(read_c_string_or_comment): Add SAW_USAGE parameter, and implement

scanning for a `usage:' keyword.
(scan_c_file): Pass SAW_USAGE argument to read_c_string_or_comment.
Don't output a usage-string if there was one in the doc string.

1 files changed, 68 insertions, 9 deletions

diff --git a/lib-src/make-docfile.c b/lib-src/make-docfile.c
index 8a74de40301..ed786b0951e 100644
--- a/lib-src/make-docfile.c
+++ b/lib-src/make-docfile.c
@@ -238,16 +238,26 @@ put_char (ch, printflag, bufp, pending_newlines, pending_spaces)
    character that follows.  COMMENT non-zero means skip a comment.  If
    PRINTFLAG is positive, output string contents to outfile.  If it is
    negative, store contents in buf.  Convert escape sequences \n and
-   \t to newline and tab; discard \ followed by newline.  */
+   \t to newline and tab; discard \ followed by newline.
+   If SAW_USAGE is non-zero, then any occurances of the string `usage:'
+   at the beginning of a line will be removed, and *SAW_USAGE set to
+   true if any were encountered.  */
 
 int
-read_c_string_or_comment (infile, printflag, comment)
+read_c_string_or_comment (infile, printflag, comment, saw_usage)
      FILE *infile;
      int printflag;
+     int *saw_usage;
 {
   register int c;
   unsigned pending_spaces = 0, pending_newlines = 0;
   char *p = buf;
+  /* When this keyword occurs at the beginning of a line, we remove it,
+     and set *SAW_USAGE to true.  */
+  static char usage_keyword[] = "usage:";
+  /* The current point we've reached in an occurance of USAGE_KEYWORD in
+     the input stream.  */
+  char *cur_usage_ptr = usage_keyword;
 
   if (comment)
     {
@@ -258,6 +268,9 @@ read_c_string_or_comment (infile, printflag, comment)
   else
     c = getc (infile);
   
+  if (saw_usage)
+    *saw_usage = 0;
+
   while (c != EOF)
     {
       while (c != EOF && (comment ? c != '*' : c != '"'))
@@ -284,7 +297,52 @@ read_c_string_or_comment (infile, printflag, comment)
               pending_spaces = 0;
             }
           else
-            put_char (c, printflag, &p, &pending_newlines, &pending_spaces);
+            {
+              if (saw_usage
+                  && *cur_usage_ptr == c
+                  && (cur_usage_ptr > usage_keyword || pending_newlines > 0))
+                /* We might be looking at USAGE_KEYWORD at some point.
+                   Keep looking until we know for sure.  */
+                {
+                  if (*++cur_usage_ptr == '\0')
+                    /* Saw the whole keyword.  Set *SAW_USAGE to true.  */
+                    {
+                      *saw_usage = 1;
+
+                      /* Reset the scanning pointer.  */
+                      cur_usage_ptr = usage_keyword;
+
+                      /* Canonicalize whitespace preceding a usage string. */
+                      pending_newlines = 2;
+                      pending_spaces = 0;
+
+                      /* Skip any whitespace between the keyword and the
+                         usage string.  */
+                      do
+                        c = getc (infile);
+                      while (c == ' ' || c == '\n');
+
+                      continue; /* This just skips the getc at end-of-loop. */
+                    }
+                }
+              else
+                {
+                  if (cur_usage_ptr > usage_keyword)
+                    /* We scanned the beginning of a potential usage
+                       keyword, but it was a false alarm.  Output the
+                       part we scanned.  */
+                    {
+                      char *p;
+                      for (p = usage_keyword; p < cur_usage_ptr; p++)
+                        put_char (*p, printflag, &p,
+                                  &pending_newlines, &pending_spaces);
+                      cur_usage_ptr = usage_keyword;
+                    }
+
+                  put_char (c, printflag, &p,
+                            &pending_newlines, &pending_spaces);
+                }
+            }
 
           c = getc (infile);
         }
@@ -507,7 +565,7 @@ scan_c_file (filename, mode)
       c = getc (infile);
       if (c != '"')
         continue;
-      c = read_c_string_or_comment (infile, -1, 0);
+      c = read_c_string_or_comment (infile, -1, 0, 0);
 
       /* DEFVAR_LISP ("name", addr, "doc")
          DEFVAR_LISP ("name", addr /\* doc *\/)
@@ -555,7 +613,7 @@ scan_c_file (filename, mode)
         c = getc (infile);
       
       if (c == '"')
-        c = read_c_string_or_comment (infile, 0, 0);
+        c = read_c_string_or_comment (infile, 0, 0, 0);
       
       while (c != EOF && c != ',' && c != '/')
         c = getc (infile);
@@ -582,6 +640,7 @@ scan_c_file (filename, mode)
                   c == '*')))
         {
           int comment = c != '"';
+          int saw_usage;
           
           putc (037, outfile);
           putc (defvarflag ? 'V' : 'F', outfile);
@@ -589,7 +648,7 @@ scan_c_file (filename, mode)
 
           if (comment)
             getc (infile);      /* Skip past `*' */
-          c = read_c_string_or_comment (infile, 1, comment);
+          c = read_c_string_or_comment (infile, 1, comment, &saw_usage);
 
           /* If this is a defun, find the arguments and print them.  If
              this function takes MANY or UNEVALLED args, then the C source
@@ -601,7 +660,7 @@ scan_c_file (filename, mode)
               1: DEFUN (..., /\* DOC *\/ (args))      [comment && !doc_keyword]
               2: DEFUN (..., doc: /\* DOC *\/) (args) [comment && doc_keyword]
           */
-          if (defunflag && maxargs != -1)
+          if (defunflag && maxargs != -1 && !saw_usage)
             {
               char argbuf[1024], *p = argbuf;
 
@@ -1021,7 +1080,7 @@ scan_lisp_file (filename, mode)
                        buffer, filename);
               continue;
             }
-          read_c_string_or_comment (infile, 0, 0);
+          read_c_string_or_comment (infile, 0, 0, 0);
           skip_white (infile);
 
           if (saved_string == 0)
@@ -1074,7 +1133,7 @@ scan_lisp_file (filename, mode)
           saved_string = 0;
         }
       else
-        read_c_string_or_comment (infile, 1, 0);
+        read_c_string_or_comment (infile, 1, 0, 0);
     }
   fclose (infile);
   return 0;