Revert "Make literal strings (i.e., returned by `read') read-only."

This reverts commit fb2f8886c4d537b0c7d3e9e78a8d4e5e272a36f4.

The rationale is that `read' must return mutable strings, as reported
by szgyg <szgyg@ludens.elte.hu>.

diff --git a/NEWS b/NEWS
index 2c3e226..567fc1b 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -66,7 +66,6 @@ available: Guile is now always configured in "maintainer mode".
 * Bugs fixed
 
 ** `symbol->string' now returns a read-only string, as per R5RS
-** Literal strings as returned by `read' are now read-only, as per R5RS
 ** Fix incorrect handling of the FLAGS argument of `fold-matches'
 ** `guile-config link' now prints `-L$libdir' before `-lguile'
 ** Fix memory corruption involving GOOPS' `class-redefinition'

diff --git a/libguile/read.c b/libguile/read.c
index abe1cb9..47b8004 100644 (file)
--- a/libguile/read.c
+++ b/libguile/read.c
@@ -484,7 +484,7 @@ scm_read_string (int chr, SCM port)
   else
     str = (str == SCM_BOOL_F) ? scm_nullstr : str;
 
-  return scm_i_make_read_only_string (str);
+  return str;
 }
 #undef FUNC_NAME
 

diff --git a/libguile/strings.c b/libguile/strings.c
index ffc1eb3..7399d88 100644 (file)
--- a/libguile/strings.c
+++ b/libguile/strings.c
@@ -217,12 +217,6 @@ get_str_buf_start (SCM *str, SCM *buf, size_t *start)
   *buf = STRING_STRINGBUF (*str);
 }
 
-SCM
-scm_i_make_read_only_string (SCM str)
-{
-  return scm_i_substring_read_only (str, 0, STRING_LENGTH (str));
-}
-
 SCM
 scm_i_substring (SCM str, size_t start, size_t end)
 {
@@ -240,28 +234,15 @@ scm_i_substring (SCM str, size_t start, size_t end)
 SCM
 scm_i_substring_read_only (SCM str, size_t start, size_t end)
 {
-  SCM result;
-
-  if (SCM_UNLIKELY (STRING_LENGTH (str) == 0))
-    /* We want the empty string to be `eq?' with the read-only empty
-       string.  */
-    result = str;
-  else
-    {
-      SCM buf;
-      size_t str_start;
-
-      get_str_buf_start (&str, &buf, &str_start);
-      scm_i_pthread_mutex_lock (&stringbuf_write_mutex);
-      SET_STRINGBUF_SHARED (buf);
-      scm_i_pthread_mutex_unlock (&stringbuf_write_mutex);
-
-      result = scm_double_cell (RO_STRING_TAG, SCM_UNPACK (buf),
-                               (scm_t_bits) str_start + start,
-                               (scm_t_bits) end - start);
-    }
-
-  return result;
+  SCM buf;
+  size_t str_start;
+  get_str_buf_start (&str, &buf, &str_start);
+  scm_i_pthread_mutex_lock (&stringbuf_write_mutex);
+  SET_STRINGBUF_SHARED (buf);
+  scm_i_pthread_mutex_unlock (&stringbuf_write_mutex);
+  return scm_double_cell (RO_STRING_TAG, SCM_UNPACK(buf),
+                         (scm_t_bits)str_start + start,
+                         (scm_t_bits) end - start);
 }
 
 SCM

diff --git a/libguile/strings.h b/libguile/strings.h
index cf58628..ca5f52c 100644 (file)
--- a/libguile/strings.h
+++ b/libguile/strings.h
@@ -152,7 +152,6 @@ SCM_INTERNAL void scm_i_get_substring_spec (size_t len,
                                            SCM start, size_t *cstart,
                                            SCM end, size_t *cend);
 SCM_INTERNAL SCM scm_i_take_stringbufn (char *str, size_t len);
-SCM_INTERNAL SCM scm_i_make_read_only_string (SCM str);
 
 /* deprecated stuff */
 

diff --git a/test-suite/tests/strings.test b/test-suite/tests/strings.test
index 735258a..aa9196e 100644 (file)
--- a/test-suite/tests/strings.test
+++ b/test-suite/tests/strings.test
@@ -1,7 +1,7 @@
 ;;;; strings.test --- test suite for Guile's string functions    -*- scheme -*-
 ;;;; Jim Blandy <jimb@red-bean.com> --- August 1999
 ;;;;
-;;;; Copyright (C) 1999, 2001, 2004, 2005, 2006, 2008 Free Software Foundation, Inc.
+;;;; Copyright (C) 1999, 2001, 2004, 2005, 2006 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
@@ -168,11 +168,7 @@
 
   (pass-if-exception "read-only string"
     exception:read-only-string
-    (string-set! (substring/read-only "abc" 0) 1 #\space))
-
-  (pass-if-exception "literal string"
-    exception:read-only-string
-    (string-set! "an immutable string" 0 #\a)))
+    (string-set! (substring/read-only "abc" 0) 1 #\space)))
 
 (with-test-prefix "string-split"