symbols.pl: provide LIBCURL_HAS macro for apps

Experience has shown that the symbols-in-versions file is very useful to
applications that want to build with a wide range of libcurl versions.
It is however easy to get it wrong and the source gets a bit messy with
all the fixed numerical comparisions.

The point of this script is to provide an easy-to-use macro for libcurl-
using applications to do preprocessor checks for specific libcurl
defines, and yet make the code clearly show what the macro is used for.

2 files changed, 101 insertions, 1 deletions

diff --git a/docs/libcurl/Makefile.am b/docs/libcurl/Makefile.am
index 45c8fee97..50f1a3b23 100644
--- a/docs/libcurl/Makefile.am
+++ b/docs/libcurl/Makefile.am
@@ -82,7 +82,7 @@ PDFPAGES = curl_easy_cleanup.pdf curl_easy_getinfo.pdf			 \
 CLEANFILES = $(HTMLPAGES) $(PDFPAGES)
 
 EXTRA_DIST = $(man_MANS) $(HTMLPAGES) index.html $(PDFPAGES) libcurl.m4 ABI \
-  symbols-in-versions
+  symbols-in-versions symbols.pl
 MAN2HTML= roffit --mandir=. < $< >$@
 
 SUFFIXES = .3 .html
diff --git a/docs/libcurl/symbols.pl b/docs/libcurl/symbols.pl
new file mode 100755
index 000000000..d1ff7a656
--- /dev/null
+++ b/docs/libcurl/symbols.pl
@@ -0,0 +1,100 @@
+#!/usr/bin/perl
+#***************************************************************************
+#                                  _   _ ____  _
+#  Project                     ___| | | |  _ \| |
+#                             / __| | | | |_) | |
+#                            | (__| |_| |  _ <| |___
+#                             \___|\___/|_| \_\_____|
+#
+# Copyright (C) 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at http://curl.haxx.se/docs/copyright.html.
+#
+# You may opt to use, copy, modify, merge, publish, distribute and/or sell
+# copies of the Software, and permit persons to whom the Software is
+# furnished to do so, under the terms of the COPYING file.
+#
+# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+# KIND, either express or implied.
+#
+###########################################################################
+#
+# Experience has shown that the symbols-in-versions file is very useful to
+# applications that want to build with a wide range of libcurl versions.
+# It is however easy to get it wrong and the source gets a bit messy with all
+# the fixed numerical comparisions.
+#
+# The point of this script is to provide an easy-to-use macro for libcurl-
+# using applications to do preprocessor checks for specific libcurl defines,
+# and yet make the code clearly show what the macro is used for.
+#
+# Run this script and generate libcurl-symbols.h and then use that header in
+# a fashion similar to:
+#
+# #include "libcurl-symbols.h"
+#
+# #if LIBCURL_HAS(CURLOPT_MUTE)
+#   has mute
+# #else
+#   no mute
+# #endif
+#
+#
+open F, "<symbols-in-versions";
+
+sub str2num {
+    my ($str)=@_;
+    if($str =~ /([0-9]*)\.([0-9]*)\.*([0-9]*)/) {
+        return sprintf("0x%06x", $1<<16 | $2 << 8 | $3);
+    }
+}
+
+print <<EOS
+
+#include <curl/curl.h>
+
+#define LIBCURL_HAS(x) \\
+  (defined(x ## _FIRST) && (x ## _FIRST <= LIBCURL_VERSION_NUM) && \\
+   (!defined(x ## _LAST) || ( x ## _LAST >= LIBCURL_VERSION_NUM)))
+
+EOS
+    ;
+
+while(<F>) {
+    if(/^(CURL[^ ]*)[ \t]*(.*)/) {
+        my ($sym, $vers)=($1, $2);
+
+        my $intr;
+        my $rm;
+        my $dep;
+
+        # is there removed info?
+        if($vers =~ /([\d.]+)[ \t-]+([\d.]+)[ \t]+([\d.]+)/) {
+            ($intr, $dep, $rm)=($1, $2, $3);
+        }
+        # is it a dep-only line?
+        elsif($vers =~ /([\d.]+)[ \t-]+([\d.]+)/) {
+            ($intr, $dep)=($1, $2);
+        }
+        else {
+            $intr = $vers;
+        }
+
+        my $inum = str2num($intr);
+
+        print <<EOS
+#define ${sym}_FIRST $inum /* Added in $intr */
+EOS
+;
+        my $irm = str2num($rm);
+        if($rm) {
+        print <<EOS
+#define ${sym}_LAST $irm /* Last featured in $rm */
+EOS
+;
+        }
+
+    }
+}