Use SHADERC_BUILD_SHARED to control static/shared library

CMakeLists.txt

@@ -2,8 +2,16 @@ cmake_minimum_required(VERSION 2.8.12)
 project(shaderc)
 enable_testing()
 
+set (CMAKE_CXX_STANDARD 11)
+
 message(STATUS "Shaderc: build type is \"${CMAKE_BUILD_TYPE}\".")
 
+# Note that we are not using or setting CMake BUILD_SHARED_LIBS here since that
+# also affects external projects and makes libshaderc.so to depend on shared
+# libraries compiled from external projects. We want libshaderc.so to depend
+# on only standard system libraries.
+option(SHADERC_BUILD_SHARED "Build Shaderc as shared library" OFF)
+
 option(SHADERC_SKIP_INSTALL "Skip installation" ${SHADERC_SKIP_INSTALL})
 if(NOT ${SHADERC_SKIP_INSTALL})
   set(SHADERC_ENABLE_INSTALL ON)
@@ -19,8 +27,6 @@ else()
   message(STATUS "Configuring Shaderc to avoid building tests.")
 endif()
 
-set (CMAKE_CXX_STANDARD 11)
-
 option(SHADERC_ENABLE_NV_EXTENSIONS "Enables support of Nvidia-specific extensions" ON)
 
 include(GNUInstallDirs)

libshaderc/CMakeLists.txt

@@ -10,19 +10,20 @@ set(SHADERC_SOURCES
   src/shaderc_private.h
 )
 
-add_library(shaderc STATIC ${SHADERC_SOURCES})
+if (${SHADERC_BUILD_SHARED})
+  add_library(shaderc SHARED ${SHADERC_SOURCES})
+  target_compile_definitions(shaderc
+      PRIVATE SHADERC_IMPLEMENTATION
+      PUBLIC SHADERC_SHAREDLIB
+  )
+  set_target_properties(shaderc PROPERTIES SOVERSION 1)
+else()
+  add_library(shaderc STATIC ${SHADERC_SOURCES})
+endif (${SHADERC_BUILD_SHARED})
+
 shaderc_default_compile_options(shaderc)
 target_include_directories(shaderc PUBLIC include PRIVATE ${glslang_SOURCE_DIR})
 
-add_library(shaderc_shared SHARED ${SHADERC_SOURCES})
-shaderc_default_compile_options(shaderc_shared)
-target_include_directories(shaderc_shared PUBLIC include PRIVATE ${glslang_SOURCE_DIR})
-target_compile_definitions(shaderc_shared
-    PRIVATE SHADERC_IMPLEMENTATION
-    PUBLIC SHADERC_SHAREDLIB
-)
-set_target_properties(shaderc_shared PROPERTIES SOVERSION 1)
-
 if(SHADERC_ENABLE_INSTALL)
   install(
     FILES
@@ -31,7 +32,7 @@ if(SHADERC_ENABLE_INSTALL)
     DESTINATION
       ${CMAKE_INSTALL_INCLUDEDIR}/shaderc)
 
-  install(TARGETS shaderc shaderc_shared
+  install(TARGETS shaderc
     LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
     RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
     ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
@@ -46,7 +47,6 @@ set(SHADERC_LIBS
 )
 
 target_link_libraries(shaderc PRIVATE ${SHADERC_LIBS})
-target_link_libraries(shaderc_shared PRIVATE ${SHADERC_LIBS})
 
 shaderc_add_tests(
   TEST_PREFIX shaderc
@@ -58,42 +58,34 @@ shaderc_add_tests(
     shaderc_cpp
     shaderc_private)
 
-shaderc_add_tests(
-  TEST_PREFIX shaderc_shared
-  LINK_LIBS shaderc_shared SPIRV-Tools
-  INCLUDE_DIRS include ${shaderc_SOURCE_DIR}/libshaderc_util/include ${glslang_SOURCE_DIR}
-               ${spirv-tools_SOURCE_DIR}/include
-  TEST_NAMES
-    shaderc
-    shaderc_cpp
-    shaderc_private)
-
-shaderc_combine_static_lib(shaderc_combined shaderc)
+if (NOT ${SHADERC_BUILD_SHARED})
+  shaderc_combine_static_lib(shaderc_combined shaderc)
 
-if(SHADERC_ENABLE_INSTALL)
-  # Since shaderc_combined is defined as an imported library, we cannot use the
-  # install() directive to install it. Install it like a normal file.
-  get_target_property(generated_location shaderc_combined LOCATION)
-  string(REGEX MATCH "Visual Studio .*" vs_generator "${CMAKE_GENERATOR}")
-  if (NOT "${vs_generator}" STREQUAL "")
-    # With Visual Studio generators, the LOCATION property is not properly
-    # expanded according to the current build configuration. We need to work
-    # around this problem by manually substitution.
-    string(REPLACE "$(Configuration)" "\${CMAKE_INSTALL_CONFIG_NAME}"
-      install_location "${generated_location}")
-    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${install_location} DESTINATION ${CMAKE_INSTALL_LIBDIR})
-  else()
-    install(FILES ${generated_location} DESTINATION ${CMAKE_INSTALL_LIBDIR})
-  endif()
-endif(SHADERC_ENABLE_INSTALL)
+  if(SHADERC_ENABLE_INSTALL)
+    # Since shaderc_combined is defined as an imported library, we cannot use the
+    # install() directive to install it. Install it like a normal file.
+    get_target_property(generated_location shaderc_combined LOCATION)
+    string(REGEX MATCH "Visual Studio .*" vs_generator "${CMAKE_GENERATOR}")
+    if (NOT "${vs_generator}" STREQUAL "")
+      # With Visual Studio generators, the LOCATION property is not properly
+      # expanded according to the current build configuration. We need to work
+      # around this problem by manually substitution.
+      string(REPLACE "$(Configuration)" "\${CMAKE_INSTALL_CONFIG_NAME}"
+        install_location "${generated_location}")
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${install_location} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    else()
+      install(FILES ${generated_location} DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif()
+  endif(SHADERC_ENABLE_INSTALL)
 
-shaderc_add_tests(
-  TEST_PREFIX shaderc_combined
-  LINK_LIBS shaderc_combined ${CMAKE_THREAD_LIBS_INIT}
-  INCLUDE_DIRS include ${glslang_SOURCE_DIR} ${spirv-tools_SOURCE_DIR}/include
-  TEST_NAMES
-    shaderc
-    shaderc_cpp)
+  shaderc_add_tests(
+    TEST_PREFIX shaderc_combined
+    LINK_LIBS shaderc_combined ${CMAKE_THREAD_LIBS_INIT}
+    INCLUDE_DIRS include ${glslang_SOURCE_DIR} ${spirv-tools_SOURCE_DIR}/include
+    TEST_NAMES
+      shaderc
+      shaderc_cpp)
+endif(NOT ${SHADERC_BUILD_SHARED})
 
 if(${SHADERC_ENABLE_TESTS})
   add_executable(shaderc_c_smoke_test ./src/shaderc_c_smoke_test.c)