Add asprintf() implementation for platforms without it

Provides a portable implementation of this common allocating sprintf()
API found in many, but not yet all, of the platforms we support.
If the platform provides vasprintf() we simply wrap it, otherwise we
implement it - either way callers can use it regardless of platform.

Since not all platforms guarantee to NULL out the return pointer on
failure, we don't either, and require callers to check the return
value for -1.

The old Xprintf() API is deprecated, but left for compatibility for now.

The new API is added in a new header so that it can be used in parts of
the server such as hw/xfree86/parser that don't include all the server
headers.

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Mikhail Gusarov <dottedmag@dottedmag.net>

1 files changed, 146 insertions, 24 deletions

diff --git a/os/xprintf.c b/os/xprintf.c
index 71a4424f7..0a8bd0687 100644
--- a/os/xprintf.c
+++ b/os/xprintf.c
@@ -1,6 +1,13 @@
-/* 
- * printf routines which xalloc their buffer
- */ 
+/**
+ * @file
+ *
+ * @section DESCRIPTION
+ *
+ * These functions provide a portable implementation of the common (but not
+ * yet universal) asprintf & vasprintf routines to allocate a buffer big
+ * enough to sprintf the arguments to.  The XNF variants terminate the server
+ * if the allocation fails.
+ */
 /*
  * Copyright (c) 2004 Alexander Gottwald
  *
@@ -26,6 +33,29 @@
  * holders shall not be used in advertising or otherwise to promote the sale,
  * use or other dealings in this Software without prior written authorization.
  */
+/*
+ * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
 #ifdef HAVE_DIX_CONFIG_H
 #include <dix-config.h>
 #endif
@@ -35,6 +65,13 @@
 #include <stdarg.h>
 #include <stdio.h>
 
+#ifdef asprintf
+# undef asprintf
+#endif
+#ifdef vasprintf
+# undef vasprintf
+#endif
+
 #ifndef va_copy
 # ifdef __va_copy
 #  define va_copy __va_copy
@@ -42,11 +79,23 @@
 #  error "no working va_copy was found"
 # endif
 #endif
-    
-char *
-Xvprintf(const char *format, va_list va)
+
+/**
+ * Varargs sprintf that allocates a string buffer the right size for
+ * the pattern & data provided and prints the requested data to it.
+ *
+ * @param ret     Pointer to which the newly allocated buffer is written
+ *                (contents undefined on error)
+ * @param format  printf style format string
+ * @param va      variable argument list
+ * @return        size of allocated buffer, or -1 on error.
+ */
+int
+Xvasprintf(char **ret, const char * _X_RESTRICT_KYWD format, va_list va)
 {
-    char *ret;
+#ifdef HAVE_VASPRINTF
+    return vasprintf(ret, format, va);
+#else
     int size;
     va_list va2;
 
@@ -54,12 +103,94 @@ Xvprintf(const char *format, va_list va)
     size = vsnprintf(NULL, 0, format, va2);
     va_end(va2);
 
-    ret = (char *)malloc(size + 1);
-    if (ret == NULL)
-        return NULL;
+    *ret = malloc(size + 1);
+    if (*ret == NULL)
+        return -1;
 
-    vsnprintf(ret, size + 1, format, va);
+    vsnprintf(*ret, size + 1, format, va);
     ret[size] = 0;
+    return size;
+#endif
+}
+
+#ifndef HAVE_VASPRINTF
+# define vasprintf Xvasprintf
+#endif
+
+/**
+ * sprintf that allocates a string buffer the right size for
+ * the pattern & data provided and prints the requested data to it.
+ *
+ * @param ret     Pointer to which the newly allocated buffer is written
+ *                (contents undefined on error)
+ * @param format  printf style format string
+ * @param ...     arguments for specified format
+ * @return        size of allocated buffer, or -1 on error.
+ */
+int
+Xasprintf(char ** ret, const char * _X_RESTRICT_KYWD format, ...)
+{
+    int size;
+    va_list va;
+    va_start(va, format);
+    size = vasprintf(ret, format, va);
+    va_end(va);
+    return size;
+}
+
+/**
+ * Varargs sprintf that allocates a string buffer the right size for
+ * the pattern & data provided and prints the requested data to it.
+ * On failure, issues a FatalError message and aborts the server.
+ *
+ * @param ret     Pointer to which the newly allocated buffer is written
+ *                (contents undefined on error)
+ * @param format  printf style format string
+ * @param va      variable argument list
+ * @return        size of allocated buffer
+ */
+int
+XNFvasprintf(char **ret, const char * _X_RESTRICT_KYWD format, va_list va)
+{
+    int size = vasprintf(ret, format, va);
+    if ((size == -1) || (*ret == NULL)) {
+	Error("XNFvasprintf");
+	FatalError("XNFvasprintf failed");
+    }
+    return size;
+}
+
+/**
+ * sprintf that allocates a string buffer the right size for
+ * the pattern & data provided and prints the requested data to it.
+ * On failure, issues a FatalError message and aborts the server.
+ *
+ * @param ret     Pointer to which the newly allocated buffer is written
+ *                (contents undefined on error)
+ * @param format  printf style format string
+ * @param ...     arguments for specified format
+ * @return        size of allocated buffer
+ */
+int
+XNFasprintf(char ** ret, const char * _X_RESTRICT_KYWD format, ...)
+{
+    int size;
+    va_list va;
+    va_start(va, format);
+    size = XNFvasprintf(ret, format, va);
+    va_end(va);
+    return size;
+}
+
+/* Old api, now deprecated, may be removed in the future */
+char *
+Xvprintf(const char *format, va_list va)
+{
+    char *ret;
+
+    if (vasprintf(&ret, format, va) == -1)
+	ret = NULL;
+
     return ret;
 }
 
@@ -68,7 +199,8 @@ char *Xprintf(const char *format, ...)
     char *ret;
     va_list va;
     va_start(va, format);
-    ret = Xvprintf(format, va);
+    if (vasprintf(&ret, format, va) == -1)
+	ret = NULL;
     va_end(va);
     return ret;
 }
@@ -77,19 +209,9 @@ char *
 XNFvprintf(const char *format, va_list va)
 {
     char *ret;
-    int size;
-    va_list va2;
-
-    va_copy(va2, va);
-    size = vsnprintf(NULL, 0, format, va2);
-    va_end(va2);
 
-    ret = (char *)xnfalloc(size + 1);
-    if (ret == NULL)
-        return NULL;
+    XNFvasprintf(&ret, format, va);
 
-    vsnprintf(ret, size + 1, format, va);
-    ret[size] = 0;
     return ret;
 }
 
@@ -98,7 +220,7 @@ char *XNFprintf(const char *format, ...)
     char *ret;
     va_list va;
     va_start(va, format);
-    ret = XNFvprintf(format, va);
+    XNFvasprintf(&ret, format, va);
     va_end(va);
     return ret;
 }