diff --git a/debian/changelog b/debian/changelog
index 789089d5..e8df8616 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -231,8 +231,129 @@ llvm-toolchain-snapshot (1:13~++20210129063721+010b176cdefb-1~exp1) experimental
 
  -- Sylvestre Ledru <sylvestre@debian.org>  Sat, 30 Jan 2021 17:31:15 +0100
 
-llvm-toolchain-12 (1:12.0.1-10) UNRELEASED; urgency=medium
+llvm-toolchain-12 (1:12.0.1-16) unstable; urgency=medium
 
+  [ Erik Maciejewski ]
+  * use make variables populated by /usr/share/dpkg/buildflags.mk and remove
+    _EXTRA suffix from STAGE_1_ and STAGE_2_ flag vars to improve clarity and
+    readability for the multi-stage setup in debian/rules
+  * remove some redundant cmake options (options with the same value as their
+    default) from, and move PYTHON_EXECUTABLE cmake option to, the cmake
+    configure command in debian/rules
+  * re-disable fixfilepath in dpkg-buildflags in favor of using the more llvm
+    aware implementation provided by the llvm-project by setting
+    LLVM_USE_RELATIVE_PATHS_IN_FILES=ON in both stages of the toolchain
+    build in debian/rules
+
+  [ Sylvestre Ledru ]
+  * autopkgtest/integration-test-suite-test: restrict to arm64/amd64 for now
+
+ -- Sylvestre Ledru <sylvestre@debian.org>  Thu, 28 Oct 2021 16:45:49 +0200
+
+llvm-toolchain-12 (1:12.0.1-15) unstable; urgency=medium
+
+  * Disable lldb on mipsel and mips64el as it isn't supported
+    See https://reviews.llvm.org/D102872
+    (Closes: #997011)
+
+  [ Erik Maciejewski ]
+  * disable compiler-rt builtins for unsupported arch s390x in debian/rules
+  * set arm toolchain arch profiles explicitly to debian baselines in
+    debian/rules as the target host triples alone are ambiguous and compiler
+    defaults and debian baselines may not align
+  * add arch specific config for powerpc to debian/rules and set host target
+    triple and compiler-rt config to force correct arch profile for builtins
+  * set LIBCXX_USE_COMPILER_RT to OFF in debian/rules to disable builtins when
+    libunwind is not enabled since the unwind implementation with gnu builtins
+    will then be required
+
+ -- Sylvestre Ledru <sylvestre@debian.org>  Sat, 23 Oct 2021 10:33:56 +0200
+
+llvm-toolchain-12 (1:12.0.1-14) unstable; urgency=medium
+
+  * fix build flag inconsistencies (potentially causing build failures) by
+    utilizing dpkg-buildflags for defaults where appropriate and making sure all
+    flags intended for a given stage are also applied to the stage's builtins
+    and runtimes builds
+  * re-enable fixfilepath for use with dpkg-buildflags in debian/rules as it has
+    been supported since clang-10
+  * establish a consistent STAGE_[stage]_ prefix naming scheme for stage
+    variables and replace STAGE1_AND_STAGE2_ prefix with STAGE_ALL_ prefix for
+    better future-proofing in debian/rules
+  * modify stage dir var names to use new prefix scheme in debian/rules
+  * add explicit s390x build options to debian/rules, set
+    LLVM_HOST_TRIPLE=s390x-linux-gnu and COMPILER_RT_DEFAULT_TARGET_ONLY=ON
+    so that builtins are only built for the explicit host arch (Closes: #996802)
+
+ -- Erik Maciejewski <mr.emacski@gmail.com>  Fri, 22 Oct 2021 03:12:48 -0700
+
+llvm-toolchain-12 (1:12.0.1-13) unstable; urgency=medium
+
+  * update rules to incorporate relevant arch specific configs from snapshot
+  * patch llvm runtimes cmake build to add a check and only set up and build
+    compiler-rt builtins if they have not been disabled in a runtimes build
+  * patch compiler-rt builtins cmake build to fix default arch detection for
+    armhf by adding the same target triple handling used for compiler-rt libs
+  * remove legacy var for use when libcxx was a standalone build
+
+ -- Erik Maciejewski <mr.emacski@gmail.com>  Wed, 20 Oct 2021 09:04:42 -0700
+
+llvm-toolchain-12 (1:12.0.1-12) unstable; urgency=medium
+
+  * re-disable building builtins on armel as they still fail (Closes: #996828)
+  * add patch to libcxxabi cmake build for adding builtins to lib flags fixing
+    an issue where builtins were not being linked into libcxxabi when
+    LIBCXXABI_USE_COMPILER_RT=ON (Closes: #996796)
+
+ -- Erik Maciejewski <mr.emacski@gmail.com>  Tue, 19 Oct 2021 01:28:50 -0700
+
+llvm-toolchain-12 (1:12.0.1-11) unstable; urgency=medium
+
+  * add missing LIBUNWIND_USE_COMPILER_RT to CLANG_BOOTSTRAP_PASSTHROUGH to link
+    correct compiler-rt lib in stage2
+  * consolidate two conditionals for libatomic that were essentially the same,
+    but the one removed could conflict with BOOTSTRAP_SHARED_LINK_FLAGS
+    elsewhere in the rules file
+  * attempt to fix arm builtins by adding COMPILER_RT_DEFAULT_TARGET_ONLY=ON to
+    armel and armhf toolchain build options to prevent related arches that might
+    not be supported on the build host from being included in the build (like
+    armv6m soft-float on the armhf build host)
+  * reorganize flags and cmake options around stages for the toolchain build
+  * set baseline arch to armv5t, remove older 3.8 workaround for armel build
+  * update to debian host triple for the armhf build
+
+  [ Jordan Justen ]
+  * d/rules: Add amdgcn-mesa-mesa3d to libclc build.
+    Closes: #993904, #995069
+
+  [ Sylvestre Ledru ]
+  * Bring back the llvm manpages (Closes: #995684)
+    Were generated at the wrong place
+
+ -- Erik Maciejewski <mr.emacski@gmail.com>  Sat, 16 Oct 2021 09:07:25 -0700
+
+llvm-toolchain-12 (1:12.0.1-10) unstable; urgency=medium
+
+  * evolve llvm build configuration in rules to leverage the two stage build
+    with runtimes support whereby the resulting stage2 (final) compiler is used
+    to build the stage2 (final) runtimes as part of a single monolithic build
+  * the stage2 runtimes build now includes compiler-rt, libcxx and libcxxabi as
+    well as libunwind and openmp where supported. Additionally, legacy
+    corresponding standalone build targets are removed from the rules file
+  * patch openmp build to include required runtimes as dependencies to build
+    targets so they are built first when included as part of a runtimes build
+    since openmp can depend on them
+  * patch libclc build to set rpath for prepare_builtins build utility to find
+    correct stage2 libs at runtime when executed as part of a build
+  * patch libcxx build so that if libatomic is found, only link it if libgcc is
+    the rtlib
+  * patch compiler-rt build to suppress xray and testing warns when not enabled
+  * patch llvm linker detection to account for vendor being prepended to lld
+    version string
+  * remove several existing patches incorporating workarounds no longer required
+    by the modified build configuration
+
+  [ Sylvestre Ledru ]
   * If parallel is not set in DEB_BUILD_OPTIONS, use nproc
   * Add source-is-missing llvm/test/* / lldb/test/* / lld/test/*
     to the source override
@@ -241,7 +362,7 @@ llvm-toolchain-12 (1:12.0.1-10) UNRELEASED; urgency=medium
   [ John Paul Adrian Glaubitz ]
   * Disable libunwind on sparc, sparc64 and x32
 
- -- Sylvestre Ledru <sylvestre@debian.org>  Sat, 02 Oct 2021 10:50:27 +0200
+ -- Erik Maciejewski <mr.emacski@gmail.com>  Wed, 06 Oct 2021 01:25:08 -0700
 
 llvm-toolchain-12 (1:12.0.1-9) unstable; urgency=medium
 
diff --git a/debian/control b/debian/control
index 337f2a03..80a6a6d8 100644
--- a/debian/control
+++ b/debian/control
@@ -6,6 +6,7 @@ Maintainer: LLVM Packaging Team <pkg-llvm-team@lists.alioth.debian.org>
 Uploaders: Sylvestre Ledru <sylvestre@debian.org>, Gianfranco Costamagna <locutusofborg@debian.org>
 Build-Depends: debhelper (>= 11.0), cmake, ninja-build,
     chrpath, texinfo, sharutils,
+    libelf-dev,
     libffi-dev,
     lsb-release, patchutils, diffstat, xz-utils, python3-dev,
     libedit-dev, libncurses5-dev, swig, python3-six, python3-sphinx (>= 1.3.6),
@@ -13,7 +14,7 @@ Build-Depends: debhelper (>= 11.0), cmake, ninja-build,
     libxml2-dev,
     libjsoncpp-dev, pkg-config,
     lcov, procps, help2man, zlib1g-dev,
-    g++-multilib [amd64 i386 kfreebsd-amd64 mips mips64 mips64el mipsel powerpc ppc64 s390 s390x sparc sparc64 x32],
+    g++-multilib [amd64 i386 kfreebsd-amd64 mips64 mips64el mipsel powerpc ppc64 s390 s390x sparc sparc64 x32],
     libjs-mathjax, python3-recommonmark,
     doxygen, gfortran,
     ocaml-nox [amd64 arm64 armhf ppc64el riscv64 s390x],
@@ -457,7 +458,7 @@ Description: Modular compiler and toolchain technologies, examples
 # ------------- lld -------------
 
 Package: lld-13
-Architecture: amd64 arm64 armel armhf i386 mips mipsel mips64el ppc64el kfreebsd-amd64 kfreebsd-i386 s390 s390x sparc alpha hppa m68k powerpcspe ppc64 sh4 sparc64 x32 riscv64
+Architecture: amd64 arm64 armel armhf i386 mipsel mips64el ppc64el kfreebsd-amd64 kfreebsd-i386 s390 s390x sparc alpha hppa m68k powerpcspe ppc64 sh4 sparc64 x32 riscv64
 # ia64 hurd powerpc have been removed
 Depends: ${shlibs:Depends}, ${misc:Depends}, libllvm13 (= ${binary:Version})
 Pre-Depends: ${misc:Pre-Depends}
@@ -467,7 +468,7 @@ Description: LLVM-based linker
  Project.
 
 Package: liblld-13
-Architecture: amd64 arm64 armel armhf i386 mips mipsel mips64el ppc64el kfreebsd-amd64 kfreebsd-i386 s390 s390x sparc alpha hppa m68k powerpcspe ppc64 sh4 sparc64 x32 riscv64
+Architecture: amd64 arm64 armel armhf i386 mipsel mips64el ppc64el kfreebsd-amd64 kfreebsd-i386 s390 s390x sparc alpha hppa m68k powerpcspe ppc64 sh4 sparc64 x32 riscv64
 # ia64 hurd powerpc have been removed
 Depends: ${shlibs:Depends}, ${misc:Depends}, libllvm13 (= ${binary:Version})
 Pre-Depends: ${misc:Pre-Depends}
@@ -481,7 +482,7 @@ Description: LLVM-based linker, library
 
 Package: liblld-13-dev
 Section: libdevel
-Architecture: amd64 arm64 armel armhf i386 mips mipsel mips64el ppc64el kfreebsd-amd64 kfreebsd-i386 s390 s390x sparc alpha hppa m68k powerpcspe ppc64 sh4 sparc64 x32 riscv64
+Architecture: amd64 arm64 armel armhf i386 mipsel mips64el ppc64el kfreebsd-amd64 kfreebsd-i386 s390 s390x sparc alpha hppa m68k powerpcspe ppc64 sh4 sparc64 x32 riscv64
 # ia64 hurd powerpc have been removed
 Depends: ${shlibs:Depends}, ${misc:Depends}, lld-13 (= ${binary:Version}),
  liblld-13 (= ${binary:Version})
diff --git a/debian/patches/compilerrt-builtins-arch-fix-armhf.diff b/debian/patches/compilerrt-builtins-arch-fix-armhf.diff
new file mode 100644
index 00000000..d762b29c
--- /dev/null
+++ b/debian/patches/compilerrt-builtins-arch-fix-armhf.diff
@@ -0,0 +1,18 @@
+fix builtins armhf default arch detection by adding the same armhf triple
+handling use for compiler-rt
+Index: llvm-toolchain-12_12.0.1/compiler-rt/lib/builtins/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/compiler-rt/lib/builtins/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/compiler-rt/lib/builtins/CMakeLists.txt
+@@ -16,6 +16,11 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURR
+ 
+   load_llvm_config()
+   construct_compiler_rt_default_triple()
++  if ("${COMPILER_RT_DEFAULT_TARGET_TRIPLE}" MATCHES ".*hf$")
++    if (${COMPILER_RT_DEFAULT_TARGET_ARCH} MATCHES "^arm")
++      set(COMPILER_RT_DEFAULT_TARGET_ARCH "armhf")
++    endif()
++  endif()
+ 
+   if(APPLE)
+     include(CompilerRTDarwinUtils)
diff --git a/debian/patches/compilerrt-fix-warn-xray-testing.diff b/debian/patches/compilerrt-fix-warn-xray-testing.diff
new file mode 100644
index 00000000..38babc96
--- /dev/null
+++ b/debian/patches/compilerrt-fix-warn-xray-testing.diff
@@ -0,0 +1,33 @@
+suppress warnings for xray and testing when not enabled
+Index: llvm-toolchain-12_12.0.1/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
++++ llvm-toolchain-12_12.0.1/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+@@ -242,15 +242,15 @@ macro(load_llvm_config)
+ 
+     # Detect if we have the LLVMXRay and TestingSupport library installed and
+     # available from llvm-config.
++    set(COMPILER_RT_HAS_LLVMXRAY FALSE)
+     execute_process(
+       COMMAND ${LLVM_CONFIG_PATH} "--ldflags" "--libs" "xray"
+       RESULT_VARIABLE HAD_ERROR
+       OUTPUT_VARIABLE CONFIG_OUTPUT
+       ERROR_QUIET)
+-    if (HAD_ERROR)
++    if (HAD_ERROR AND COMPILER_RT_BUILD_XRAY)
+       message(WARNING "llvm-config finding xray failed with status ${HAD_ERROR}")
+-      set(COMPILER_RT_HAS_LLVMXRAY FALSE)
+-    else()
++    elseif(COMPILER_RT_BUILD_XRAY)
+       string(REGEX REPLACE "[ \t]*[\r\n]+[ \t]*" ";" CONFIG_OUTPUT ${CONFIG_OUTPUT})
+       list(GET CONFIG_OUTPUT 0 LDFLAGS)
+       list(GET CONFIG_OUTPUT 1 LIBLIST)
+@@ -267,7 +267,7 @@ macro(load_llvm_config)
+       RESULT_VARIABLE HAD_ERROR
+       OUTPUT_VARIABLE CONFIG_OUTPUT
+       ERROR_QUIET)
+-    if (HAD_ERROR)
++    if (HAD_ERROR AND COMPILER_RT_INCLUDE_TESTS)
+       message(WARNING "llvm-config finding testingsupport failed with status ${HAD_ERROR}")
+     elseif(COMPILER_RT_INCLUDE_TESTS)
+       string(REGEX REPLACE "[ \t]*[\r\n]+[ \t]*" ";" CONFIG_OUTPUT ${CONFIG_OUTPUT})
diff --git a/debian/patches/fix-llvm-config-obj-src-root.patch b/debian/patches/fix-llvm-config-obj-src-root.patch
deleted file mode 100644
index 2981e9b7..00000000
--- a/debian/patches/fix-llvm-config-obj-src-root.patch
+++ /dev/null
@@ -1,20 +0,0 @@
----
- tools/llvm-config/llvm-config.cpp |    4 ++--
- 1 file changed, 2 insertions(+), 2 deletions(-)
-
-Index: llvm-toolchain-snapshot_11~++20200326111000+4673699a470/llvm/tools/llvm-config/llvm-config.cpp
-===================================================================
---- llvm-toolchain-snapshot_11~++20200326111000+4673699a470.orig/llvm/tools/llvm-config/llvm-config.cpp
-+++ llvm-toolchain-snapshot_11~++20200326111000+4673699a470/llvm/tools/llvm-config/llvm-config.cpp
-@@ -561,9 +561,9 @@ int main(int argc, char **argv) {
-       } else if (Arg == "--shared-mode") {
-         PrintSharedMode = true;
-       } else if (Arg == "--obj-root") {
--        OS << ActivePrefix << '\n';
-+        OS << ActivePrefix << "/build/" << '\n';
-       } else if (Arg == "--src-root") {
--        OS << LLVM_SRC_ROOT << '\n';
-+        OS << ActivePrefix << "/build/" << '\n';
-       } else if (Arg == "--ignore-libllvm") {
-         LinkDyLib = false;
-         LinkMode = BuiltSharedLibs ? LinkModeShared : LinkModeAuto;
diff --git a/debian/patches/libclc-fix-prepare_builtins-rpath.diff b/debian/patches/libclc-fix-prepare_builtins-rpath.diff
new file mode 100644
index 00000000..c1f87571
--- /dev/null
+++ b/debian/patches/libclc-fix-prepare_builtins-rpath.diff
@@ -0,0 +1,16 @@
+set rpath for prepare_builtins build utility to find correct stage2
+libs at runtime when executed as part of a build
+Index: llvm-toolchain-12_12.0.1/libclc/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/libclc/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/libclc/CMakeLists.txt
+@@ -139,6 +139,9 @@ target_compile_options( prepare_builtins
+ target_compile_definitions( prepare_builtins PRIVATE ${LLVM_VERSION_DEFINE} )
+ target_link_libraries( prepare_builtins PRIVATE ${LLVM_LIBS} )
+ target_link_libraries( prepare_builtins PRIVATE ${LLVM_SYSTEM_LIBS} )
++set_target_properties( prepare_builtins
++                       PROPERTIES INSTALL_RPATH "${LLVM_LIBDIR}"
++                       BUILD_WITH_INSTALL_RPATH "ON")
+ 
+ # Setup arch devices
+ set( r600--_devices cedar cypress barts cayman )
diff --git a/debian/patches/libcxx-libatomic-only-with-gcc-rtlib.diff b/debian/patches/libcxx-libatomic-only-with-gcc-rtlib.diff
new file mode 100644
index 00000000..41662966
--- /dev/null
+++ b/debian/patches/libcxx-libatomic-only-with-gcc-rtlib.diff
@@ -0,0 +1,24 @@
+if libatomic is found only link it if libgcc is the rtlib
+Index: llvm-toolchain-12_12.0.1/libcxx/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/libcxx/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/libcxx/CMakeLists.txt
+@@ -756,12 +756,14 @@ function(cxx_link_system_libraries targe
+     endif()
+   elseif (LIBCXX_HAS_GCC_LIB)
+     target_link_libraries(${target} PRIVATE gcc)
++    if (LIBCXX_HAS_ATOMIC_LIB)
++      target_link_libraries(${target} PRIVATE atomic)
++    endif()
+   elseif (LIBCXX_HAS_GCC_S_LIB)
+     target_link_libraries(${target} PRIVATE gcc_s)
+-  endif()
+-
+-  if (LIBCXX_HAS_ATOMIC_LIB)
+-    target_link_libraries(${target} PRIVATE atomic)
++    if (LIBCXX_HAS_ATOMIC_LIB)
++      target_link_libraries(${target} PRIVATE atomic)
++    endif()
+   endif()
+ 
+   if (MINGW)
diff --git a/debian/patches/libcxxabi-fix-link-builtins.diff b/debian/patches/libcxxabi-fix-link-builtins.diff
new file mode 100644
index 00000000..7a71c4f1
--- /dev/null
+++ b/debian/patches/libcxxabi-fix-link-builtins.diff
@@ -0,0 +1,16 @@
+if LIBCXXABI_USE_COMPILER_RT=ON, add builtins to libcxxabi library
+flags, otherwise add libgcc following how libunwind does the same
+Index: llvm-toolchain-12_12.0.1/libcxxabi/src/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/libcxxabi/src/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/libcxxabi/src/CMakeLists.txt
+@@ -104,7 +104,9 @@ if (ANDROID AND ANDROID_PLATFORM_LEVEL L
+   list(APPEND LIBCXXABI_LIBRARIES android_support)
+ endif()
+
+-if (NOT LIBCXXABI_USE_COMPILER_RT)
++if (LIBCXXABI_USE_COMPILER_RT)
++  add_library_flags("${LIBCXXABI_BUILTINS_LIBRARY}")
++else()
+   add_library_flags_if(LIBCXXABI_HAS_GCC_LIB gcc)
+ endif ()
diff --git a/debian/patches/lld-use-link-atomic-i386.diff b/debian/patches/lld-use-link-atomic-i386.diff
deleted file mode 100644
index d27fbc00..00000000
--- a/debian/patches/lld-use-link-atomic-i386.diff
+++ /dev/null
@@ -1,32 +0,0 @@
-Index: llvm-toolchain-snapshot_13~++20210603111529+5c0d1b2f902a/lld/tools/lld/CMakeLists.txt
-===================================================================
---- llvm-toolchain-snapshot_13~++20210603111529+5c0d1b2f902a.orig/lld/tools/lld/CMakeLists.txt
-+++ llvm-toolchain-snapshot_13~++20210603111529+5c0d1b2f902a/lld/tools/lld/CMakeLists.txt
-@@ -1,10 +1,18 @@
-+set(LLD_ATOMIC_LIB "")
-+
- set(LLVM_LINK_COMPONENTS
-   Support
-   )
- 
-+if(CMAKE_HOST_SYSTEM_PROCESSOR MATCHES "i386" OR
-+    CMAKE_HOST_SYSTEM_PROCESSOR MATCHES "i686" OR
-+    CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" OR CMAKE_SYSTEM_PROCESSOR STREQUAL "amd64"
-+  )
-+  list(APPEND LLD_ATOMIC_LIB "atomic")
-+endif()
-+
- add_lld_tool(lld
-   lld.cpp
--
-   SUPPORT_PLUGINS
-   )
- export_executable_symbols_for_plugins(lld)
-@@ -18,6 +26,7 @@ target_link_libraries(lld
-   lldMachO2
-   lldMinGW
-   lldWasm
-+  ${LLD_ATOMIC_LIB}
-   )
- 
- install(TARGETS lld
diff --git a/debian/patches/llvm-fix-lld-linker-check.diff b/debian/patches/llvm-fix-lld-linker-check.diff
new file mode 100644
index 00000000..bad28992
--- /dev/null
+++ b/debian/patches/llvm-fix-lld-linker-check.diff
@@ -0,0 +1,15 @@
+remove regex anchor in lld linker detection to account for vendor, if
+specified, being prepended to lld version string
+Index: llvm-toolchain-12_12.0.1/llvm/cmake/modules/AddLLVM.cmake
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/llvm/cmake/modules/AddLLVM.cmake
++++ llvm-toolchain-12_12.0.1/llvm/cmake/modules/AddLLVM.cmake
+@@ -196,7 +196,7 @@ if (NOT DEFINED LLVM_LINKER_DETECTED)
+       set(LLVM_LINKER_DETECTED YES CACHE INTERNAL "")
+       set(LLVM_LINKER_IS_GOLD YES CACHE INTERNAL "")
+       message(STATUS "Linker detection: GNU Gold")
+-    elseif("${stdout}" MATCHES "^LLD")
++    elseif("${stdout}" MATCHES "LLD")
+       set(LLVM_LINKER_DETECTED YES CACHE INTERNAL "")
+       set(LLVM_LINKER_IS_LLD YES CACHE INTERNAL "")
+       message(STATUS "Linker detection: LLD")
diff --git a/debian/patches/llvm-runtimes-builtins-build-check.diff b/debian/patches/llvm-runtimes-builtins-build-check.diff
new file mode 100644
index 00000000..b4f7eab9
--- /dev/null
+++ b/debian/patches/llvm-runtimes-builtins-build-check.diff
@@ -0,0 +1,20 @@
+add a check and only set up and build compiler-rt builtins if they have
+not been disabled
+Index: llvm-toolchain-12_12.0.1/llvm/runtimes/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/llvm/runtimes/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/llvm/runtimes/CMakeLists.txt
+@@ -131,7 +131,12 @@ endfunction()
+ # is required because the other runtimes need the builtin libraries present
+ # before the just-built compiler can pass the configuration tests.
+ get_compiler_rt_path(compiler_rt_path)
+-if(compiler_rt_path)
++# check if builtins have been disabled
++set(RUNTIMES_BUILD_BUILTINS ON)
++if(DEFINED COMPILER_RT_BUILD_BUILTINS)
++  set(RUNTIMES_BUILD_BUILTINS ${COMPILER_RT_BUILD_BUILTINS})
++endif()
++if(compiler_rt_path AND RUNTIMES_BUILD_BUILTINS)
+   if(NOT LLVM_BUILTIN_TARGETS)
+     builtin_default_target(${compiler_rt_path}
+       DEPENDS clang-resource-headers)
diff --git a/debian/patches/openmp-fix-runtimes-build.diff b/debian/patches/openmp-fix-runtimes-build.diff
new file mode 100644
index 00000000..b8d20cd0
--- /dev/null
+++ b/debian/patches/openmp-fix-runtimes-build.diff
@@ -0,0 +1,162 @@
+include required runtimes as dependencies to openmp targets to make sure
+they are built first when included as part of a runtimes build since openmp
+can depend on them
+Index: llvm-toolchain-12_12.0.1/llvm/runtimes/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/llvm/runtimes/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/llvm/runtimes/CMakeLists.txt
+@@ -236,6 +236,7 @@ function(runtime_default_target)
+                                       -DLLVM_DEFAULT_TARGET_TRIPLE=${TARGET_TRIPLE}
+                                       -DLLVM_ENABLE_PROJECTS_USED=${LLVM_ENABLE_PROJECTS_USED}
+                                       -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=${LLVM_ENABLE_PER_TARGET_RUNTIME_DIR_default}
++                                      -DCMAKE_SYSTEM_PROCESSOR=${CMAKE_SYSTEM_PROCESSOR}
+                                       -DCMAKE_C_COMPILER_TARGET=${TARGET_TRIPLE}
+                                       -DCMAKE_CXX_COMPILER_TARGET=${TARGET_TRIPLE}
+                                       -DCMAKE_ASM_COMPILER_TARGET=${TARGET_TRIPLE}
+@@ -440,7 +441,7 @@ if(runtimes)
+     # build directory cannot find the C++ headers in certain configurations.
+     # I need to build a mechanism for runtime projects to provide CMake code
+     # that executes at LLVM configuration time to handle this case.
+-    add_dependencies(clang-bootstrap-deps runtimes-configure)
++    #add_dependencies(clang-bootstrap-deps runtimes-configure)
+     # We need to add the runtimes as a dependency because compiler-rt can be
+     # built as part of runtimes and we need the profile runtime for PGO
+     add_dependencies(clang-bootstrap-deps runtimes)
+Index: llvm-toolchain-12_12.0.1/openmp/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/openmp/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/openmp/CMakeLists.txt
+@@ -83,6 +83,28 @@ option(OPENMP_ENABLE_LIBOMPTARGET_PROFIL
+        ${ENABLE_LIBOMPTARGET})
+ option(OPENMP_ENABLE_LIBOMP_PROFILING "Enable time profiling for libomp." OFF)
+ 
++option(OPENMP_USE_LLVM_UNWINDER "Build and use the LLVM unwinder" OFF)
++
++option(LIBOMP_ENABLE_RTTI "Enabling RTTI forces libomp to be a c++ lib" ${LLVM_ENABLE_RTTI})
++
++macro(add_runtimes_build_depends_if_needed target)
++  if(RUNTIMES_BUILD)
++    # required for rtti and libomp/libomptarget profiling if enabled
++    add_dependencies(${target} cxx-headers cxxabi_static cxx_static cxxabi_shared cxx_shared)
++    if(OPENMP_USE_LLVM_UNWINDER AND (NOT target STREQUAL "omp" AND NOT LIBOMP_ENABLE_RTTI))
++      add_dependencies(${target} unwind_static unwind_shared)
++      get_target_property(target_link_flags ${target} LINK_FLAGS)
++      set(runtimes_link_flags "-lunwind")
++      if(target_link_flags)
++        set(runtimes_link_flags "${target_link_flags} -lunwind")
++      endif()
++      set_target_properties(${target}
++        PROPERTIES
++        LINK_FLAGS "${runtimes_link_flags}")
++    endif()
++  endif()
++endmacro()
++
+ # Build host runtime library, after LIBOMPTARGET variables are set since they are needed
+ # to enable time profiling support in the OpenMP runtime.
+ add_subdirectory(runtime)
+Index: llvm-toolchain-12_12.0.1/openmp/cmake/HandleOpenMPOptions.cmake
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/openmp/cmake/HandleOpenMPOptions.cmake
++++ llvm-toolchain-12_12.0.1/openmp/cmake/HandleOpenMPOptions.cmake
+@@ -29,7 +29,8 @@ append_if(OPENMP_HAVE_WNO_EXTRA_FLAG "-W
+ append_if(OPENMP_HAVE_WNO_PEDANTIC_FLAG "-Wno-pedantic" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+ append_if(OPENMP_HAVE_WNO_MAYBE_UNINITIALIZED_FLAG "-Wno-maybe-uninitialized" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+ 
+-append_if(OPENMP_HAVE_STD_GNUPP14_FLAG "-std=gnu++14" CMAKE_CXX_FLAGS)
+-if (NOT OPENMP_HAVE_STD_GNUPP14_FLAG)
+-  append_if(OPENMP_HAVE_STD_CPP14_FLAG "-std=c++14" CMAKE_CXX_FLAGS)
++# prefer c++14 over gnu++14?
++append_if(OPENMP_HAVE_STD_CPP14_FLAG "-std=c++14" CMAKE_CXX_FLAGS)
++if (NOT OPENMP_HAVE_STD_CPP14_FLAG)
++  append_if(OPENMP_HAVE_STD_GNUPP14_FLAG "-std=gnu++14" CMAKE_CXX_FLAGS)
+ endif()
+Index: llvm-toolchain-12_12.0.1/openmp/libomptarget/plugins/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/openmp/libomptarget/plugins/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/openmp/libomptarget/plugins/CMakeLists.txt
+@@ -36,6 +36,8 @@ if(CMAKE_SYSTEM_PROCESSOR MATCHES "${tma
+       add_library("omptarget.rtl.${tmachine_libname}" SHARED
+         ${CMAKE_CURRENT_SOURCE_DIR}/../generic-elf-64bit/src/rtl.cpp)
+ 
++      add_runtimes_build_depends_if_needed("omptarget.rtl.${tmachine_libname}")
++
+       # Install plugin under the lib destination folder.
+       install(TARGETS "omptarget.rtl.${tmachine_libname}"
+         LIBRARY DESTINATION "${OPENMP_INSTALL_LIBDIR}")
+Index: llvm-toolchain-12_12.0.1/openmp/libomptarget/plugins/cuda/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/openmp/libomptarget/plugins/cuda/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/openmp/libomptarget/plugins/cuda/CMakeLists.txt
+@@ -44,6 +44,8 @@ else()
+   set (LIBOMPTARGET_DEP_LIBRARIES ${CMAKE_DL_LIBS})
+ endif()
+ 
++add_runtimes_build_depends_if_needed(omptarget.rtl.cuda)
++
+ # Install plugin under the lib destination folder.
+ install(TARGETS omptarget.rtl.cuda LIBRARY DESTINATION "${OPENMP_INSTALL_LIBDIR}")
+ 
+Index: llvm-toolchain-12_12.0.1/openmp/libomptarget/src/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/openmp/libomptarget/src/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/openmp/libomptarget/src/CMakeLists.txt
+@@ -48,6 +48,8 @@ set_target_properties(omptarget
+   PROPERTIES
+   LIBRARY_OUTPUT_DIRECTORY ${LIBOMPTARGET_LIBRARY_DIR})
+ 
++add_runtimes_build_depends_if_needed(omptarget)
++
+ # Install libomptarget under the lib destination folder.
+ install(TARGETS omptarget LIBRARY COMPONENT omptarget
+   DESTINATION "${OPENMP_INSTALL_LIBDIR}")
+Index: llvm-toolchain-12_12.0.1/openmp/runtime/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/openmp/runtime/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/openmp/runtime/CMakeLists.txt
+@@ -287,6 +287,10 @@ if(LIBOMP_STATS)
+   set(LIBOMP_USE_STDCPPLIB TRUE)
+ endif()
+ 
++if(LIBOMP_ENABLE_RTTI)
++  set(LIBOMP_USE_STDCPPLIB TRUE)
++endif()
++
+ # Shared library can be switched to a static library
+ set(LIBOMP_ENABLE_SHARED TRUE CACHE BOOL
+   "Shared library instead of static library?")
+Index: llvm-toolchain-12_12.0.1/openmp/runtime/src/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/openmp/runtime/src/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/openmp/runtime/src/CMakeLists.txt
+@@ -134,6 +134,7 @@ endif()
+ if(NOT ${LIBOMP_USE_STDCPPLIB})
+   set(LIBOMP_LINKER_LANGUAGE C)
+   set(CMAKE_CXX_IMPLICIT_LINK_LIBRARIES)
++  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nostdlib++")
+ else()
+   set(LIBOMP_LINKER_LANGUAGE CXX)
+ endif()
+@@ -162,6 +163,8 @@ set_target_properties(omp PROPERTIES
+   LINKER_LANGUAGE ${LIBOMP_LINKER_LANGUAGE}
+ )
+ 
++add_runtimes_build_depends_if_needed(omp)
++
+ # Get the library's location within the build tree for the unit tester
+ if(NOT WIN32)
+   get_target_property(LIBOMP_LIBRARY_DIR omp LIBRARY_OUTPUT_DIRECTORY)
+Index: llvm-toolchain-12_12.0.1/openmp/tools/archer/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/openmp/tools/archer/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/openmp/tools/archer/CMakeLists.txt
+@@ -14,6 +14,9 @@ if(LIBOMP_OMPT_SUPPORT)
+   add_library(archer SHARED ompt-tsan.cpp)
+   add_library(archer_static STATIC ompt-tsan.cpp)
+ 
++  add_runtimes_build_depends_if_needed(archer)
++  add_runtimes_build_depends_if_needed(archer_static)
++
+   install(TARGETS archer archer_static
+     LIBRARY DESTINATION ${OPENMP_INSTALL_LIBDIR}
+     ARCHIVE DESTINATION ${OPENMP_INSTALL_LIBDIR})
diff --git a/debian/patches/series b/debian/patches/series
index f035e4d0..4a619575 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -27,7 +27,6 @@ do-not-fail-on-unexpected-pass.diff
 disable-display-PASS-UNSUPPORTED-XFAIL.diff
 
 # llvm-config
-fix-llvm-config-obj-src-root.patch
 0001-llvm-cmake-resolve-symlinks-in-LLVMConfig.cmake.patch
 
 # Lib names
@@ -125,9 +124,6 @@ risc/clang-riscv64-multiarch.diff
 D98574.patch
 D98575.patch
 
-# Compiler-rt - workaround
-workaround-bug-42994-use-linker.diff
-
 # bug 939472
 #try-to-unbreak-thinlto.diff
 #D67877-cmake-clang-example.patch
@@ -137,7 +133,6 @@ x86-fuzzer.patch
 python3-shebang.patch
 print-lldb-path.patch
 libcxx-armhf-ftbfs.diff
-lld-use-link-atomic-i386.diff
 lower-python-dep.diff
 scan-build-py-fix-analyze-path.diff
 scan-build-py-fix-default-bin.diff
@@ -146,3 +141,11 @@ libclc-llvm-spirv.diff
 omp-riscv64.patch
 test-disable-lldb-i386.diff
 unbreak-atomic-mips.diff
+llvm-fix-lld-linker-check.diff
+compilerrt-fix-warn-xray-testing.diff
+openmp-fix-runtimes-build.diff
+libclc-fix-prepare_builtins-rpath.diff
+libcxx-libatomic-only-with-gcc-rtlib.diff
+libcxxabi-fix-link-builtins.diff
+llvm-runtimes-builtins-build-check.diff
+compilerrt-builtins-arch-fix-armhf.diff
diff --git a/debian/patches/symbolizer-path.diff b/debian/patches/symbolizer-path.diff
index 3eaaaf84..69caab13 100644
--- a/debian/patches/symbolizer-path.diff
+++ b/debian/patches/symbolizer-path.diff
@@ -1,7 +1,7 @@
-Index: llvm-toolchain-snapshot_11~++20200326111000+4673699a470/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
+Index: llvm-toolchain-12_12.0.1/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
 ===================================================================
---- llvm-toolchain-snapshot_11~++20200326111000+4673699a470.orig/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
-+++ llvm-toolchain-snapshot_11~++20200326111000+4673699a470/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
+--- llvm-toolchain-12_12.0.1.orig/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
++++ llvm-toolchain-12_12.0.1/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cpp
 @@ -25,6 +25,10 @@
  #include "sanitizer_symbolizer_internal.h"
  #include "sanitizer_symbolizer_libbacktrace.h"
@@ -13,7 +13,7 @@ Index: llvm-toolchain-snapshot_11~++20200326111000+4673699a470/compiler-rt/lib/s
  
  #include <dlfcn.h>   // for dlsym()
  #include <errno.h>
-@@ -428,7 +432,7 @@ static SymbolizerTool *ChooseExternalSym
+@@ -433,7 +437,7 @@ static SymbolizerTool *ChooseExternalSym
      return new(*allocator) AtosSymbolizer(found_path, allocator);
    }
  #endif  // SANITIZER_MAC
@@ -22,3 +22,15 @@ Index: llvm-toolchain-snapshot_11~++20200326111000+4673699a470/compiler-rt/lib/s
      VReport(2, "Using llvm-symbolizer found at: %s\n", found_path);
      return new(*allocator) LLVMSymbolizer(found_path, allocator);
    }
+Index: llvm-toolchain-12_12.0.1/compiler-rt/lib/sanitizer_common/CMakeLists.txt
+===================================================================
+--- llvm-toolchain-12_12.0.1.orig/compiler-rt/lib/sanitizer_common/CMakeLists.txt
++++ llvm-toolchain-12_12.0.1/compiler-rt/lib/sanitizer_common/CMakeLists.txt
+@@ -195,6 +195,7 @@ set(SANITIZER_IMPL_HEADERS
+   )
+ 
+ include_directories(..)
++include_directories(${LLVM_INCLUDE_DIR})
+ 
+ set(SANITIZER_COMMON_DEFINITIONS
+   HAVE_RPC_XDR_H=${HAVE_RPC_XDR_H})
diff --git a/debian/patches/workaround-bug-42994-use-linker.diff b/debian/patches/workaround-bug-42994-use-linker.diff
deleted file mode 100644
index f2cfa116..00000000
--- a/debian/patches/workaround-bug-42994-use-linker.diff
+++ /dev/null
@@ -1,34 +0,0 @@
-Index: llvm-toolchain-snapshot_13~++20210517085206+0f417789192e/compiler-rt/lib/hwasan/CMakeLists.txt
-===================================================================
---- llvm-toolchain-snapshot_13~++20210517085206+0f417789192e.orig/compiler-rt/lib/hwasan/CMakeLists.txt
-+++ llvm-toolchain-snapshot_13~++20210517085206+0f417789192e/compiler-rt/lib/hwasan/CMakeLists.txt
-@@ -45,9 +45,9 @@ append_list_if(COMPILER_RT_HWASAN_WITH_I
- 
- set(HWASAN_RTL_CFLAGS ${SANITIZER_COMMON_CFLAGS})
- append_rtti_flag(OFF HWASAN_RTL_CFLAGS)
--append_list_if(COMPILER_RT_HAS_FPIC_FLAG -fPIC HWASAN_RTL_CFLAGS)
-+append_list_if(COMPILER_RT_HAS_FPIC_FLAG -fPIC -fuse-ld=gold HWASAN_RTL_CFLAGS)
- # Prevent clang from generating libc calls.
--append_list_if(COMPILER_RT_HAS_FFREESTANDING_FLAG -ffreestanding HWASAN_RTL_CFLAGS)
-+append_list_if(COMPILER_RT_HAS_FFREESTANDING_FLAG -ffreestanding -fuse-ld=gold HWASAN_RTL_CFLAGS)
- 
- set(HWASAN_DYNAMIC_LINK_FLAGS ${SANITIZER_COMMON_LINK_FLAGS})
- 
-@@ -59,7 +59,7 @@ if(ANDROID)
-   endif()
- endif()
- 
--set(HWASAN_DYNAMIC_CFLAGS ${HWASAN_RTL_CFLAGS})
-+set(HWASAN_DYNAMIC_CFLAGS ${HWASAN_RTL_CFLAGS} -fuse-ld=gold)
- append_list_if(COMPILER_RT_HAS_FTLS_MODEL_INITIAL_EXEC
-   -ftls-model=initial-exec HWASAN_DYNAMIC_CFLAGS)
- append_list_if(MSVC /DEBUG HWASAN_DYNAMIC_LINK_FLAGS)
-@@ -153,7 +153,7 @@ function(add_hwasan_runtimes arch use_al
-                                   LIBS ${hwasan_runtime}-${arch} ${hwasan_runtime}_cxx-${arch}
-                                   EXTRA hwasan.syms.extra)
-     set(VERSION_SCRIPT_FLAG
--         -Wl,--version-script,${CMAKE_CURRENT_BINARY_DIR}/${hwasan_runtime}-dynamic-${arch}.vers)
-+         -Wl,--version-script,${CMAKE_CURRENT_BINARY_DIR}/${hwasan_runtime}-dynamic-${arch}.vers -fuse-ld=gold)
-     set_property(SOURCE
-       ${CMAKE_CURRENT_BINARY_DIR}/dummy.cpp
-       APPEND PROPERTY
diff --git a/debian/qualify-clang.sh b/debian/qualify-clang.sh
index b1b7fcb7..45671d98 100755
--- a/debian/qualify-clang.sh
+++ b/debian/qualify-clang.sh
@@ -45,7 +45,7 @@ if grep "File format not recognized" foo.log; then
 fi
 
 # Test #995684
-if test /usr/share/man/man1/llc-$VERSION.1.gz; then
+if test ! -f /usr/share/man/man1/llc-$VERSION.1.gz; then
     echo "llvm manpage are missing (using llc as an example)"
     exit 1
 fi
@@ -1067,6 +1067,12 @@ if test ! -f /usr/lib/clc/amdgcn--amdhsa.bc; then
     exit -1;
 fi
 
+if test ! -f /usr/lib/clc/polaris10-amdgcn-mesa-mesa3d.bc; then
+    # Make sure that #993904 and #995069 don't come back
+    echo "/usr/lib/clc/polaris10-amdgcn-mesa-mesa3d.bc doesn't exist"
+    exit 1
+fi
+
 LLVM_CONFIG=llvm-config-$VERSION /usr/lib/llvm-$VERSION/share/libclc/check_external_calls.sh /usr/lib/clc/amdgcn--amdhsa.bc > /dev/null
 
 # libunwind
@@ -1328,6 +1334,7 @@ if dpkg -l|grep -q clang-$VERSION-dbgsym; then
     if ! grep "main at driver.cpp" foo.log; then
         echo "Could not find the debug info"
         echo "Or the main() of clang isn't in driver.cpp anymore"
+        cat foo.log
         exit -1
     fi
 else
@@ -1457,8 +1464,9 @@ echo "Testing all other sanitizers ..."
 echo "int main() { return 1; }" > foo.c
 # fails to run on i386 with the following error:
 #clang: error: unsupported option '-fsanitize=efficiency-working-set' for target 'i686-pc-linux-gnu'
-clang-$VERSION -fsanitize=efficiency-working-set -o foo foo.c || true
-./foo &> /dev/null || true
+# seems like esan was removed from clang: https://github.com/llvm/llvm-project/commit/885b790f89b6068ec4caad8eaa51aa8098327059
+#clang-$VERSION -fsanitize=efficiency-working-set -o foo foo.c || true
+#./foo &> /dev/null || true
 
 cat > "$TEMPDIR/test.c" <<EOF
 #include <stdlib.h>
diff --git a/debian/rules b/debian/rules
index ea9f7bde..22f5dda2 100755
--- a/debian/rules
+++ b/debian/rules
@@ -1,7 +1,9 @@
 #!/usr/bin/make -f
 
-# polly, openmp & lldb aren't enabled for every platform
-PROJECTS = clang;clang-tools-extra;libcxx;libcxxabi;compiler-rt;lld;debuginfo-tests
+# polly & lldb aren't enabled for every platform
+PROJECTS = clang;clang-tools-extra;lld;debuginfo-tests
+# openmp & libunwind aren't enabled for every platform
+RUNTIMES = compiler-rt;libcxx;libcxxabi
 
 TARGET_BUILD	:= build-llvm
 TARGET_BUILD_STAGE2    := $(TARGET_BUILD)/tools/clang/stage2-bins
@@ -39,42 +41,68 @@ DH_VERSION := $(shell dpkg -s debhelper | grep '^Version' | awk '{print $$2}')
 
 include /usr/share/dpkg/architecture.mk
 
-LDFLAGS_EXTRA =
-CXXFLAGS_EXTRA =
-CFLAGS_EXTRA =
 CONFIGURE_EXTRA =
-CMAKE_EXTRA = -DPYTHON_EXECUTABLE=/usr/bin/python3
-CMAKE_LIBCXX_EXTRA =
 
-BASE_PATH	:= $(CURDIR)
-LIBCXX_EXCEPTIONS :=ON
+# dpkg-buildflags support
+# disable fixfilepath in favor of the llvm-project supplied flavor, disable lto
+export DEB_BUILD_MAINT_OPTIONS = reproducible=-fixfilepath,-fixdebugpath optimize=-lto
+# these are handled on a per stage / build basis
+export DEB_CFLAGS_MAINT_STRIP = -g -O2
+export DEB_CXXFLAGS_MAINT_STRIP = -g -O2
 
-ifneq (,$(filter $(DEB_HOST_ARCH),s390x))
-	LIBCXX_EXCEPTIONS :=OFF
-endif
+include /usr/share/dpkg/buildflags.mk
 
-ifneq (,$(filter $(DEB_HOST_ARCH),i386 armel mips mipsel powerpc powerpcspe riscv64))
-CMAKE_EXTRA += -DLIBOMP_LIBFLAGS="-latomic" -DCMAKE_SHARED_LINKER_FLAGS="-latomic"
-endif
+# We use a stage2 build. It means that a first clang is built using gcc,
+# a second clang is built with the first
+# And the various compoments are built using the second clang.
+# See https://llvm.org/docs/AdvancedBuilds.html
+
+# collect additional flags for all stages all builds
+CFLAGS_EXTRA = -Wno-unused-command-line-argument
+CXXFLAGS_EXTRA = -Wno-unused-command-line-argument
+LDFLAGS_EXTRA = -Wl,--build-id
+
+# collect all flags for stage 1 toolchain build only
+STAGE_1_CFLAGS = $(CFLAGS) $(CFLAGS_EXTRA) $(CPPFLAGS)
+STAGE_1_CXXFLAGS = $(CXXFLAGS) $(CXXFLAGS_EXTRA) $(CPPFLAGS)
+STAGE_1_LDFLAGS = $(LDFLAGS) $(LDFLAGS_EXTRA)
+
+# collect all flags for stage 2 toolchain and stand-alone builds
+STAGE_2_CFLAGS = $(CFLAGS) $(CFLAGS_EXTRA) $(CPPFLAGS)
+STAGE_2_CXXFLAGS = $(CXXFLAGS) $(CXXFLAGS_EXTRA) $(CPPFLAGS)
+STAGE_2_LDFLAGS = $(LDFLAGS) $(LDFLAGS_EXTRA)
+
+# collect additional cmake options for toolchain build configuration
+STAGE_1_CMAKE_EXTRA =
+STAGE_2_CMAKE_EXTRA =
+STAGE_ALL_CMAKE_EXTRA =
+# toolchain config-only var combining all stage 1 cmake options
+CMAKE_EXTRA = $(STAGE_1_CMAKE_EXTRA) $(STAGE_ALL_CMAKE_EXTRA)
+# toolchain config-only var prepending BOOTSTRAP_ to all stage 2 cmake options
+BOOTSTRAP_CMAKE_EXTRA = $(foreach extra,$(STAGE_2_CMAKE_EXTRA) $(STAGE_ALL_CMAKE_EXTRA), $(subst -D,-DBOOTSTRAP_,$(extra)))
+
+BASE_PATH := $(CURDIR)
+STAGE_1_BIN_DIR := $(BASE_PATH)/$(TARGET_BUILD)/bin
+STAGE_1_LIB_DIR := $(BASE_PATH)/$(TARGET_BUILD)/lib
+STAGE_2_BIN_DIR := $(BASE_PATH)/$(TARGET_BUILD_STAGE2)/bin
+STAGE_2_LIB_DIR := $(BASE_PATH)/$(TARGET_BUILD_STAGE2)/lib
+
+# toggleable defaults
+COMPILER_RT_USE_BUILTINS_LIBRARY := ON
+LIBCXX_EXCEPTIONS := ON
+LIBCXX_USE_COMPILER_RT := ON
 
 ifneq (,$(filter $(DEB_HOST_ARCH),sparc sparc64))
-CMAKE_EXTRA += -DLLVM_PARALLEL_LINK_JOBS=4
+STAGE_1_CMAKE_EXTRA += -DLLVM_PARALLEL_LINK_JOBS=4
 endif
 
-ifneq (,$(filter $(DEB_HOST_ARCH),armel mipsel powerpc riscv64))
+ifneq (,$(filter $(DEB_HOST_ARCH),i386 armel mipsel powerpc powerpcspe riscv64))
 # For some reason, in the stage2 build, when clang is used to compile
-# itself. The atomic detection is failing on armel and riscv64. Forcing the inclusion everywhere.
+# itself. The atomic detection is failing on armel and riscv64. Forcing the inclusion
+# everywhere and in all stages
 LDFLAGS_EXTRA += -latomic
 endif
 
-# Ensure fixfilepath feature is disabled.  The fixfilepath feature
-# sets a -ffile-prefix-map flag, which is only supported in clang-10.
-# Disable also lto
-export DEB_BUILD_MAINT_OPTIONS=reproducible=-fixfilepath optimize=-lto
-
-# Cxx flags for building libcxx and libcxxabi
-LIBCXXFLAGS := $(shell dpkg-buildflags --get CXXFLAGS) $(shell dpkg-buildflags --get CPPFLAGS)
-
 ifeq ($(shell dpkg --compare-versions $(shell dpkg-query -W -f '$${Version}' g++-$(GCC_VERSION)) lt 4.9-20140411-1~ ; echo $$?),0)
 # Too old version of gcc. Force 4.9
 	GCC_VERSION := 4.9
@@ -87,13 +115,14 @@ ifneq ($(shell dpkg-vendor --derives-from Ubuntu && echo yes),yes)
 	Z3_FLAG = -DLLVM_ENABLE_Z3_SOLVER=ON
 endif
 endif
+STAGE_2_CMAKE_EXTRA += $(Z3_FLAG)
 
 # Change the default CPU for s390x
 ZARCH=z196
 ifeq ($(shell dpkg-vendor --derives-from Ubuntu && echo yes),yes)
 ZARCH=z13
 endif
-CMAKE_EXTRA += -DCLANG_SYSTEMZ_DEFAULT_ARCH=$(ZARCH)
+STAGE_2_CMAKE_EXTRA += -DCLANG_SYSTEMZ_DEFAULT_ARCH=$(ZARCH)
 
 export CC=gcc-$(GCC_VERSION)
 export CXX=g++-$(GCC_VERSION)
@@ -101,32 +130,57 @@ export CXX=g++-$(GCC_VERSION)
 opt_flags = -O2 -DNDEBUG -g1
 
 ifneq (,$(findstring $(DEB_HOST_ARCH),armel))
-  opt_flags += -marm
-  # 3.8 fails to build, disable the compiler_rt builtins
-  # See http://lists.llvm.org/pipermail/llvm-dev/2016-May/099761.html
-  CMAKE_EXTRA += -DCOMPILER_RT_BUILD_BUILTINS=OFF
-  # Check for ancient libstdc++ fails due to atomics usage
-  CMAKE_LIBCXX_EXTRA += -DLLVM_COMPILER_CHECKED=ON
-  # Prevent clang from getting a > v4t default
-  # See bug #868779
-  CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=arm-linux-gnueabi
+  STAGE_ALL_CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=arm-linux-gnueabi
+  STAGE_ALL_CMAKE_EXTRA += -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON
+# align arch profile with debian baseline
+# https://wiki.debian.org/ArmEabiPort
+  CFLAGS_EXTRA += -march=armv5t
+  CXXFLAGS_EXTRA += -march=armv5t
+# disable compiler-rt builtins (not supported for baseline armel arch: armv5t)
+# See http://lists.llvm.org/pipermail/llvm-dev/2016-May/099761.html
+  STAGE_ALL_CMAKE_EXTRA += -DCOMPILER_RT_BUILD_BUILTINS=OFF
+  COMPILER_RT_USE_BUILTINS_LIBRARY := OFF
+  LIBCXX_USE_COMPILER_RT := OFF
 endif
 
-
 ifneq (,$(findstring $(DEB_HOST_ARCH),armhf))
-# avoid an issue with openmp on armhf
-  CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=armv7l-unknown-linux-gnueabihf
+  STAGE_ALL_CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=arm-linux-gnueabihf
+  STAGE_ALL_CMAKE_EXTRA += -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON
+# align arch profile with debian baseline
+# https://wiki.debian.org/ArmHardFloatPort#Minimum_CPU_.26_FPU
+  CFLAGS_EXTRA += -march=armv7-a -mfpu=vfpv3-d16
+  CXXFLAGS_EXTRA += -march=armv7-a -mfpu=vfpv3-d16
+endif
+
+ifneq (,$(filter $(DEB_HOST_ARCH),i386))
+# Sometimes, i386 needs help with the triple
+  STAGE_ALL_CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=i386-linux-gnu
 endif
 
 ifneq (,$(filter $(DEB_HOST_ARCH),mips64el))
 # avoid an issue with search path on mips64el
 # https://bugs.llvm.org/show_bug.cgi?id=41204
-  CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=mips64el-linux-gnuabi64
+  STAGE_ALL_CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=mips64el-linux-gnuabi64
+endif
+
+ifneq (,$(filter $(DEB_HOST_ARCH),powerpc))
+  STAGE_ALL_CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=powerpc-linux-gnu
+  STAGE_ALL_CMAKE_EXTRA += -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON
+endif
+
+ifneq (,$(filter $(DEB_HOST_ARCH),s390x))
+  STAGE_ALL_CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=s390x-linux-gnu
+  STAGE_ALL_CMAKE_EXTRA += -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON
+  LIBCXX_EXCEPTIONS := OFF
+# disable compiler-rt builtins (not supported for s390x)
+  STAGE_ALL_CMAKE_EXTRA += -DCOMPILER_RT_BUILD_BUILTINS=OFF
+  COMPILER_RT_USE_BUILTINS_LIBRARY := OFF
+  LIBCXX_USE_COMPILER_RT := OFF
 endif
 
 ifneq (,$(filter $(DEB_HOST_ARCH),x32))
-  CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=x86_64-linux-gnux32
-  CMAKE_EXTRA += -DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-linux-gnux32
+  STAGE_ALL_CMAKE_EXTRA += -DLLVM_HOST_TRIPLE=x86_64-linux-gnux32
+  STAGE_ALL_CMAKE_EXTRA += -DLLVM_DEFAULT_TARGET_TRIPLE=x86_64-linux-gnux32
 endif
 
 ifeq ($(shell dpkg --compare-versions $(shell dpkg-query -W -f '$${Version}' g++-$(GCC_VERSION)) ge 4.8-20121128-1~ ; echo $$?),0)
@@ -145,28 +199,16 @@ else
 LLVM_SPIRV_INSTALLED = yes
 endif
 
-LIBCLC_TARGETS_TO_BUILD="amdgcn--;amdgcn--amdhsa;r600--;nvptx--;nvptx64--;nvptx--nvidiacl;nvptx64--nvidiacl"
+LIBCLC_TARGETS_TO_BUILD="amdgcn--;amdgcn--amdhsa;amdgcn-mesa-mesa3d;r600--;nvptx--;nvptx64--;nvptx--nvidiacl;nvptx64--nvidiacl"
 ifeq ($(LLVM_SPIRV_INSTALLED),yes)
 	LIBCLC_TARGETS_TO_BUILD := $(LIBCLC_TARGETS_TO_BUILD)";spirv-mesa3d-;spirv64-mesa3d-"
 endif
 
-# Disabled:
-#  Host compiler does not support '-fuse-ld=lld'
-# USE_LLD_ARCHS := amd64
-# ifneq (,$(filter $(DEB_HOST_ARCH),$(USE_LLD_ARCHS)))
-# 	CMAKE_EXTRA += -DLLVM_ENABLE_LLD=ON
-# endif
-
 BINUTILS_GOLD_ARCHS := amd64 arm64 armhf i386 ppc64 ppc64el x32 s390x hurd-i386 kfreebsd-amd64 kfreebsd-i386
 ifeq ($(shell dpkg --compare-versions $(shell dpkg-query -W -f '$${Version}' binutils) ge 2.23.1-1~exp3 ; echo $$?),0)
 ifneq (,$(filter $(DEB_HOST_ARCH),$(BINUTILS_GOLD_ARCHS)))
-# -fused-ld=gold enables the gold linker (but is not supported by all archs / distro)
-	LDFLAGS_EXTRA += -fuse-ld=gold
-#--no-keep-files-mapped --no-map-whole-files
-	CXXFLAGS_EXTRA += -fuse-ld=gold
-	CFLAGS_EXTRA += -fuse-ld=gold
-#-Wl,--no-keep-files-mapped -Wl,--no-map-whole-files
-	CMAKE_EXTRA += -DLLVM_BINUTILS_INCDIR=/usr/include/
+	STAGE_ALL_CMAKE_EXTRA += -DLLVM_USE_LINKER=gold
+	STAGE_ALL_CMAKE_EXTRA += -DLLVM_BINUTILS_INCDIR=/usr/include/
 endif
 endif
 
@@ -179,16 +221,9 @@ ifneq (,$(filter codecoverage,$(DEB_BUILD_OPTIONS)))
 	LDFLAGS_EXTRA += -coverage -lgcov
 	RUN_TEST=yes
     # OpenMP doesn't respect LDFLAGS
-    CMAKE_EXTRA+= -DLIBOMP_LDFLAGS="-coverage -lgcov" # don't pass LDFLAGS_EXTRA because it expects gcc arg
+    STAGE_2_CMAKE_EXTRA+= -DLIBOMP_LDFLAGS="-coverage -lgcov" # don't pass LDFLAGS_EXTRA because it expects gcc arg
 endif
 
-# Enable for bootstrap
-LDFLAGS_EXTRA            += -fPIC -Wno-unused-command-line-argument -Wno-unknown-warning-option -Wl,--build-id
-CXXFLAGS_EXTRA           += -fPIC -Wno-unused-command-line-argument -Wno-unknown-warning-option
-BOOTSTRAP_CXXFLAGS_EXTRA  = $(CXXFLAGS_EXTRA) # Nothing for now. Keeping in case we need it
-CFLAGS_EXTRA             += -fPIC -Wno-unused-command-line-argument -Wno-unknown-warning-option
-BOOTSTRAP_CFLAGS_EXTRA    = $(CFLAGS_EXTRA) # Nothing for now. Keeping in case we need it
-
 # Enable polly (or not)
 POLLY_ENABLE=yes
 ifneq (,$(filter $(DEB_HOST_ARCH), powerpc powerpcspe))
@@ -197,22 +232,28 @@ else
   PROJECTS+=;polly
 endif
 
-# Enable openmp (or not)
-OPENMP_ENABLE=yes
-ifneq (,$(filter $(DEB_HOST_ARCH), m68k mips mipsel powerpc powerpcspe sparc64 s390x x32))
-  OPENMP_ENABLE=no
-else
-  PROJECTS+=;openmp
-endif
-
 # Enable libunwind (or not)
 LIBUNWIND_ENABLE=yes
 ifneq (,$(filter $(DEB_HOST_ARCH), s390x armel m68k mipsel hurd-i386 powerpc sparc sparc64 x32))
   LIBUNWIND_ENABLE=no
+# do not use compiler-rt builtins for libcxx (libcxxabi) when libunwind is
+# disabled since the gnu implementation in libgcc_s will then be required
+  LIBCXX_USE_COMPILER_RT := OFF
 else
-  PROJECTS += ;libunwind
-  CMAKE_LIBCXX_EXTRA += -DLIBCXXABI_USE_LLVM_UNWINDER=ON \
-	-DLIBUNWIND_USE_COMPILER_RT=ON
+  RUNTIMES += ;libunwind
+  STAGE_ALL_CMAKE_EXTRA += -DLIBCXXABI_USE_LLVM_UNWINDER=ON
+endif
+
+# Enable openmp (or not)
+OPENMP_ENABLE=yes
+ifneq (,$(filter $(DEB_HOST_ARCH), m68k mipsel powerpc powerpcspe sparc64 s390x x32))
+  OPENMP_ENABLE=no
+else
+  RUNTIMES+=;openmp
+  STAGE_ALL_CMAKE_EXTRA += -DLIBOMP_LIBFLAGS="-lm"
+ifeq ($(LIBUNWIND_ENABLE),yes)
+  STAGE_ALL_CMAKE_EXTRA += -DOPENMP_USE_LLVM_UNWINDER=ON
+endif
 endif
 
 RUN_TEST=yes
@@ -241,7 +282,7 @@ ifneq (,$(filter scan-build,$(DEB_BUILD_OPTIONS)))
 # no need to run tests in this case
 	RUN_TEST=no
 	CONFIGURE_EXTRA += --enable-assertions
-	CMAKE_EXTRA += -DLLVM_ENABLE_ASSERTIONS=ON
+	STAGE_ALL_CMAKE_EXTRA += -DLLVM_ENABLE_ASSERTIONS=ON
 endif
 
 ifneq (,$(filter coverity,$(DEB_BUILD_OPTIONS)))
@@ -254,7 +295,7 @@ ifneq (,$(filter coverity,$(DEB_BUILD_OPTIONS)))
 	PRE_PROCESS_CONF=
 	COVERITY_ENABLE=1
 	CONFIGURE_EXTRA += --enable-assertions
-	CMAKE_EXTRA += -DLLVM_ENABLE_ASSERTIONS=ON
+	STAGE_ALL_CMAKE_EXTRA += -DLLVM_ENABLE_ASSERTIONS=ON
 # no need to run tests in this case
 	RUN_TEST=no
 else
@@ -268,9 +309,6 @@ ifeq (,$(filter-out $(LLDB_DISABLE_ARCHS), $(DEB_HOST_ARCH)))
 # Disable LLDB for this arch.
 	LLDB_ENABLE=no
 else
-# See https://llvm.org/bugs/show_bug.cgi?id=28898
-# Enable it again as it seems it is fixed upstream https://bugs.llvm.org/show_bug.cgi?id=35291
-#	CMAKE_EXTRA += -DLLDB_DISABLE_LIBEDIT=ON
 	PROJECTS+=;lldb
 endif
 
@@ -278,7 +316,7 @@ LLD_ENABLE=yes
 
 ifneq (,$(filter $(DEB_HOST_ARCH_OS),linux))
 # only for linux
-	CMAKE_EXTRA += -DLLVM_USE_PERF=yes -DLLVM_ENABLE_LIBPFM=ON
+	STAGE_2_CMAKE_EXTRA += -DLLVM_USE_PERF=ON -DLLVM_ENABLE_LIBPFM=ON
 endif
 
 # Only enable it for archs supporting gold
@@ -292,7 +330,7 @@ ifeq (,$(filter $(DEB_HOST_ARCH), armhf))
 # * LLVM_ENABLE_LTO doesn't work with gcc >= 9 (option not accepted)
 # * BOOTSTRAP_LLVM_ENABLE_LTO is producing some large binary
 #   See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=943623
-#	CMAKE_EXTRA += -DBOOTSTRAP_LLVM_ENABLE_LTO="Thin"
+#	STAGE_2_CMAKE_EXTRA += -DLLVM_ENABLE_LTO="Thin"
 endif
 endif
 
@@ -311,7 +349,7 @@ ifeq (,$(filter $(DEB_HOST_ARCH_OS),linux))
 	LIBFUZZER_ENABLE=no
 endif
 
-ifneq (,$(filter $(DEB_HOST_ARCH), mips mipsel))
+ifneq (,$(filter $(DEB_HOST_ARCH), mipsel))
 	LIBOMP_ARCH = mips
 endif
 
@@ -329,12 +367,15 @@ endif
 
 GENERATOR=Ninja
 
+# enables cmake build targets like stage2-[target_name]
+ENABLED_STAGE2_CMAKE_BUILD_TARGETS = check-all;check-llvm;check-clang;check-clang-tools;check-lld;check-libcxx;check-libcxxabi;check-sanitizer;llvm-config;test-suite
+
 %:
 	dh $@ $(DH_OPTIONS)
 
 # For some reasons, some spaces are added, removing them
 PROJECTS_LIST := $(shell echo "$(PROJECTS)"|sed -e "s| ||g")
-#RUNTIMES_LIST := $(shell echo "$(RUNTIMES)"|sed -e "s| ||g")
+RUNTIMES_LIST := $(shell echo "$(RUNTIMES)"|sed -e "s| ||g")
 
 preconfigure:
 
@@ -351,7 +392,7 @@ preconfigure:
 	@echo "DISTRO=$(DISTRO)"
 	@echo "GCC_VERSION=$(GCC_VERSION)"
 	@echo "PROJECTS=$(PROJECTS_LIST)"
-#	@echo "RUNTIMES=$(RUNTIMES_LIST)"
+	@echo "RUNTIMES=$(RUNTIMES_LIST)"
 	@echo "LLVM_VERSION=$(LLVM_VERSION)"
 	@echo "LLVM_VERSION_FULL=$(LLVM_VERSION_FULL)"
 	@echo "LLVM_VERSION_SNAPSHOT=$(LLVM_VERSION_SNAPSHOT)"
@@ -421,57 +462,110 @@ override_dh_auto_configure: preconfigure
 			--xml-option append_arg:"replace/llvm::AlignOf<NextTy>::Alignment/(llvm::AlignOf<NextTy>::Alignment)"; \
 	fi)
 
+# Fails with No target "unwind_static"
+#    -DLIBCXXABI_ENABLE_STATIC_UNWINDER=ON \
+#    -DLIBCXXABI_STATICALLY_LINK_UNWINDER_IN_SHARED_LIBRARY=OFF \
+#    -DLIBCXXABI_STATICALLY_LINK_UNWINDER_IN_STATIC_LIBRARY=ON \
+#-    to libc++ when libunwind is built
+#-    Matches what is done on brew:
+#-    https://bit.ly/3kDNpC9
+
 	echo "Running tests: $(RUN_TEST)"
 	echo "Using cmake: $(CMAKE_BIN)"; \
-	CFLAGS="$(CFLAGS_EXTRA)" \
-	CXXFLAGS="$(CXXFLAGS_EXTRA)"  \
-	LDFLAGS="$(LDFLAGS_EXTRA)" \
-	LD_LIBRARY_PATH=$$LD_LIBRARY_PATH $(PRE_PROCESS_CONF) $(CMAKE_BIN) -S llvm/ -B $(TARGET_BUILD) \
+	LD_LIBRARY_PATH=$$LD_LIBRARY_PATH \
+	$(PRE_PROCESS_CONF) $(CMAKE_BIN) -S llvm/ -B $(TARGET_BUILD) \
 	-G $(GENERATOR) \
-	-DLLVM_ENABLE_PROJECTS="$(PROJECTS_LIST)" \
-	-DCMAKE_SUPPRESS_REGENERATION=ON \
 	-DCMAKE_INSTALL_PREFIX=/usr/lib/llvm-$(LLVM_VERSION) \
-	-DCMAKE_VERBOSE_MAKEFILE=ON \
-	-DCMAKE_BUILD_TYPE=RelWithDebInfo \
-	-DCMAKE_CXX_FLAGS_RELWITHDEBINFO="$(opt_flags)" \
-	-DLLVM_LINK_LLVM_DYLIB=ON \
-	-DLLVM_INSTALL_UTILS=ON \
-	-DLLVM_VERSION_SUFFIX= \
-	-DLLVM_ENABLE_SPHINX=ON \
-	-DSPHINX_WARNINGS_AS_ERRORS=OFF \
-	-DLLVM_ENABLE_RTTI=ON \
-	-DLLVM_ENABLE_FFI=ON \
-	-DLLVM_ENABLE_DUMP=ON \
-	-DLIBCLANG_LIBRARY_VERSION=$(SONAME_EXT) \
-	-DCLANG_LINK_CLANG_DYLIB=ON \
+	-DCMAKE_SUPPRESS_REGENERATION=ON \
+	-DCMAKE_BUILD_TYPE=Release \
+	-DCMAKE_C_FLAGS="$(STAGE_1_CFLAGS)" \
+	-DCMAKE_CXX_FLAGS="$(STAGE_1_CXXFLAGS)" \
+	-DCMAKE_SHARED_LINKER_FLAGS="$(STAGE_1_LDFLAGS)" \
+	-DCMAKE_MODULE_LINKER_FLAGS="$(STAGE_1_LDFLAGS)" \
+	-DCMAKE_EXE_LINKER_FLAGS="$(STAGE_1_LDFLAGS)" \
+	-DPACKAGE_VENDOR=$(VENDOR) \
 	-DENABLE_LINKER_BUILD_ID=ON \
-	-DCOMPILER_RT_USE_LIBCXX=NO \
-	$(CMAKE_EXTRA) \
-	$(Z3_FLAG) \
-	-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="AVR;M68k" \
+	-DLLVM_TARGETS_TO_BUILD=Native \
+	-DLLVM_ENABLE_PROJECTS="$(PROJECTS_LIST)" \
+	-DLLVM_ENABLE_RUNTIMES="$(RUNTIMES_LIST)" \
+	-DLLVM_ENABLE_PIC=ON \
+	-DLLVM_ENABLE_RTTI=ON \
+	-DLVVM_ENABLE_ZLIB=OFF \
+	-DLLVM_BUILD_DOCS=OFF \
+	-DLLVM_INCLUDE_GO_TESTS=OFF \
+	-DLLVM_USE_RELATIVE_PATHS_IN_FILES=ON \
 	-DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON \
-	-DCLANG_VENDOR=$(VENDOR) \
-	-DCLANG_ENABLE_BOOTSTRAP=ON \
+	-DCLANG_PLUGIN_SUPPORT=OFF \
 	-DCLANG_BUILD_EXAMPLES=OFF \
-	-DLLVM_POLLY_LINK_INTO_TOOLS=ON \
-	-DBOOTSTRAP_CMAKE_CXX_FLAGS='$(BOOTSTRAP_CXXFLAGS_EXTRA)' \
-	-DBOOTSTRAP_CMAKE_C_FLAGS='$(BOOTSTRAP_CFLAGS_EXTRA)' \
-        -DBOOTSTRAP_CMAKE_SHARED_LINKER_FLAGS="$(LDFLAGS_EXTRA)" \
-        -DBOOTSTRAP_CMAKE_MODULE_LINKER_FLAGS="$(LDFLAGS_EXTRA)" \
-        -DBOOTSTRAP_CMAKE_EXE_LINKER_FLAGS="$(LDFLAGS_EXTRA)" \
-	-DCLANG_BOOTSTRAP_PASSTHROUGH="CMAKE_INSTALL_PREFIX;CMAKE_VERBOSE_MAKEFILE;CMAKE_BUILD_TYPE;CMAKE_CXX_FLAGS_RELWITHDEBINFO;LLVM_LINK_LLVM_DYLIB;LLVM_INSTALL_UTILS;LLVM_VERSION_SUFFIX;LLVM_ENABLE_SPHINX;SPHINX_WARNINGS_AS_ERRORS;LLVM_BUILD_LLVM_DYLIB;LLVM_ENABLE_RTTI;LLVM_ENABLE_FFI;LIBCLANG_LIBRARY_VERSION;ENABLE_LINKER_BUILD_ID;POLLY_BUNDLED_JSONCPP;LLVM_EXPERIMENTAL_TARGETS_TO_BUILD;LLVM_USE_PERF;LLVM_ENABLE_ASSERTIONS;LLVM_BINUTILS_INCDIR;LLVM_HOST_TRIPLE;LLVM_COMPILER_CHECKED;COMPILER_RT_BUILD_BUILTINS;LIBOMP_LIBFLAGS;CMAKE_SHARED_LINKER_FLAGS;PYTHON_EXECUTABLE;LLVM_ENABLE_Z3_SOLVER;LLVM_POLLY_LINK_INTO_TOOLS;CLANG_VENDOR;LIBUNWIND_USE_COMPILER_RT"|| tail -100 build-llvm/CMakeFiles/CMakeError.log
+	-DCLANG_DEFAULT_LINKER=ld \
+	-DCLANG_DEFAULT_CXX_STDLIB=libstdc++ \
+	-DCLANG_DEFAULT_RTLIB=libgcc \
+	-DCOMPILER_RT_BUILD_XRAY=OFF \
+	-DCOMPILER_RT_INCLUDE_TESTS=OFF \
+	-DCOMPILER_RT_USE_LIBCXX=OFF \
+	-DCOMPILER_RT_USE_BUILTINS_LIBRARY=$(COMPILER_RT_USE_BUILTINS_LIBRARY) \
+	-DLIBUNWIND_USE_COMPILER_RT=ON \
+	-DLIBUNWIND_INSTALL_LIBRARY=OFF \
+	-DLIBCXXABI_ENABLE_EXCEPTIONS=$(LIBCXX_EXCEPTIONS) \
+	-DLIBCXXABI_USE_COMPILER_RT=$(LIBCXX_USE_COMPILER_RT) \
+	-DLIBCXXABI_INSTALL_LIBRARY=OFF \
+	-DLIBCXX_ENABLE_EXCEPTIONS=$(LIBCXX_EXCEPTIONS) \
+	-DLIBCXX_USE_COMPILER_RT=$(LIBCXX_USE_COMPILER_RT) \
+	-DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=ON \
+	-DLIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY=ON \
+	-DLIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY=OFF \
+	-DLIBCXX_INSTALL_LIBRARY=OFF \
+	-DOPENMP_ENABLE_LIBOMP_PROFILING=OFF \
+	-DOPENMP_ENABLE_LIBOMPTARGET_PROFILING=OFF \
+	-DLIBOMP_ENABLE_RTTI=OFF \
+	-DLIBOMP_OMPT_SUPPORT=OFF \
+	$(CMAKE_EXTRA) \
+	-DBUILTINS_CMAKE_ARGS="-DCMAKE_C_FLAGS=$(STAGE_1_CFLAGS);-DCMAKE_CXX_FLAGS=$(STAGE_1_CXXFLAGS);-DCMAKE_EXE_LINKER_FLAGS=$(STAGE_1_LDFLAGS);-DCMAKE_SHARED_LINKER_FLAGS=$(STAGE_1_LDFLAGS);-DCMAKE_MODULE_LINKER_FLAGS=$(STAGE_1_LDFLAGS);-DCMAKE_SYSTEM_NAME=Linux;-DCMAKE_BUILD_TYPE=Release;-DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=OFF" \
+	-DRUNTIMES_CMAKE_ARGS="-DCMAKE_C_FLAGS=$(STAGE_1_CFLAGS);-DCMAKE_CXX_FLAGS=$(STAGE_1_CXXFLAGS);-DCMAKE_EXE_LINKER_FLAGS=$(STAGE_1_LDFLAGS);-DCMAKE_SHARED_LINKER_FLAGS=$(STAGE_1_LDFLAGS);-DCMAKE_MODULE_LINKER_FLAGS=$(STAGE_1_LDFLAGS);-DCMAKE_SYSTEM_NAME=Linux;-DCMAKE_BUILD_TYPE=Release;-DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=OFF" \
+	-DCLANG_ENABLE_BOOTSTRAP=ON \
+	-DCLANG_BOOTSTRAP_TARGETS="$(ENABLED_STAGE2_CMAKE_BUILD_TARGETS)" \
+	-DCLANG_BOOTSTRAP_PASSTHROUGH="CMAKE_INSTALL_PREFIX;CMAKE_SUPPRESS_REGENERATION;ENABLE_LINKER_BUILD_ID;LLVM_ENABLE_PIC;LLVM_ENABLE_RTTI;LLVM_INCLUDE_GO_TESTS;LLVM_USE_RELATIVE_PATHS_IN_FILES;CLANG_DEFAULT_LINKER;CLANG_DEFAULT_CXX_STDLIB;CLANG_DEFAULT_RTLIB;COMPILER_RT_USE_LIBCXX;COMPILER_RT_USE_BUILTINS_LIBRARY;COMPILER_RT_INCLUDE_TESTS;LIBUNWIND_USE_COMPILER_RT;LIBCXXABI_ENABLE_EXCEPTIONS;LIBCXXABI_USE_COMPILER_RT;LIBCXX_USE_COMPILER_RT;LIBCXX_ENABLE_EXCEPTIONS;LIBCXX_ENABLE_STATIC_ABI_LIBRARY;LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY;LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY;LIBOMP_ENABLE_RTTI" \
+	-DBOOTSTRAP_CMAKE_BUILD_TYPE=RelWithDebInfo \
+	-DBOOTSTRAP_CMAKE_C_FLAGS_RELWITHDEBINFO="$(opt_flags)" \
+	-DBOOTSTRAP_CMAKE_CXX_FLAGS_RELWITHDEBINFO="$(opt_flags)" \
+	-DBOOTSTRAP_CMAKE_C_FLAGS="$(STAGE_2_CFLAGS)" \
+	-DBOOTSTRAP_CMAKE_CXX_FLAGS="$(STAGE_2_CXXFLAGS)" \
+	-DBOOTSTRAP_CMAKE_SHARED_LINKER_FLAGS="$(STAGE_2_LDFLAGS)" \
+	-DBOOTSTRAP_CMAKE_MODULE_LINKER_FLAGS="$(STAGE_2_LDFLAGS)" \
+	-DBOOTSTRAP_CMAKE_EXE_LINKER_FLAGS="$(STAGE_2_LDFLAGS)" \
+	-DBOOTSTRAP_LLVM_ENABLE_FFI=ON \
+	-DBOOTSTRAP_LLVM_ENABLE_DUMP=ON \
+	-DBOOTSTRAP_LLVM_ENABLE_LIBPFM=ON \
+	-DBOOTSTRAP_LLVM_ENABLE_SPHINX=ON \
+	-DBOOTSTRAP_SPHINX_WARNINGS_AS_ERRORS=OFF \
+	-DBOOTSTRAP_LLVM_USE_RELATIVE_PATHS_IN_FILES=ON \
+	-DBOOTSTRAP_LLVM_INSTALL_UTILS=ON \
+	-DBOOTSTRAP_LLVM_VERSION_SUFFIX= \
+	-DBOOTSTRAP_LLVM_POLLY_LINK_INTO_TOOLS=ON \
+	-DBOOTSTRAP_LLVM_EXPERIMENTAL_TARGETS_TO_BUILD="AVR;M68k" \
+	-DBOOTSTRAP_LLVM_LINK_LLVM_DYLIB=ON \
+	-DBOOTSTRAP_CLANG_LINK_CLANG_DYLIB=ON \
+	-DBOOTSTRAP_LIBCLANG_LIBRARY_VERSION=$(SONAME_EXT) \
+	-DBOOTSTRAP_LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY=ON \
+	-DBOOTSTRAP_PYTHON_EXECUTABLE=/usr/bin/python3 \
+	$(BOOTSTRAP_CMAKE_EXTRA) \
+	-DBOOTSTRAP_BUILTINS_CMAKE_ARGS="-DCMAKE_C_FLAGS=$(STAGE_2_CFLAGS);-DCMAKE_CXX_FLAGS=$(STAGE_2_CXXFLAGS);-DCMAKE_EXE_LINKER_FLAGS=$(STAGE_2_LDFLAGS);-DCMAKE_SHARED_LINKER_FLAGS=$(STAGE_2_LDFLAGS);-DCMAKE_MODULE_LINKER_FLAGS=$(STAGE_2_LDFLAGS);-DCMAKE_SYSTEM_NAME=Linux;-DCMAKE_BUILD_TYPE=RelWithDebInfo;-DCMAKE_C_FLAGS_RELWITHDEBINFO=$(opt_flags);-DCMAKE_CXX_FLAGS_RELWITHDEBINFO=$(opt_flags);-DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=OFF" \
+	-DBOOTSTRAP_RUNTIMES_CMAKE_ARGS="-DCMAKE_C_FLAGS=$(STAGE_2_CFLAGS);-DCMAKE_CXX_FLAGS=$(STAGE_2_CXXFLAGS);-DCMAKE_EXE_LINKER_FLAGS=$(STAGE_2_LDFLAGS) -L$(STAGE_1_LIB_DIR);-DCMAKE_SHARED_LINKER_FLAGS=$(STAGE_2_LDFLAGS) -L$(STAGE_1_LIB_DIR);-DCMAKE_MODULE_LINKER_FLAGS=$(STAGE_2_LDFLAGS) -L$(STAGE_1_LIB_DIR);-DCMAKE_SYSTEM_NAME=Linux;-DCMAKE_BUILD_TYPE=RelWithDebInfo;-DCMAKE_C_FLAGS_RELWITHDEBINFO=$(opt_flags);-DCMAKE_CXX_FLAGS_RELWITHDEBINFO=$(opt_flags);-DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=OFF"
+
 	FOUND_VERSION=`grep LLVM_VERSION_STRING build-llvm/include/llvm/Config/llvm-config.h|cut -d\" -f2`; \
 	if ! echo "$(LLVM_VERSION_FULL)"|grep "$$FOUND_VERSION"; then \
 		echo "mistmatch of version. Found: $$FOUND_VERSION / Expected: $(LLVM_VERSION_FULL)"; \
 		exit 1; \
 	fi
 
-
 # ninja
 VERBOSE=-v
 
 debian-full-build:
-	$(PRE_PROCESS) ninja $(NJOBS) -C $(TARGET_BUILD) $(VERBOSE) stage2
+	echo "Using cmake: $(CMAKE_BIN)"
+#	linker hack so stage2 can link against stage1 libs at runtime
+	LD_LIBRARY_PATH=$(STAGE_1_LIB_DIR):$$LD_LIBRARY_PATH \
+	VERBOSE=1 $(PRE_PROCESS) $(CMAKE_BIN) --build $(TARGET_BUILD) $(NJOBS) --target stage2
 
 # Check the stage 2 build worked
 	if ! readelf --string-dump .comment  $(TARGET_BUILD_STAGE2)/bin/clang 2>&1|grep -q "clang version"; then \
@@ -482,115 +576,41 @@ debian-full-build:
 		echo "libclang-$(LLVM_VERSION).so.1 depends on libclang-cpp. Should not be the case"; \
 		exit 2; \
 	fi
-#	$(PRE_PROCESS) make $(NJOBS) -C $(TARGET_BUILD) $(VERBOSE) CFLAGS="$(CFLAGS_EXTRA)" CXXFLAGS="$(CXXFLAGS_EXTRA)"  LDFLAGS="$(LDFLAGS_EXTRA)" REQUIRES_RTTI=1 DEBUGMAKE=1 runtimes
-
 	touch $@
 
 debian-libfuzzer-build:
 ifeq (${LIBFUZZER_ENABLE},yes)
 	cd $(TARGET_BUILD); \
-	CFLAGS=`dpkg-buildflags --get CFLAGS`; \
-	CFLAGS="$$CFLAGS `dpkg-buildflags --get CPPFLAGS`"; \
+	CFLAGS="$(opt_flags) $(STAGE_2_CFLAGS)"; \
 	echo $$CFLAGS; \
-	$(BASE_PATH)/$(TARGET_BUILD_STAGE2)/bin/clang++ -c $$CFLAGS -std=c++11 $(BASE_PATH)/compiler-rt/lib/fuzzer/*.cpp -IFuzzer; \
+	$(STAGE_2_BIN_DIR)/clang++ -c $$CFLAGS -std=c++11 $(BASE_PATH)/compiler-rt/lib/fuzzer/*.cpp -IFuzzer; \
 	ar ruv libFuzzer.a Fuzzer*.o
 endif
 	touch $@
 
-# The various options to build libc++ and libc++abi
-
-LIBCXX_CMAKE_OPTIONS := \
-	-DCMAKE_INSTALL_PREFIX=/usr/lib/llvm-$(LLVM_VERSION) \
-	-DCMAKE_POSITION_INDEPENDENT_CODE=ON \
-	-DLLVM_CONFIG_PATH=$(CURDIR)/$(TARGET_BUILD_STAGE2)/bin/llvm-config \
-	-DCMAKE_BUILD_TYPE=RelWithDebInfo \
-	-DCMAKE_CXX_COMPILER=$(CURDIR)/$(TARGET_BUILD_STAGE2)/bin/clang++ \
-	-DCMAKE_C_COMPILER=$(CURDIR)/$(TARGET_BUILD_STAGE2)/bin/clang \
-	-DCMAKE_CXX_FLAGS="$(LIBCXXFLAGS)" \
-	-DCMAKE_EXE_LINKER_FLAGS="" \
-	-DCMAKE_SHARED_LINKER_FLAGS="" \
-	-DCMAKE_MODULE_LINKER_FLAGS="" \
-	-DCMAKE_AR=$(CURDIR)/$(TARGET_BUILD_STAGE2)/bin/llvm-ar \
-	-DCMAKE_RANLIB=$(CURDIR)/$(TARGET_BUILD_STAGE2)/bin/llvm-ranlib \
-	-DLLVM_EXTERNAL_LIT=$(BASE_PATH)/llvm/utils/lit/lit.py \
-	-DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON \
-	$(CMAKE_EXTRA)
-
-debian-libcxxabi-build:
-# Builds libcxxabi
-	echo "Using cmake: $(CMAKE_BIN)"; \
-	cd libcxxabi && \
-	CXXFLAGS="$(CXXFLAGS_EXTRA)" LDFLAGS="$(LDFLAGS_EXTRA)" \
-	$(PRE_PROCESS_CONF) $(CMAKE_BIN) \
-	-S . -B build \
-	-G $(GENERATOR) \
-	$(LIBCXX_CMAKE_OPTIONS) \
-	-DLIBCXXABI_LIBCXX_PATH=$(BASE_PATH)/libcxx \
-	-DLIBCXXABI_LIBCXX_LIBRARY_PATH=$(BASE_PATH)/libcxx/build/lib \
-	-DLIBCXXABI_LIBCXX_INCLUDES=$(BASE_PATH)/$(TARGET_BUILD_STAGE2)/include/c++/v1/ \
-	-DLIBCXXABI_ENABLE_EXCEPTIONS=$(LIBCXX_EXCEPTIONS) \
-	-DLIBCXXABI_USE_COMPILER_RT=ON \
-	-DLLVM_ENABLE_RTTI=ON \
-	$(CMAKE_LIBCXX_EXTRA) &&  \
-	$(PRE_PROCESS_CONF) ninja -C build/ $(VERBOSE)
-	touch $@
-
-# Fails with    $<TARGET_LINKER_FILE:unwind_static>
-#  No target "unwind_static"
-# on 12. Will test with 13
-# -DLIBCXXABI_ENABLE_STATIC_UNWINDER=ON \
-#    -DLIBCXXABI_STATICALLY_LINK_UNWINDER_IN_SHARED_LIBRARY=OFF \
-#    -DLIBCXXABI_STATICALLY_LINK_UNWINDER_IN_STATIC_LIBRARY=ON \
-N
-#-    to libc++ when libunwind is built
-#-    Matches what is done on brew:
-#-    https://bit.ly/3kDNpC9
-
-debian-libcxx-build:
-# Builds libcxx
-	echo "Using cmake: $(CMAKE_BIN)"; \
-	cd libcxx && \
-	$(PRE_PROCESS_CONF) $(CMAKE_BIN) \
-	CXXFLAGS="$(CXXFLAGS_EXTRA)" LDFLAGS="$(LDFLAGS_EXTRA)" \
-	-S . -B build \
-	-G $(GENERATOR) \
-	$(LIBCXX_CMAKE_OPTIONS) \
-	-DLIBCXX_CXX_ABI=libcxxabi \
-	-DLIBCXX_CXX_ABI_INCLUDE_PATHS=$(BASE_PATH)/libcxxabi/include \
-	-DLIBCXX_CXX_ABI_LIBRARY_PATH=$(BASE_PATH)/libcxxabi/build/lib \
-	-DLIBCXX_ENABLE_EXCEPTIONS=$(LIBCXX_EXCEPTIONS) \
-	-DLIBCXX_INSTALL_EXPERIMENTAL_LIBRARY=ON \
-	-DLIBCXX_USE_COMPILER_RT=ON \
-	-DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=ON \
-	-DLIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY=ON \
-	-DLIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY=OFF \
-	$(CMAKE_LIBCXX_EXTRA) && \
-	$(PRE_PROCESS_CONF) ninja -C build/ $(VERBOSE)
-	touch $@
-
-
 debian-libclc-build:
 # Builds libclc
-
 	mkdir -p libclc/build
-
-	CMAKE_BIN=cmake; \
-	if test -f /tmp/cmake/bin/cmake; then \
-		CMAKE_BIN=/tmp/cmake/bin/cmake; \
-	fi; \
-	echo "Using cmake: $$CMAKE_BIN"; \
+	echo "Using cmake: $(CMAKE_BIN)"
 	cd libclc/build && \
-	$$CMAKE_BIN ../ \
+	$(CMAKE_BIN) ../ \
 	-G $(GENERATOR) \
+	-DCMAKE_C_COMPILER=$(STAGE_2_BIN_DIR)/clang \
+	-DCMAKE_CXX_COMPILER=$(STAGE_2_BIN_DIR)/clang++ \
+	-DCMAKE_C_FLAGS="$(opt_flags) $(STAGE_2_CFLAGS)" \
+	-DCMAKE_CXX_FLAGS="$(opt_flags) $(STAGE_2_CXXFLAGS)" \
+	-DCMAKE_SHARED_LINKER_FLAGS="$(STAGE_2_LDFLAGS) -L$(STAGE_2_LIB_DIR)" \
+	-DCMAKE_MODULE_LINKER_FLAGS="$(STAGE_2_LDFLAGS) -L$(STAGE_2_LIB_DIR)" \
+	-DCMAKE_EXE_LINKER_FLAGS="$(STAGE_2_LDFLAGS) -L$(STAGE_2_LIB_DIR)" \
 	-DCMAKE_INSTALL_PREFIX=/usr \
 	-DCMAKE_INSTALL_DATADIR=lib \
 	-DCMAKE_INSTALL_INCLUDEDIR=include \
-	-DLLVM_CONFIG=$(CURDIR)/$(TARGET_BUILD_STAGE2)/bin/llvm-config \
+	-DLLVM_CONFIG=$(STAGE_2_BIN_DIR)/llvm-config \
 	-DLIBCLC_TARGETS_TO_BUILD=$(LIBCLC_TARGETS_TO_BUILD); \
-	ninja $(VERBOSE)
+	ninja $(NJOBS) $(VERBOSE)
 	touch $@
 
-override_dh_auto_build: debian-full-build debian-libfuzzer-build debian-libcxxabi-build debian-libcxx-build debian-libclc-build
+override_dh_auto_build: debian-full-build debian-libfuzzer-build debian-libclc-build
 
 override_dh_prep: build_doc
 	dh_prep
@@ -620,7 +640,7 @@ endif
 	fi
 # the clang doc generation only generates clang manpage
 # When it will do more, we should move that in the loop above
-	cd $(CURDIR)/clang/docs/_build/man/; mv clang.1 clang-$(LLVM_VERSION).1
+	cd $(CURDIR)/clang/docs/_build/man/ && mv clang.1 clang-$(LLVM_VERSION).1
 
 # Remove the copy of jquery. See bug #701087
 	for d in $(TARGET_BUILD_STAGE2)/docs/html/_static/ $(TARGET_BUILD_STAGE2)/tools/clang/docs/html/_static/ $(TARGET_BUILD_STAGE2)/tools/clang/tools/extra/docs/html/_static/; do \
@@ -664,27 +684,22 @@ override_dh_auto_install:
 
 	# Only run on executable, not script
 	chrpath -d `find $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/bin/ -type f -executable -exec file -i '{}' \; | grep 'x-executable; charset=binary'|cut -d: -f1`
-	chrpath -d libcxxabi/build/lib/libc++abi.so.1.0
-	chrpath -d libcxx/build/lib/libc++.so.1.0
 
 	: # libclang
 	cd debian/tmp/usr/lib/llvm-$(LLVM_VERSION)/lib/ && \
 	ln -s libclang-$(LLVM_VERSION).so.$(SONAME_CLANG) libclang.so.$(SONAME_EXT) && \
 	ln -s libclang-$(LLVM_VERSION).so.$(SONAME_CLANG) libclang-$(SONAME_CLANG).so.$(SONAME_EXT)
 
-	: # libomp
-	cd debian/tmp/usr/lib/llvm-$(LLVM_VERSION)/lib && rm -f libomp.so; \
-	ln -s libomp.so.$(SONAME_OPENMP) libomp.so
-
 	if test "$(LIBUNWIND_ENABLE)" = yes; then \
 		mkdir -p debian/tmp/usr/include/libunwind; \
 		cp -R libunwind/include/* debian/tmp/usr/include/libunwind/; \
 	fi
 
+	: # libomp
 	if test "$(OPENMP_ENABLE)" = yes; then \
-		mkdir -p debian/tmp/usr/lib/llvm-$(LLVM_VERSION)/include/openmp; \
-		cp -f openmp/runtime/exports/common*/include/* debian/tmp/usr/lib/llvm-$(LLVM_VERSION)/include/openmp; \
-		cd debian/tmp/usr/lib/llvm-$(LLVM_VERSION)/lib && cp libomp.so.$(SONAME_OPENMP) libomp-$(LLVM_VERSION).so.$(SONAME_OPENMP); \
+		cd debian/tmp/usr/lib/llvm-$(LLVM_VERSION)/lib; \
+		ln -s libomp.so.$(SONAME_OPENMP) libomp.so; \
+		cp libomp.so.$(SONAME_OPENMP) libomp-$(LLVM_VERSION).so.$(SONAME_OPENMP); \
 	fi
 
 # Remove artifact (where compiler-rt is built)
@@ -724,8 +739,6 @@ endif
 	rm -rf $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/build/utils/lit/lit/__pycache__/ \
 	$(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/build/utils/lit/lit/*/__pycache__/
 
-	DESTDIR=$(DEB_INST) ninja $(VERBOSE) -C libcxxabi/build install
-	DESTDIR=$(DEB_INST) ninja $(VERBOSE) -C libcxx/build install
 	DESTDIR=$(DEB_INST) ninja $(VERBOSE) -C libclc/build install
 
 # Rename binaries
@@ -782,8 +795,8 @@ endif
 # Manage the polly files. Sometimes, we build them. Sometimes not.
 	if test "$(POLLY_ENABLE)" = yes; then \
 		mkdir -p $(CURDIR)/debian/libclang-$(LLVM_VERSION)-dev/usr/lib/llvm-$(LLVM_VERSION)/lib/ $(CURDIR)/debian/libclang-common-$(LLVM_VERSION)-dev/usr/lib/llvm-$(LLVM_VERSION)/include/polly/; \
-		mv -f $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/lib/libpolly* \
-		$(CURDIR)/debian/libclang-$(LLVM_VERSION)-dev/usr/lib/llvm-$(LLVM_VERSION)/lib/; \
+		mv -f $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/lib/libPolly* \
+		$(CURDIR)/debian/libclang-common-$(LLVM_VERSION)-dev/usr/lib/llvm-$(LLVM_VERSION)/lib/; \
 		rm -rf $(CURDIR)/debian/libclang-common-$(LLVM_VERSION)-dev/usr/lib/llvm-$(LLVM_VERSION)/include/polly; \
 		mv -f $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/include/polly/ \
 		$(CURDIR)/debian/libclang-common-$(LLVM_VERSION)-dev/usr/lib/llvm-$(LLVM_VERSION)/include/; \
@@ -924,10 +937,10 @@ endif
 	ninja $(VERBOSE) -C $(TARGET_BUILD_STAGE2) check-sanitizer || true
 
 # Libcxx
-	ninja $(VERBOSE) -C libcxx/build check-libcxx || true
+	ninja $(VERBOSE) -C $(TARGET_BUILD_STAGE2) check-libcxx || true
 
 # Libcxxabi
-	ninja $(VERBOSE) -C libcxxabi/build check-libcxxabi || true
+	ninja $(VERBOSE) -C $(TARGET_BUILD_STAGE2) check-libcxxabi || true
 
 # Libclc
 	ninja $(VERBOSE) -C libclc/build test || true
diff --git a/debian/tests/control b/debian/tests/control
index 5af6a774..6bff47a6 100644
--- a/debian/tests/control
+++ b/debian/tests/control
@@ -8,6 +8,7 @@ Restrictions: allow-stderr
 Tests: integration-test-suite-test
 Depends: @, cmake, make, g++, libstdc++-10-dev
 Restrictions: allow-stderr
+Architecture: amd64 arm64
 
 Tests: cmake-test
 Depends: gcc, build-essential, cmake, llvm-13-dev