Add support to llvm and cmark to cross-compile using an external sysroot

utils/build-script-impl

@@ -1117,7 +1117,7 @@ function false_true() {
 CROSS_COMPILE_HOSTS=($CROSS_COMPILE_HOSTS)
 for t in "${CROSS_COMPILE_HOSTS[@]}"; do
     case ${t} in
-        macosx* | iphone* | appletv* | watch* | linux-armv5 | linux-armv6 | linux-armv7 | android-* | openbsd-* | linux-static-* )
+        macosx* | iphone* | appletv* | watch* | android-* | openbsd-* | linux-* | linux-static-* )
             ;;
         *)
             echo "Unknown host to cross-compile for: ${t}"

utils/swift_build_support/swift_build_support/products/product.py

@@ -379,6 +379,11 @@ def get_linux_target_components(self, arch):
     def get_linux_sysroot(self, platform, arch):
         if not self.is_cross_compile_target('{}-{}'.format(platform, arch)):
             return None
+
+        # If the deps path was passed, use it instead
+        if self.args.cross_compile_deps_path:
+            return self.args.cross_compile_deps_path
+
         sysroot_arch, _, abi = self.get_linux_target_components(arch)
         # $ARCH-$PLATFORM-$ABI
         # E.x.: aarch64-linux-gnu
@@ -479,6 +484,11 @@ def common_cross_c_flags(self, platform, arch, include_arch=False):
         if self.is_release():
             cross_flags.append('-fno-stack-protector')
 
+        # Use lld when cross-compiling to a Linux arch
+        if (self.is_cross_compile_target("{}-{}".format(platform, arch))
+                and platform == 'linux'):
+            cross_flags.append('-w -fuse-ld=lld')
+
         return self.common_c_flags + cross_flags
 
 

utils/swift_build_support/tests/products/test_llvm_linux_cross_compile.py

@@ -40,7 +40,8 @@ def setUp(self):
             clang_compiler_version=None,
             clang_user_visible_version=None,
             cross_compile_hosts='linux-aarch64',
-            cross_compile_deps_path='sysroot'
+            cross_compile_deps_path=None,
+            build_variant='Release'
         )
 
         # Setup shell
@@ -59,11 +60,38 @@ def tearDown(self):
         self.toolchain = None
         self.args = None
 
-    def test_llvm_get_linux_sysroot(self):
+    def test_llvm_get_linux_sysroot_default(self):
         llvm = LLVM(
             args=self.args,
             toolchain=self.toolchain,
             source_dir='/path/to/src',
             build_dir='/path/to/build')
         expected_arg = '/usr/aarch64-linux-gnu'
         self.assertIn(expected_arg, llvm.get_linux_sysroot("linux", "aarch64"))
+
+    def test_llvm_get_linux_sysroot_external(self):
+        self.args = argparse.Namespace(
+            llvm_targets_to_build='X86;ARM;AArch64',
+            llvm_assertions='true',
+            compiler_vendor='none',
+            clang_compiler_version=None,
+            clang_user_visible_version=None,
+            cross_compile_hosts='linux-armv7',
+            cross_compile_deps_path='sysroot'
+        )
+        llvm = LLVM(
+            args=self.args,
+            toolchain=self.toolchain,
+            source_dir='/path/to/src',
+            build_dir='/path/to/build')
+        expected_arg = 'sysroot'
+        self.assertIn(expected_arg, llvm.get_linux_sysroot("linux", "armv7"))
+
+    def test_llvm_c_flags_includes_lld(self):
+        llvm = LLVM(
+            args=self.args,
+            toolchain=self.toolchain,
+            source_dir='/path/to/src',
+            build_dir='/path/to/build')
+        expected_flag = '-w -fuse-ld=lld'
+        self.assertIn(expected_flag, llvm.llvm_c_flags("linux", "aarch64"))