kvp.c kvp.h \
log.c log.h log-impl.h \
logfd.c logfd.h \
- macros.c macros.h \
+ macros.c macros-builtin.c macros.h \
mem.c mem.h mem-impl.h \
mime.h mime.c \
mixer.c mixer.h mixer-oss.c mixer-alsa.c \
--- /dev/null
+/*
+ * This file is part of DisOrder
+ * Copyright (C) 2008 Richard Kettlewell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+
+/** @file lib/macros-builtin.c
+ * @brief Built-in expansions
+ *
+ * This is a grab-bag of non-domain-specific expansions. Note that
+ * documentation will be generated from the comments at the head of
+ * each function.
+ */
+
+#include <config.h>
+#include "types.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <unistd.h>
+
+#include "macros.h"
+#include "sink.h"
+#include "syscalls.h"
+#include "log.h"
+#include "wstat.h"
+#include "kvp.h"
+
+/** @brief Return 1 if @p s is 'true' else 0 */
+int mx_str2bool(const char *s) {
+ return !strcmp(s, "true");
+}
+
+/** @brief Return "true" if @p n is nonzero else "false" */
+const char *mx_bool2str(int n) {
+ return n ? "true" : "false";
+}
+
+/* @include{TEMPLATE}@
+ *
+ * Includes TEMPLATE as if its text were substituted for the @include
+ * expansion. TODO
+ */
+static int exp_include(int attribute((unused)) nargs,
+ char attribute((unused)) **args,
+ struct sink attribute((unused)) *output,
+ void attribute((unused)) *u) {
+ assert(!"TODO implement search path");
+}
+
+/* @include{COMMAND}
+ *
+ * Executes COMMAND via the shell (using "sh -c") and copies its
+ * standard output to the template output. The shell command output
+ * is not expanded or modified in any other way.
+ *
+ * The shell command's standard error is copied to the error log.
+ *
+ * If the shell exits nonzero then this is reported to the error log
+ * but otherwise no special action is taken.
+ */
+static int exp_shell(int attribute((unused)) nargs,
+ char **args,
+ struct sink *output,
+ void attribute((unused)) *u) {
+ int w, p[2], n;
+ char buffer[4096];
+ pid_t pid;
+
+ xpipe(p);
+ if(!(pid = xfork())) {
+ exitfn = _exit;
+ xclose(p[0]);
+ xdup2(p[1], 1);
+ xclose(p[1]);
+ execlp("sh", "sh", "-c", args[0], (char *)0);
+ fatal(errno, "error executing sh");
+ }
+ xclose(p[1]);
+ while((n = read(p[0], buffer, sizeof buffer))) {
+ if(n < 0) {
+ if(errno == EINTR)
+ continue;
+ else
+ fatal(errno, "error reading from pipe");
+ }
+ if(output->write(output, buffer, n) < 0)
+ return -1;
+ }
+ xclose(p[0]);
+ while((n = waitpid(pid, &w, 0)) < 0 && errno == EINTR)
+ ;
+ if(n < 0)
+ fatal(errno, "error calling waitpid");
+ if(w)
+ error(0, "shell command '%s' %s", args[0], wstat(w));
+ return 0;
+}
+
+/* @if{CONDITION}{IF-TRUE}{IF-FALSE}
+ *
+ * If CONDITION is "true" then evaluates to IF-TRUE. Otherwise
+ * evaluates to IF-FALSE. The IF-FALSE part is optional.
+ */
+static int exp_if(int nargs,
+ const struct mx_node **args,
+ struct sink *output,
+ void *u) {
+ char *s;
+ int rc;
+
+ if((rc = mx_expandstr(args[0], &s, u)))
+ return rc;
+ if(mx_str2bool(s))
+ return mx_expand(args[1], output, u);
+ else if(nargs > 2)
+ return mx_expand(args[2], output, u);
+ else
+ return 0;
+}
+
+/* @and{BRANCH}{BRANCH}...
+ *
+ * Expands to "true" if all the branches are "true" otherwise to "false". If
+ * there are no brances then the result is "true". Only as many branches as
+ * necessary to compute the answer are evaluated (starting from the first one),
+ * so if later branches have side effects they may not take place.
+ */
+static int exp_and(int nargs,
+ const struct mx_node **args,
+ struct sink *output,
+ void *u) {
+ int n, result = 1, rc;
+ char *s;
+
+ for(n = 0; n < nargs; ++n) {
+ if((rc = mx_expandstr(args[n], &s, u)))
+ return rc;
+ if(!mx_str2bool(s)) {
+ result = 0;
+ break;
+ }
+ }
+ if(sink_writes(output, mx_bool2str(result)) < 0)
+ return -1;
+ else
+ return 0;
+}
+
+/* @or{BRANCH}{BRANCH}...
+ *
+ * Expands to "true" if any of the branches are "true" otherwise to "false".
+ * If there are no brances then the result is "false". Only as many branches
+ * as necessary to compute the answer are evaluated (starting from the first
+ * one), so if later branches have side effects they may not take place.
+ */
+static int exp_or(int nargs,
+ const struct mx_node **args,
+ struct sink *output,
+ void *u) {
+ int n, result = 0, rc;
+ char *s;
+
+ for(n = 0; n < nargs; ++n) {
+ if((rc = mx_expandstr(args[n], &s, u)))
+ return rc;
+ if(mx_str2bool(s)) {
+ result = 1;
+ break;
+ }
+ }
+ if(sink_writes(output, mx_bool2str(result)) < 0)
+ return -1;
+ else
+ return 0;
+}
+
+/* @not{CONDITION}
+ *
+ * Expands to "true" unless CONDITION is "true" in which case "false".
+ */
+static int exp_not(int attribute((unused)) nargs,
+ char **args,
+ struct sink *output,
+ void attribute((unused)) *u) {
+ if(sink_writes(output, mx_bool2str(!mx_str2bool(args[0]))) < 0)
+ return -1;
+ else
+ return 0;
+}
+
+/* @#{...}
+ *
+ * Expands to nothing. The argument(s) are not fully evaluated, and no side
+ * effects occur.
+ */
+static int exp_comment(int attribute((unused)) nargs,
+ const struct mx_node attribute((unused)) **args,
+ struct sink attribute((unused)) *output,
+ void attribute((unused)) *u) {
+ return 0;
+}
+
+/* @urlquote{STRING}
+ *
+ * URL-quotes a string, i.e. replaces any characters not safe to use unquoted
+ * in a URL with %-encoded form.
+ */
+static int exp_urlquote(int attribute((unused)) nargs,
+ char **args,
+ struct sink *output,
+ void attribute((unused)) *u) {
+ if(sink_writes(output, urlencodestring(args[0])) < 0)
+ return -1;
+ else
+ return 0;
+}
+
+void mx_register_builtin(void) {
+ mx_register("include", 1, 1, exp_include);
+ mx_register("shell", 1, 1, exp_shell);
+ mx_magic_register("if", 2, 3, exp_if);
+ mx_magic_register("and", 0, INT_MAX, exp_and);
+ mx_magic_register("or", 0, INT_MAX, exp_or);
+ mx_register("not", 1, 1, exp_not);
+ mx_magic_register("#", 0, INT_MAX, exp_comment);
+ mx_register("urlquote", 1, 1, exp_urlquote);
+ /* TODO: eq */
+ /* TODO: ne */
+ /* TODO: define */
+ /* TODO: discard */
+}
+
+/*
+Local Variables:
+c-basic-offset:2
+comment-column:40
+fill-column:79
+indent-tabs-mode:nil
+End:
+*/
#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
#ifndef MACROS_H
#define MACROS_H
+struct sink;
+
/** @brief One node in a macro expansion parse tree */
struct mx_node {
/** @brief Next element or NULL at end of list */
int line,
const char *input,
const char *end);
-
char *mx_dump(const struct mx_node *m);
+
+/** @brief Callback for simple expansions
+ * @param nargs Number of arguments
+ * @param args Pointer to array of arguments
+ * @param output Where to send output
+ * @param u User data
+ * @return 0 on success, non-zero on error
+ */
+typedef int mx_simple_callback(int nargs,
+ char **args,
+ struct sink *output,
+ void *u);
+
+/** @brief Callback for magic expansions
+ * @param nargs Number of arguments
+ * @param args Pointer to array of arguments
+ * @param output Where to send output
+ * @param u User data
+ * @return 0 on success, non-zero on error
+ */
+typedef int mx_magic_callback(int nargs,
+ const struct mx_node **args,
+ struct sink *output,
+ void *u);
+
+void mx_register(const char *name,
+ int min,
+ int max,
+ mx_simple_callback *callback);
+void mx_magic_register(const char *name,
+ int min,
+ int max,
+ mx_magic_callback *callback);
+
+void mx_register_builtin(void);
+
+int mx_expand_file(const char *path,
+ struct sink *output,
+ void *u);
+int mx_expand(const struct mx_node *m,
+ struct sink *output,
+ void *u);
+int mx_expandstr(const struct mx_node *m,
+ char **sp,
+ void *u);
+
+int mx_str2bool(const char *s);
+const char *mx_bool2str(int n);
+
#endif /* MACROS_H */
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