xstring-buffer: New module.

* lib/string-buffer.h (sb_xappend1, sb_xappend_desc, sb_xappend_c,
sb_xappendvf, sb_xappendf, sb_xcontents_c, sb_xdupfree, sb_xdupfree_c):
New declarations.
* lib/xstring-buffer.c: New file.
* lib/xstring-buffer-printf.c: New file.
* modules/xstring-buffer: New file.

ChangeLog

@@ -1,3 +1,13 @@
+2024-09-25  Bruno Haible  <bruno@clisp.org>
+
+	xstring-buffer: New module.
+	* lib/string-buffer.h (sb_xappend1, sb_xappend_desc, sb_xappend_c,
+	sb_xappendvf, sb_xappendf, sb_xcontents_c, sb_xdupfree, sb_xdupfree_c):
+	New declarations.
+	* lib/xstring-buffer.c: New file.
+	* lib/xstring-buffer-printf.c: New file.
+	* modules/xstring-buffer: New file.
+
 2024-09-25  Bruno Haible  <bruno@clisp.org>
 
 	string-buffer: Add more API.

lib/string-buffer.h

@@ -19,8 +19,9 @@
 #ifndef _STRING_BUFFER_H
 #define _STRING_BUFFER_H
 
-/* This file uses _GL_ATTRIBUTE_MALLOC, _GL_ATTRIBUTE_CAPABILITY_TYPE,
-   _GL_ATTRIBUTE_ACQUIRE_CAPABILITY, _GL_ATTRIBUTE_RELEASE_CAPABILITY.  */
+/* This file uses _GL_ATTRIBUTE_MALLOC, _GL_ATTRIBUTE_RETURNS_NONNULL,
+   _GL_ATTRIBUTE_CAPABILITY_TYPE, _GL_ATTRIBUTE_ACQUIRE_CAPABILITY,
+   _GL_ATTRIBUTE_RELEASE_CAPABILITY.  */
 #if !_GL_CONFIG_H_INCLUDED
  #error "Please include config.h first."
 #endif
@@ -48,6 +49,8 @@ struct string_buffer
 extern "C" {
 #endif
 
+/* ================== Functions in module 'string-buffer' ================== */
+
 /* Initializes BUFFER to the empty string.  */
 extern void sb_init (struct string_buffer *buffer)
   _GL_ATTRIBUTE_ACQUIRE_CAPABILITY (buffer->data);
@@ -56,7 +59,7 @@ extern void sb_init (struct string_buffer *buffer)
    Returns 0, or -1 in case of out-of-memory error.  */
 extern int sb_append1 (struct string_buffer *buffer, char c);
 
-/* Appends the contents of the memory area STR to BUFFER.
+/* Appends the contents of the memory area S to BUFFER.
    Returns 0, or -1 in case of out-of-memory error.  */
 extern int sb_append_desc (struct string_buffer *buffer, string_desc_t s);
 
@@ -123,6 +126,78 @@ extern string_desc_t sb_dupfree (struct string_buffer *buffer)
 extern char * sb_dupfree_c (struct string_buffer *buffer)
   _GL_ATTRIBUTE_RELEASE_CAPABILITY (buffer->data);
 
+/* ================== Functions in module 'xstring-buffer' ================== */
+
+#if GNULIB_XSTRING_BUFFER
+
+/* The following functions invoke xalloc_die () in case of out-of-memory
+   error.  */
+
+/* Appends the character C to BUFFER.  */
+extern void sb_xappend1 (struct string_buffer *buffer, char c);
+
+/* Appends the contents of the memory area S to BUFFER.  */
+extern void sb_xappend_desc (struct string_buffer *buffer, string_desc_t s);
+
+/* Appends the contents of the C string STR to BUFFER.  */
+extern void sb_xappend_c (struct string_buffer *buffer, const char *str);
+
+/* Appends the result of the printf-compatible FORMATSTRING with the argument
+   list LIST to BUFFER.
+   Returns 0, or -1 in case of error other than out-of-memory error.
+   Error code EOVERFLOW can only occur when a width > INT_MAX is used.
+   Therefore, if the format string is valid and does not use %ls/%lc
+   directives nor widths, no error is possible.  */
+extern int sb_xappendvf (struct string_buffer *buffer,
+                         const char *formatstring, va_list list)
+  #if (__GNUC__ + (__GNUC_MINOR__ >= 4) > 4) && !defined __clang__
+  ATTRIBUTE_FORMAT ((__gnu_printf__, 2, 0))
+  #else
+  ATTRIBUTE_FORMAT ((__printf__, 2, 0))
+  #endif
+  ;
+
+/* Appends the result of the printf-compatible FORMATSTRING with the following
+   arguments to BUFFER.
+   Returns 0, or -1 in case of error other than out-of-memory error.
+   Error code EOVERFLOW can only occur when a width > INT_MAX is used.
+   Therefore, if the format string is valid and does not use %ls/%lc
+   directives nor widths, no error is possible.  */
+extern int sb_xappendf (struct string_buffer *buffer,
+                        const char *formatstring, ...)
+  #if (__GNUC__ + (__GNUC_MINOR__ >= 4) > 4) && !defined __clang__
+  ATTRIBUTE_FORMAT ((__gnu_printf__, 2, 3))
+  #else
+  ATTRIBUTE_FORMAT ((__printf__, 2, 3))
+  #endif
+  ;
+
+/* Ensures the contents of BUFFER is followed by a NUL byte (without
+   incrementing the length of the contents).
+   Then returns a read-only view of the current contents of BUFFER,
+   that is, the current contents of BUFFER as a C string.
+   The result is only valid until the next operation on BUFFER.  */
+extern const char * sb_xcontents_c (struct string_buffer *buffer)
+  _GL_ATTRIBUTE_RETURNS_NONNULL;
+
+/* Returns the contents of BUFFER and frees all other memory held by BUFFER.
+   Returns (0, NULL) if there was an error earlier.
+   It is the responsibility of the caller to string_desc_free() the result.  */
+extern string_desc_t sb_xdupfree (struct string_buffer *buffer)
+  _GL_ATTRIBUTE_RELEASE_CAPABILITY (buffer->data);
+
+/* Returns the contents of BUFFER (with an added trailing NUL, that is,
+   as a C string), and frees all other memory held by BUFFER.
+   Returns NULL if there was an error earlier.
+   It is the responsibility of the caller to free() the result.  */
+extern char * sb_xdupfree_c (struct string_buffer *buffer)
+  _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
+  _GL_ATTRIBUTE_RELEASE_CAPABILITY (buffer->data);
+
+#endif /* GNULIB_XSTRING_BUFFER */
+
+/* ========================================================================== */
+
 #ifdef __cplusplus
 }
 #endif

lib/xstring-buffer-printf.c

@@ -0,0 +1,51 @@
+/* Error-checking functions on a string buffer.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation, either version 3 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2024.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "string-buffer.h"
+
+#include <errno.h>
+
+#include "xalloc.h"
+
+int
+sb_xappendvf (struct string_buffer *buffer,
+              const char *formatstring, va_list list)
+{
+  if (sb_appendvf (buffer, formatstring, list) < 0)
+    {
+      if (errno == ENOMEM)
+        xalloc_die ();
+      return -1;
+    }
+  return 0;
+}
+
+int
+sb_xappendf (struct string_buffer *buffer, const char *formatstring, ...)
+{
+  va_list args;
+  int ret;
+
+  va_start (args, formatstring);
+  ret = sb_xappendvf (buffer, formatstring, args);
+  va_end (args);
+  return ret;
+}

lib/xstring-buffer.c

@@ -0,0 +1,82 @@
+/* Error-checking functions on a string buffer.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation, either version 3 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2024.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "string-buffer.h"
+
+#include "xalloc.h"
+
+void
+sb_xappend1 (struct string_buffer *buffer, char c)
+{
+  if (sb_append1 (buffer, c) < 0)
+    xalloc_die ();
+}
+
+void
+sb_xappend_desc (struct string_buffer *buffer, string_desc_t s)
+{
+  if (sb_append_desc (buffer, s) < 0)
+    xalloc_die ();
+}
+
+void
+sb_xappend_c (struct string_buffer *buffer, const char *str)
+{
+  if (sb_append_c (buffer, str) < 0)
+    xalloc_die ();
+}
+
+const char *
+sb_xcontents_c (struct string_buffer *buffer)
+{
+  const char *contents = sb_contents_c (buffer);
+  if (contents == NULL)
+    xalloc_die ();
+  return contents;
+}
+
+string_desc_t
+sb_xdupfree (struct string_buffer *buffer)
+{
+  if (buffer->error)
+    {
+      sb_free (buffer);
+      return string_desc_new_addr (0, NULL);
+    }
+  string_desc_t contents = sb_dupfree (buffer);
+  if (string_desc_data (contents) == NULL)
+    xalloc_die ();
+  return contents;
+}
+
+char *
+sb_xdupfree_c (struct string_buffer *buffer)
+{
+  if (buffer->error)
+    {
+      sb_free (buffer);
+      return NULL;
+    }
+  char *contents = sb_dupfree_c (buffer);
+  if (contents == NULL)
+    xalloc_die ();
+  return contents;
+}

modules/xstring-buffer

@@ -0,0 +1,25 @@
+Description:
+Error-checking functions on a string buffer.
+
+Files:
+lib/xstring-buffer.c
+lib/xstring-buffer-printf.c
+
+Depends-on:
+string-buffer
+xalloc-die
+
+configure.ac:
+gl_MODULE_INDICATOR([xstring-buffer])
+
+Makefile.am:
+lib_SOURCES += xstring-buffer.c xstring-buffer-printf.c
+
+Include:
+"string-buffer.h"
+
+License:
+GPL
+
+Maintainer:
+all