Merge pull request #92 from cpp-best-practices/lto

aminya · Mar 7, 2022 · 592ba69 · 592ba69
2 parents fe896ba + cc84b78
commit 592ba69
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Showing 4 changed files with 12 additions and 5 deletions.
diff --git a/src/Index.cmake b/src/Index.cmake
@@ -105,7 +105,7 @@ macro(project_options)
     set(ProjectOptions_ENABLE_INTERPROCEDURAL_OPTIMIZATION ${ProjectOptions_ENABLE_IPO})
   endif()
   if(${ProjectOptions_ENABLE_INTERPROCEDURAL_OPTIMIZATION})
-    enable_interprocedural_optimization()
+    enable_interprocedural_optimization(project_options)
   endif()
 
   if(${ProjectOptions_ENABLE_NATIVE_OPTIMIZATION})

diff --git a/src/Optimization.cmake b/src/Optimization.cmake
@@ -1,11 +1,18 @@
-macro(enable_interprocedural_optimization)
+macro(enable_interprocedural_optimization project_name)
   if(CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
     include(CheckIPOSupported)
     check_ipo_supported(RESULT result OUTPUT output)
     if(result)
+      # If a static library of this project is used in another project that does not have `CMAKE_INTERPROCEDURAL_OPTIMIZATION` enabled, a linker error might happen.
+      # TODO set this option in `package_project` function.
+      message(
+        STATUS
+          "Interprocedural optimization is enabled. In other projects, linking with the compiled libraries of this project might require `set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)`"
+      )
       set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
+      set_target_properties(${project_name} PROPERTIES INTERPROCEDURAL_OPTIMIZATION ON)
     else()
-      message(SEND_ERROR "IPO is not supported: ${output}")
+      message(WARNING "Interprocedural Optimization is not supported. Not using it. Here is the error log: ${output}")
     endif()
   endif()
 endmacro()

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
@@ -31,7 +31,7 @@ project_options(
   # ENABLE_PCH
   # PCH_HEADERS <Eigen/Dense> <fmt/core.h> <vector> <utility> <string> <string_view>
   ENABLE_DOXYGEN
-  # ENABLE_INTERPROCEDURAL_OPTIMIZATION
+  ENABLE_INTERPROCEDURAL_OPTIMIZATION
   ENABLE_NATIVE_OPTIMIZATION
   # ENABLE_USER_LINKER
   # ENABLE_BUILD_WITH_TIME_TRACE

diff --git a/test_install/CMakeLists.txt b/test_install/CMakeLists.txt
@@ -22,7 +22,7 @@ project_options(
   # ENABLE_PCH
   # PCH_HEADERS <Eigen/Dense> <fmt/core.h> <vector> <utility> <string> <string_view>
   # ENABLE_DOXYGEN
-  # ENABLE_INTERPROCEDURAL_OPTIMIZATION
+  ENABLE_INTERPROCEDURAL_OPTIMIZATION
   # ENABLE_USER_LINKER
   # ENABLE_BUILD_WITH_TIME_TRACE
   # ENABLE_UNITY