Merge pull request #669 from ligfx/friendlycmake

CMake improvements when embedding in another project

build/cmake/CMakeLists.txt

@@ -9,13 +9,14 @@
 
 PROJECT(zstd)
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8.9)
-SET(ZSTD_SOURCE_DIR "${CMAKE_SOURCE_DIR}/../..")
+SET(ZSTD_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../..")
+LIST(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/CMakeModules")
 
 #-----------------------------------------------------------------------------
 # Add extra compilation flags
 #-----------------------------------------------------------------------------
-INCLUDE(CMakeModules/AddExtraCompilationFlags.cmake)
-ADD_EXTRA_COMPILATION_FLAGS()
+INCLUDE(AddZstdCompilationFlags)
+ADD_ZSTD_COMPILATION_FLAGS()
 
 #-----------------------------------------------------------------------------
 # Options

build/cmake/CMakeModules/AddZstdCompilationFlags.cmake

@@ -2,24 +2,25 @@ include(CheckCXXCompilerFlag)
 include(CheckCCompilerFlag)
 
 function(EnableCompilerFlag _flag _C _CXX)
-    message("Checking flag ${_flag}")
+    string(REGEX REPLACE "\\+" "PLUS" varname "${_flag}")
+    string(REGEX REPLACE "[^A-Za-z0-9]+" "_" varname "${varname}")
+    string(REGEX REPLACE "^_+" "" varname "${varname}")
+    string(TOUPPER "${varname}" varname)
     if (_C)
-        CHECK_C_COMPILER_FLAG(${_flag} C_FLAG)
-        if (C_FLAG)
-            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_flag}" CACHE INTERNAL "C Flags")
+        CHECK_C_COMPILER_FLAG(${_flag} C_FLAG_${varname})
+        if (C_FLAG_${varname})
+            set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${_flag}" PARENT_SCOPE)
         endif ()
-        unset(C_FLAG CACHE)
     endif ()
     if (_CXX)
-        CHECK_CXX_COMPILER_FLAG(${_flag} CXX_FLAG)
-        if (CXX_FLAG)
-            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_flag}" CACHE INTERNAL "CXX Flags")
+        CHECK_CXX_COMPILER_FLAG(${_flag} CXX_FLAG_${varname})
+        if (CXX_FLAG_${varname})
+            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${_flag}" PARENT_SCOPE)
         endif ()
-        unset(CXX_FLAG CACHE)
     endif ()
 endfunction()
 
-MACRO(ADD_EXTRA_COMPILATION_FLAGS)
+MACRO(ADD_ZSTD_COMPILATION_FLAGS)
     if (CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang" OR MINGW) #Not only UNIX but also WIN32 for MinGW
         #Set c++11 by default
         EnableCompilerFlag("-std=c++11" false true)
@@ -68,8 +69,7 @@ MACRO(ADD_EXTRA_COMPILATION_FLAGS)
         separate_arguments(${flag_var})
         list(REMOVE_DUPLICATES ${flag_var})
         string(REPLACE ";" " " ${flag_var} "${${flag_var}}")
-        set(${flag_var} "${${flag_var}}" CACHE STRING "common build flags" FORCE)
-    ENDFOREACH (flag_var)  
+    ENDFOREACH (flag_var)
 
     if (MSVC)
         # Replace /MT to /MD flag
@@ -80,19 +80,7 @@ MACRO(ADD_EXTRA_COMPILATION_FLAGS)
                  CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO)
             STRING(REGEX REPLACE "/MT" "/MD" ${flag_var} "${${flag_var}}")
             STRING(REGEX REPLACE "/O2" "/Ox" ${flag_var} "${${flag_var}}")
-        ENDFOREACH (flag_var)      
+        ENDFOREACH (flag_var)
     endif ()
 
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}" CACHE STRING "Updated flags" FORCE)
-    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}" CACHE STRING "Updated flags" FORCE)
-    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}" CACHE STRING "Updated flags" FORCE)
-    set(CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL}" CACHE STRING "Updated flags" FORCE)
-    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}" CACHE STRING "Updated flags" FORCE)
-
-    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}" CACHE STRING "Updated flags" FORCE)
-    set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG}" CACHE STRING "Updated flags" FORCE)
-    set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE}" CACHE STRING "Updated flags" FORCE)
-    set(CMAKE_C_FLAGS_MINSIZEREL "${CMAKE_C_FLAGS_MINSIZEREL}" CACHE STRING "Updated flags" FORCE)
-    set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO}" CACHE STRING "Updated flags" FORCE)
-
-ENDMACRO(ADD_EXTRA_COMPILATION_FLAGS)
+ENDMACRO(ADD_ZSTD_COMPILATION_FLAGS)

build/cmake/CMakeModules/GetZstdLibraryVersion.cmake

@@ -1,4 +1,4 @@
-function(GetLibraryVersion _header _major _minor _release)
+function(GetZstdLibraryVersion _header _major _minor _release)
     # Read file content
     FILE(READ ${_header} CONTENT)
 

build/cmake/contrib/gen_html/CMakeLists.txt

@@ -11,7 +11,7 @@
 # ################################################################
 
 PROJECT(gen_html)
-INCLUDE(${CMAKE_SOURCE_DIR}/CMakeModules/GetLibraryVersion.cmake)
+INCLUDE(GetZstdLibraryVersion)
 
 SET(CMAKE_INCLUDE_CURRENT_DIR TRUE)
 
@@ -24,7 +24,7 @@ INCLUDE_DIRECTORIES(${PROGRAMS_DIR} ${LIBRARY_DIR} ${LIBRARY_DIR}/common ${GENHT
 
 ADD_EXECUTABLE(gen_html ${GENHTML_DIR}/gen_html.cpp)
 
-GetLibraryVersion(${LIBRARY_DIR}/zstd.h VMAJOR VMINOR VRELEASE)
+GetZstdLibraryVersion(${LIBRARY_DIR}/zstd.h VMAJOR VMINOR VRELEASE)
 SET(LIBVERSION "${VMAJOR}.${VMINOR}.${VRELEASE}")
 ADD_CUSTOM_TARGET(zstd_manual.html ALL
                   ${GENHTML_BINARY} "${LIBVERSION}" "${LIBRARY_DIR}/zstd.h" "${PROJECT_BINARY_DIR}/zstd_manual.html"

build/cmake/lib/CMakeLists.txt

@@ -11,7 +11,6 @@
 # ################################################################
 
 PROJECT(libzstd)
-INCLUDE(${CMAKE_SOURCE_DIR}/CMakeModules/GetLibraryVersion.cmake)
 
 SET(CMAKE_INCLUDE_CURRENT_DIR TRUE)
 OPTION(ZSTD_BUILD_STATIC "BUILD STATIC LIBRARIES" OFF)
@@ -21,7 +20,8 @@ SET(LIBRARY_DIR ${ZSTD_SOURCE_DIR}/lib)
 INCLUDE_DIRECTORIES(${LIBRARY_DIR} ${LIBRARY_DIR}/common)
 
 # Parse version
-GetLibraryVersion(${LIBRARY_DIR}/zstd.h LIBVER_MAJOR LIBVER_MINOR LIBVER_RELEASE)
+INCLUDE(GetZstdLibraryVersion)
+GetZstdLibraryVersion(${LIBRARY_DIR}/zstd.h LIBVER_MAJOR LIBVER_MINOR LIBVER_RELEASE)
 MESSAGE("ZSTD VERSION ${LIBVER_MAJOR}.${LIBVER_MINOR}.${LIBVER_RELEASE}")
 
 SET(Sources
@@ -138,7 +138,7 @@ IF (UNIX)
     ADD_CUSTOM_TARGET(libzstd.pc ALL
             ${CMAKE_COMMAND} -DIN="${LIBRARY_DIR}/libzstd.pc.in" -DOUT="libzstd.pc"
             -DPREFIX="${PREFIX}" -DLIBDIR="${LIBDIR}" -DINCLUDEDIR="${INCLUDEDIR}" -DVERSION="${VERSION}"
-            -P "${CMAKE_SOURCE_DIR}/lib/pkgconfig.cmake"
+            -P "${CMAKE_CURRENT_SOURCE_DIR}/pkgconfig.cmake"
             COMMENT "Creating pkg-config file")
 
     # install target
@@ -151,10 +151,10 @@ IF (UNIX)
 
     # uninstall target
     CONFIGURE_FILE(
-            "${CMAKE_SOURCE_DIR}/cmake_uninstall.cmake.in"
-            "${CMAKE_BINARY_DIR}/cmake_uninstall.cmake"
+            "${CMAKE_CURRENT_SOURCE_DIR}/cmake_uninstall.cmake.in"
+            "${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake"
             IMMEDIATE @ONLY)
 
     ADD_CUSTOM_TARGET(uninstall
-            COMMAND ${CMAKE_COMMAND} -P ${CMAKE_BINARY_DIR}/cmake_uninstall.cmake)
+            COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_BINARY_DIR}/cmake_uninstall.cmake)
 ENDIF (UNIX)