Rename to liblz4_vendor.

This is to make it clear that we are only vendoring
the library portion, which is BSD, rather than the rest
of it, which is GPL.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>

lz4_vendor/CMakeLists.txt → liblz4_vendor/CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.10)
-project(lz4_vendor)
+project(liblz4_vendor)
 
 find_package(ament_cmake REQUIRED)
 find_package(ament_cmake_vendor_package REQUIRED)
@@ -9,7 +9,7 @@ ament_add_default_options()
 list(INSERT CMAKE_MODULE_PATH 0 "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules")
 find_package(lz4 QUIET)
 
-ament_vendor(lz4_vendor
+ament_vendor(liblz4_vendor
   SATISFIED ${lz4_FOUND}
   VCS_URL https://github.com/lz4/lz4.git
   VCS_VERSION v1.9.4
@@ -23,4 +23,4 @@ ament_vendor(lz4_vendor
 
 install(DIRECTORY cmake DESTINATION share/${PROJECT_NAME})
 
-ament_package(CONFIG_EXTRAS lz4_vendor-extras.cmake)
+ament_package(CONFIG_EXTRAS liblz4_vendor-extras.cmake)

liblz4_vendor/README.md

@@ -0,0 +1,12 @@
+# liblz4_vendor
+
+Vendor package for the [LZ4](https://github.com/lz4/lz4) library.
+
+The licensing on lz4 is complicated; see
+https://github.com/lz4/lz4/blob/a3be31154f2e4c928ae6dcba9fe7e89e7678c74b/LICENSE
+for details.  In short, the library itself (everything in the lib directory)
+is BSD, while everything else in the package is GPLv2.
+
+ROS 2 only wants to depend on the BSD-licensed portion, so the name of this
+package is very specifically chosen to emphasize that we are only vendoring
+the library.

liblz4_vendor/liblz4_vendor-extras.cmake

@@ -0,0 +1 @@
+list(INSERT CMAKE_MODULE_PATH 0 "${liblz4_vendor_DIR}/Modules")

lz4_vendor/package.xml → liblz4_vendor/package.xml

@@ -1,22 +1,23 @@
 <?xml version="1.0"?>
 <?xml-model href="http://download.ros.org/schema/package_format2.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
 <package format="2">
-  <name>lz4_vendor</name>
+  <name>liblz4_vendor</name>
   <version>0.24.0</version>
   <description>LZ4 compression vendor package, providing a dependency for LZ4.</description>
   <maintainer email="michael.orlov@apex.ai">Michael Orlov</maintainer>
   <maintainer email="me@emersonknapp.com">Emerson Knapp</maintainer>
   <maintainer email="ros-tooling@googlegroups.com">ROS Tooling Working Group</maintainer>
   <license>Apache License 2.0</license>  <!-- the contents of this package are Apache 2.0 -->
-  <license>BSD</license>  <!-- LZ4 is BSD -->
-  <license>GPLv2</license>  <!-- LZ4 is GPLv2 -->
+  <license>BSD</license>  <!-- The LZ4 library is BSD; see README.md for more information -->
+  <license>GPLv2</license>  <!-- All other LZ4 files are GPLv2; see README.md for more information -->
 
-  <url type="website">https://facebook.github.io/zstd/</url>
+  <url type="website">https://github.com/lz4/lz4/</url>
 
   <buildtool_depend>ament_cmake</buildtool_depend>
   <buildtool_depend>ament_cmake_vendor_package</buildtool_depend>
 
-  <depend>lz4</depend>
+  <build_depend>liblz4-dev</build_depend>
+  <exec_depend>liblz4</exec_depend>
 
   <export>
     <build_type>ament_cmake</build_type>

mcap_vendor/CMakeLists.txt

@@ -3,7 +3,7 @@ project(mcap_vendor LANGUAGES C CXX)
 
 ## Dependencies
 find_package(ament_cmake REQUIRED)
-find_package(lz4_vendor REQUIRED)
+find_package(liblz4_vendor REQUIRED)
 find_package(lz4 REQUIRED)
 find_package(zstd_vendor REQUIRED)
 find_package(zstd REQUIRED)
@@ -71,7 +71,7 @@ build_mcap_vendor()
 
 ament_export_include_directories(include/${PROJECT_NAME})
 ament_export_targets(mcap HAS_LIBRARY_TARGET)
-ament_export_dependencies(lz4_vendor lz4 zstd_vendor zstd)
+ament_export_dependencies(liblz4_vendor lz4 zstd_vendor zstd)
 
 ## Package
 ament_package()

mcap_vendor/package.xml

@@ -12,7 +12,7 @@
   <buildtool_depend>ament_cmake</buildtool_depend>
   <buildtool_depend>git</buildtool_depend>
 
-  <depend>lz4_vendor</depend>
+  <depend>liblz4_vendor</depend>
   <depend>zstd_vendor</depend>
 
   <export>