/** @brief Expand a template storing the result in a string
+ * @param m Where to start
+ * @param sp Where to store string
+ * @param u User data
+ * @return 0 on success, non-0 on error
+ *
+ * Same return conventions as mx_expand(). This wrapper is slightly more
+ * convenient to use from 'magic' expansions.
+ */
+int mx_expandstr(const struct mx_node *m,
+ char **sp,
+ void *u) {
+ struct dynstr d[1];
+ int rc;
+
+ if(!(rc = mx_expand(m, sink_dynstr(d), u))) {
+ dynstr_terminate(d);
+ *sp = d->vec;
+ }
+ return rc;
+}
+
+/** @brief Expand a template file
+ * @param path Filename
+ * @param output Where to send output
+ * @param u User data
+ * @return 0 on success, non-0 on error
+ *
+ * Same return conventions as mx_expand().
+ */
+int mx_expand_file(const char *path,
+ struct sink *output,
+ void *u) {
+ int fd, n;
+ struct stat sb;
+ char *b;
+ off_t sofar;
+
+ if((fd = open(path, O_RDONLY)) < 0)
+ fatal(errno, "error opening %s", path);
+ if(fstat(fd, &sb) < 0)
+ fatal(errno, "error statting %s", path);
+ if(!S_ISREG(sb.st_mode))
+ fatal(0, "%s: not a regular file", path);
+ sofar = 0;
+ b = xmalloc_noptr(sb.st_size);
+ while(sofar < sb.st_size) {
+ n = read(fd, b + sofar, sb.st_size - sofar);
+ if(n > 0)
+ sofar += n;
+ else if(n == 0)
+ fatal(0, "unexpected EOF reading %s", path);
+ else if(errno != EINTR)
+ fatal(errno, "error reading %s", path);
+ }
+ xclose(fd);
+ return mx_expand(mx_parse(path, 1, b, b + sb.st_size),
+ output,
+ u);
+}
+
/*
Local Variables:
c-basic-offset:2
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