| enable_language(CXX) |
| |
| if(CMAKE_CXX_COMPILE_OPTIONS_USE_PCH) |
| add_definitions(-DHAVE_PCH_SUPPORT) |
| endif() |
| |
| ###################################################################### |
| |
| file(WRITE ${CMAKE_BINARY_DIR}/pch.cxx [=[ |
| void nothing() |
| { |
| } |
| ]=]) |
| |
| file(WRITE ${CMAKE_BINARY_DIR}/string.hxx [=[ |
| #include <string.h> |
| |
| namespace std { |
| struct string |
| { |
| char storage[20]; |
| |
| string(const char* s) { |
| strcpy(storage, s); |
| } |
| |
| const char* c_str() const { |
| return storage; |
| } |
| }; |
| } |
| ]=]) |
| |
| add_library(pch-generator ${CMAKE_BINARY_DIR}/pch.cxx) |
| target_precompile_headers(pch-generator PRIVATE ${CMAKE_BINARY_DIR}/string.hxx) |
| set_property(TARGET pch-generator PROPERTY DISABLE_PRECOMPILE_HEADERS 1) |
| |
| ###################################################################### |
| |
| file(WRITE ${CMAKE_BINARY_DIR}/message.cxx [=[ |
| #include "message.hxx" |
| |
| #ifndef HAVE_PCH_SUPPORT |
| #include "string.hxx" |
| #endif |
| |
| const char* message() |
| { |
| static std::string greeting("hi there"); |
| return greeting.c_str(); |
| } |
| ]=]) |
| |
| file(WRITE ${CMAKE_BINARY_DIR}/message.hxx [=[ |
| const char* message(); |
| ]=]) |
| |
| add_library(reuse_from_nopch ${CMAKE_BINARY_DIR}/message.cxx) |
| target_precompile_headers(reuse_from_nopch REUSE_FROM pch-generator) |
| target_include_directories(reuse_from_nopch PRIVATE ${CMAKE_BINARY_DIR}) |
