Build with the system's http-parser installation if available

CMakeLists.txt

@@ -14,7 +14,8 @@
 PROJECT(libgit2 C)
 CMAKE_MINIMUM_REQUIRED(VERSION 2.6)
 
-set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
+# Add find modules to the path
+SET(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
 
 # Build options
 #
@@ -100,8 +101,16 @@ ELSE ()
 	IF (NOT AMIGA)
 		FIND_PACKAGE(OpenSSL)
 	ENDIF ()
-	FILE(GLOB SRC_HTTP deps/http-parser/*.c)
-	INCLUDE_DIRECTORIES(deps/http-parser)
+
+	FIND_PACKAGE(HTTP_Parser QUIET)
+	IF (HTTP_PARSER_FOUND AND HTTP_PARSER_VERSION_MAJOR EQUAL 2)
+		INCLUDE_DIRECTORIES(${HTTP_PARSER_INCLUDE_DIRS})
+		LINK_LIBRARIES(${HTTP_PARSER_LIBRARIES})
+	ELSE()
+		MESSAGE("http-parser was not found or is too old; using bundled 3rd-party sources.")
+		INCLUDE_DIRECTORIES(deps/http-parser)
+		FILE(GLOB SRC_HTTP deps/http-parser/*.c)
+	ENDIF()
 ENDIF()
 
 # Specify sha1 implementation

cmake/Modules/FindHTTP_Parser.cmake

+# - Try to find http-parser
+#
+# Defines the following variables:
+#
+# HTTP_PARSER_FOUND - system has http-parser
+# HTTP_PARSER_INCLUDE_DIR - the http-parser include directory
+# HTTP_PARSER_LIBRARIES - Link these to use http-parser
+# HTTP_PARSER_VERSION_MAJOR - major version
+# HTTP_PARSER_VERSION_MINOR - minor version
+# HTTP_PARSER_VERSION_STRING - the version of http-parser found
+
+# Find the header and library
+FIND_PATH(HTTP_PARSER_INCLUDE_DIR NAMES http_parser.h)
+FIND_LIBRARY(HTTP_PARSER_LIBRARY NAMES http_parser libhttp_parser)
+
+# Found the header, read version
+if (HTTP_PARSER_INCLUDE_DIR AND EXISTS "${HTTP_PARSER_INCLUDE_DIR}/http_parser.h")
+	FILE(READ "${HTTP_PARSER_INCLUDE_DIR}/http_parser.h" HTTP_PARSER_H)
+	IF (HTTP_PARSER_H)
+		STRING(REGEX REPLACE ".*#define[\t ]+HTTP_PARSER_VERSION_MAJOR[\t ]+([0-9]+).*" "\\1" HTTP_PARSER_VERSION_MAJOR "${HTTP_PARSER_H}")
+		STRING(REGEX REPLACE ".*#define[\t ]+HTTP_PARSER_VERSION_MINOR[\t ]+([0-9]+).*" "\\1" HTTP_PARSER_VERSION_MINOR "${HTTP_PARSER_H}")
+		SET(HTTP_PARSER_VERSION_STRING "${HTTP_PARSER_VERSION_MAJOR}.${HTTP_PARSER_VERSION_MINOR}")
+	ENDIF()
+	UNSET(HTTP_PARSER_H)
+ENDIF()
+
+# Handle the QUIETLY and REQUIRED arguments and set HTTP_PARSER_FOUND
+# to TRUE if all listed variables are TRUE
+INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(HTTP_Parser REQUIRED_VARS HTTP_PARSER_INCLUDE_DIR HTTP_PARSER_LIBRARY)
+
+# Hide advanced variables
+MARK_AS_ADVANCED(HTTP_PARSER_INCLUDE_DIR HTTP_PARSER_LIBRARY)
+
+# Set standard variables
+IF (HTTP_PARSER_FOUND)
+	SET(HTTP_PARSER_LIBRARIES ${HTTP_PARSER_LIBRARY})
+	set(HTTP_PARSER_INCLUDE_DIRS ${HTTP_PARSER_INCLUDE_DIR})
+ENDIF()