liblib60870 CMake OUTPUT_NAME

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Summary

CMakeLists.txt disagree with static Makefiles on the library file name.

Makefile compiles a lib60870.a static archive and a lib60870.so dynamic shared library. CMake creates incorrect liblib60870.a and liblib60870.so.2.3.1 with a symlink named liblib60870.so because of this line (for lib60870-shared cmake target): https://github.com/mz-automation/lib60870/blob/63481bd35aff1db8b397d712401e9ef2f0d23a5c/lib60870-C/src/CMakeLists.txt#L127

Affected

Everybody who was using cmake to build this library and/or link with it, e.g. applications with a dependency on this, and maybe Yocto-based embedded distros package maintainers. Static makefiles work fine.

Suggested changes

I suggest a couple changes to CMakeLists to follow Makefile behaviour. I think this library was named libiec60870 once, then something was renamed iec60870->lib60870 in commit 6b70099989eda4b2098905ef40226bff82a37689 in 2018 for v2.0.0 release. liblib60870 is confusing.

This change allows me to build CPack DEB packages for both Ubuntu 18.04 amd64 host "lib60870-C_2.3.1_x86_64.deb" and OpenSTLinux 3.0.0 armhf target (STM32MP157) "lib60870-C_2.3.1_cortexa7t2hf-neon-vfpv4-ostl.deb" with corresponding correct library names and architectures; also I can rely on the naming convention for dynamic linking in application development (compare -liec61850 and -l60870 to LDFLAGS="-llib60870"). Tested build with CMake 3.10.2, the examples launch, although they got linked statically.

The pkgconfig file added in #116 might need to get updated too, I didn't have to use it because a) the target doesn't have a native compiler; b) the host's build system doesn't rely on lib60870.pc (yet). But it would be nice to be able to find the library via CMake+PkgConfig in an upstream application, I did something like this against libiec61850.

If we reach a consensus on this breaking change, I might create a pull request for CI testing.

diff --git a/lib60870-C/src/CMakeLists.txt b/lib60870-C/src/CMakeLists.txt
index e66dd1b..b9dc601 100644
--- a/lib60870-C/src/CMakeLists.txt
+++ b/lib60870-C/src/CMakeLists.txt
@@ -115,7 +115,7 @@ endif( WIN32 )
 add_library (lib60870-shared SHARED ${library_SRCS} )
 
 set_target_properties(lib60870-shared PROPERTIES
-           OUTPUT_NAME lib60870
+           OUTPUT_NAME 60870
            SOVERSION "${LIB_VERSION_MAJOR}.${LIB_VERSION_MINOR}.${LIB_VERSION_PATCH}"
           WINDOWS_EXPORT_ALL_SYMBOLS true
 )
@@ -130,6 +130,10 @@ GENERATE_EXPORT_HEADER(lib60870-shared
 
 add_library (lib60870 STATIC ${library_SRCS})
 
+set_target_properties(lib60870 PROPERTIES
+           OUTPUT_NAME 60870
+)
+
 IF(UNIX)
   IF (CONFIG_SYSTEM_HAS_CLOCK_GETTIME)
      target_link_libraries (lib60870