ensure tune flags are passed to clang when building Swift recipes

Yocto defines target-specific tune flags in the TARGET_CC_ARCH variable. Expand
these and include them in destination.json so they are used when SwiftPM is
compiling C.

Author: lhoward

classes/swift-cmake-base.bbclass

@@ -12,10 +12,27 @@ TARGET_CPU_NAME = "${@oe.utils.conditional('TARGET_ARCH', 'arm', 'armv7-a', '${T
 # Determine SWIFT_GCC_VERSION by examining bitbake's context dictionary key
 # RECIPE_MAINTAINER:pn-gcc-source-<version>
 python () {
+    import shlex
+
     gcc_src_maint_pkg = [x for x in d if x.startswith("RECIPE_MAINTAINER:pn-gcc-source-")][0]
     gcc_ver = gcc_src_maint_pkg.rpartition("-")[2]
 
     d.setVar("SWIFT_GCC_VERSION", gcc_ver)
+
+    def expand_swiftc_cc_flags(flags):
+        flags = [['-Xcc', flag] for flag in flags]
+        return sum(flags, [])
+
+    def concat_flags(flags):
+        return " ".join(flags)
+
+    # ensure target-specific tune CC flags are propagated to clang and swiftc.
+    # Note we are not doing this at present for LD flags, as there are none in
+    # the architectures we support (and it would make the string expansion more
+    # complicated).
+    target_cc_arch = shlex.split(d.getVar("TARGET_CC_ARCH"))
+
+    d.setVar("SWIFT_EXTRA_SWIFTC_CC_FLAGS", concat_flags(expand_swiftc_cc_flags(target_cc_arch)))
 }
 
 EXTRA_INCLUDE_FLAGS ?= "\
@@ -48,8 +65,8 @@ OECMAKE_C_COMPILER = "clang"
 OECMAKE_CXX_COMPILER = "clang++"
 
 # Point clang to where the C++ runtime is for our target arch
-RUNTIME_FLAGS = "-w -fuse-ld=lld -B${STAGING_DIR_TARGET}/usr/lib/${TARGET_SYS}/${SWIFT_GCC_VERSION}"
-TARGET_LDFLAGS:append = " -w -fuse-ld=lld -L${STAGING_DIR_TARGET}/usr/lib/${TARGET_SYS}/${SWIFT_GCC_VERSION}"
+RUNTIME_FLAGS = "${TARGET_CC_ARCH} -w -fuse-ld=lld -B${STAGING_DIR_TARGET}/usr/lib/${TARGET_SYS}/${SWIFT_GCC_VERSION}"
+TARGET_LDFLAGS:append = " ${TARGET_LD_ARCH} -w -fuse-ld=lld -L${STAGING_DIR_TARGET}/usr/lib/${TARGET_SYS}/${SWIFT_GCC_VERSION}"
 
 OECMAKE_C_FLAGS:append = " ${RUNTIME_FLAGS} ${EXTRA_INCLUDE_FLAGS}"
 OECMAKE_CXX_FLAGS:append = " ${RUNTIME_FLAGS} ${EXTRA_INCLUDE_FLAGS}"
@@ -70,6 +87,7 @@ SWIFT_FLAGS = "-target ${SWIFT_TARGET_NAME} -use-ld=lld \
     -module-cache-path ${B}/${BUILD_MODE}/ModuleCache \
     -Xclang-linker -B${STAGING_DIR_TARGET}/usr/lib \
     -Xclang-linker -B${STAGING_DIR_TARGET}/usr/lib/${TARGET_SYS}/${SWIFT_GCC_VERSION} \
+    ${SWIFT_EXTRA_SWIFTC_CC_FLAGS} \
     -Xcc -I${STAGING_DIR_NATIVE}/usr/lib/${TARGET_SYS}/gcc/${TARGET_SYS}/${SWIFT_GCC_VERSION}/include \
     -Xcc -I${STAGING_DIR_NATIVE}/usr/lib/${TARGET_SYS}/gcc/${TARGET_SYS}/${SWIFT_GCC_VERSION}/include-fixed \
     -L${STAGING_DIR_TARGET} \

classes/swift.bbclass

@@ -90,6 +90,7 @@ python swift_do_configure() {
     import os
     import os.path
     import shutil
+    import shlex
 
     workdir = d.getVar("WORKDIR", True)
     recipe_sysroot = d.getVar("STAGING_DIR_TARGET", True)
@@ -114,13 +115,31 @@ python swift_do_configure() {
 
     d.setVar('SWIFT_CXX_VERSION', cxx_version)
 
+    def expand_swiftc_cc_flags(flags):
+        flags = [['-Xcc', flag] for flag in flags]
+        return sum(flags, [])
+
+    def concat_flags(flags):
+        flags = [f'"{flag}"' for flag in flags]
+        return ", ".join(flags)
+
+    # ensure target-specific tune CC flags are propagated to clang and swiftc.
+    # Note we are not doing this at present for LD flags, as there are none in
+    # the architectures we support (and it would make the string expansion more
+    # complicated).
+    target_cc_arch = shlex.split(d.getVar("TARGET_CC_ARCH"))
+
+    d.setVar("SWIFT_EXTRA_CC_FLAGS", concat_flags(target_cc_arch))
+    d.setVar("SWIFT_EXTRA_SWIFTC_CC_FLAGS", concat_flags(expand_swiftc_cc_flags(target_cc_arch)))
+
     swift_destination_template = """{
         "version":1,
         "sdk":"${STAGING_DIR_TARGET}/",
         "toolchain-bin-dir":"${STAGING_DIR_NATIVE}/usr/bin",
         "target":"${SWIFT_TARGET_NAME}",
         "dynamic-library-extension":"so",
         "extra-cc-flags":[
+            ${SWIFT_EXTRA_CC_FLAGS},
             "-fPIC",
             "-I${STAGING_INCDIR}",
             "-I${STAGING_DIR_TARGET}/usr/include/c++/${SWIFT_CXX_VERSION}",
@@ -166,9 +185,11 @@ python swift_do_configure() {
 
             "-resource-dir", "${STAGING_DIR_TARGET}/usr/lib/swift",
             "-module-cache-path", "${B}/${BUILD_MODE}/ModuleCache",
+
             "-Xclang-linker", "-B${STAGING_DIR_TARGET}/usr/lib/${TARGET_SYS}/${SWIFT_CXX_VERSION}",
             "-Xclang-linker", "-B${STAGING_DIR_TARGET}/usr/lib",
 
+            ${SWIFT_EXTRA_SWIFTC_CC_FLAGS},
             "-Xcc", "--gcc-install-dir=${STAGING_DIR_TARGET}/usr/lib/gcc/${TARGET_SYS}/${SWIFT_CXX_VERSION}",
 
             "-sdk", "${STAGING_DIR_TARGET}"
@@ -182,6 +203,9 @@ python swift_do_configure() {
 
     d.delVar("SWIFT_CXX_VERSION")
 
+    d.delVar("SWIFT_EXTRA_CC_FLAGS")
+    d.delVar("SWIFT_EXTRA_SWIFTC_CC_FLAGS")
+
     configJSON = open(workdir + "/destination.json", "w")
     configJSON.write(swift_destination)
     configJSON.close()

recipes-devtools/swift/swift-stdlib.bb

@@ -151,7 +151,7 @@ set(SWIFT_ENABLE_SYNCHRONIZATION ON)
 set(SWIFT_PATH_TO_STRING_PROCESSING_SOURCE ${WORKDIR}/swift-experimental-string-processing)
 set(SWIFT_SYNTAX_SOURCE_DIR ${WORKDIR}/swift-syntax)
 set(SWIFTSYNTAX_SOURCE_DIR ${WORKDIR}/swift-syntax)
-set(SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS -Xcc --gcc-install-dir=${STAGING_DIR_TARGET}/usr/lib/gcc/${TARGET_SYS}/${SWIFT_GCC_VERSION} -I${STAGING_DIR_TARGET}/usr/include/c++/${SWIFT_GCC_VERSION} -I${STAGING_DIR_TARGET}/usr/include/c++/${SWIFT_GCC_VERSION}/${TARGET_SYS} -no-verify-emitted-module-interface)
+set(SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS -Xcc --gcc-install-dir=${STAGING_DIR_TARGET}/usr/lib/gcc/${TARGET_SYS}/${SWIFT_GCC_VERSION} -I${STAGING_DIR_TARGET}/usr/include/c++/${SWIFT_GCC_VERSION} -I${STAGING_DIR_TARGET}/usr/include/c++/${SWIFT_GCC_VERSION}/${TARGET_SYS} -no-verify-emitted-module-interface ${SWIFT_EXTRA_SWIFTC_CC_FLAGS})
 set(SWIFT_SDK_LINUX_CXX_OVERLAY_SWIFT_COMPILE_FLAGS "")
 
 set(ICU_I18N_LIBRARIES ${STAGING_DIR_TARGET}/usr/lib/libicui18n.so)