pw_toolchain: Explicitly link with lld when using clang
Adds an explicit -fuse-ld=lld to clang toolchains to prevent system
configuration from causing another linker to be selected by clang.
Bug: b/363070027
Change-Id: I472c8189a402fe57c0a47748638c9e1d83349b84
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/232931
Reviewed-by: Ted Pudlik <tpudlik@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Pigweed-Auto-Submit: Armando Montanez <amontanez@google.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Petr Hosek <phosek@google.com>
diff --git a/pw_build/BUILD.gn b/pw_build/BUILD.gn
index 25fd6fd..3c9d009 100644
--- a/pw_build/BUILD.gn
+++ b/pw_build/BUILD.gn
@@ -384,6 +384,10 @@
write_file(pw_build_RELATIVE_PATH_TRANSFORM_JSON, _transformations, "json")
}
+config("link_with_lld") {
+ ldflags = [ "-fuse-ld=lld" ]
+}
+
# This group is linked into all pw_executable, pw_static_library, and
# pw_shared_library targets. This makes it possible to ensure symbols are
# defined without a dependency on them.
diff --git a/pw_toolchain/arm_clang/toolchains.gni b/pw_toolchain/arm_clang/toolchains.gni
index 95e17e9..7a84e22 100644
--- a/pw_toolchain/arm_clang/toolchains.gni
+++ b/pw_toolchain/arm_clang/toolchains.gni
@@ -46,16 +46,19 @@
# Configs specific to different architectures.
_cortex_m0plus = [
+ "$dir_pw_build:link_with_lld",
"$dir_pw_toolchain/arm_clang:nosys",
"$dir_pw_toolchain/arm_clang:cortex_m0plus",
]
_cortex_m3 = [
+ "$dir_pw_build:link_with_lld",
"$dir_pw_toolchain/arm_clang:nosys",
"$dir_pw_toolchain/arm_clang:cortex_m3",
]
_cortex_m4 = [
+ "$dir_pw_build:link_with_lld",
"$dir_pw_toolchain/arm_clang:nosys",
"$dir_pw_toolchain/arm_clang:cortex_m4",
]
@@ -66,26 +69,31 @@
]
_cortex_m7 = [
+ "$dir_pw_build:link_with_lld",
"$dir_pw_toolchain/arm_clang:nosys",
"$dir_pw_toolchain/arm_clang:cortex_m7",
]
_cortex_m7f = [
+ "$dir_pw_build:link_with_lld",
"$dir_pw_toolchain/arm_clang:nosys",
"$dir_pw_toolchain/arm_clang:cortex_m7f",
]
_cortex_m33 = [
+ "$dir_pw_build:link_with_lld",
"$dir_pw_toolchain/arm_clang:nosys",
"$dir_pw_toolchain/arm_clang:cortex_m33",
]
_cortex_m33f = [
+ "$dir_pw_build:link_with_lld",
"$dir_pw_toolchain/arm_clang:nosys",
"$dir_pw_toolchain/arm_clang:cortex_m33f",
]
_cortex_m55 = [
+ "$dir_pw_build:link_with_lld",
"$dir_pw_toolchain/arm_clang:nosys",
"$dir_pw_toolchain/arm_clang:cortex_m55",
]
diff --git a/pw_toolchain/host_clang/BUILD.bazel b/pw_toolchain/host_clang/BUILD.bazel
index 77e4b28..9dcf49d 100644
--- a/pw_toolchain/host_clang/BUILD.bazel
+++ b/pw_toolchain/host_clang/BUILD.bazel
@@ -33,6 +33,12 @@
filegroup(name = "empty")
pw_cc_flag_set(
+ name = "link_with_lld",
+ actions = ["@pw_toolchain//actions:all_link_actions"],
+ flags = ["-fuse-ld=lld"],
+)
+
+pw_cc_flag_set(
name = "macos_link_libs",
actions = ["@pw_toolchain//actions:all_link_actions"],
flags = [
@@ -325,6 +331,7 @@
"//conditions:default": [],
}) + [
":thread_safety_warnings",
+ ":link_with_lld",
"@pw_toolchain//flag_sets:debugging",
"@pw_toolchain//flag_sets:reduced_size",
"@pw_toolchain//flag_sets:no_canonical_prefixes",
diff --git a/pw_toolchain/host_clang/toolchain.cmake b/pw_toolchain/host_clang/toolchain.cmake
index 6df6124..7e5a065 100644
--- a/pw_toolchain/host_clang/toolchain.cmake
+++ b/pw_toolchain/host_clang/toolchain.cmake
@@ -96,6 +96,11 @@
set(CMAKE_SYSROOT "$ENV{PW_PIGWEED_CIPD_INSTALL_DIR}/clang_sysroot")
endif()
+# Explicitly use lld to link.
+foreach(TYPE IN ITEMS EXE SHARED MODULE)
+ set(CMAKE_${TYPE}_LINKER_FLAGS_INIT "${CMAKE_${TYPE}_LINKER_FLAGS_INIT} -fuse-ld=lld")
+endforeach()
+
set(pw_build_WARNINGS
pw_build.strict_warnings
pw_build.extra_strict_warnings
diff --git a/pw_toolchain/host_clang/toolchains.gni b/pw_toolchain/host_clang/toolchains.gni
index 4646b90..9098712 100644
--- a/pw_toolchain/host_clang/toolchains.gni
+++ b/pw_toolchain/host_clang/toolchains.gni
@@ -60,6 +60,7 @@
# remove this hack.
default_configs = []
default_configs = pigweed_default_configs + [
+ "$dir_pw_build:link_with_lld",
"$dir_pw_build:extra_debugging",
"$dir_pw_toolchain/host_clang:no_system_libcpp",
"$dir_pw_toolchain/host_clang:xcode_sysroot",
diff --git a/pw_toolchain_bazel/build_external/llvm_clang.BUILD b/pw_toolchain_bazel/build_external/llvm_clang.BUILD
index 240d80a..d083c25 100644
--- a/pw_toolchain_bazel/build_external/llvm_clang.BUILD
+++ b/pw_toolchain_bazel/build_external/llvm_clang.BUILD
@@ -78,11 +78,13 @@
"@platforms//os:windows": "//:bin/llvm-ar.exe",
"//conditions:default": "//:bin/llvm-ar",
}),
+ additional_files = glob(["bin/llvm"]),
)
pw_cc_tool(
name = "llvm_libtool_darwin_tool",
tool = "//:bin/llvm-libtool-darwin",
+ additional_files = glob(["bin/llvm"]),
)
pw_cc_action_config(
@@ -109,6 +111,7 @@
"//conditions:default": "//:bin/clang++",
}),
additional_files = glob([
+ "bin/llvm",
"include/**",
"lib/clang/**/include/**",
]),
@@ -127,6 +130,7 @@
"//conditions:default": "//:bin/clang",
}),
additional_files = glob([
+ "bin/llvm",
"include/**",
"lib/clang/**/include/**",
]),
@@ -150,8 +154,12 @@
"//conditions:default": "//:bin/clang++",
}),
additional_files = glob([
+ "bin/llvm",
+ "bin/lld*",
+ "bin/ld*",
"lib/**/*.a",
"lib/**/*.so*",
+ "lib/**/*.o",
]),
)
@@ -167,6 +175,7 @@
"@platforms//os:windows": "//:bin/llvm-cov.exe",
"//conditions:default": "//:bin/llvm-cov",
}),
+ additional_files = glob(["bin/llvm"]),
)
pw_cc_action_config(
@@ -181,6 +190,7 @@
"@platforms//os:windows": "//:bin/llvm-objcopy.exe",
"//conditions:default": "//:bin/llvm-objcopy",
}),
+ additional_files = glob(["bin/llvm"]),
)
pw_cc_action_config(
@@ -195,6 +205,7 @@
"@platforms//os:windows": "//:bin/llvm-objdump.exe",
"//conditions:default": "//:bin/llvm-objdump",
}),
+ additional_files = glob(["bin/llvm"]),
)
pw_cc_action_config(
@@ -209,6 +220,7 @@
"@platforms//os:windows": "//:bin/llvm-strip.exe",
"//conditions:default": "//:bin/llvm-strip",
}),
+ additional_files = glob(["bin/llvm"]),
)
pw_cc_action_config(
