Merge pull request libgit2#4398 from pks-t/pks/generic-sha1

cmake: allow explicitly choosing SHA1 backend

Author: ethomson

CMakeLists.txt

@@ -42,7 +42,7 @@ OPTION( PROFILE				"Generate profiling information"		OFF )
 OPTION( ENABLE_TRACE		"Enables tracing support"				OFF )
 OPTION( LIBGIT2_FILENAME	"Name of the produced binary"			OFF )
 
-OPTION( USE_SHA1DC			"Use SHA-1 with collision detection"	OFF )
+SET(SHA1_BACKEND "CollisionDetection" CACHE STRING "Backend to use for SHA1. One of Generic, OpenSSL, Win32, CommonCrypto, CollisionDetection. ")
 OPTION( USE_SSH				"Link with libssh to enable SSH support" ON )
 OPTION( USE_HTTPS			"Enable HTTPS support. Can be set to a specific backend"	ON )
 OPTION( USE_GSSAPI			"Link with libgssapi for SPNEGO auth"   OFF )

src/CMakeLists.txt

@@ -122,10 +122,6 @@ ELSE ()
 		PKG_CHECK_MODULES(CURL libcurl)
 	ENDIF ()
 
-	IF (NOT AMIGA AND (USE_HTTPS STREQUAL "OpenSSL" OR USE_HTTPS STREQUAL "ON"))
-		FIND_PACKAGE(OpenSSL QUIET)
-	ENDIF ()
-
 	IF (CURL_FOUND)
 		SET(GIT_CURL 1)
 		LIST(APPEND LIBGIT2_INCLUDES ${CURL_INCLUDE_DIRS})
@@ -178,6 +174,8 @@ IF (USE_HTTPS)
 		LIST(APPEND LIBGIT2_LIBS ${COREFOUNDATION_LIBRARIES} ${SECURITY_LIBRARIES})
 		LIST(APPEND LIBGIT2_PC_LIBS ${COREFOUNDATION_LDFLAGS} ${SECURITY_LDFLAGS})
 	ELSEIF (HTTPS_BACKEND STREQUAL "OpenSSL")
+		FIND_PACKAGE(OpenSSL)
+
 		IF (NOT OPENSSL_FOUND)
 			MESSAGE(FATAL_ERROR "Asked for OpenSSL TLS backend, but it wasn't found")
 		ENDIF()
@@ -199,34 +197,42 @@ ELSE()
 ENDIF()
 
 # Specify sha1 implementation
-IF (USE_SHA1DC)
-	ADD_FEATURE_INFO(SHA ON "using SHA1DC")
+IF(SHA1_BACKEND STREQUAL "OpenSSL")
+	IF(NOT OPENSSL_FOUND)
+		FIND_PACKAGE(OpenSSL)
+		IF(NOT OPENSSL_FOUND)
+		    MESSAGE(FATAL_ERROR "Requested OpenSSL SHA1 backend, but OpenSSL could not be found")
+		ENDIF()
+	ENDIF()
+
+	ADD_FEATURE_INFO(SHA ON "using OpenSSL")
+	SET(GIT_SHA1_OPENSSL 1)
+	IF(CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
+		LIST(APPEND LIBGIT2_PC_LIBS "-lssl")
+	ELSE()
+		SET(LIBGIT2_PC_REQUIRES "${LIBGIT2_PC_REQUIRES} openssl")
+	ENDIF()
+ELSEIF(SHA1_BACKEND STREQUAL "CollisionDetection")
+	ADD_FEATURE_INFO(SHA ON "using CollisionDetection")
 	SET(GIT_SHA1_COLLISIONDETECT 1)
 	ADD_DEFINITIONS(-DSHA1DC_NO_STANDARD_INCLUDES=1)
 	ADD_DEFINITIONS(-DSHA1DC_CUSTOM_INCLUDE_SHA1_C=\"common.h\")
 	ADD_DEFINITIONS(-DSHA1DC_CUSTOM_INCLUDE_UBC_CHECK_C=\"common.h\")
 	FILE(GLOB SRC_SHA1 hash/hash_collisiondetect.c hash/sha1dc/*)
-ELSEIF (WIN32 AND NOT MINGW)
-	ADD_FEATURE_INFO(SHA ON "using SHA1_WIN32")
+ELSEIF(SHA1_BACKEND STREQUAL "Generic")
+	ADD_FEATURE_INFO(SHA ON "using Generic")
+	FILE(GLOB SRC_SHA1 hash/hash_generic.c)
+ELSEIF(SHA1_BACKEND STREQUAL "Win32")
+	ADD_FEATURE_INFO(SHA ON "using Win32")
 	SET(GIT_SHA1_WIN32 1)
 	FILE(GLOB SRC_SHA1 hash/hash_win32.c)
-ELSEIF (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
+ELSEIF(SHA1_BACKEND STREQUAL "CommonCrypto")
 	ADD_FEATURE_INFO(SHA ON "using CommonCrypto")
 	SET(GIT_SHA1_COMMON_CRYPTO 1)
-ELSEIF (OPENSSL_FOUND)
-	ADD_FEATURE_INFO(SHA ON "using OpenSSL")
-	SET(GIT_SHA1_OPENSSL 1)
-	IF (CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
-		LIST(APPEND LIBGIT2_PC_LIBS "-lssl")
-	ELSE()
-		SET(LIBGIT2_PC_REQUIRES "${LIBGIT2_PC_REQUIRES} openssl")
-	ENDIF ()
 ELSE()
-	ADD_FEATURE_INFO(SHA ON "using generic")
-	FILE(GLOB SRC_SHA1 hash/hash_generic.c)
+	MESSAGE(FATAL_ERROR "Asked for unknown SHA1 backend ${SHA1_BACKEND}")
 ENDIF()
 
-
 # Include POSIX regex when it is required
 IF(WIN32 OR AMIGA OR CMAKE_SYSTEM_NAME MATCHES "(Solaris|SunOS)")
 	ADD_SUBDIRECTORY("${libgit2_SOURCE_DIR}/deps/regex" "${libgit2_BINARY_DIR}/deps/regex")