X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/f640bcb3ba82576ec131c564f2b347e2f3accdd3..985bb670b4e07d35cb1580780253ded2524a342e:/lib/macros-builtin.c

diff --git a/lib/macros-builtin.c b/lib/macros-builtin.c
index 63aa930..3d49c25 100644
--- a/lib/macros-builtin.c
+++ b/lib/macros-builtin.c
@@ -2,45 +2,56 @@
  * This file is part of DisOrder
  * Copyright (C) 2008 Richard Kettlewell
  *
- * This program is free software; you can redistribute it and/or modify
+ * 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
+ * the Free Software Foundation, either version 3 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.
- *
+ * 
+ * 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
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 /** @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.
+ * This is a grab-bag of non-domain-specific expansions
+ *
+ * Documentation is generated from the comments at the head of each function.
+ * The comment should have a '$' and the expansion name on the first line and
+ * should have a blank line between each paragraph.
+ *
+ * To make a bulleted list, put a '-' at the start of each line.
+ *
+ * You can currently get away with troff markup but this is horribly ugly and
+ * might be changed.
  */
 
-#include <config.h>
-#include "types.h"
+#include "common.h"
 
-#include <stdio.h>
-#include <string.h>
 #include <errno.h>
-#include <assert.h>
 #include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
 
+#include "hash.h"
+#include "mem.h"
 #include "macros.h"
 #include "sink.h"
 #include "syscalls.h"
 #include "log.h"
 #include "wstat.h"
 #include "kvp.h"
+#include "split.h"
+#include "printf.h"
+#include "vector.h"
+#include "filepart.h"
+
+static struct vector include_path;
 
 /** @brief Return 1 if @p s is 'true' else 0 */
 int mx_str2bool(const char *s) {
@@ -52,19 +63,98 @@ const char *mx_bool2str(int n) {
   return n ? "true" : "false";
 }
 
-/* @include{TEMPLATE}@
+/** @brief Write a boolean result */
+int mx_bool_result(struct sink *output, int result) {
+  if(sink_writes(output, mx_bool2str(result)) < 0)
+    return -1;
+  else
+    return 0;
+}
+
+/** @brief Search the include path */
+char *mx_find(const char *name, int report) {
+  char *path;
+  int n;
+  
+  if(name[0] == '/') {
+    if(access(name, O_RDONLY) < 0) {
+      if(report)
+        error(errno, "cannot read %s", name);
+      return 0;
+    }
+    path = xstrdup(name);
+  } else {
+    /* Search the include path */
+    for(n = 0; n < include_path.nvec; ++n) {
+      byte_xasprintf(&path, "%s/%s", include_path.vec[n], name);
+      if(access(path, O_RDONLY) == 0)
+        break;
+    }
+    if(n >= include_path.nvec) {
+      if(report)
+        error(0, "cannot find '%s' in search path", name);
+      return 0;
+    }
+  }
+  return path;
+}
+
+/*$ @include{TEMPLATE}
+ *
+ * Includes TEMPLATE.
  *
- * Includes TEMPLATE as if its text were substituted for the @include
- * expansion.   TODO
+ * TEMPLATE can be an absolute filename starting with a '/'; only the file with
+ * exactly this name will be included.
+ *
+ * Alternatively it can be a relative filename, not starting with a '/'.  In
+ * this case the file will be searched for in the include path.  When searching
+ * paths, unreadable files are treated as if they do not exist (rather than
+ * matching then producing an error).
+ *
+ * If the name chosen ends ".tmpl" then the file will be expanded as a
+ * template.  Anything else is included byte-for-byte without further
+ * modification.
+ *
+ * Only regular files are allowed (no devices, sockets or name pipes).
  */
 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");
+		       char **args,
+		       struct sink *output,
+		       void *u) {
+  const char *path;
+  int fd, n;
+  char buffer[4096];
+  struct stat sb;
+
+  if(!(path = mx_find(args[0], 1/*report*/))) {
+    if(sink_printf(output, "[[cannot find '%s']]", args[0]) < 0)
+      return 0;
+    return 0;
+  }
+  /* If it's a template expand it */
+  if(strlen(path) >= 5 && !strncmp(path + strlen(path) - 5, ".tmpl", 5))
+    return mx_expand_file(path, output, u);
+  /* Read the raw file.  As with mx_expand_file() we insist that the file is a
+   * regular file. */
+  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);
+  while((n = read(fd, buffer, sizeof buffer)) > 0) {
+    if(sink_write(output, buffer, n) < 0) {
+      xclose(fd);
+      return -1;
+    }
+  }
+  if(n < 0)
+    fatal(errno, "error reading %s", path);
+  xclose(fd);
+  return 0;
 }
 
-/* @include{COMMAND}
+/*$ @include{COMMAND}
  *
  * Executes COMMAND via the shell (using "sh -c") and copies its
  * standard output to the template output.  The shell command output
@@ -113,7 +203,7 @@ static int exp_shell(int attribute((unused)) nargs,
   return 0;
 }
 
-/* @if{CONDITION}{IF-TRUE}{IF-FALSE}
+/*$ @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.
@@ -125,7 +215,7 @@ static int exp_if(int nargs,
   char *s;
   int rc;
 
-  if((rc = mx_expandstr(args[0], &s, u)))
+  if((rc = mx_expandstr(args[0], &s, u, "argument #0 (CONDITION)")))
     return rc;
   if(mx_str2bool(s))
     return mx_expand(args[1], output, u);
@@ -135,7 +225,7 @@ static int exp_if(int nargs,
     return 0;
 }
 
-/* @and{BRANCH}{BRANCH}...
+/*$ @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
@@ -147,23 +237,21 @@ static int exp_and(int nargs,
 		   struct sink *output,
 		   void *u) {
   int n, result = 1, rc;
-  char *s;
+  char *s, *argname;
 
   for(n = 0; n < nargs; ++n) {
-    if((rc = mx_expandstr(args[n], &s, u)))
+    byte_xasprintf(&argname, "argument #%d", n);
+    if((rc = mx_expandstr(args[n], &s, u, argname)))
       return rc;
     if(!mx_str2bool(s)) {
       result = 0;
       break;
     }
   }
-  if(sink_writes(output, mx_bool2str(result)) < 0)
-    return -1;
-  else
-    return 0;
+  return mx_bool_result(output, result);
 }
 
-/* @or{BRANCH}{BRANCH}...
+/*$ @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
@@ -175,23 +263,21 @@ static int exp_or(int nargs,
 		  struct sink *output,
 		  void *u) {
   int n, result = 0, rc;
-  char *s;
+  char *s, *argname;
 
   for(n = 0; n < nargs; ++n) {
-    if((rc = mx_expandstr(args[n], &s, u)))
+    byte_xasprintf(&argname, "argument #%d", n);
+    if((rc = mx_expandstr(args[n], &s, u, argname)))
       return rc;
     if(mx_str2bool(s)) {
       result = 1;
       break;
     }
   }
-  if(sink_writes(output, mx_bool2str(result)) < 0)
-    return -1;
-  else
-    return 0;
+  return mx_bool_result(output, result);
 }
 
-/* @not{CONDITION}
+/*$ @not{CONDITION}
  *
  * Expands to "true" unless CONDITION is "true" in which case "false".
  */
@@ -199,13 +285,10 @@ 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;
+  return mx_bool_result(output, !mx_str2bool(args[0]));
 }
 
-/* @#{...}
+/*$ @#{...}
  *
  * Expands to nothing.  The argument(s) are not fully evaluated, and no side
  * effects occur.
@@ -217,7 +300,7 @@ static int exp_comment(int attribute((unused)) nargs,
   return 0;
 }
 
-/* @urlquote{STRING}
+/*$ @urlquote{STRING}
  *
  * URL-quotes a string, i.e. replaces any characters not safe to use unquoted
  * in a URL with %-encoded form.
@@ -232,19 +315,147 @@ static int exp_urlquote(int attribute((unused)) nargs,
     return 0;
 }
 
+/*$ @eq{S1}{S2}...
+ *
+ * Expands to "true" if all the arguments are identical, otherwise to "false"
+ * (i.e. if any pair of arguments differs).
+ *
+ * If there are no arguments then expands to "true".  Evaluates all arguments
+ * (with their side effects) even if that's not strictly necessary to discover
+ * the result.
+ */
+static int exp_eq(int nargs,
+		  char **args,
+		  struct sink *output,
+		  void attribute((unused)) *u) {
+  int n, result = 1;
+  
+  for(n = 1; n < nargs; ++n) {
+    if(strcmp(args[n], args[0])) {
+      result = 0;
+      break;
+    }
+  }
+  return mx_bool_result(output, result);
+}
+
+/*$ @ne{S1}{S2}...
+ *
+ * Expands to "true" if all of the arguments differ from one another, otherwise
+ * to "false" (i.e. if any value appears more than once).
+ *
+ * If there are no arguments then expands to "true".  Evaluates all arguments
+ * (with their side effects) even if that's not strictly necessary to discover
+ * the result.
+ */
+static int exp_ne(int nargs,
+		  char **args,
+		  struct sink *output,
+		  void  attribute((unused))*u) {
+  hash *h = hash_new(sizeof (char *));
+  int n, result = 1;
+
+  for(n = 0; n < nargs; ++n)
+    if(hash_add(h, args[n], "", HASH_INSERT)) {
+      result = 0;
+      break;
+    }
+  return mx_bool_result(output, result);
+}
+
+/*$ @discard{...}
+ *
+ * Expands to nothing.  Unlike the comment expansion @#{...}, side effects of
+ * arguments are not suppressed.  So this can be used to surround a collection
+ * of macro definitions with whitespace, free text commentary, etc.
+ */
+static int exp_discard(int attribute((unused)) nargs,
+                       char attribute((unused)) **args,
+                       struct sink attribute((unused)) *output,
+                       void attribute((unused)) *u) {
+  return 0;
+}
+
+/*$ @define{NAME}{ARG1 ARG2...}{DEFINITION}
+ *
+ * Define a macro.  The macro will be called NAME and will act like an
+ * expansion.  When it is expanded, the expansion is replaced by DEFINITION,
+ * with each occurence of @ARG1@ etc replaced by the parameters to the
+ * expansion.
+ */
+static int exp_define(int attribute((unused)) nargs,
+                      const struct mx_node **args,
+                      struct sink attribute((unused)) *output,
+                      void attribute((unused)) *u) {
+  char **as, *name, *argnames;
+  int rc, nas;
+  
+  if((rc = mx_expandstr(args[0], &name, u, "argument #0 (NAME)")))
+    return rc;
+  if((rc = mx_expandstr(args[1], &argnames, u, "argument #1 (ARGS)")))
+    return rc;
+  as = split(argnames, &nas, 0, 0, 0);
+  mx_register_macro(name, nas, as, args[2]);
+  return 0;
+}
+
+/*$ @basename{PATH}
+ *
+ * Expands to the UNQUOTED basename of PATH.
+ */
+static int exp_basename(int attribute((unused)) nargs,
+                        char **args,
+                        struct sink attribute((unused)) *output,
+                        void attribute((unused)) *u) {
+  return sink_writes(output, d_basename(args[0])) < 0 ? -1 : 0;
+}
+
+/*$ @dirname{PATH}
+ *
+ * Expands to the UNQUOTED directory name of PATH.
+ */
+static int exp_dirname(int attribute((unused)) nargs,
+                       char **args,
+                       struct sink attribute((unused)) *output,
+                       void attribute((unused)) *u) {
+  return sink_writes(output, d_dirname(args[0])) < 0 ? -1 : 0;
+}
+
+/*$ @q{STRING}
+ *
+ * Expands to STRING.
+ */
+static int exp_q(int attribute((unused)) nargs,
+                 char **args,
+                 struct sink attribute((unused)) *output,
+                 void attribute((unused)) *u) {
+  return sink_writes(output, args[0]) < 0 ? -1 : 0;
+}
+
+/** @brief Register built-in expansions */
 void mx_register_builtin(void) {
+  mx_register("basename", 1, 1, exp_basename);
+  mx_register("dirname", 1, 1, exp_dirname);
+  mx_register("discard", 0, INT_MAX, exp_discard);
+  mx_register("eq", 0, INT_MAX, exp_eq);
   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("ne", 0, INT_MAX, exp_ne);
   mx_register("not", 1, 1, exp_not);
-  mx_magic_register("#", 0, INT_MAX, exp_comment);
+  mx_register("shell", 1, 1, exp_shell);
   mx_register("urlquote", 1, 1, exp_urlquote);
-  /* TODO: eq */
-  /* TODO: ne */
-  /* TODO: define */
-  /* TODO: discard */
+  mx_register("q", 1, 1, exp_q);
+  mx_register_magic("#", 0, INT_MAX, exp_comment);
+  mx_register_magic("and", 0, INT_MAX, exp_and);
+  mx_register_magic("define", 3, 3, exp_define);
+  mx_register_magic("if", 2, 3, exp_if);
+  mx_register_magic("or", 0, INT_MAX, exp_or);
+}
+
+/** @brief Add a directory to the search path
+ * @param s Directory to add
+ */
+void mx_search_path(const char *s) {
+  vector_append(&include_path, xstrdup(s));
 }
 
 /*