4e027b72de
Issue
When `CMAKE_INSTALL_LIBDIR` and `CMAKE_INSTALL_INCLUDEDIR` are set to absolute paths, the `msgpack-c.pc` file generated by CMake improperly configures `libdir` and `includedir`. This leads to incorrect paths that prevent the compiler from locating necessary header and library files.
How to reproduce
Build and install `msgpack-c`.
```console
% cmake -S . -B ../msgpack-c.build -DCMAKE_INSTALL_LIBDIR=/tmp/local/lib -DCMAKE_INSTALL_INCLUDEDIR=/tmp/local/include
% cmake --build ../msgpack-c.build
% sudo cmake --install ../msgpack-c.build
```
Compile `example/simple_c.c` using installed msgpack-c. The following error happens because the linker cannot find paths provided by pkg-config.
```console
% export PKG_CONFIG_PATH=/tmp/local/lib/pkgconfig:$PKG_CONFIG_PATH
% gcc -o simple_c example/simple_c.c $(pkg-config --cflags --libs msgpack-c)
/usr/bin/ld: cannot find -lmsgpack-c: No such file or directory
collect2: error: ld returned 1 exit status
```
Expected
Successfully compile `example/simple_c.c` using installed msgpack-c. We can execute `simple_c` like the following.
```console
% gcc -o simple_c example/simple_c.c $(pkg-config --cflags --libs msgpack-c)
% ./simple_c
93 01 c3 a7 65 78 61 6d 70 6c 65
[1, true, "example"]
```
Explain the problem in detail
The generated `msgpack-c.pc` file does not handle absolute paths correctly. Here is the result of the incorrect configuration in `How to reproduce` section. In the following `msgpack-c.pc` file, `libdir` and `includedir` are showing unrecognized paths, leading to incorrect paths.
```console
% cat /tmp/local/lib/pkgconfig/msgpack-c.pc
prefix=/usr/local
exec_prefix=/usr/local
libdir=${prefix}//tmp/local/lib <- Here the path is wrong. We expected `/tmp/local/lib`
includedir=${prefix}//tmp/local/include <- Here the path is wrong. We expected `/tmp/local/include`
Name: MessagePack
Description: Binary-based efficient object serialization library
Version: 6.0.1
Libs: -L${libdir} -lmsgpack-c
Cflags: -I${includedir}
```
Solution
Modify the `CMakeLists.txt` file to ensure that `libdir` and `includedir` use absolute paths. This change addresses the issue by providing correct paths to the compiler and linker.
msgpack for C
Version 6.0.1 
It's like JSON but smaller and faster.
Overview
MessagePack is an efficient binary serialization format, which lets you exchange data among multiple languages like JSON, except that it's faster and smaller. Small integers are encoded into a single byte and short strings require only one extra byte in addition to the strings themselves.
Example
#include <msgpack.h>
#include <stdio.h>
int main(void)
{
/* msgpack::sbuffer is a simple buffer implementation. */
msgpack_sbuffer sbuf;
msgpack_sbuffer_init(&sbuf);
/* serialize values into the buffer using msgpack_sbuffer_write callback function. */
msgpack_packer pk;
msgpack_packer_init(&pk, &sbuf, msgpack_sbuffer_write);
msgpack_pack_array(&pk, 3);
msgpack_pack_int(&pk, 1);
msgpack_pack_true(&pk);
msgpack_pack_str(&pk, 7);
msgpack_pack_str_body(&pk, "example", 7);
/* deserialize the buffer into msgpack_object instance. */
/* deserialized object is valid during the msgpack_zone instance alive. */
msgpack_zone mempool;
msgpack_zone_init(&mempool, 2048);
msgpack_object deserialized;
msgpack_unpack(sbuf.data, sbuf.size, NULL, &mempool, &deserialized);
/* print the deserialized object. */
msgpack_object_print(stdout, deserialized);
puts("");
msgpack_zone_destroy(&mempool);
msgpack_sbuffer_destroy(&sbuf);
return 0;
}
See QUICKSTART-C.md for more details.
Usage
Building and Installing
Install from git repository
Using the Terminal (CLI)
You will need:
gcc >= 4.1.0cmake >= 2.8.0
How to build:
$ git clone https://github.com/msgpack/msgpack-c.git
$ cd msgpack-c
$ git checkout c_master
$ cmake .
$ make
$ sudo make install
How to run tests:
In order to run tests you must have the GoogleTest framework installed. If you do not currently have it, install it and re-run cmake.
Then:
$ make test
When you use the C part of msgpack-c, you need to build and link the library. By default, both static/shared libraries are built. If you want to build only static library, set BUILD_SHARED_LIBS=OFF to cmake. If you want to build only shared library, set BUILD_SHARED_LIBS=ON.
GUI on Windows
Clone msgpack-c git repository.
$ git clone https://github.com/msgpack/msgpack-c.git
or using GUI git client.
e.g.) tortoise git https://code.google.com/p/tortoisegit/
-
Checkout to c_master branch
-
Launch cmake GUI client.
-
Set 'Where is the source code:' text box and 'Where to build the binaries:' text box.
-
Click 'Configure' button.
-
Choose your Visual Studio version.
-
Click 'Generate' button.
-
Open the created msgpack.sln on Visual Studio.
-
Build all.
Documentation
You can get additional information including the tutorial on the wiki.
Contributing
msgpack-c is developed on GitHub at msgpack/msgpack-c.
To report an issue or send a pull request, use the
issue tracker.
Here's the list of great contributors.
License
msgpack-c is licensed under the Boost Software License, Version 1.0. See
the LICENSE_1_0.txt file for details.