1 files changed, 66 insertions, 0 deletions
diff --git a/cmake/Ccache.cmake b/cmake/Ccache.cmake
new file mode 100644
index 00000000..09e81756
--- /dev/null
+++ b/cmake/Ccache.cmake
@@ -0,0 +1,66 @@
+#
+# CMake module to support ccache
+#
+# see https://crascit.com/2016/04/09/using-ccache-with-cmake/
+#
+
+find_program(CCACHE_PROGRAM ccache)
+# Note: REQUIRED keyword introduced in CMake 3.18
+
+if(CCACHE_PROGRAM)
+  message(STATUS "Configuring ccache with ${CCACHE_PROGRAM}")
+
+  set(C_LAUNCHER   "${CCACHE_PROGRAM}")
+  set(CXX_LAUNCHER "${CCACHE_PROGRAM}")
+
+  # Set up wrapper scripts
+  set(CCACHE_LAUNCH_C ${CMAKE_BINARY_DIR}/ccache-launch-c)
+  file(WRITE ${CCACHE_LAUNCH_C} "\
+#!/bin/sh
+
+# Xcode generator doesn't include the compiler as the
+# first argument, Ninja and Makefiles do. Handle both cases.
+if [ \"$1\" = \"${CMAKE_C_COMPILER}\" ] ; then
+    shift
+fi
+
+export CCACHE_CPP2=true
+exec \"${C_LAUNCHER}\" \"${CMAKE_C_COMPILER}\" \"$@\"
+")
+
+  set(CCACHE_LAUNCH_CXX ${CMAKE_BINARY_DIR}/ccache-launch-cxx)
+  file(WRITE ${CCACHE_LAUNCH_CXX} "\
+#!/bin/sh
+
+# Xcode generator doesn't include the compiler as the
+# first argument, Ninja and Makefiles do. Handle both cases.
+if [ \"$1\" = \"${CMAKE_CXX_COMPILER}\" ] ; then
+    shift
+fi
+
+export CCACHE_CPP2=true
+exec \"${CXX_LAUNCHER}\" \"${CMAKE_CXX_COMPILER}\" \"$@\"
+")
+
+  # Note: file(CHMOD) introduced in CMake 3.19
+  execute_process(
+    COMMAND chmod a+rx
+      "${CCACHE_LAUNCH_C}"
+      "${CCACHE_LAUNCH_CXX}"
+  )
+
+  if(CMAKE_GENERATOR STREQUAL "Xcode")
+    # Set Xcode project attributes to route compilation and linking
+    # through our scripts
+    set(CMAKE_XCODE_ATTRIBUTE_CC         "${CCACHE_LAUNCH_C}")
+    set(CMAKE_XCODE_ATTRIBUTE_CXX        "${CCACHE_LAUNCH_CXX}")
+    set(CMAKE_XCODE_ATTRIBUTE_LD         "${CCACHE_LAUNCH_C}")
+    set(CMAKE_XCODE_ATTRIBUTE_LDPLUSPLUS "${CCACHE_LAUNCH_CXX}")
+  else()
+    # Support Unix Makefiles and Ninja
+    set(CMAKE_C_COMPILER_LAUNCHER   "${CCACHE_LAUNCH_C}")
+    set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE_LAUNCH_CXX}")
+  endif()
+else()
+  message(SEND_ERROR "Ccache requested, but ccache was not found")
+endif()