>From 288993e0b1fedeaea6dec34a8c01404b66fee1ba Mon Sep 17 00:00:00 2001
From: Martin Zenzes (spacelab1-u) <mzenzes@xxxxxxxxxxx>
Date: Thu, 8 Jul 2010 15:23:09 +0200
Subject: [PATCH] added function-call get version information
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I had some trouble with different versions of libftdi installed on the same system -- leading to confusion because i didn't notice the wrong version of the library was linked. I found no way to extract the versionnumber as a normal user.

I modified the code to provide the minor and major version number to the user trough a normal functioncall. Therefore, I introduced a new headerfile, which is generated by cmake. Two preprocessor #defines MAJOR_VERSION and MINOR_VERSION are build from the ones provided in CMakeLists.txt. They can be accessed by a call to ftdi_library_version(int* major, int* minor, char[8] snapshot_version). An additional char-array is supplied, which may later be used to encode the exact revision of the git-repo at build time, but this is not implemented yet, only zeros are returned. A fix-sized array is used to prevent possible memory leaks.

The technique used to provide version information is taken from online-tutorial, see http://www.cmake.org/cmake/help/cmake_tutorial.html

I'm sure, my solution is far from perfect, but it works for me. Sending the patch to provide some input for a discussion about how to implement his properly. See the patch for more details, its not very complicated.

There are currently two TODOs:
    - I only use cmake, but there are people using autotools, I suppose...
	- add shell script which should be invoked from make at build time and defines a #define to be feed into this function as a return-array

Signed-off-by: Martin Zenzes (spacelab1-u) <mzenzes@xxxxxxxxxxx>

added thomas vorschläge

Signed-off-by: Martin Zenzes (spacelab1-u) <mzenzes@xxxxxxxxxxx>
---
 .gitignore       |    1 +
 CMakeLists.txt   |    5 +++++
 src/ftdi.c       |   17 +++++++++++++++++
 src/ftdi.h       |    2 ++
 versioninfo.h.in |    7 +++++++
 5 files changed, 32 insertions(+), 0 deletions(-)
 create mode 100644 versioninfo.h.in

diff --git a/.gitignore b/.gitignore
index 0426964..cc38edc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -60,6 +60,7 @@ bindings/python/ftdi_wrap.c
 # libftdi specific
 libftdi-config
 libftdi.spec
+src/versioninfo.h
 
 # CMake
 CMakeCache.txt
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8197615..f959a37 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,6 +5,11 @@ set(MINOR_VERSION 18)
 set(VERSION_STRING ${MAJOR_VERSION}.${MINOR_VERSION})
 SET(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}")
 
+configure_file (
+  "versioninfo.h.in"
+  "${CMAKE_SOURCE_DIR}/src/versioninfo.h"
+  )
+
 # CMake
 if("${CMAKE_BUILD_TYPE}" STREQUAL "")
    set(CMAKE_BUILD_TYPE     Debug)
diff --git a/src/ftdi.c b/src/ftdi.c
index bbbeb9a..988dadf 100644
--- a/src/ftdi.c
+++ b/src/ftdi.c
@@ -34,6 +34,7 @@
 #include <stdio.h>
 
 #include "ftdi.h"
+#include "versioninfo.h"
 
 /* stuff needed for async write */
 #ifdef LIBFTDI_LINUX_ASYNC_MODE
@@ -84,6 +85,22 @@ int gettimeofday(  struct timeval *tv, void null)
 #endif
 
 /**
+    Get some status informatio about currently used library-version.
+    \todo Access somehow the current git-hash
+
+    \param major Major-versionnumber of current build
+    \param minor Minor-versionnumber of current build
+    \param snapshot_version char-array which may contain the revision of the actual repository. not implemented yet...
+
+    \retval none
+*/
+void ftdi_get_library_version(int *major, int *minor, char snapshot_version[8]){
+    *major = MAJOR_VERSION;
+    *minor = MINOR_VERSION;
+    memset(&snapshot_version,0,8);
+}
+
+/**
     Internal function to close usb device pointer.
     Sets ftdi->usb_dev to NULL.
     \internal
diff --git a/src/ftdi.h b/src/ftdi.h
index 24a7f5b..cb4a0ac 100644
--- a/src/ftdi.h
+++ b/src/ftdi.h
@@ -279,6 +279,8 @@ extern "C"
 {
 #endif
 
+    void ftdi_get_library_version(int *major, int *minor, char snapshot_version[8]);
+
     int ftdi_init(struct ftdi_context *ftdi);
     struct ftdi_context *ftdi_new(void);
     int ftdi_set_interface(struct ftdi_context *ftdi, enum ftdi_interface interface);
diff --git a/versioninfo.h.in b/versioninfo.h.in
new file mode 100644
index 0000000..8ec4bdd
--- /dev/null
+++ b/versioninfo.h.in
@@ -0,0 +1,7 @@
+#ifndef _VERSIONINFO_H_
+#define _VERSIONINFO_H_
+
+#define MAJOR_VERSION @MAJOR_VERSION@
+#define MINOR_VERSION @MINOR_VERSION@
+
+#endif // _VERSIONINFO_H_
-- 
1.7.0.4