Ports: Add mold port

The port exposes some dynamic loader and toolchain shortcomings,
namely RTLD_NEXT, RTLD_NOLOAD, and std::filesystem. Hopefully we can
discover a ton of multi-threading bugs in Serenity with this port :^)

Ports/AvailablePorts.md

@@ -112,6 +112,7 @@ Please make sure to keep this list up to date when adding and updating ports. :^
 | [`mawk`](mawk/)                        | mawk                                                            | 1.3.4-20200120           | https://invisible-island.net/mawk/                                             |
 | [`mbedtls`](mbedtls/)                  | Mbed TLS                                                        | 2.16.2                   | https://tls.mbed.org/                                                          |
 | [`milkytracker`](milkytracker/)        | milkytracker                                                    | 1.03.00                  | https://github.com/milkytracker/MilkyTracker                                   |
+| [`mold`](mold/)                        |                                                                 | 1.0.1                    | https://github.com/rui314/mold                                                 |
 | [`mpc`](mpc/)                          | GNU Multiple Precision Complex Library (MPC)                    | 1.2.1                    | http://www.multiprecision.org/mpc/                                             |
 | [`mpfr`](mpfr/)                        | GNU Multiple Precision Floating-Point Reliable Library (MPFR)   | 4.1.0                    | https://www.mpfr.org/                                                          |
 | [`mruby`](mruby/)                      | mruby                                                           | 3.0.0                    | https://mruby.org/                                                             |

Ports/mold/package.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env -S bash ../.port_include.sh
+port=mold
+version=1.0.1
+files="https://github.com/rui314/mold/archive/refs/tags/v${version}.tar.gz mold-${version}.tgz b0d54602d1229c26583ee8a0132e53463c4d755f9dbc456475f388fd8a1aa3e4"
+auth_type=sha256
+depends=("zlib" "openssl")
+makeopts=("OS=SerenityOS" "EXTRA_LDFLAGS=-L${DESTDIR}/usr/local/lib -lcore" "-j$(nproc)")
+installopts=("OS=SerenityOS")

Ports/mold/patches/0001-Disable-mold_preload.so-for-Serenity.patch

@@ -0,0 +1,40 @@
+From e1ceb7155ee680f1fdd83773e9702735e5a46bd6 Mon Sep 17 00:00:00 2001
+From: Andrew Kaster <akaster@serenityos.org>
+Date: Tue, 11 Jan 2022 01:42:36 -0700
+Subject: [PATCH 1/7] Disable mold_preload.so for Serenity
+
+This feature depends on RTLD_NEXT capabilities which are not yet
+implemented in the Serenity DynamicLoader.
+---
+ Makefile | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/Makefile b/Makefile
+index 7f134b89..5b4f8576 100644
+--- a/Makefile
++++ b/Makefile
+@@ -112,7 +112,7 @@ ifneq ($(OS), Darwin)
+   LIBS += -lcrypto
+ endif
+ 
+-all: mold mold-wrapper.so
++all: mold
+ 
+ mold: $(OBJS) $(MIMALLOC_LIB) $(TBB_LIB) $(XXHASH_LIB)
+ 	$(CXX) $(CPPFLAGS) $(CXXFLAGS) $(LDFLAGS) $(EXTRA_LDFLAGS) $(OBJS) -o $@ $(LIBS)
+@@ -165,9 +165,9 @@ install: all
+ 	install -m 755 mold $D$(BINDIR)
+ 	$(STRIP) $D$(BINDIR)/mold
+ 
+-	install -m 755 -d $D$(LIBDIR)/mold
+-	install -m 644 mold-wrapper.so $D$(LIBDIR)/mold
+-	$(STRIP) $D$(LIBDIR)/mold/mold-wrapper.so
++	# install -m 755 -d $D$(LIBDIR)/mold
++	# install -m 644 mold-wrapper.so $D$(LIBDIR)/mold
++	# $(STRIP) $D$(LIBDIR)/mold/mold-wrapper.so
+ 
+ 	install -m 755 -d $D$(LIBEXECDIR)/mold
+ 	ln -sf $(BINDIR)/mold $D$(LIBEXECDIR)/mold/ld
+-- 
+2.25.1
+

Ports/mold/patches/0002-Disable-mimalloc-for-serenity.patch

@@ -0,0 +1,27 @@
+From 3912ec0acdd0e01bf32b4fe38004194e4f42fa93 Mon Sep 17 00:00:00 2001
+From: Andrew Kaster <akaster@serenityos.org>
+Date: Tue, 11 Jan 2022 01:43:35 -0700
+Subject: [PATCH 2/7] Disable mimalloc for serenity
+
+mimalloc needs some help to compile on serenity. That's one yak too
+far for right now.
+---
+ Makefile | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/Makefile b/Makefile
+index 5b4f8576..e946c6fd 100644
+--- a/Makefile
++++ b/Makefile
+@@ -59,6 +59,8 @@ endif
+ USE_MIMALLOC = 1
+ ifeq ($(OS), Darwin)
+   USE_MIMALLOC = 0
++else ifeq ($(OS), SerenityOS)
++  USE_MIMALLOC = 0
+ else ifneq (, $(findstring android, $(shell uname -r)))
+   USE_MIMALLOC = 0
+ else ifeq ($(ASAN), 1)
+-- 
+2.25.1
+

Ports/mold/patches/0003-Replace-std-filesystem-usage-with-Core-File.patch

@@ -0,0 +1,89 @@
+From b7141fc8a74705a0a772f5495a9a92ed7768a6af Mon Sep 17 00:00:00 2001
+From: Andrew Kaster <akaster@serenityos.org>
+Date: Tue, 11 Jan 2022 01:02:44 -0700
+Subject: [PATCH 3/7] Replace std::filesystem usage with Core::File
+
+At least the Clang toolchain does not support std::filesystem, so hack
+up the two files that use it to use Core::File abstractions instead.
+---
+ elf/subprocess.cc | 11 +++++++++++
+ filepath.cc       | 19 +++++++++++++++++++
+ 2 files changed, 30 insertions(+)
+
+diff --git a/elf/subprocess.cc b/elf/subprocess.cc
+index 3ed66c89..9e2fa9f6 100644
+--- a/elf/subprocess.cc
++++ b/elf/subprocess.cc
+@@ -1,6 +1,12 @@
+ #include "mold.h"
+ 
++#ifdef __serenity__
++#define AK_DONT_REPLACE_STD
++#include <LibCore/File.h>
++#else
+ #include <filesystem>
++#endif
++
+ #include <signal.h>
+ #include <sys/socket.h>
+ #include <sys/stat.h>
+@@ -251,7 +257,12 @@ void daemonize(Context<E> &ctx, std::function<void()> *wait_for_client,
+ }
+ 
+ static std::string get_self_path() {
++#ifdef __serenity__
++  auto str = Core::File::read_link("/proc/self/exe");
++  return { str.characters(), str.length() };
++#else
+   return std::filesystem::read_symlink("/proc/self/exe");
++#endif
+ }
+ 
+ static bool is_regular_file(const std::string &path) {
+diff --git a/filepath.cc b/filepath.cc
+index e12043bf..0e158da2 100644
+--- a/filepath.cc
++++ b/filepath.cc
+@@ -1,20 +1,39 @@
+ #include "mold.h"
+ 
++#ifdef __serenity__
++#define AK_DONT_REPLACE_STD
++#include <LibCore/File.h>
++#else
+ #include <filesystem>
++#endif
+ #include <sys/stat.h>
+ 
+ namespace mold {
+ 
+ std::string get_current_dir() {
++#ifdef __serenity__
++  auto str = Core::File::current_working_directory();
++  return { str.characters(), str.length() };
++#else
+   return std::filesystem::current_path();
++#endif
+ }
+ 
+ std::string get_realpath(std::string_view path) {
++#ifdef __serenity__
++  StringView sv{ path.data(), path.length() };
++  errno = 0;
++  auto str = Core::File::real_path_for(sv);
++  if (str.is_empty() || errno != 0)
++      return std::string(path);
++  return { str.characters(), str.length() };
++#else
+   std::error_code ec;
+   std::string ret = std::filesystem::canonical(path, ec);
+   if (ec)
+     return std::string(path);
+   return ret;
++#endif
+ }
+ 
+ bool path_is_dir(std::string_view path) {
+-- 
+2.25.1
+

Ports/mold/patches/0004-Add-POSIX-headers-for-timeval-and-select.patch

@@ -0,0 +1,28 @@
+From a55b1a4d2ca37c0c4ef2516d71a6555de118cc68 Mon Sep 17 00:00:00 2001
+From: Andrew Kaster <akaster@serenityos.org>
+Date: Tue, 11 Jan 2022 01:02:59 -0700
+Subject: [PATCH 4/7] Add POSIX headers for timeval and select
+
+mold was relying on other libc implementations leaking these definitions
+from other headers.
+---
+ elf/subprocess.cc | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/elf/subprocess.cc b/elf/subprocess.cc
+index 9e2fa9f6..410e568b 100644
+--- a/elf/subprocess.cc
++++ b/elf/subprocess.cc
+@@ -10,7 +10,9 @@
+ #include <signal.h>
+ #include <sys/socket.h>
+ #include <sys/stat.h>
++#include <sys/time.h>
+ #include <sys/types.h>
++#include <sys/select.h>
+ #include <sys/un.h>
+ #include <sys/wait.h>
+ #include <unistd.h>
+-- 
+2.25.1
+

Ports/mold/patches/0005-Tell-TBB-that-SerenityOS-does-not-support-weak-symbo.patch

@@ -0,0 +1,29 @@
+From 232eff20c3e16160b841b786017ed7c509c3c65a Mon Sep 17 00:00:00 2001
+From: Andrew Kaster <akaster@serenityos.org>
+Date: Tue, 11 Jan 2022 01:04:05 -0700
+Subject: [PATCH 5/7] Tell TBB that SerenityOS does not support weak symbols
+
+Something about the Clang toolchain configuration causes undefined weak
+references to scalable_malloc to remain in the mold executable even
+though there's no chance we'll be loading the tbbmalloc library at
+runtime. So, just lie to TBB that we don't support weak symbols.
+---
+ third-party/tbb/include/oneapi/tbb/detail/_config.h | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/third-party/tbb/include/oneapi/tbb/detail/_config.h b/third-party/tbb/include/oneapi/tbb/detail/_config.h
+index 278beeb3..d2962374 100644
+--- a/third-party/tbb/include/oneapi/tbb/detail/_config.h
++++ b/third-party/tbb/include/oneapi/tbb/detail/_config.h
+@@ -193,7 +193,7 @@
+ 
+ /** __TBB_WEAK_SYMBOLS_PRESENT denotes that the system supports the weak symbol mechanism **/
+ #ifndef __TBB_WEAK_SYMBOLS_PRESENT
+-    #define __TBB_WEAK_SYMBOLS_PRESENT ( !_WIN32 && !__APPLE__ && !__sun && (__TBB_GCC_VERSION >= 40000 || __INTEL_COMPILER ) )
++    #define __TBB_WEAK_SYMBOLS_PRESENT ( !_WIN32 && !__APPLE__ && !__sun && !__serenity__ && (__TBB_GCC_VERSION >= 40000 || __INTEL_COMPILER ) )
+ #endif
+ 
+ /** Presence of compiler features **/
+-- 
+2.25.1
+

Ports/mold/patches/0006-Tell-TBB-that-SerenityOS-libraries-are-named-like-BS.patch

@@ -0,0 +1,42 @@
+From 271f83f66d67ce88512cfd128241ccff1919972b Mon Sep 17 00:00:00 2001
+From: Andrew Kaster <akaster@serenityos.org>
+Date: Tue, 11 Jan 2022 01:04:13 -0700
+Subject: [PATCH 6/7] Tell TBB that SerenityOS libraries are named like BSD
+ ones
+
+We won't be loading these libraries when building TBB as a static
+library for mold, but the OS detection logic still needs updated.
+---
+ third-party/tbb/src/tbb/allocator.cpp | 2 +-
+ third-party/tbb/src/tbb/rml_tbb.cpp   | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/third-party/tbb/src/tbb/allocator.cpp b/third-party/tbb/src/tbb/allocator.cpp
+index 6bf5a0be..c779361e 100644
+--- a/third-party/tbb/src/tbb/allocator.cpp
++++ b/third-party/tbb/src/tbb/allocator.cpp
+@@ -95,7 +95,7 @@ static const dynamic_link_descriptor MallocLinkTable[] = {
+ #define MALLOCLIB_NAME "tbbmalloc" DEBUG_SUFFIX ".dll"
+ #elif __APPLE__
+ #define MALLOCLIB_NAME "libtbbmalloc" DEBUG_SUFFIX ".dylib"
+-#elif __FreeBSD__ || __NetBSD__ || __OpenBSD__ || __sun || _AIX || __ANDROID__
++#elif __FreeBSD__ || __NetBSD__ || __OpenBSD__ || __sun || _AIX || __ANDROID__ || __serenity__
+ #define MALLOCLIB_NAME "libtbbmalloc" DEBUG_SUFFIX ".so"
+ #elif __linux__  // Note that order of these #elif's is important!
+ #define MALLOCLIB_NAME "libtbbmalloc" DEBUG_SUFFIX ".so.2"
+diff --git a/third-party/tbb/src/tbb/rml_tbb.cpp b/third-party/tbb/src/tbb/rml_tbb.cpp
+index 122e2709..fc8d7fa8 100644
+--- a/third-party/tbb/src/tbb/rml_tbb.cpp
++++ b/third-party/tbb/src/tbb/rml_tbb.cpp
+@@ -52,7 +52,7 @@ namespace rml {
+ #define RML_SERVER_NAME "libirml" DEBUG_SUFFIX ".dylib"
+ #elif __linux__
+ #define RML_SERVER_NAME "libirml" DEBUG_SUFFIX ".so.1"
+-#elif __FreeBSD__ || __NetBSD__ || __OpenBSD__ || __sun || _AIX
++#elif __FreeBSD__ || __NetBSD__ || __OpenBSD__ || __sun || _AIX || __serenity__
+ #define RML_SERVER_NAME "libirml" DEBUG_SUFFIX ".so"
+ #else
+ #error Unknown OS
+-- 
+2.25.1
+

Ports/mold/patches/0007-Stub-out-a-definition-of-RTLD_NOLOAD.patch

@@ -0,0 +1,28 @@
+From e48745461894370e3b47c14fe53417dd2bc7515f Mon Sep 17 00:00:00 2001
+From: Andrew Kaster <akaster@serenityos.org>
+Date: Tue, 11 Jan 2022 01:04:20 -0700
+Subject: [PATCH 7/7] Stub out a definition of RTLD_NOLOAD
+
+SerenityOs's DynamicLoader doesn't support this flag. However, we won't
+be dynamically loading any tbb extensions for the static library build
+mold uses, so we can just define it as a no-op as the code paths that
+use it will never be used.
+---
+ third-party/tbb/src/tbb/dynamic_link.cpp | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/third-party/tbb/src/tbb/dynamic_link.cpp b/third-party/tbb/src/tbb/dynamic_link.cpp
+index f9b25ee1..4bacaae8 100644
+--- a/third-party/tbb/src/tbb/dynamic_link.cpp
++++ b/third-party/tbb/src/tbb/dynamic_link.cpp
+@@ -53,6 +53,7 @@
+     #pragma weak dlclose
+ #endif /* __TBB_WEAK_SYMBOLS_PRESENT && !__TBB_DYNAMIC_LOAD_ENABLED */
+ 
++#define RTLD_NOLOAD 0
+ 
+ #define __USE_STATIC_DL_INIT    ( !__ANDROID__ )
+ 
+-- 
+2.25.1
+