cppfiles.c (safe_read): Deleted.

1999-01-26 12:11 -0500  Zack Weinberg  <zack@midnite.ec.rhno.columbia.edu>
	* cppfiles.c (safe_read): Deleted.
	(read_and_prescan): New function, replaces safe_read, converts
	and/or warns about trigraphs, silently converts odd line
	terminators (\r, \n\r, \r\n).  Warns about no newline at EOF.
	(finclude): Use read_and_prescan; turn off nonblocking mode on
	the input descriptor; remove file-size-examination and
	no-newline-at-EOF gunk which is	longer necessary; be more
	careful about checking that we've been handed a legitimate
	file to read (only real files, pipes, and ttys are acceptable).
	* cpplib.h (cpp_options): Rename no_trigraphs flag to
	`trigraphs' and invert its sense.
	(trigraph_table): Declare.
	(cpp_warning_with_line): Prototype.
	* cpplib.c: Remove all references to trigraph_pcp. Define
	trigraph_table; initialize it in initialize_char_syntax.  Open
	files in nonblocking mode.  s/no_trigraphs/trigraphs/
	throughout, and invert sense.  Put cpp_warning_with_line back
	in and export it.

From-SVN: r24870

4 files changed, 293 insertions, 133 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 07102f9..7ab3030 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,24 @@
+1999-01-26 12:11 -0500  Zack Weinberg  <zack@midnite.ec.rhno.columbia.edu>
+
+	* cppfiles.c (safe_read): Deleted.  
+	(read_and_prescan): New function, replaces safe_read, converts
+	and/or warns about trigraphs, silently converts odd line
+	terminators (\r, \n\r, \r\n).  Warns about no newline at EOF.
+	(finclude): Use read_and_prescan; turn off nonblocking mode on
+	the input descriptor; remove file-size-examination and
+	no-newline-at-EOF gunk which is	longer necessary; be more
+	careful about checking that we've been handed a legitimate
+	file to read (only real files, pipes, and ttys are acceptable).
+	* cpplib.h (cpp_options): Rename no_trigraphs flag to 
+	`trigraphs' and invert its sense.
+	(trigraph_table): Declare.
+	(cpp_warning_with_line): Prototype.
+	* cpplib.c: Remove all references to trigraph_pcp. Define
+	trigraph_table; initialize it in initialize_char_syntax.  Open
+	files in nonblocking mode.  s/no_trigraphs/trigraphs/
+	throughout, and invert sense.  Put cpp_warning_with_line back
+	in and export it.
+
 Tue Jan 26 23:21:49 1999  Michael Hayes  <m.hayes@elec.canterbury.ac.nz>
 
 	* config/c4x/c4x.h (COUNTER_REGS): New register class.
diff --git a/gcc/cppfiles.c b/gcc/cppfiles.c
index b020cc1..20e939c 100644
--- a/gcc/cppfiles.c
+++ b/gcc/cppfiles.c
@@ -41,7 +41,8 @@ static struct file_name_map *read_name_map	PROTO ((cpp_reader *,
 static char *read_filename_string	PROTO ((int, FILE *));
 static char *remap_filename 		PROTO ((cpp_reader *, char *,
 						struct file_name_list *));
-static long safe_read			PROTO ((int, char *, int));
+static long read_and_prescan		PROTO ((cpp_reader *, cpp_buffer *,
+						int, size_t));
 static void simplify_pathname		PROTO ((char *));
 static struct file_name_list *actual_directory PROTO ((cpp_reader *, char *));
 
@@ -435,8 +436,8 @@ find_include_file (pfile, fname, search_start, ihash, before)
       simplify_pathname (name);
       if (CPP_OPTIONS (pfile)->remap)
 	name = remap_filename (pfile, name, l);
-      
-      f = open (name, O_RDONLY, 0666);
+
+      f = open (name, O_RDONLY|O_NONBLOCK|O_NOCTTY, 0666);
 #ifdef EACCES
       if (f == -1 && errno == EACCES)
 	{
@@ -672,94 +673,72 @@ finclude (pfile, fd, ihash)
 {
   struct stat st;
   size_t st_size;
-  long i, length;
+  long length;
   cpp_buffer *fp;
 
   if (fstat (fd, &st) < 0)
     goto perror_fail;
-  
+  if (fcntl (fd, F_SETFL, 0) == -1)  /* turn off nonblocking mode */
+    goto perror_fail;
+
   fp = CPP_BUFFER (pfile);
-  fp->nominal_fname = fp->fname = ihash->name;
-  fp->ihash = ihash;
-  fp->system_header_p = (ihash->foundhere != ABSOLUTE_PATH
-			 && ihash->foundhere->sysp);
-  fp->lineno = 1;
-  fp->colno = 1;
-  fp->cleanup = file_cleanup;
 
-  /* The ->actual_dir field is only used when ignore_srcdir is not in effect;
-     see do_include */
-  if (!CPP_OPTIONS (pfile)->ignore_srcdir)
-    fp->actual_dir = actual_directory (pfile, fp->fname);
-	
   if (S_ISREG (st.st_mode))
     {
+      /* off_t might have a wider range than size_t - in other words,
+	 the max size of a file might be bigger than the address
+	 space, and we need to detect that now. */
       st_size = (size_t) st.st_size;
-      if (st_size != st.st_size || st_size + 2 < st_size)
-      {
-        cpp_error (pfile, "file `%s' too large", ihash->name);
-	goto fail;
-      }
-      fp->buf = (U_CHAR *) xmalloc (st_size + 2);
-      fp->alimit = fp->buf + st_size + 2;
-      fp->cur = fp->buf;
-      
-      /* Read the file contents, knowing that st_size is an upper bound
-	 on the number of bytes we can read.  */
-      length = safe_read (fd, fp->buf, st_size);
-      fp->rlimit = fp->buf + length;
-      if (length < 0)
-	  goto perror_fail;
+      if ((unsigned HOST_WIDE_INT) st_size
+	  != (unsigned HOST_WIDE_INT) st.st_size)
+	{
+	  cpp_error (pfile, "file `%s' is too large", ihash->name);
+	  goto fail;
+	}
     }
-  else if (S_ISDIR (st.st_mode))
+  else if (S_ISFIFO (st.st_mode) || (S_ISCHR (st.st_mode) && isatty (fd)))
     {
-      cpp_pop_buffer (pfile);
-      cpp_error (pfile, "directory `%s' specified in #include", ihash->name);
-      goto fail;
+      /* Cannot get its file size before reading.  4k is a decent
+         first guess. */
+      st_size = 4096;
     }
   else
     {
-      /* Cannot count its file size before reading.
-	 First read the entire file into heap and
-	 copy them into buffer on stack.  */
-
-      size_t bsize = 2000;
-
-      st_size = 0;
-      fp->buf = (U_CHAR *) xmalloc (bsize + 2);
-
-      for (;;)
-        {
-	  i = safe_read (fd, fp->buf + st_size, bsize - st_size);
-	  if (i < 0)
-	    goto perror_fail;
-	  st_size += i;
-	  if (st_size != bsize)
-	    break;	/* End of file */
-	  bsize *= 2;
-	  fp->buf = (U_CHAR *) xrealloc (fp->buf, bsize + 2);
-	}
-      fp->cur = fp->buf;
-      length = st_size;
+      cpp_error (pfile, "`%s' is not a file, pipe, or tty", ihash->name);
+      goto fail;
     }
 
-  /* FIXME: Broken in presence of trigraphs (consider ??/<EOF>)
-     and doesn't warn about a missing newline. */
-  if ((length > 0 && fp->buf[length - 1] != '\n')
-      || (length > 1 && fp->buf[length - 2] == '\\'))
-    fp->buf[length++] = '\n';
-
-  fp->buf[length] = '\0';
-  fp->rlimit = fp->buf + length;
+  /* Read the file, converting end-of-line characters and trigraphs
+     (if enabled). */
+  fp->ihash = ihash;
+  fp->nominal_fname = fp->fname = ihash->name;
+  length = read_and_prescan (pfile, fp, fd, st_size);
+  if (length < 0)
+    goto fail;
+  if (length == 0)
+    ihash->control_macro = "";  /* never re-include */
 
   close (fd);
+  fp->rlimit = fp->alimit = fp->buf + length;
+  fp->cur = fp->buf;
+  fp->system_header_p = (ihash->foundhere != ABSOLUTE_PATH
+			 && ihash->foundhere->sysp);
+  fp->lineno = 1;
+  fp->colno = 1;
+  fp->cleanup = file_cleanup;
+
+  /* The ->actual_dir field is only used when ignore_srcdir is not in effect;
+     see do_include */
+  if (!CPP_OPTIONS (pfile)->ignore_srcdir)
+    fp->actual_dir = actual_directory (pfile, fp->fname);
+
   pfile->input_stack_listing_current = 0;
   return 1;
 
  perror_fail:
-  cpp_pop_buffer (pfile);
   cpp_error_from_errno (pfile, ihash->name);
  fail:
+  cpp_pop_buffer (pfile);
   close (fd);
   return 0;
 }
@@ -818,42 +797,205 @@ actual_directory (pfile, fname)
   return x;
 }
 
-/* Read LEN bytes at PTR from descriptor DESC, for file FILENAME,
-   retrying if necessary.  If MAX_READ_LEN is defined, read at most
-   that bytes at a time.  Return a negative value if an error occurs,
-   otherwise return the actual number of bytes read,
-   which must be LEN unless end-of-file was reached.  */
+/* Read the entire contents of file DESC into buffer BUF, convert end-of-line
+   markers to canonical form, and convert trigraphs if enabled.  Also, make
+   sure there is a newline at the end of the file.  LEN is how much room we
+   have to start with (this can be expanded if necessary).
+   Returns -1 on failure, or the actual length of the data to be scanned.
+
+   N.B. This function has been rearranged to out-of-line the uncommon cases
+   as much as possible; this is important to prevent it from being a
+   performance bottleneck.  */
 
 static long
-safe_read (desc, ptr, len)
+read_and_prescan (pfile, fp, desc, len)
+     cpp_reader *pfile;
+     cpp_buffer *fp;
      int desc;
-     char *ptr;
-     int len;
+     size_t len;
 {
-  int left, rcount, nchars;
-
-  left = len;
-  while (left > 0) {
-    rcount = left;
-#ifdef MAX_READ_LEN
-    if (rcount > MAX_READ_LEN)
-      rcount = MAX_READ_LEN;
-#endif
-    nchars = read (desc, ptr, rcount);
-    if (nchars < 0)
-      {
-#ifdef EINTR
-	if (errno == EINTR)
-	  continue;
-#endif
-	return nchars;
-      }
-    if (nchars == 0)
-      break;
-    ptr += nchars;
-    left -= nchars;
-  }
-  return len - left;
+
+  U_CHAR *buf = (U_CHAR *) xmalloc (len);
+  U_CHAR *ip, *op, *line_base;
+  U_CHAR *ibase;
+  unsigned int line;
+  int count, seen_eof;
+  size_t offset;
+  /* 4096 bytes of buffer proper, 2 to detect running off the end without
+     address arithmetic all the time, and 2 for pushback in the case there's
+     a potential trigraph or end-of-line digraph at the end of a block. */
+#define INTERMED_BUFFER_SIZE 4096
+  U_CHAR intermed[INTERMED_BUFFER_SIZE + 2 + 2];
+
+  offset = 0;
+  op = buf;
+  line_base = buf;
+  line = 1;
+  ibase = intermed + 2;
+  seen_eof = 0;
+
+  for (;;)
+    {
+    read_next:
+      count = read (desc, intermed + 2, INTERMED_BUFFER_SIZE);
+      if (count < 0)
+	  goto error;
+      if (count == 0)
+	seen_eof = 1;
+      count += 2 - (ibase - intermed);
+      if (count == 0)
+	break;
+
+      ip = ibase;
+      ip[count] = ip[count+1] = '\0';
+      ibase = intermed + 2;
+      offset += count;
+
+      if (offset > len)
+	{
+	  size_t delta_op = op - buf;
+	  size_t delta_line_base = line_base - buf;
+	  len *= 2;
+	  if (offset > len)
+	      /* len overflowed.
+		 This could happen if the file is larger than half the
+		 maximum address space of the machine. */
+	    goto too_big;
+	  buf = xrealloc (buf, len);
+	  op = buf + delta_op;
+	  line_base = buf + delta_line_base;
+	}
+
+      for (;;)
+	{
+	  U_CHAR c;
+	  c = *ip++;
+	  switch (c)
+	    {
+	      /* The default case is at the top so gcc will realize
+		 it's the common case, and leave c in a register.
+	         Also, cache utilization is a little better this way. */
+	    default:
+	      *op++ = c;
+	      break;
+	      
+	    case '\0':
+	      if (seen_eof)
+		goto eof;
+	      else
+		goto read_next;
+	    case '\r':
+	      if (*ip == '\n') ip++;
+	      else if (*ip == '\0' && !seen_eof)
+		{
+		  *--ibase = '\r';
+		  break;
+		}
+	      *op++ = '\n';
+	      line++;
+	      line_base = op;
+	      break;
+
+	    case '\n':
+	      if (*ip == '\r') ip++;
+	      else if (*ip == '\0' && !seen_eof)
+		{
+		  *--ibase = '\n';
+		  break;
+		}
+	      *op++ = '\n';
+	      line++;
+	      line_base = op;
+	      break;
+
+	    case '?':
+	      if (CPP_OPTIONS (pfile)->trigraphs
+		  || CPP_OPTIONS (pfile)->warn_trigraphs)
+		{
+		  /* If we're at the end of the intermediate buffer,
+		     we have to shift the ?'s down to the start and
+		     come back next pass. */
+		  c = ip[0];
+		  if (c == '\0' && !seen_eof)
+		    {
+		      *--ibase = '?';
+		      break;
+		    }
+		  if (c != '?')
+		    {
+		      *op++ = '?';
+		      break;
+		    }
+		  c = ip[1];
+		  if (c == '\0' && !seen_eof)
+		    {
+		      *--ibase = '?';
+		      *--ibase = '?';
+		      break;
+		    }
+		  if (!trigraph_table[c])
+		    {
+		      *op++ = '?';
+		      break;
+		    }
+
+		  if (CPP_OPTIONS (pfile)->warn_trigraphs)
+		    cpp_warning_with_line (pfile, line, op-line_base,
+					   "trigraph ??%c encountered", c);
+		  if (CPP_OPTIONS (pfile)->trigraphs)
+		    {
+		      *op++ = trigraph_table[c];
+		      ip += 2;
+		      break;
+		    }
+		  else
+		    {
+		      *op++ = '?';
+		      *op++ = '?';
+		      *op++ = c;
+		      ip += 2;
+		    }
+		}
+	      else
+		*op++ = c;
+	    }
+	}
+    }
+ eof:
+
+  if (op == buf)
+    return 0;
+
+  if (op[-1] != '\n' || op[-2] == '\\')
+    {
+      cpp_pedwarn_with_line (pfile, line, op - line_base,
+			     "no newline at end of file");
+      if (offset + 2 > len)
+	{
+	  len += 2;
+	  if (offset + 2 > len)
+	    goto too_big;
+	  buf = xrealloc (buf, len);
+	  op = buf + offset;
+	}
+      if (op[-1] == '\\')
+	*op++ = '\n';
+      *op++ = '\n';
+    }
+
+  buf = xrealloc (buf, op - buf);
+  fp->buf = buf;
+  return op - buf;
+
+ too_big:
+  cpp_error (pfile, "file is too large");
+  free (buf);
+  return -1;
+
+ error:
+  cpp_error_from_errno (pfile, fp->fname);
+  free (buf);
+  return -1;
 }
 
 /* Add output to `deps_buffer' for the -M switch.
diff --git a/gcc/cpplib.c b/gcc/cpplib.c
index 8aa20c4..df2dbc7 100644
--- a/gcc/cpplib.c
+++ b/gcc/cpplib.c
@@ -130,9 +130,6 @@ static void make_assertion		PROTO ((cpp_reader *, char *, U_CHAR *));
 static void path_include		PROTO ((cpp_reader *, char *));
 static void initialize_builtins		PROTO ((cpp_reader *));
 static void initialize_char_syntax	PROTO ((void));
-#if 0
-static void trigraph_pcp ();
-#endif
 static void validate_else		PROTO ((cpp_reader *, char *));
 static int comp_def_part		PROTO ((int, U_CHAR *, int, U_CHAR *,
 						int, int));
@@ -290,6 +287,18 @@ U_CHAR is_idstart[256] = { 0 };
 U_CHAR is_hor_space[256] = { 0 };
 /* table to tell if c is horizontal or vertical space.  */
 U_CHAR is_space[256] = { 0 };
+/* Table to handle trigraph conversion, which occurs before all other
+   processing, everywhere in the file.  (This is necessary since one
+   of the trigraphs encodes backslash.)  Note it's off by default.
+
+	from	to	from	to	from	to
+	?? =	#	?? )	]	?? !	|
+	?? (	[	?? '	^	?? >	}
+	?? /	\	?? <	{	?? -	~
+
+   There is not a space between the ?? and the third char.  I put spaces
+   there to avoid warnings when compiling this file. */
+U_CHAR trigraph_table[256] = { 0 };
 
 /* Initialize syntactic classifications of characters. */
 static void
@@ -330,8 +339,14 @@ initialize_char_syntax ()
   is_space['\f'] = 1;
   is_space['\n'] = 1;
   is_space['\r'] = 1;
-}
 
+  /* trigraph conversion */
+  trigraph_table['='] = '#';  trigraph_table[')'] = ']';
+  trigraph_table['!'] = '|';  trigraph_table['('] = '[';
+  trigraph_table['\''] = '^'; trigraph_table['>'] = '}';
+  trigraph_table['/'] = '\\'; trigraph_table['<'] = '{';
+  trigraph_table['-'] = '~';
+}
 
 /* Place into PFILE a quoted string representing the string SRC.
    Caller must reserve enough space in pfile->token_buffer.  */
@@ -554,7 +569,7 @@ cpp_options_init (opts)
   initialize_char_syntax ();
 
   opts->no_line_commands = 0;
-  opts->no_trigraphs = 1;
+  opts->trigraphs = 0;
   opts->put_out_comments = 0;
   opts->print_include_names = 0;
   opts->dump_macros = dump_none;
@@ -4953,7 +4968,7 @@ cpp_start_read (pfile, fname)
   if (fname == NULL || *fname == 0) {
     fname = "";
     f = 0;
-  } else if ((f = open (fname, O_RDONLY, 0666)) < 0)
+  } else if ((f = open (fname, O_RDONLY|O_NONBLOCK|O_NOCTTY, 0666)) < 0)
     cpp_pfatal_with_name (pfile, fname);
 
   /* -MG doesn't select the form of output and must be specified with one of
@@ -5075,23 +5090,6 @@ cpp_start_read (pfile, fname)
 	}
     }
 
-#if 0
-  /* Make sure data ends with a newline.  And put a null after it.  */
-
-  if ((fp->length > 0 && fp->buf[fp->length - 1] != '\n')
-      /* Backslash-newline at end is not good enough.  */
-      || (fp->length > 1 && fp->buf[fp->length - 2] == '\\')) {
-    fp->buf[fp->length++] = '\n';
-    missing_newline = 1;
-  }
-  fp->buf[fp->length] = '\0';
-
-  /* Unless inhibited, convert trigraphs in the input.  */
-
-  if (!no_trigraphs)
-    trigraph_pcp (fp);
-#endif
-
   /* Must call finclude() on the main input before processing
      -include switches; otherwise the -included text winds up
      after the main input. */
@@ -5123,7 +5121,7 @@ cpp_start_read (pfile, fname)
         {
 	  if (strcmp (pend->cmd, "-imacros") == 0)
 	    {
-	      int fd = open (pend->arg, O_RDONLY, 0666);
+	      int fd = open (pend->arg, O_RDONLY|O_NONBLOCK|O_NOCTTY, 0666);
 	      if (fd < 0)
 	        {
 	          cpp_perror_with_name (pfile, pend->arg);
@@ -5155,7 +5153,7 @@ cpp_start_read (pfile, fname)
         {
 	  if (strcmp (pend->cmd, "-include") == 0)
 	    {
-	      int fd = open (pend->arg, O_RDONLY, 0666);
+	      int fd = open (pend->arg, O_RDONLY|O_NONBLOCK|O_NOCTTY, 0666);
 	      if (fd < 0)
 	        {
 	          cpp_perror_with_name (pfile, pend->arg);
@@ -5505,7 +5503,7 @@ cpp_handle_option (pfile, argc, argv)
 	opts->cplusplus_comments = 0;
       } else if (!strcmp (argv[i], "-trigraphs")) {
 	if (!opts->chill)
-	  opts->no_trigraphs = 0;
+	  opts->trigraphs = 1;
       }
       break;
       
@@ -5531,7 +5529,7 @@ cpp_handle_option (pfile, argc, argv)
 	opts->for_lint = 1;
       if (! strcmp (argv[i], "-lang-chill"))
 	opts->objc = 0, opts->cplusplus = 0, opts->chill = 1,
-	  opts->traditional = 1, opts->no_trigraphs = 1;
+	  opts->traditional = 1, opts->trigraphs = 0;
       break;
       
     case '+':
@@ -6377,8 +6375,7 @@ v_cpp_warning_with_line (pfile, line, column, msg, ap)
   v_cpp_message (pfile, 0, msg, ap);
 }  
 
-#if 0
-static void
+void
 cpp_warning_with_line VPROTO ((cpp_reader * pfile, int line, int column, const char *msg, ...))
 {
 #ifndef ANSI_PROTOTYPES
@@ -6401,7 +6398,6 @@ cpp_warning_with_line VPROTO ((cpp_reader * pfile, int line, int column, const c
   v_cpp_warning_with_line (pfile, line, column, msg, ap);
   va_end(ap);
 }
-#endif
 
 void
 cpp_pedwarn_with_line VPROTO ((cpp_reader * pfile, int line, int column, const char *msg, ...))
@@ -6536,8 +6532,6 @@ cpp_perror_with_name (pfile, name)
  *
  * Find and cleanup remaining uses of static variables,
  *
- * Support for trigraphs.
- *
  * Support -dM flag (dump_all_macros).
  *
  * Support for_lint flag.
diff --git a/gcc/cpplib.h b/gcc/cpplib.h
index 978c38e..b5f5ba1 100644
--- a/gcc/cpplib.h
+++ b/gcc/cpplib.h
@@ -334,9 +334,9 @@ struct cpp_options {
 
   char put_out_comments;
 
-  /* Nonzero means don't process the ANSI trigraph sequences.  */
+  /* Nonzero means process the ANSI trigraph sequences.  */
 
-  char no_trigraphs;
+  char trigraphs;
 
   /* Nonzero means print the names of included files rather than
      the preprocessed output.  1 means just the #include "...",
@@ -642,6 +642,7 @@ struct definition {
 extern unsigned char is_idchar[256];
 extern unsigned char is_hor_space[256];
 extern unsigned char is_space[256];
+extern unsigned char trigraph_table[256];
 
 /* Stack of conditionals currently in progress
    (including both successful and failing conditionals).  */
@@ -677,6 +678,8 @@ extern void cpp_pedwarn PVPROTO ((cpp_reader *, const char *, ...))
   ATTRIBUTE_PRINTF_2;
 extern void cpp_error_with_line PVPROTO ((cpp_reader *, int, int, const char *, ...))
   ATTRIBUTE_PRINTF_4;
+extern void cpp_warning_with_line PVPROTO ((cpp_reader *, int, int, const char *, ...))
+  ATTRIBUTE_PRINTF_4;
 extern void cpp_pedwarn_with_line PVPROTO ((cpp_reader *, int, int, const char *, ...))
   ATTRIBUTE_PRINTF_4;
 extern void cpp_pedwarn_with_file_and_line PVPROTO ((cpp_reader *, char *, int, const char *, ...))