sys-devel/mold: workaround linux-6.11 incompatibility

Don't write to existing files, instead replace them. This fixes (or works
around) an incompatibility with linux-6.11.

Bug: https://github.com/rui314/mold/issues/1361
Bug: https://bugs.gentoo.org/938659
Closes: https://bugs.gentoo.org/941070
Thanks-to: Jinghao Jia <jinghao7@illinois.edu>
Thanks-to: ernsteiswuerfel <erhard_f@mailbox.org>
Signed-off-by: Sam James <sam@gentoo.org>

3 files changed, 133 insertions, 0 deletions

diff --git a/sys-devel/mold/files/mold-2.34.1-linux-6.11.patch b/sys-devel/mold/files/mold-2.34.1-linux-6.11.patch
new file mode 100644
index 000000000000..8540ec0cb246
--- /dev/null
+++ b/sys-devel/mold/files/mold-2.34.1-linux-6.11.patch
@@ -0,0 +1,22 @@
+https://lore.kernel.org/stable/CACKH++YAtEMYu2nTLUyfmxZoGO37fqogKMDkBpddmNaz5HE6ng@mail.gmail.com/T/#u
+https://github.com/rui314/mold/issues/1361
+https://bugs.gentoo.org/941070
+--- a/src/output-file-unix.cc
++++ b/src/output-file-unix.cc
+@@ -19,16 +19,6 @@ template <typename E>
+ static int
+ open_or_create_file(Context<E> &ctx, std::string path, std::string tmpfile,
+                     int perm) {
+-  // Reuse an existing file if exists and writable because on Linux,
+-  // writing to an existing file is much faster than creating a fresh
+-  // file and writing to it.
+-  if (ctx.overwrite_output_file && rename(path.c_str(), tmpfile.c_str()) == 0) {
+-    i64 fd = ::open(tmpfile.c_str(), O_RDWR | O_CREAT, perm);
+-    if (fd != -1)
+-      return fd;
+-    unlink(tmpfile.c_str());
+-  }
+-
+   i64 fd = ::open(tmpfile.c_str(), O_RDWR | O_CREAT, perm);
+   if (fd == -1)
+     Fatal(ctx) << "cannot open " << tmpfile << ": " << errno_string();
diff --git a/sys-devel/mold/mold-2.34.1-r1.ebuild b/sys-devel/mold/mold-2.34.1-r1.ebuild
new file mode 100644
index 000000000000..e9cd29a7fe47
--- /dev/null
+++ b/sys-devel/mold/mold-2.34.1-r1.ebuild
@@ -0,0 +1,107 @@
+# Copyright 2021-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+inherit cmake flag-o-matic toolchain-funcs
+
+DESCRIPTION="A Modern Linker"
+HOMEPAGE="https://github.com/rui314/mold"
+if [[ ${PV} == 9999 ]] ; then
+	EGIT_REPO_URI="https://github.com/rui314/mold.git"
+	inherit git-r3
+else
+	SRC_URI="https://github.com/rui314/mold/archive/refs/tags/v${PV}.tar.gz -> ${P}.tar.gz"
+	# -alpha: https://github.com/rui314/mold/commit/3711ddb95e23c12991f6b8c7bfeba4f1421d19d4
+	KEYWORDS="-alpha ~amd64 ~arm ~arm64 ~loong ~ppc ~riscv ~sparc ~x86"
+fi
+
+# mold (MIT)
+#  - xxhash (BSD-2)
+#  - siphash ( MIT CC0-1.0 )
+LICENSE="MIT BSD-2 CC0-1.0"
+SLOT="0"
+IUSE="debug"
+
+RDEPEND="
+	app-arch/zstd:=
+	>=dev-cpp/tbb-2021.7.0-r1:=
+	dev-libs/blake3:=
+	sys-libs/zlib
+	!kernel_Darwin? (
+		>=dev-libs/mimalloc-2:=
+	)
+"
+DEPEND="${RDEPEND}"
+
+PATCHES=(
+	"${FILESDIR}"/${PN}-2.34.1-linux-6.11.patch
+)
+
+pkg_pretend() {
+	# Requires a c++20 compiler, see #831473
+	if [[ ${MERGE_TYPE} != binary ]]; then
+		if tc-is-gcc && [[ $(gcc-major-version) -lt 10 ]]; then
+			die "${PN} needs at least gcc 10"
+		elif tc-is-clang && [[ $(clang-major-version) -lt 12 ]]; then
+			die "${PN} needs at least clang 12"
+		fi
+	fi
+}
+
+src_prepare() {
+	cmake_src_prepare
+
+	# Needs unpackaged dwarfdump
+	rm test/{{dead,compress}-debug-sections,compressed-debug-info}.sh || die
+
+	# Heavy tests, need qemu
+	rm test/gdb-index-{compress-output,dwarf{2,3,4,5}}.sh || die
+	rm test/lto-{archive,dso,gcc,llvm,version-script}.sh || die
+
+	# Sandbox sadness
+	rm test/run.sh || die
+	sed -i 's|`pwd`/mold-wrapper.so|"& ${LD_PRELOAD}"|' \
+		test/mold-wrapper{,2}.sh || die
+
+	# static-pie tests require glibc built with static-pie support
+	if ! has_version -d 'sys-libs/glibc[static-pie(+)]'; then
+		rm test/{,ifunc-}static-pie.sh || die
+	fi
+}
+
+src_configure() {
+	use debug || append-cppflags "-DNDEBUG"
+
+	local mycmakeargs=(
+		-DMOLD_ENABLE_QEMU_TESTS=OFF
+		-DMOLD_LTO=OFF # Should be up to the user to decide this with CXXFLAGS.
+		-DMOLD_USE_MIMALLOC=$(usex !kernel_Darwin)
+		-DMOLD_USE_SYSTEM_MIMALLOC=ON
+		-DMOLD_USE_SYSTEM_TBB=ON
+	)
+	cmake_src_configure
+}
+
+src_install() {
+	dobin "${BUILD_DIR}"/${PN}
+
+	# https://bugs.gentoo.org/872773
+	insinto /usr/$(get_libdir)/mold
+	doins "${BUILD_DIR}"/${PN}-wrapper.so
+
+	dodoc docs/{design,execstack}.md
+	doman docs/${PN}.1
+
+	dosym ${PN} /usr/bin/ld.${PN}
+	dosym ${PN} /usr/bin/ld64.${PN}
+	dosym -r /usr/bin/${PN} /usr/libexec/${PN}/ld
+}
+
+src_test() {
+	export TEST_CC="$(tc-getCC)" \
+		   TEST_GCC="$(tc-getCC)" \
+		   TEST_CXX="$(tc-getCXX)" \
+		   TEST_GXX="$(tc-getCXX)"
+	cmake_src_test
+}
diff --git a/sys-devel/mold/mold-9999.ebuild b/sys-devel/mold/mold-9999.ebuild
index 456f654912e4..e9cd29a7fe47 100644
--- a/sys-devel/mold/mold-9999.ebuild
+++ b/sys-devel/mold/mold-9999.ebuild
@@ -34,6 +34,10 @@ RDEPEND="
 "
 DEPEND="${RDEPEND}"
 
+PATCHES=(
+	"${FILESDIR}"/${PN}-2.34.1-linux-6.11.patch
+)
+
 pkg_pretend() {
 	# Requires a c++20 compiler, see #831473
 	if [[ ${MERGE_TYPE} != binary ]]; then