xemacs-beta: lib-src/make-msgfile.c comparison

comparison lib-src/make-msgfile.c @ 70:131b0175ea99 r20-0b30

Import from CVS: tag r20-0b30

author	cvs
date	Mon, 13 Aug 2007 09:02:59 +0200
parents
children	8626e4521993

comparison

equal deleted inserted replaced

-:804d1389bcd6
+:131b0175ea99
+/*
+PROPOSAL FOR HOW THIS ALL OUGHT TO WORK
+this isn't implemented yet, but this is the plan-in-progress
+In general, it's accepted that the best way to internationalize is for all
+messages to be referred to by a symbolic name (or number) and come out of a
+table or tables, which are easy to change.
+However, with Emacs, we've got the task of internationalizing a huge body
+of existing code, which already contains messages internally.
+For the C code we've got two options:
+- Use a Sun-like gettext() form, which takes an "english" string which
+appears literally in the source, and uses that as a hash key to find
+a translated string;
+- Rip all of the strings out and put them in a table.
+In this case, it's desirable to make as few changes as possible to the C
+code, to make it easier to merge the code with the FSF version of emacs
+which won't ever have these changes made to it.  So we should go with the
+former option.
+The way it has been done (between 19.8 and 19.9) was to use gettext(), but
+*also* to make massive changes to the source code.  The goal now is to use
+gettext() at run-time and yet not require a textual change to every line
+in the C code which contains a string constant.  A possible way to do this
+is described below.
+(gettext() can be implemented in terms of catgets() for non-Sun systems, so
+that in itself isn't a problem.)
+For the Lisp code, we've got basically the same options: put everything in
+a table, or translate things implicitly.
+Another kink that lisp code introduces is that there are thousands of third-
+party packages, so changing the source for all of those is simply not an
+option.
+Is it a goal that if some third party package displays a message which is
+one we know how to translate, then we translate it?  I think this is a
+worthy goal.  It remains to be seen how well it will work in practice.
+So, we should endeavor to minimize the impact on the lisp code.  Certain
+primitive lisp routines (the stuff in lisp/prim/, and especially in
+cmdloop.el and minibuf.el) may need to be changed to know about translation,
+but that's an ideologically clean thing to do because those are considered
+a part of the emacs substrate.
+However, if we find ourselves wanting to make changes to, say, RMAIL, then
+something has gone wrong.  (Except to do things like remove assumptions
+about the order of words within a sentence, or how pluralization works.)
+There are two parts to the task of displaying translated strings to the
+user: the first is to extract the strings which need to be translated from
+the sources; and the second is to make some call which will translate those
+strings before they are presented to the user.
+The old way was to use the same form to do both, that is, GETTEXT() was both
+the tag that we searched for to build a catalog, and was the form which did
+the translation.  The new plan is to separate these two things more: the
+tags that we search for to build the catalog will be stuff that was in there
+already, and the translation will get done in some more centralized, lower
+level place.
+This program (make-msgfile.c) addresses the first part, extracting the
+strings.
+For the emacs C code, we need to recognise the following patterns:
+message ("string" ... )
+error ("string")
+report_file_error ("string" ... )
+signal_simple_error ("string" ... )
+signal_simple_error_2 ("string" ... )
+build_translated_string ("string")
+#### add this and use it instead of build_string() in some places.
+yes_or_no_p ("string" ... )
+#### add this instead of funcalling Qyes_or_no_p directly.
+barf_or_query_if_file_exists	#### restructure this
+check all callers of Fsignal	#### restructure these
+signal_error (Qerror ... )		#### change all of these to error()
+And we also parse out the `interactive' prompts from DEFUN() forms.
+#### When we've got a string which is a candidate for translation, we
+should ignore it if it contains only format directives, that is, if
+there are no alphabetic characters in it that are not a part of a `%'
+directive.  (Careful not to translate either "%s%s" or "%s: ".)
+For the emacs Lisp code, we need to recognise the following patterns:
+(message "string" ... )
+(error "string" ... )
+(format "string" ... )
+(read-from-minibuffer "string" ... )
+(read-shell-command "string" ... )
+(y-or-n-p "string" ... )
+(yes-or-no-p "string" ... )
+(read-file-name "string" ... )
+(temp-minibuffer-message "string")
+(query-replace-read-args "string" ... )
+I expect there will be a lot like the above; basically, any function which
+is a commonly used wrapper around an eventual call to `message' or
+`read-from-minibuffer' needs to be recognised by this program.
+(dgettext "domain-name" "string")		#### do we still need this?
+things that should probably be restructured:
+`princ' in cmdloop.el
+`insert' in debug.el
+face-interactive
+help.el, syntax.el all messed up
+Menu descriptors: one way to extract the strings in menu labels would be
+to teach this program about "^(defvar .*menu\n" forms; that's probably
+kind of hard, though, so perhaps a better approach would be to make this
+program recognise lines of the form
+"string" ... ;###translate
+where the magic token ";###translate" on a line means that the string
+constant on this line should go into the message catalog.  This is analagous
+to the magic ";###autoload" comments, and to the magic comments used in the
+EPSF structuring conventions.
+-----
+So this program manages to build up a catalog of strings to be translated.
+To address the second part of the problem, of actually looking up the
+translations, there are hooks in a small number of low level places in
+emacs.
+Assume the existence of a C function gettext(str) which returns the
+translation of `str' if there is one, otherwise returns `str'.
+- message() takes a char* as its argument, and always filters it through
+gettext() before displaying it.
+- errors are printed by running the lisp function `display-error' which
+doesn't call `message' directly (it princ's to streams), so it must be
+carefully coded to translate its arguments.  This is only a few lines
+of code.
+- Fread_minibuffer_internal() is the lowest level interface to all minibuf
+interactions, so it is responsible for translating the value that will go
+into Vminibuf_prompt.
+- Fpopup_menu filters the menu titles through gettext().
+The above take care of 99% of all messages the user ever sees.
+- The lisp function temp-minibuffer-message translates its arg.
+- query-replace-read-args is funny; it does
+(setq from (read-from-minibuffer (format "%s: " string) ... ))
+(setq to (read-from-minibuffer (format "%s %s with: " string from) ... ))
+What should we do about this?  We could hack query-replace-read-args to
+translate its args, but might this be a more general problem?  I don't
+think we ought to translate all calls to format.  We could just change
+the calling sequence, since this is odd in that the first %s wants to be
+translated but the second doesn't.
+Solving the "translating too much" problem:
+The concern has been raised that in this situation:
+- "Help" is a string for which we know a translation;
+- someone visits a file called Help, and someone does something
+contrived like (error buffer-file-name)
+then we would display the translation of Help, which would not be correct.
+We can solve this by adding a bit to Lisp_String objects which identifies
+them as having been read as literal constants from a .el or .elc file (as
+opposed to having been constructed at run time as it would in the above
+case.)  To solve this:
+- Fmessage() takes a lisp string as its first argument.
+If that string is a constant, that is, was read from a source file
+as a literal, then it calls message() with it, which translates.
+Otherwise, it calls message_no_translate(), which does not translate.
+- Ferror() (actually, Fsignal() when condition is Qerror) works similarly.
+*/
+/* Scan specified C and Lisp files, extracting the following messages:
+C files:
+	GETTEXT (...)
+	DEFER_GETTEXT (...)
+	DEFUN interactive prompts
+Lisp files:
+	(gettext ...)
+	(dgettext "domain-name" ...)
+	(defer-gettext ...)
+	(interactive ...)
+The arguments given to this program are all the C and Lisp source files
+of GNU Emacs.  .el and .c files are allowed.  There is no support for .elc
+files at this time, but they may be specified; the corresponding .el file
+will be used.  Similarly, .o files can also be specified, and the corresponding
+.c file will be used.  This helps the makefile pass the correct list of files.
+The results, which go to standard output or to a file specified with -a or -o
+(-a to append, -o to start from nothing), are quoted strings wrapped in
+gettext(...).  The results can be passed to xgettext to produce a .po message
+file.
+*/
+#include <stdio.h>
+#include <string.h>
+#define LINESIZE 256
+#define GET_LINE	fgets (line, LINESIZE, infile)
+#define CHECK_EOL(p)	if (*(p) == '\0')  (p) = GET_LINE
+#define SKIP_BLANKS(p)	while ((*p) == ' ' || (*p) == '\t')  (p)++
+enum filetype { C_FILE, LISP_FILE, INVALID_FILE };
+/* some brain-dead headers define this ... */
+#undef FALSE
+#undef TRUE
+enum boolean { FALSE, TRUE };
+FILE *infile;
+FILE *outfile;
+char line[LINESIZE];
+void scan_file (char *filename);
+void process_C_file (void);
+void process_Lisp_file (void);
+char *copy_up_to_paren (register char *p);
+char *copy_quoted_string (register char *p);
+enum boolean no_interactive_prompt (register char *q);
+char *skip_blanks (register char *p);
+main (int argc, char *argv[])
+{
+register int i;
+outfile = stdout;
+/* If first two args are -o FILE, output to FILE. */
+i = 1;
+if (argc > i + 1 && strcmp (argv[i], "-o") == 0) {
+outfile = fopen (argv[++i], "w");
+++i;
+}
+/* ...Or if args are -a FILE, append to FILE. */
+if (argc > i + 1 && strcmp (argv[i], "-a") == 0) {
+outfile = fopen (argv[++i], "a");
+++i;
+}
+if (!outfile) {
+fprintf (stderr, "Unable to open output file %s\n", argv[--i]);
+return;
+}
+for (; i < argc; i++)
+scan_file (argv[i]);
+return 0;
+}
+void scan_file (char *filename)
+{
+enum filetype type = INVALID_FILE;
+register char *p = filename + strlen (filename);
+if (strcmp (p - 4, ".elc") == 0) {
+*--p = '\0';				/* Use .el file instead */
+type = LISP_FILE;
+} else if (strcmp (p - 3, ".el") == 0)
+type = LISP_FILE;
+else if (strcmp (p - 2, ".o") == 0) {
+*--p = 'c';					/* Use .c file instead */
+type = C_FILE;
+} else if (strcmp (p - 2, ".c") == 0)
+type = C_FILE;
+if (type == INVALID_FILE) {
+fprintf (stderr, "File %s being ignored\n", filename);
+return;
+}
+infile = fopen (filename, "r");
+if (!infile) {
+fprintf (stderr, "Unable to open input file %s\n", filename);
+return;
+}
+fprintf (outfile, "/* %s */\n", filename);
+if (type == C_FILE)
+process_C_file ();
+else
+process_Lisp_file ();
+fputc ('\n', outfile);
+fclose (infile);
+}
+void process_C_file (void)
+{
+register char *p;
+char *gettext, *defun;
+while (p = GET_LINE) {
+gettext = strstr (p, "GETTEXT");
+defun = strstr (p, "DEFUN");
+if (gettext || defun) {
+if (gettext) {
+	p = gettext;
+	p += 7;			/* Skip over "GETTEXT" */
+}
+else if (defun) {
+	p = defun;
+	p += 5;			/* Skip over "DEFUN" */
+}
+p = skip_blanks (p);
+if (*p++ != '(')
+	continue;
+if (defun) {
+	register int i;
+	for (i = 0; i < 5; i++)	/* Skip over commas to doc string */
+	  while (*p++ != ',')
+	    CHECK_EOL (p);
+	if (*p == '\n')
+	  p = GET_LINE;
+}
+p = skip_blanks (p);
+if (*p != '\"')		/* Make sure there is a quoted string */
+	continue;
+if (defun && no_interactive_prompt (p))
+	continue;
+fprintf (outfile, "gettext(");
+if (gettext)
+	p = copy_up_to_paren (p);
+else
+	p = copy_quoted_string (p);
+fprintf (outfile, ")\n");
+}
+}
+}
+void process_Lisp_file (void)
+{
+register char *p;
+char *gettext, *interactive;
+enum boolean dgettext = FALSE;
+while (p = GET_LINE) {
+gettext = strstr (p, "gettext");
+interactive = strstr (p, "(interactive");
+if (gettext || interactive) {
+if (!interactive)
+	p = gettext;
+else if (!gettext)
+	p = interactive;
+else if (gettext < interactive) {
+	p = gettext;
+	interactive = NULL;
+} else {
+	p = interactive;
+	gettext = NULL;
+}
+if (gettext) {
+	if (p > line && *(p-1) == 'd')
+	  dgettext = TRUE;
+	p += 7;		/* Skip over "gettext" */
+} else
+	p += 12;	/* Skip over "(interactive" */
+p = skip_blanks (p);
+if (*p != '\"')		/* Make sure there is a quoted string */
+	continue;
+if (dgettext) {		/* Skip first quoted string (domain name) */
+	while (*++p != '"')
+	  ;  /* null statement */
+	++p;
+	p = skip_blanks (p);
+	if (*p != '\"')		/* Check for second quoted string (message) */
+	  continue;
+}
+if (interactive && no_interactive_prompt (p))
+	continue;
+fprintf (outfile, "gettext(");
+p = copy_up_to_paren (p);
+fprintf (outfile, ")\n");
+}
+}
+}
+/* Assuming p points to some character beyond an opening parenthesis, copy
+everything to outfile up to but not including the closing parenthesis.
+*/
+char *copy_up_to_paren (register char *p)
+{
+for (;;) {
+SKIP_BLANKS (p);	/* We don't call skip_blanks() in order to */
+CHECK_EOL (p);	/* preserve blanks at the beginning of the line */
+if (*p == ')')
+break;
+if (*p == '\"')
+p = copy_quoted_string (p);
+else
+fputc (*p++, outfile);
+}
+return p;
+}
+/* Assuming p points to a quote character, copy the quoted string to outfile.
+*/
+char *copy_quoted_string (register char *p)
+{
+do {
+if (*p == '\\')
+fputc (*p++, outfile);
+fputc (*p++, outfile);
+CHECK_EOL (p);
+} while (*p != '\"');
+fputc (*p++, outfile);
+return p;
+}
+/* Return TRUE if the interactive specification consists only
+of code letters and no prompt.
+*/
+enum boolean no_interactive_prompt (register char *q)
+{
+while (++q, *q == '*' || *q == '@')
+; /* null statement */
+if (*q == '\"')
+return TRUE;
+skip_code_letter:
+if (*++q == '\"')
+return TRUE;
+if (*q == '\\' && *++q == 'n') {
+++q;
+goto skip_code_letter;
+}
+return FALSE;
+}
+char *skip_blanks (register char *p)
+{
+while (*p == ' ' || *p == '\t' || *p == '\n') {
+p++;
+CHECK_EOL (p);
+}
+return p;
+}

Mercurial > hg > xemacs-beta

comparison lib-src/make-msgfile.c @ 70:131b0175ea99 r20-0b30