From 9f440fb38b36f2d602710695dd53ad9c80e84c2c Mon Sep 17 00:00:00 2001
From: Mike Buland <eichlan@xagasoft.com>
Date: Wed, 6 Apr 2011 14:14:01 +0000
Subject: Libbu++ generates it's own system specific config file as well as a
 fancy version header file all programs can now use to determine which
 version, api version, and svn revision of libbu++ they're linking against. 
 It doesn't quite work for windows yet, but it will, eventually.

---
 autoconfig.cpp    | 87 +++++++++++++++++++++++++++++++++++++++++++++----------
 default.bld       | 23 +++++----------
 src/config.h      |  8 +++--
 src/utfstring.cpp |  4 +--
 4 files changed, 86 insertions(+), 36 deletions(-)

diff --git a/autoconfig.cpp b/autoconfig.cpp
index aa8b6a4..1402704 100644
--- a/autoconfig.cpp
+++ b/autoconfig.cpp
@@ -1,29 +1,84 @@
 #include <stdint.h>
 #include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+FILE *fOut = NULL;
+
+bool testCpp( const char *prog )
+{
+	FILE *pop = popen("g++ -x c++ - -o /dev/null", "w");
+	fwrite( prog, 1, strlen( prog ), pop );
+	return pclose(pop) == 0;
+}
 
 void detectEndianness()
 {
-	uint16_t x=0x0100;
-	fprintf( stderr,
-		"#define LITTLE_ENDIAN 0\n"
-		"#define BIG_ENDIAN 1\n"
-		"#define ENDIANNESS %d\n\n",
-		((uint8_t *)&x)[0]
-		);
-	printf("Archetecture is: %s Endian\n", ((uint8_t *)&x)[0]?"Big":"Little" );
+	printf("Detecting endian support...");
+	fflush( stdout );
+	if( testCpp("#include <endian.h>\n\nint main() { return BYTE_ORDER; }\n") )
+	{
+		fprintf( fOut, "#include <endian.h>\n\n");
+		printf("header file endian.h found, using that.\n");
+	}
+	else
+	{
+		uint16_t x=0x0100;
+		fprintf( fOut,
+			"#define LITTLE_ENDIAN 0\n"
+			"#define BIG_ENDIAN 1\n"
+			"#define BYTE_ORDER %d\n\n",
+			((uint8_t *)&x)[0]
+			);
+		printf("no header file found, faking it...\n"
+			"\tArchetecture is: %s Endian\n",
+			((uint8_t *)&x)[0]?"Big":"Little"
+			);
+	}
 }
 
-int main()
+int main( int argc, char *argv[] )
 {
-	fprintf( stderr,
-		"#ifndef BU_AUTO_CONFIG_H\n"
-		"#define BU_AUTO_CONFIG_H\n\n"
-		);
+	if( argc == 1 )
+	{
+		fprintf( stderr,
+			"Invalid usage: specify a file to generate:\n"
+			"    src/autoconfig.h\n"
+			"    src/version.h\n"
+			"\n"
+			);
+		return 127;
+	}
+	if( strcmp( argv[1], "src/autoconfig.h" ) == 0 )
+	{
+		fOut = fopen( argv[1], "w" );
+		fprintf( fOut,
+			"#ifndef BU_AUTO_CONFIG_H\n"
+			"#define BU_AUTO_CONFIG_H\n\n"
+			);
 
-	// huh, turns out #include <endian.h> covers this...
-//	detectEndianness();
+		detectEndianness();
 
-	fprintf( stderr, "#endif\n");
+		fprintf( fOut, "#endif\n");
+	}
+	else if( strcmp( argv[1], "src/version.h" ) == 0 )
+	{
+		fOut = fopen( argv[1], "w" );
+		fprintf( fOut,
+			"#ifndef BU_VERSION_H\n"
+			"#define BU_VERSION_H\n\n"
+			"#define LIBBU_VERSION		0\n"
+			"#define LIBBU_REVISION		1\n"
+			"#define LIBBU_VERSION_STR	\"0.1\"\n"
+			"#define LIBBU_API			0\n"
+			"#define LIBBU_VC_ID		\"");
+		FILE *psub = popen("svnversion -n", "r");
+		char buf[1024];
+		fwrite( buf, fread( buf, 1, 1024, psub ), 1, fOut );
+		pclose( psub );
+		fprintf( fOut, "\"\n\n#endif\n");
+	}
 
 	return 0;
 }
diff --git a/default.bld b/default.bld
index 1aca56a..9391c68 100644
--- a/default.bld
+++ b/default.bld
@@ -34,28 +34,20 @@ action "unit"
 {
 	build: targets("unit tests");
 }
-/*
-target "src/autoconfig.h"
+
+target ["src/autoconfig.h", "src/version.h"]
 {
 	input "autoconfig";
 	display "autoconfig";
 	profile "build"
 	{
-		execute("./autoconfig 2>src/autoconfig.h");
+		execute("./autoconfig ${OUTPUT}");
 	}
 }
 
-target "bu/autoconfig.h"
+target "src/version.h"
 {
-	tag "header-links";
-	display "symlink";
-	input "src/autoconfig.h";
-	profile "build"
-	{
-		execute("echo ${INPUT}");
-		execute("echo ${OUTPUT}");
-		execute("mkdir -p $(dirname ${OUTPUT}); ln -s ../${INPUT} ${OUTPUT}");
-	}
+	input ".svn";
 }
 
 target "autoconfig"
@@ -63,9 +55,9 @@ target "autoconfig"
 	rule "exe";
 	input "autoconfig.cpp";
 }
-*/
 
-target files("src/*.h").replace("src/", "bu/")
+target [files("src/*.h").replace("src/", "bu/"), "bu/autoconfig.h",
+	"bu/version.h"]
 {
 	tag "header-links";
 	display "symlink";
@@ -75,6 +67,7 @@ target files("src/*.h").replace("src/", "bu/")
 		execute("mkdir -p $(dirname ${OUTPUT}); ln -s ../${INPUT} ${OUTPUT}");
 	}
 }
+
 target files("src/compat/*.h").replace("src/", "bu/")
 {
 	tag "header-links";
diff --git a/src/config.h b/src/config.h
index ce954de..260d406 100644
--- a/src/config.h
+++ b/src/config.h
@@ -17,7 +17,11 @@
 
 #include "bu/extratypes.h"
 
-// Later if we need autoconfig stuff, here's where it'll go.
-// #include "bu/autoconfig.h"
+#ifndef WIN32
+#include "bu/autoconfig.h"
+#else
+#warning Cannot generate an autoinclude file for windows yet
+#endif
+
 
 #endif
diff --git a/src/utfstring.cpp b/src/utfstring.cpp
index 7c4ba19..c9da52f 100644
--- a/src/utfstring.cpp
+++ b/src/utfstring.cpp
@@ -9,9 +9,7 @@
 
 #include "bu/string.h"
 #include "bu/stream.h"
-
-#include <endian.h>
-
+#include "bu/config.h"
 #include "bu/sio.h"
 using Bu::sio;
 
-- 
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