Toolchain: Enable LLVM Profile instrumentation

Add a patch to let llvm's InstrProfiling modules know serenity supports
all the Unix-y features required to make -fprofile-instr-generate and
-fcoverage-mapping work properly on target.

Toolchain/BuildClang.sh

@@ -232,7 +232,7 @@ pushd "$DIR/Tarballs"
                 git init > /dev/null
                 git add . > /dev/null
                 git commit -am "BASE" > /dev/null
-                git am "$DIR"/Patches/llvm/*.patch > /dev/null
+                git am --keep-non-patch "$DIR"/Patches/llvm/*.patch > /dev/null
             else
                 for patch in "$DIR"/Patches/llvm/*.patch; do
                     patch -p1 < "$patch" > /dev/null

Toolchain/CMake/LLVMConfig.cmake

@@ -37,7 +37,7 @@ foreach(target i686-pc-serenity;x86_64-pc-serenity;aarch64-pc-serenity)
     set(RUNTIMES_${target}_COMPILER_RT_BUILD_SANITIZERS OFF CACHE BOOL "")
     set(RUNTIMES_${target}_COMPILER_RT_BUILD_LIBFUZZER OFF CACHE BOOL "")
     set(RUNTIMES_${target}_COMPILER_RT_BUILD_MEMPROF OFF CACHE BOOL "")
-    set(RUNTIMES_${target}_COMPILER_RT_BUILD_PROFILE OFF CACHE BOOL "")
+    set(RUNTIMES_${target}_COMPILER_RT_BUILD_PROFILE ON CACHE BOOL "")
     set(RUNTIMES_${target}_COMPILER_RT_BUILD_XRAY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_COMPILER_RT_BUILD_ORC OFF CACHE BOOL "")
     set(RUNTIMES_${target}_CMAKE_SYSTEM_NAME SerenityOS CACHE STRING "")

Toolchain/Patches/llvm/0001-Support-Add-support-for-building-LLVM-on-SerenityOS.patch

@@ -1,7 +1,7 @@
 From 9ff3d5362c71dfa9b6aba1dd65a33bb6d8971164 Mon Sep 17 00:00:00 2001
 From: Daniel Bertalan <dani@danielbertalan.dev>
 Date: Thu, 14 Apr 2022 09:54:22 +0200
-Subject: [PATCH 1/8] [Support] Add support for building LLVM on SerenityOS
+Subject: [PATCH 1/9] [Support] Add support for building LLVM on SerenityOS
 
 Adds SerenityOS `#ifdef`s for platform-specific code.
 

Toolchain/Patches/llvm/0002-Triple-Add-triple-for-SerenityOS.patch

@@ -1,7 +1,7 @@
 From 0cf66d1dbcd3b7c0e2ddd65177066955c41352b7 Mon Sep 17 00:00:00 2001
 From: Daniel Bertalan <dani@danielbertalan.dev>
 Date: Thu, 14 Apr 2022 09:51:24 +0200
-Subject: [PATCH 2/8] [Triple] Add triple for SerenityOS
+Subject: [PATCH 2/9] [Triple] Add triple for SerenityOS
 
 ---
  llvm/include/llvm/ADT/Triple.h | 8 +++++++-

Toolchain/Patches/llvm/0003-Driver-Add-support-for-SerenityOS.patch

@@ -1,7 +1,7 @@
 From 70cbf6e9ed46f0d39f43ac4a43b9bd2cc10da6c3 Mon Sep 17 00:00:00 2001
 From: Daniel Bertalan <dani@danielbertalan.dev>
 Date: Thu, 14 Apr 2022 10:09:50 +0200
-Subject: [PATCH 3/8] [Driver] Add support for SerenityOS
+Subject: [PATCH 3/9] [Driver] Add support for SerenityOS
 
 Adds support for the `$arch-pc-serenity` target to the Clang front end.
 This makes the compiler look for libraries and headers in the right

Toolchain/Patches/llvm/0004-Driver-Default-to-ftls-model-initial-exec-on-Serenit.patch

@@ -1,7 +1,7 @@
 From 50e7b15efa5f7e2ff57e998879fee28fff4a5305 Mon Sep 17 00:00:00 2001
 From: Daniel Bertalan <dani@danielbertalan.dev>
 Date: Thu, 14 Apr 2022 10:12:54 +0200
-Subject: [PATCH 4/8] [Driver] Default to -ftls-model=initial-exec on
+Subject: [PATCH 4/9] [Driver] Default to -ftls-model=initial-exec on
  SerenityOS
 
 This is a hack to make Clang use the initial-exec TLS model instead of

Toolchain/Patches/llvm/0005-libc-Add-support-for-SerenityOS.patch

@@ -1,7 +1,7 @@
 From fae5030852da34db641d636ad4c599e56b92ccdf Mon Sep 17 00:00:00 2001
 From: Daniel Bertalan <dani@danielbertalan.dev>
 Date: Thu, 14 Apr 2022 10:17:13 +0200
-Subject: [PATCH 5/8] [libc++] Add support for SerenityOS
+Subject: [PATCH 5/9] [libc++] Add support for SerenityOS
 
 This commit teaches libc++ about what features are available in our
 LibC, namely:

Toolchain/Patches/llvm/0006-compiler-rt-Build-crtbegin.o-crtend.o-for-SerenityOS.patch

@@ -1,7 +1,7 @@
 From 1cf9ec98aa817c13b94b42e4df80804a6757aa8a Mon Sep 17 00:00:00 2001
 From: Daniel Bertalan <dani@danielbertalan.dev>
 Date: Thu, 14 Apr 2022 10:20:46 +0200
-Subject: [PATCH 6/8] [compiler-rt] Build crtbegin.o/crtend.o for SerenityOS
+Subject: [PATCH 6/9] [compiler-rt] Build crtbegin.o/crtend.o for SerenityOS
 
 ---
  compiler-rt/cmake/config-ix.cmake | 2 +-

Toolchain/Patches/llvm/0007-cmake-Allow-undefined-symbols-on-SerenityOS.patch

@@ -1,7 +1,7 @@
 From ac91fd973bdf23b24645336a470d5dfb31811aa6 Mon Sep 17 00:00:00 2001
 From: Daniel Bertalan <dani@danielbertalan.dev>
 Date: Thu, 14 Apr 2022 10:21:19 +0200
-Subject: [PATCH 7/8] [cmake] Allow undefined symbols on SerenityOS
+Subject: [PATCH 7/9] [cmake] Allow undefined symbols on SerenityOS
 
 Allow undefined symbols in LLVM libraries, which is needed because only
 stubs are available for SerenityOS libraries when libc++ and libunwind

Toolchain/Patches/llvm/0008-cmake-Support-building-shared-libLLVM-and-libClang-f.patch

@@ -1,7 +1,7 @@
 From eb1dbc59eaebdefd9735b738ca30478ce1788dca Mon Sep 17 00:00:00 2001
 From: Daniel Bertalan <dani@danielbertalan.dev>
 Date: Mon, 18 Apr 2022 22:32:29 +0200
-Subject: [PATCH 8/8] [cmake] Support building shared libLLVM and libClang for
+Subject: [PATCH 8/9] [cmake] Support building shared libLLVM and libClang for
  SerenityOS
 
 This patch tells CMake that the --whole-archive linker option should be

Toolchain/Patches/llvm/0009-compiler-rt-llvm-Enable-profile-instrumentation-for-.patch

@@ -0,0 +1,75 @@
+From 539a12f2955a737f550be655c56a1a993eaa1ae2 Mon Sep 17 00:00:00 2001
+From: Andrew Kaster <akaster@serenityos.org>
+Date: Fri, 4 Mar 2022 15:13:42 -0700
+Subject: [PATCH 9/9] [compiler-rt/llvm] Enable profile instrumentation
+ for SerenityOS
+
+Treat SerenityOS the same as other *NIX platforms that behave close
+enough to linux to use the pre-canned InstrProfiling implementation.
+
+Curiously, enabling profiling for the SerenityOS target changes the ELF
+OS ABI for userspace binaries to 3, or GNU/Linux.
+---
+ compiler-rt/cmake/config-ix.cmake                      | 2 +-
+ compiler-rt/lib/profile/InstrProfilingPlatformLinux.c  | 3 ++-
+ compiler-rt/lib/profile/InstrProfilingPlatformOther.c  | 2 +-
+ llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp | 3 ++-
+ 4 files changed, 6 insertions(+), 4 deletions(-)
+
+diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
+index 7a47b7f..8d4211d 100644
+--- a/compiler-rt/cmake/config-ix.cmake
++++ b/compiler-rt/cmake/config-ix.cmake
+@@ -738,7 +738,7 @@ else()
+ endif()
+ 
+ if (PROFILE_SUPPORTED_ARCH AND NOT LLVM_USE_SANITIZER AND
+-    OS_NAME MATCHES "Darwin|Linux|FreeBSD|Windows|Android|Fuchsia|SunOS|NetBSD|AIX")
++    OS_NAME MATCHES "Darwin|Linux|FreeBSD|Windows|Android|Fuchsia|SunOS|NetBSD|AIX|SerenityOS")
+   set(COMPILER_RT_HAS_PROFILE TRUE)
+ else()
+   set(COMPILER_RT_HAS_PROFILE FALSE)
+diff --git a/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c b/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
+index 592c09b..1833682 100644
+--- a/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
++++ b/compiler-rt/lib/profile/InstrProfilingPlatformLinux.c
+@@ -7,7 +7,8 @@
+ \*===----------------------------------------------------------------------===*/
+ 
+ #if defined(__linux__) || defined(__FreeBSD__) || defined(__Fuchsia__) || \
+-    (defined(__sun__) && defined(__svr4__)) || defined(__NetBSD__)
++    (defined(__sun__) && defined(__svr4__)) || defined(__NetBSD__) || \
++    defined(__serenity__)
+ 
+ #include <elf.h>
+ #include <link.h>
+diff --git a/compiler-rt/lib/profile/InstrProfilingPlatformOther.c b/compiler-rt/lib/profile/InstrProfilingPlatformOther.c
+index 3e9b3ca..d257013 100644
+--- a/compiler-rt/lib/profile/InstrProfilingPlatformOther.c
++++ b/compiler-rt/lib/profile/InstrProfilingPlatformOther.c
+@@ -8,7 +8,7 @@
+ 
+ #if !defined(__APPLE__) && !defined(__linux__) && !defined(__FreeBSD__) &&     \
+     !(defined(__sun__) && defined(__svr4__)) && !defined(__NetBSD__) &&        \
+-    !defined(_WIN32)
++    !defined(_WIN32) && !defined(__serenity__)
+ 
+ #include <stdlib.h>
+ #include <stdio.h>
+diff --git a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+index 6868408..eaa1b64 100644
+--- a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
++++ b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+@@ -857,7 +857,8 @@ static bool needsRuntimeRegistrationOfSectionRange(const Triple &TT) {
+     return false;
+   // Use linker script magic to get data/cnts/name start/end.
+   if (TT.isOSLinux() || TT.isOSFreeBSD() || TT.isOSNetBSD() ||
+-      TT.isOSSolaris() || TT.isOSFuchsia() || TT.isPS4CPU() || TT.isOSWindows())
++      TT.isOSSolaris() || TT.isOSFuchsia() || TT.isPS4CPU() ||
++      TT.isOSWindows() || TT.isOSSerenity())
+     return false;
+ 
+   return true;
+-- 
+2.32.0
+

Toolchain/Patches/llvm/ReadMe.md

@@ -76,3 +76,12 @@ shared libraries.
 Symbol versioning is disabled, as the SerenityOS loader doesn't support
 it, and the ELF sections that store version data would just waste space.
 
+## `0009-compiler-rt-llvm-Enable-profile-instrumentation-for-.patch`
+
+Enable profile instrumentation for SerenityOS
+
+Treat SerenityOS the same as other *NIX platforms that behave close
+enough to linux to use the pre-canned InstrProfiling implementation.
+
+Curiously, enabling profiling for the SerenityOS target changes the ELF
+OS ABI for userspace binaries to 3, or GNU/Linux.