Don't assume a huge stack.

8 files changed, 177 insertions, 72 deletions

diff --git a/ChangeLog b/ChangeLog
index b4da2f8..90ecc7e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2002-10-03  Bruno Haible  <bruno@clisp.org>
 
+	* lib/getline.h: New file.
+	* lib/getline.cc: New file.
+	* lib/Makefile.in (OBJECTS): Add getline.o.
+	(getline.o): New rule.
+	* src/read-line.h (Read_Line::readln_aux): Remove declaration.
+	* src/read-line.cc (Read_Line::readln_aux): Remove function.
+	* src/read-line.icc (Read_Line::get_line): Use ::get_line.
+	* src/options.h (LARGE_STACK): Remove macro.
+
 	* src/bool-array.h (STORAGE_TYPE): Remove type.
 	Use 'unsigned int' instead of STORAGE_TYPE.
 	* src/bool-array.cc: Likewise.
diff --git a/lib/Makefile.in b/lib/Makefile.in
index 3b1ee9d..fde08bd 100644
--- a/lib/Makefile.in
+++ b/lib/Makefile.in
@@ -1,6 +1,6 @@
 # Makefile for gperf/lib
 
-# Copyright (C) 1989, 1992, 1993, 1998 Free Software Foundation, Inc.
+# Copyright (C) 1989, 1992, 1993, 1998, 2002 Free Software Foundation, Inc.
 # written by Douglas C. Schmidt (schmidt@ics.uci.edu)
 #
 # This file is part of GNU GPERF.
@@ -58,7 +58,7 @@ SHELL = /bin/sh
 
 VPATH = $(srcdir)
 
-OBJECTS  = getopt.o getopt1.o hash.o
+OBJECTS  = getopt.o getopt1.o getline.o hash.o
 CPPFLAGS = -I$(srcdir)
 
 TARGETLIB = libgp.a
@@ -85,6 +85,9 @@ getopt.o : getopt.c getopt.h
 getopt1.o : getopt1.c getopt.h
 	$(CC) $(CFLAGS) $(CPPFLAGS) -c $(srcdir)/getopt1.c
 
+getline.o : getline.cc getline.h
+	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/getline.cc
+
 hash.o : hash.cc hash.h
 	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $(srcdir)/hash.cc
 
diff --git a/lib/getline.cc b/lib/getline.cc
new file mode 100644
index 0000000..90e027b
--- /dev/null
+++ b/lib/getline.cc
@@ -0,0 +1,118 @@
+/* getline.c -- Replacement for GNU C library function getline
+
+Copyright (C) 1993, 1996, 2001-2002 Free Software Foundation, Inc.
+
+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. */
+
+/* Written by Jan Brittenson, bson@gnu.ai.mit.edu.  */
+
+/* Specification.  */
+#include "getline.h"
+
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+/* Always add at least this many bytes when extending the buffer.  */
+#define MIN_CHUNK 64
+
+/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
+   + OFFSET (and null-terminate it). *LINEPTR is a pointer returned from
+   malloc (or NULL), pointing to *N characters of space.  It is realloc'd
+   as necessary.  Return the number of characters read (not including the
+   null terminator), or -1 on error or EOF.
+   NOTE: There is another getstr() function declared in <curses.h>.  */
+
+static int
+getstr (char **lineptr, size_t *n, FILE *stream, char terminator, size_t offset)
+{
+  size_t nchars_avail;          /* Allocated but unused chars in *LINEPTR.  */
+  char *read_pos;               /* Where we're reading into *LINEPTR. */
+
+  if (!lineptr || !n || !stream)
+    return -1;
+
+  if (!*lineptr)
+    {
+      *n = MIN_CHUNK;
+      *lineptr = new char[*n];
+    }
+
+  nchars_avail = *n - offset;
+  read_pos = *lineptr + offset;
+
+  for (;;)
+    {
+      register int c = getc (stream);
+
+      /* We always want at least one char left in the buffer, since we
+         always (unless we get an error while reading the first char)
+         NUL-terminate the line buffer.  */
+
+      assert (*n - nchars_avail == (size_t) (read_pos - *lineptr));
+      if (nchars_avail < 2)
+        {
+          if (*n > MIN_CHUNK)
+            *n *= 2;
+          else
+            *n += MIN_CHUNK;
+
+          nchars_avail = *n + *lineptr - read_pos;
+          char *new_line = new char[*n];
+          if (*lineptr)
+            {
+              memcpy (new_line, *lineptr, read_pos - *lineptr);
+              delete[] *lineptr;
+            }
+          *lineptr = new_line;
+          read_pos = *n - nchars_avail + *lineptr;
+          assert (*n - nchars_avail == (size_t) (read_pos - *lineptr));
+        }
+
+      if (c == EOF || ferror (stream))
+        {
+          /* Return partial line, if any.  */
+          if (read_pos == *lineptr)
+            return -1;
+          else
+            break;
+        }
+
+      *read_pos++ = c;
+      nchars_avail--;
+
+      if (c == terminator)
+        /* Return the line.  */
+        break;
+    }
+
+  /* Done - NUL terminate and return the number of chars read.  */
+  *read_pos = '\0';
+
+  return read_pos - (*lineptr + offset);
+}
+
+int
+get_line (char **lineptr, size_t *n, FILE *stream)
+{
+  return getstr (lineptr, n, stream, '\n', 0);
+}
+
+int
+get_delim (char **lineptr, size_t *n, int delimiter, FILE *stream)
+{
+  return getstr (lineptr, n, stream, delimiter, 0);
+}
diff --git a/lib/getline.h b/lib/getline.h
new file mode 100644
index 0000000..81ddb7d
--- /dev/null
+++ b/lib/getline.h
@@ -0,0 +1,30 @@
+/*  Copyright (C) 1995, 2000-2002 Free Software Foundation, Inc.
+
+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, 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.  */
+
+#ifndef GETLINE_H_
+# define GETLINE_H_ 1
+
+# include <stddef.h>
+# include <stdio.h>
+
+/* Like the glibc functions get_line and get_delim, except that the result
+   must be freed using delete[], not free().  */
+
+extern int get_line (char **lineptr, size_t *n, FILE *stream);
+
+extern int get_delim (char **lineptr, size_t *n, int delimiter, FILE *stream);
+
+#endif /* not GETLINE_H_ */
diff --git a/src/options.h b/src/options.h
index 0cce108..0b5b88e 100644
--- a/src/options.h
+++ b/src/options.h
@@ -142,11 +142,6 @@ extern Options option;
 #endif
 #endif
 
-/* Set to 1 if the stack is large enough for holding a text line. */
-#ifndef LARGE_STACK
-#define LARGE_STACK 1
-#endif
-
 #ifdef __OPTIMIZE__
 
 #define INLINE inline
diff --git a/src/read-line.cc b/src/read-line.cc
index 38da829..4cce91c 100644
--- a/src/read-line.cc
+++ b/src/read-line.cc
@@ -23,68 +23,6 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111, USA.  */
 
 #include <stdlib.h>
 #include <string.h> /* declares memcpy() */
-#include "options.h"
-
-/* Recursively fills up the buffer. */
-
-#define CHUNK_SIZE 4096
-
-/* CHUNKS is the number of chunks (each of size CHUNK_SIZE) which have
-   already been read and which are temporarily stored on the stack.
-   This function reads the remainder of the line, allocates a buffer
-   for the entire line, fills the part beyond &buffer[chunks*CHUNK_SIZE],
-   and returns &buffer[chunks*CHUNK_SIZE].  */
-
-char *
-Read_Line::readln_aux (int chunks)
-{
-#if LARGE_STACK
-  char buf[CHUNK_SIZE];
-#else
-  // Note: we don't use new, because that invokes a custom operator new.
-  char *buf = (char*)malloc(CHUNK_SIZE);
-  if (buf == NULL)
-    abort ();
-#endif
-  char *bufptr = buf;
-  char *ptr;
-  int c;
-
-  while (c = getc (fp), c != EOF && c != '\n') /* fill the current buffer */
-    {
-      *bufptr++ = c;
-      if (bufptr - buf == CHUNK_SIZE)
-        {
-          if ((ptr = readln_aux (chunks + 1)) != NULL)
-
-            /* prepend remainder to ptr buffer */
-            {
-              ptr -= CHUNK_SIZE;
-              memcpy (ptr, buf, CHUNK_SIZE);
-            }
-
-          goto done;
-        }
-    }
-  if (c == EOF && bufptr == buf && chunks == 0)
-    ptr = NULL;
-  else
-    {
-      size_t s1 = chunks * CHUNK_SIZE;
-      size_t s2 = bufptr - buf;
-
-      ptr = new char[s1+s2+1];
-      ptr += s1;
-      ptr[s2] = '\0';
-      memcpy (ptr, buf, s2);
-    }
- done:
-#if !LARGE_STACK
-  free (buf);
-#endif
-
-  return ptr;
-}
 
 #ifndef __OPTIMIZE__
 
diff --git a/src/read-line.h b/src/read-line.h
index c4f7cfc..8f036ad 100644
--- a/src/read-line.h
+++ b/src/read-line.h
@@ -29,11 +29,11 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111, USA.  */
 #define read_line_h 1
 
 #include <stdio.h>
+#include "getline.h"
 
 class Read_Line
 {
 private:
-  char *readln_aux (int chunks);
   FILE *fp;                       /* FILE pointer to the input stream. */
 
 public:
diff --git a/src/read-line.icc b/src/read-line.icc
index b838b20..c4ea9a6 100644
--- a/src/read-line.icc
+++ b/src/read-line.icc
@@ -21,8 +21,9 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111, USA.  */
 
 // This needs:
 //#include <stdio.h>
+//#include "getline.h"
 
-/* Returns the ``next'' line, ignoring comments beginning with '#'. */
+/* Returns the "next" line, ignoring comments beginning with '#'.  */
 INLINE char *
 Read_Line::get_line (void)
 {
@@ -41,5 +42,16 @@ Read_Line::get_line (void)
     return (char *)0;
 
   ungetc (c, stdin);
-  return readln_aux (0);
+
+  char *line = (char *)0;
+  size_t linesize = 0;
+  int length = ::get_line (&line, &linesize, fp);
+  if (length < 0)
+    {
+      delete[] line;
+      return (char *)0;
+    }
+  if (length > 0 && line[length - 1] == '\n')
+    line[length - 1] = '\0';
+  return line;
 }