package-cmake: remove now-redundant target ccache support

All the complexity with the different ways that CMAKE_C_COMPILER and
CMAKE_C_COMPILER_ARG1 can be set are no longer needed, it's all handled
by the toolchain wrapper now.

Note that it is still necessary to handle this for the host build.

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Reviewed-by: Romain Naour <romain.naour@openwide.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/pkg-cmake.mk

@@ -98,7 +98,6 @@ define $(2)_CONFIGURE_CMDS
 		-DBUILD_TESTS=OFF \
 		-DBUILD_TESTING=OFF \
 		-DBUILD_SHARED_LIBS=$$(if $$(BR2_STATIC_LIBS),OFF,ON) \
-		-DUSE_CCACHE=$$(if $$(BR2_CCACHE),ON,OFF) \
 		$$(CMAKE_QUIET) \
 		$$($$(PKG)_CONF_OPTS) \
 	)
@@ -245,8 +244,8 @@ $(HOST_DIR)/usr/share/buildroot/toolchainfile.cmake:
 		-e 's#@@TARGET_CFLAGS@@#$(call qstrip,$(TARGET_CFLAGS))#' \
 		-e 's#@@TARGET_CXXFLAGS@@#$(call qstrip,$(TARGET_CXXFLAGS))#' \
 		-e 's#@@TARGET_LDFLAGS@@#$(call qstrip,$(TARGET_LDFLAGS))#' \
-		-e 's#@@TARGET_CC_NOCCACHE@@#$(subst $(HOST_DIR)/,,$(call qstrip,$(TARGET_CC_NOCCACHE)))#' \
-		-e 's#@@TARGET_CXX_NOCCACHE@@#$(subst $(HOST_DIR)/,,$(call qstrip,$(TARGET_CXX_NOCCACHE)))#' \
+		-e 's#@@TARGET_CC@@#$(subst $(HOST_DIR)/,,$(call qstrip,$(TARGET_CC)))#' \
+		-e 's#@@TARGET_CXX@@#$(subst $(HOST_DIR)/,,$(call qstrip,$(TARGET_CXX)))#' \
 		-e 's#@@CMAKE_SYSTEM_PROCESSOR@@#$(call qstrip,$(CMAKE_SYSTEM_PROCESSOR))#' \
 		$(TOPDIR)/support/misc/toolchainfile.cmake.in \
 		> $@

support/misc/toolchainfile.cmake.in

@@ -27,33 +27,5 @@ set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
 set(ENV{PKG_CONFIG_SYSROOT_DIR} "${RELOCATED_HOST_DIR}/@@STAGING_SUBDIR@@")
 
 # This toolchain file can be used both inside and outside Buildroot.
-# * When used inside Buildroot, ccache support is explicitly driven using the
-#   USE_CCACHE variable.
-# * When used outside Buildroot (i.e. when USE_CCACHE is not defined), ccache
-#   support is automatically enabled if the ccache program is available.
-if(DEFINED USE_CCACHE)
-	if(USE_CCACHE)
-		set(CMAKE_ASM_COMPILER "${RELOCATED_HOST_DIR}/@@TARGET_CC_NOCCACHE@@")
-		set(CMAKE_C_COMPILER "${RELOCATED_HOST_DIR}/usr/bin/ccache")
-		set(CMAKE_CXX_COMPILER "${RELOCATED_HOST_DIR}/usr/bin/ccache")
-		set(CMAKE_C_COMPILER_ARG1 "${RELOCATED_HOST_DIR}/@@TARGET_CC_NOCCACHE@@")
-		set(CMAKE_CXX_COMPILER_ARG1 "${RELOCATED_HOST_DIR}/@@TARGET_CXX_NOCCACHE@@")
-	else()
-		set(CMAKE_C_COMPILER "${RELOCATED_HOST_DIR}/@@TARGET_CC_NOCCACHE@@")
-		set(CMAKE_CXX_COMPILER "${RELOCATED_HOST_DIR}/@@TARGET_CXX_NOCCACHE@@")
-	endif()
-else()
-	find_program(CCACHE ccache HINTS "${RELOCATED_HOST_DIR}/usr/bin")
-	if(CCACHE)
-		set(CMAKE_ASM_COMPILER "${RELOCATED_HOST_DIR}/@@TARGET_CC_NOCCACHE@@")
-		set(CMAKE_C_COMPILER "${CCACHE}")
-		set(CMAKE_CXX_COMPILER "${CCACHE}")
-		set(CMAKE_C_COMPILER_ARG1 "${RELOCATED_HOST_DIR}/@@TARGET_CC_NOCCACHE@@")
-		set(CMAKE_CXX_COMPILER_ARG1 "${RELOCATED_HOST_DIR}/@@TARGET_CXX_NOCCACHE@@")
-		message(STATUS "ccache program has been found and will be used for the build.")
-		message(STATUS "  To disable ccache, add -DUSE_CCACHE=OFF on the cmake command line.")
-	else()
-		set(CMAKE_C_COMPILER "${RELOCATED_HOST_DIR}/@@TARGET_CC_NOCCACHE@@")
-		set(CMAKE_CXX_COMPILER "${RELOCATED_HOST_DIR}/@@TARGET_CXX_NOCCACHE@@")
-	endif()
-endif()
+set(CMAKE_C_COMPILER "${RELOCATED_HOST_DIR}/@@TARGET_CC@@")
+set(CMAKE_CXX_COMPILER "${RELOCATED_HOST_DIR}/@@TARGET_CXX@@")