build: add llhttp-specific prefix to CMake options. (#657)

* build: add llhttp-specific prefix to CMake options.

BUILD_SHARED_LIBS is now called LLHTTP_BUILD_SHARED_LIBS.

BUILD_STATIC_LIBS is now called LLHTTP_BUILD_STATIC_LIBS.

CMake options have global scope so there's the risk of conflict
otherwise. For example, libcurl has a BUILD_STATIC_LIBS option too.

Documentation updates to be discussed.

See #647

* modify docs

---------

Co-authored-by: Tom Seddon <tom@>
Co-authored-by: Aras Abbasi <aras.abbasi@googlemail.com>

Author: tom-seddon

CMakeLists.txt

@@ -24,8 +24,8 @@ endif()
 # Options
 #
 # Generic option
-option(BUILD_SHARED_LIBS "Build shared libraries (.dll/.so)" ON)
-option(BUILD_STATIC_LIBS "Build static libraries (.lib/.a)" OFF)
+option(LLHTTP_BUILD_SHARED_LIBS "Build shared libraries (.dll/.so)" ON)
+option(LLHTTP_BUILD_STATIC_LIBS "Build static libraries (.lib/.a)" OFF)
 
 # Source code
 set(LLHTTP_SOURCES
@@ -80,19 +80,19 @@ function(config_library target)
   )
 endfunction(config_library target)
 
-if(BUILD_SHARED_LIBS)
+if(LLHTTP_BUILD_SHARED_LIBS)
   add_library(llhttp_shared SHARED
       ${llhttp_src}
   )
   add_library(llhttp::llhttp ALIAS llhttp_shared)
   config_library(llhttp_shared)
 endif()
 
-if(BUILD_STATIC_LIBS)
+if(LLHTTP_BUILD_STATIC_LIBS)
   add_library(llhttp_static STATIC
       ${llhttp_src}
   )
-  if(NOT BUILD_SHARED_LIBS)
+  if(NOT LLHTTP_BUILD_SHARED_LIBS)
     add_library(llhttp::llhttp ALIAS llhttp_static)
   endif()
   config_library(llhttp_static)
@@ -111,6 +111,6 @@ message(STATUS "Project configure summary:")
 message(STATUS "")
 message(STATUS "  CMake build type .................: ${CMAKE_BUILD_TYPE}")
 message(STATUS "  Install prefix ...................: ${CMAKE_INSTALL_PREFIX}")
-message(STATUS "  Build shared library .............: ${BUILD_SHARED_LIBS}")
-message(STATUS "  Build static library .............: ${BUILD_STATIC_LIBS}")
+message(STATUS "  Build shared library .............: ${LLHTTP_BUILD_SHARED_LIBS}")
+message(STATUS "  Build static library .............: ${LLHTTP_BUILD_STATIC_LIBS}")
 message(STATUS "")

README.md

@@ -435,14 +435,16 @@ If you want to use this library in a CMake project as a static library, you can
 FetchContent_Declare(llhttp
   URL "https://github.com/nodejs/llhttp/archive/refs/tags/release/v8.1.0.tar.gz")
 
-set(BUILD_SHARED_LIBS OFF CACHE INTERNAL "")
-set(BUILD_STATIC_LIBS ON CACHE INTERNAL "")
+set(LLHTTP_BUILD_SHARED_LIBS OFF CACHE INTERNAL "")
+set(LLHTTP_BUILD_STATIC_LIBS ON CACHE INTERNAL "")
 FetchContent_MakeAvailable(llhttp)
 
 # Link with the llhttp_static target
 target_link_libraries(${EXAMPLE_PROJECT_NAME} ${PROJECT_LIBRARIES} llhttp_static ${PROJECT_NAME})
 ```
 
+If using a version prior to 9.3.0, the `LLHTTP_BUILD_SHARED_LIBS` and `LLHTTP_BUILD_STATIC_LIBS` options are known as `BUILD_SHARED_LIBS` and `BUILD_STATIC_LIBS` and should be used instead.
+
 _Note that using the git repo directly (e.g., via a git repo url and tag) will not work with FetchContent_Declare because [CMakeLists.txt](./CMakeLists.txt) requires string replacements (e.g., `_RELEASE_`) before it will build._
 
 ## Building on Windows