llvm: optionally build compiler-rt, libcxx and libunwind as runtimes (#32476)

* llvm: replace +omp_as_runtime with omp=runtime

* llvm: fetch 'libomp-libflags-as-list.patch' from upstream repo

* llvm: replace 'llvm14-hwloc-ompd.patch' with the official fix from upstream repo

* llvm: fix-up for the black reformatting

* llvm: fetch 'constexpr_longdouble.patch' from upstream repo

* llvm: optionally build libcxx as a runtime

* llvm: fetch 'llvm5-sanitizer-ustat.patch' from upstream repo

* llvm: update 'sanitizer-ipc_perm_mode.patch'

* llvm: refactor compiler conflicts when libcxx=project

* llvm: fetch 'llvm_python_path.patch' from upstream repo

* llvm: update comments and condition for 'xray_buffer_queue-cstddef.patch'

* llvm: optionally build compiler-rt as a runtime

* llvm: fetch 'lldb_external_ncurses-10.patch' from upstream repo

* llvm: fetch 'llvm_py37.patch' from upstream repo

* llvm: rename variant 'internal_unwind' to 'libunwind'

* llvm: optionally build libunwind as a runtime

* llvm: extend the list of maintainers

* llvm: allow for explicit '~clang~flang~libomptarget~lldb~omp_debug~z3'

* llvm: fetch 'llvm5-lld-ELF-Symbols.patch' from FreeBSD port repo

* llvm: fetch most of 'missing-includes.patch' from upstream repo and reuse 'llvm-gcc11.patch'

* llvm: regroup patches for missing include directives and drop compiler constraints for them

* llvm: fetch 'llvm-gcc11.patch' from upstream repo

* llvm: fetch 'no_cyclades.patch' from upstream repo

* llvm: update comments and condition for 'no_cyclades9.patch'

* llvm: rename variant 'omp' to 'openmp'

* llvm: constrain and rename variant 'omp_tsan' to 'libomp_tsan'

* llvm: rename variant 'omp_debug' to 'libomptarget_debug'

* llvm: do not apply same patch twice

* llvm: constrain and document the '*-thread.patch' patches

* llvm: document the '~lld+libomptarget' conflict

* llvm: update comments for the 'D133513.diff' patch

1 files changed, 251 insertions, 105 deletions

diff --git a/var/spack/repos/builtin/packages/llvm/package.py b/var/spack/repos/builtin/packages/llvm/package.py
index 1b17cbe7d0..7af5766b09 100644
--- a/var/spack/repos/builtin/packages/llvm/package.py
+++ b/var/spack/repos/builtin/packages/llvm/package.py
@@ -26,7 +26,7 @@ class Llvm(CMakePackage, CudaPackage):
     url = "https://github.com/llvm/llvm-project/archive/llvmorg-7.1.0.tar.gz"
     list_url = "https://releases.llvm.org/download.html"
     git = "https://github.com/llvm/llvm-project"
-    maintainers("trws", "haampie")
+    maintainers("trws", "haampie", "skosukhin")
 
     tags = ["e4s"]
 
@@ -82,44 +82,72 @@ class Llvm(CMakePackage, CudaPackage):
     variant(
         "clang", default=True, description="Build the LLVM C/C++/Objective-C compiler frontend"
     )
+
     variant(
         "flang",
         default=False,
-        when="@11: +clang",
         description="Build the LLVM Fortran compiler frontend "
         "(experimental - parser only, needs GCC)",
     )
-    variant("lldb", default=True, when="+clang", description="Build the LLVM debugger")
+    conflicts("+flang", when="@:10")
+    conflicts("+flang", when="~clang")
+
+    variant("lldb", default=True, description="Build the LLVM debugger")
+    conflicts("+lldb", when="~clang")
+
     variant("lld", default=True, description="Build the LLVM linker")
     variant("mlir", default=False, when="@10:", description="Build with MLIR support")
     variant(
-        "internal_unwind", default=True, when="+clang", description="Build the libcxxabi libunwind"
+        "libunwind",
+        values=(
+            "none",
+            conditional("project", when="@:15"),
+            conditional("runtime", when="+clang @6:"),
+        ),
+        default="runtime",
+        description="Build the LLVM unwinder library"
+        "either as a runtime (with just-build Clang) "
+        "or as a project (with the compiler in use)",
     )
     variant(
         "polly",
         default=True,
-        description="Build the LLVM polyhedral optimization plugin, " "only builds for 3.7.0+",
-    )
-    variant(
-        "libcxx", default=True, when="+clang", description="Build the LLVM C++ standard library"
+        description="Build the LLVM polyhedral optimization plugin, only builds for 3.7.0+",
     )
     variant(
-        "libomptarget",
-        default=True,
-        when="+clang",
-        description="Build the OpenMP offloading library",
+        "libcxx",
+        values=(
+            "none",
+            conditional("project", when="@:15"),
+            conditional("runtime", when="+clang @6:"),
+        ),
+        default="runtime",
+        description="Build the LLVM C++ standard library "
+        "either as a runtime (with just-build Clang) "
+        "or as a project (with the compiler in use)",
     )
+
+    variant("libomptarget", default=True, description="Build the OpenMP offloading library")
+    conflicts("+libomptarget", when="~clang")
+
     variant(
-        "omp_debug",
+        "libomptarget_debug",
         default=False,
-        when="+libomptarget",
-        description="Include debugging code in OpenMP runtime libraries",
+        description="Allow debug output with the environment variable LIBOMPTARGET_DEBUG=1",
     )
+    conflicts("+libomptarget_debug", when="~libomptarget")
+
     variant(
         "compiler-rt",
-        when="+clang",
-        default=True,
-        description="Build LLVM compiler runtime, including sanitizers",
+        values=(
+            "none",
+            conditional("project", when="+clang"),
+            conditional("runtime", when="+clang @6:"),
+        ),
+        default="runtime",
+        description="Build the LLVM compiler runtime, including sanitizers, "
+        "either as a runtime (with just-build Clang) "
+        "or as a project (with the compiler in use)",
     )
     variant(
         "gold",
@@ -170,16 +198,19 @@ class Llvm(CMakePackage, CudaPackage):
         multi=True,
     )
     variant(
-        "omp_tsan",
+        "libomp_tsan",
         default=False,
-        when="@6:",
+        # Added in https://reviews.llvm.org/D13072
+        # Removed in https://reviews.llvm.org/D103767
+        when="@4:12",
         description="Build with OpenMP capable thread sanitizer",
     )
     variant(
-        "omp_as_runtime",
-        default=True,
-        when="+clang @12:",
-        description="Build OpenMP runtime via ENABLE_RUNTIME by just-built Clang",
+        "openmp",
+        values=("project", conditional("runtime", when="+clang @12:")),
+        default="runtime",
+        description="Build OpenMP either as a runtime (with just-build Clang) "
+        "or as a project (with the compiler in use)",
     )
     variant(
         "code_signing",
@@ -195,9 +226,10 @@ class Llvm(CMakePackage, CudaPackage):
         description="Add shared library symbol version",
         when="@13:",
     )
-    variant(
-        "z3", default=False, when="+clang @8:", description="Use Z3 for the clang static analyzer"
-    )
+    variant("z3", default=False, description="Use Z3 for the clang static analyzer")
+    conflicts("+z3", when="@:7")
+    conflicts("+z3", when="~clang")
+
     variant(
         "zstd",
         default=False,
@@ -224,6 +256,12 @@ class Llvm(CMakePackage, CudaPackage):
     depends_on("cmake@3.4.3:", type="build")
     depends_on("cmake@3.13.4:", type="build", when="@12:")
     depends_on("cmake@3.20:", type="build", when="@16:")
+    with when("@:10"):
+        # Versions 10 and older cannot build runtimes with cmake@3.17:
+        # See https://reviews.llvm.org/D77284
+        for runtime in ["libunwind", "libcxx", "compiler-rt"]:
+            depends_on("cmake@:3.16", type="build", when="{0}=runtime".format(runtime))
+        del runtime
     depends_on("python", when="~python", type="build")
     depends_on("pkgconfig", type="build")
 
@@ -268,17 +306,41 @@ class Llvm(CMakePackage, CudaPackage):
     # Internal compiler error on gcc 8.4 on aarch64 https://bugzilla.redhat.com/show_bug.cgi?id=1958295
     conflicts("%gcc@8.4:8.4.9", when="@12: target=aarch64:")
 
-    # When these versions are concretized, but not explicitly with +libcxx, these
-    # conflicts will enable clingo to set ~libcxx, making the build successful:
-
-    # libc++ of LLVM13, see https://libcxx.llvm.org/#platform-and-compiler-support
-    # @13 does not support %gcc@:10 https://bugs.llvm.org/show_bug.cgi?id=51359#c1
-    # GCC    11     - latest stable release per GCC release page
-    # Clang: 11, 12 - latest two stable releases per LLVM release page
-    # AppleClang 12 - latest stable release per Xcode release page
-    conflicts("%gcc@:10", when="@13:+libcxx")
-    conflicts("%clang@:10", when="@13:+libcxx")
-    conflicts("%apple-clang@:11", when="@13:+libcxx")
+    # libcxx=project imposes compiler conflicts
+    # see https://libcxx.llvm.org/#platform-and-compiler-support for the latest release
+    # and https://github.com/llvm/www-releases for older releases
+    with when("libcxx=project"):
+        for v, compiler_conflicts in {
+            "@7:": {"clang": "@:3.4", "gcc": "@:4.6"},
+            "@9:": {"clang": "@:3.4", "gcc": "@:4"},
+            "@11:": {"clang": "@:3", "gcc": "@:4"},
+            "@13:": {"clang": "@:10", "gcc": "@:10", "apple-clang": "@:11"},
+            "@14:": {
+                "clang": "@:11",
+                "gcc": "@:10",
+                "apple-clang": "@:11",
+                "xlc": "@:17.0",
+                "xlc_r": "@:17.0",
+            },
+            "@15:": {
+                "clang": "@:12",
+                "gcc": "@:11",
+                "apple-clang": "@:12",
+                "xlc": "@:17.0",
+                "xlc_r": "@:17.0",
+            },
+            "@16:": {
+                "clang": "@:13",
+                "gcc": "@:11",
+                "apple-clang": "@:13",
+                "xlc": "@:17.0",
+                "xlc_r": "@:17.0",
+            },
+        }.items():
+            with when(v):
+                for comp in spack.compilers.supported_compilers():
+                    conflicts("%{0}{1}".format(comp, compiler_conflicts.get(comp, "")))
+        del v, compiler_conflicts, comp
 
     # libomptarget
     conflicts("+cuda", when="@15:")  # +cuda variant is obselete since LLVM 15
@@ -287,6 +349,7 @@ class Llvm(CMakePackage, CudaPackage):
         when="+libomptarget",
         msg="Non-host backends needed for offloading, set targets=all",
     )
+    # See https://github.com/spack/spack/pull/32476#issuecomment-1573770361
     conflicts("~lld", when="+libomptarget")
 
     # cuda_arch value must be specified
@@ -297,82 +360,160 @@ class Llvm(CMakePackage, CudaPackage):
     # Fixed in upstream versions of both
     conflicts("^cmake@3.19.0", when="@6:11.0.0")
 
-    # sys/ustat.h has been removed in favour of statfs from glibc-2.28. Use fixed sizes:
-    patch("llvm5-sanitizer-ustat.patch", when="@4:6.0.0+compiler-rt")
-
     # Fix lld templates: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230463
-    patch("llvm5-lld-ELF-Symbols.patch", when="@5+lld%clang@7:")
-
-    # Fix missing std:size_t in 'llvm@4:5' when built with '%clang@7:'
-    patch("xray_buffer_queue-cstddef.patch", when="@4:5+compiler-rt%clang@7:")
+    patch(
+        "https://raw.githubusercontent.com/freebsd/freebsd-ports/f8f9333d8e1e5a7a6b28c5ef0ca73785db06136e/devel/llvm50/files/lld/patch-tools_lld_ELF_Symbols.cpp",
+        sha256="c81a50c1b6b78d359c0ce3b88914477f4f2a85b8dbfa7ac745b9e7eb4e53931b",
+        when="@5+lld%clang@7:",
+    )
 
-    # https://github.com/llvm/llvm-project/commit/947f9692440836dcb8d88b74b69dd379d85974ce
-    patch("sanitizer-ipc_perm_mode.patch", when="@5:7+compiler-rt%clang@11:")
-    patch("sanitizer-ipc_perm_mode.patch", when="@5:9+compiler-rt%gcc@9:")
+    # Add missing include directives for the standard headers (the real need for the following
+    # patches depends on the implementation of the standard C++ library, the headers, however, must
+    # be included according to the standard, therefore, we apply the patches regardless of the
+    # compiler and compiler version).
+    #
+    # fix missing ::size_t in 'llvm@4:5'
+    # see comments in the patch file
+    patch(
+        "xray_buffer_queue-cstddef.patch",
+        # we do not cover compiler-rt=runtime because it is not supported when @:5
+        when="@4:5 compiler-rt=project",
+    )
+    #
+    # see https://reviews.llvm.org/D64937
+    # see https://github.com/spack/spack/issues/24270
+    patch(
+        "https://github.com/llvm/llvm-project/commit/b288d90b39f4b905c02092a9bfcfd6d78f99b191.patch?full_index=1",
+        sha256="2028d52e1a39326bb48fb7463132bbfe7fb4fa18f1adfeea9c3ed0320ed49564",
+        when="@8:9.0.0",
+    )
+    #
+    # committed upstream without a review
+    # see https://github.com/llvm/llvm-project/commit/b498303066a63a203d24f739b2d2e0e56dca70d1
+    # see https://github.com/spack/spack/pull/28547
+    patch(
+        "https://github.com/llvm/llvm-project/commit/b498303066a63a203d24f739b2d2e0e56dca70d1.patch?full_index=1",
+        sha256="514926d661635de47972c7d403c9c4669235aa51e22e56d44676d2a2709179b6",
+        when="@8:11",
+    )
 
-    # github.com/spack/spack/issues/24270: MicrosoftDemangle for %gcc@10: and %clang@13:
-    patch("missing-includes.patch", when="@8")
+    # fix building of older versions of llvm with newer versions of glibc
+    for compiler_rt_as in ["project", "runtime"]:
+        with when("compiler-rt={0}".format(compiler_rt_as)):
+            # sys/ustat.h has been removed in favour of statfs from glibc-2.28
+            # see https://reviews.llvm.org/D47281
+            patch(
+                "https://github.com/llvm/llvm-project/commit/383fe5c8668f63ef21c646b43f48da9fa41aa100.patch?full_index=1",
+                sha256="66f01ac1769a6815aba09d6f4347ac1744f77f82ec9578a1158b24daca7a89e6",
+                when="@4:6.0.0",
+            )
+            # fix sanitizer-common build with glibc 2.31
+            # see https://reviews.llvm.org/D70662
+            patch("sanitizer-ipc_perm_mode.patch", when="@5:9")
+    del compiler_rt_as
 
     # Backport from llvm upstream gcc ppc const expr long double issue
     # see https://bugs.llvm.org/show_bug.cgi?id=39696
-    # This fix was initially commited (3bf63cf3b366) for the 9.0 release
+    # This fix was initially committed (3bf63cf3b366) for the 9.0 release
     # but was then broken (0583d9ea8d5e) prior to the 9.0 release and
     # eventually unbroken (d9a42ec98adc) for the 11.0 release.  The first
     # patch backports the original correct fix to previous releases.  The
     # second patch backports the un-breaking of the original fix.
-    patch("constexpr_longdouble.patch", when="@6:8+libcxx")
-    patch("constexpr_longdouble_9.0.patch", when="@9:10+libcxx")
+    for libcxx_as in ["project", "runtime"]:
+        with when("libcxx={0}".format(libcxx_as)):
+            patch(
+                "https://github.com/llvm/llvm-project/commit/3bf63cf3b366d3a57cf5cbad4112a6abf6c0c3b1.patch?full_index=1",
+                sha256="e56489a4bcf3c3636e206adca366bfcda2722ad81a5fa9a0360faed63933191a",
+                when="@6:8",
+            )
+            patch(
+                "https://github.com/llvm/llvm-project/commit/d9a42ec98adcb1ebc0c3837715df4e5a50c7ccc0.patch?full_index=1",
+                sha256="50bfc4e82c02bb5b7739990f363d99b1e43d5d11a5104f6aabbc303ebce6fbe3",
+                when="@9:10",
+            )
+    del libcxx_as
 
-    # Backport from llvm master; see
-    # https://bugs.llvm.org/show_bug.cgi?id=38233
-    # for a bug report about this problem in llvm master.
-    patch("llvm_py37.patch", when="@4:6 ^python@3.7:")
+    # Backport from llvm to fix issues related to Python 3.7
+    # see https://bugs.llvm.org/show_bug.cgi?id=38233
+    patch(
+        "https://github.com/llvm/llvm-project/commit/5457b426f5e15a29c0acc8af1a476132f8be2a36.patch?full_index=1",
+        sha256="7a1e4aa80760167807255c3e3121b1281bfcf532396b2d8fb3dce021f3f18758",
+        when="@4:6+python+lldb ^python@3.7:",
+    )
 
-    # https://github.com/spack/spack/issues/19625,
-    # merged in llvm-11.0.0_rc2, first available in 12.0.0
-    patch("lldb_external_ncurses-10.patch", when="@10.0.0:11+lldb")
+    # fix building on SUSE (with panel.h being in /usr/include/ncurses/)
+    # see https://reviews.llvm.org/D85219
+    # see https://github.com/spack/spack/issues/19625
+    patch(
+        "https://github.com/llvm/llvm-project/commit/c952ec15d38843b69e22dfd7b0665304a0459f9f.patch?full_index=1",
+        sha256="66932ba31b5bf8808ea112e42cfd79b2480a4936e711771c06ce851eac429b2c",
+        when="@10:11+lldb",
+    )
 
-    # https://github.com/spack/spack/issues/19908
-    # merged in llvm main prior to 12.0.0
-    patch("llvm_python_path.patch", when="@:11")
+    # honor Python2_EXECUTABLE and Python3_EXECUTABLE when they are passed to cmake
+    # see https://reviews.llvm.org/D91536
+    patch(
+        "https://github.com/llvm/llvm-project/commit/16de50895e96adbe261a5ce2498366bda7b3fccd.patch?full_index=1",
+        sha256="0e121ed460aa6e117f9f5f339d597a96c0fe4f97dc2209aba47b43ffc831ea24",
+        # The patch is applicable only starting version 7.0.0 (the older version might require a
+        # different patch addressing https://github.com/spack/spack/issues/19908). It looks like
+        # the patched function is used only if both compiler-rt and libcxx are enabled but we keep
+        # it simple:
+        when="@7:11",
+    )
 
     # Workaround for issue https://github.com/spack/spack/issues/18197
     patch("llvm7_intel.patch", when="@7 %intel@18.0.2,19.0.0:19.1.99")
 
     # Remove cyclades support to build against newer kernel headers
     # https://reviews.llvm.org/D102059
-    patch("no_cyclades.patch", when="@10:12.0.0")
-    patch("no_cyclades9.patch", when="@6:9")
-
-    patch("llvm-gcc11.patch", when="@9:11%gcc@11:")
-
-    # add -lpthread to build OpenMP libraries with Fujitsu compiler
-    patch("llvm12-thread.patch", when="@12 %fj")
-
-    # add -lpthread to build OpenMP libraries
-    patch("llvm13-14-thread.patch", when="@13:14")
-    patch("llvm15-thread.patch", when="@15")
+    patch(
+        "https://github.com/llvm/llvm-project/commit/68d5235cb58f988c71b403334cd9482d663841ab.patch?full_index=1",
+        sha256="742501723642675075e617f3c38339961b2c7b6fd8290dbffc52239ab0783317",
+        when="@10:12.0.0",
+    )
+    # The patch above is not applicable when "@:9" due to the file renaming and reformatting. The
+    # following patch is applicable starting at least version 5.0.0, the oldest we try to support.
+    patch("no_cyclades9.patch", when="@5:9")
+
+    with when("+libomptarget"):
+        # libomptarget makes use of multithreading via the standard C++ library (e.g.
+        # std::call_once), which, depending on the platform and the implementation of the standard
+        # library, might or might not require linking to libpthread (note that the failure might
+        # happen at the linking time as well as at the runtime). In some cases, the required linker
+        # flag comes as a transitive dependency (e.g. from the static LLVMSupport component). The
+        # following patches enforce linking to the thread library that is relevant for the system,
+        # which might lead to overlinking in some cases though.
+        # TODO: figure out why we do not use LLVM_PTHREAD_LIB but run find_package(Threads), at
+        #  least for newer versions (the solution must work with both openmp=runtime and
+        #  openmp=project)
+        patch("llvm12-thread.patch", when="@12")
+        patch("llvm13-14-thread.patch", when="@13:14")
+        patch("llvm15-thread.patch", when="@15")
 
     # avoid build failed with Fujitsu compiler
     patch("llvm13-fujitsu.patch", when="@13 %fj")
 
     # patch for missing hwloc.h include for libompd
-    patch("llvm14-hwloc-ompd.patch", when="@14")
-
-    # make libflags a list in openmp subproject when ~omp_as_runtime
-    patch("libomp-libflags-as-list.patch", when="@3.7:14")
+    # see https://reviews.llvm.org/D123888
+    patch(
+        "https://github.com/llvm/llvm-project/commit/91ccd8248c85385a5654c63c302a37d97f811bab.patch?full_index=1",
+        sha256="b216cff38659c176c5381e9dda3252edbb204e6f6f1f33e843a9ebcc42732e5d",
+        when="@14 openmp=runtime",
+    )
 
-    # Add missing include leading to build fail with clang
+    # make libflags a list in openmp subproject when openmp=project
+    # see https://reviews.llvm.org/D125370
     patch(
-        "https://github.com/llvm/llvm-project/commit/b498303066a63a203d24f739b2d2e0e56dca70d1.patch?full_index=1",
-        sha256="514926d661635de47972c7d403c9c4669235aa51e22e56d44676d2a2709179b6",
-        when="@8:11",
+        "https://github.com/llvm/llvm-project/commit/e27ce281399dca8b08b6ca593172a1bd5dbdd5c1.patch?full_index=1",
+        sha256="6f0cfa55e3ed17ee33346b0a5bca8092adcc1dc75ca712ab83901755fba9767e",
+        when="@3.7:14 openmp=project",
     )
 
     # fix detection of LLDB_PYTHON_EXE_RELATIVE_PATH
     # see https://reviews.llvm.org/D133513
-    # TODO: adjust version constraint and switch to fetching from the upstream GitHub repo
-    #  when/if the bugfix is merged
+    # TODO: the patch is not applicable after https://reviews.llvm.org/D141042 but it is not clear
+    #  yet whether we need a version of it for when="@16:"
     patch("D133513.diff", level=0, when="@14:15+lldb+python")
 
     # Fix hwloc@:2.3 (Conditionally disable hwloc@2.0 and hwloc@2.4 code)
@@ -382,6 +523,14 @@ class Llvm(CMakePackage, CudaPackage):
         when="@14:15",
     )
 
+    # Fix false positive detection of a target when building compiler-rt as a runtime
+    # https://reviews.llvm.org/D127975
+    patch(
+        "https://github.com/llvm/llvm-project/commit/9f1d90bf91570efa124c4a86cd033de374d1049a.patch?full_index=1",
+        sha256="1f4287465b3e499911e039e6cc2f395b8cb00eb8a0a223fa0db3704ba77f9969",
+        when="@13:14 compiler-rt=runtime",
+    )
+
     # The functions and attributes below implement external package
     # detection for LLVM. See:
     #
@@ -618,7 +767,7 @@ class Llvm(CMakePackage, CudaPackage):
                     ),
                 ]
             )
-            if "+omp_as_runtime" in spec:
+            if "openmp=runtime" in spec:
                 cmake_args.extend(
                     [
                         define("LIBOMPTARGET_NVPTX_ENABLE_BCLIB", True),
@@ -637,7 +786,7 @@ class Llvm(CMakePackage, CudaPackage):
                 ]
             )
 
-        cmake_args.append(from_variant("LIBOMPTARGET_ENABLE_DEBUG", "omp_debug"))
+        cmake_args.append(from_variant("LIBOMPTARGET_ENABLE_DEBUG", "libomptarget_debug"))
 
         if "+lldb" in spec:
             projects.append("lldb")
@@ -663,9 +812,9 @@ class Llvm(CMakePackage, CudaPackage):
         if "+clang" in spec:
             projects.append("clang")
             projects.append("clang-tools-extra")
-            if "+omp_as_runtime" in spec:
+            if "openmp=runtime" in spec:
                 runtimes.append("openmp")
-            else:
+            elif "openmp=project" in spec:
                 projects.append("openmp")
 
             if "+libomptarget" in spec:
@@ -682,23 +831,20 @@ class Llvm(CMakePackage, CudaPackage):
             projects.append("flang")
         if "+lld" in spec:
             projects.append("lld")
-        if "+compiler-rt" in spec:
-            if self.spec.satisfies("@15.0.0:"):
-                runtimes.append("compiler-rt")
-            else:
-                projects.append("compiler-rt")
-        if "+libcxx" in spec:
-            if self.spec.satisfies("@15.0.0:"):
-                runtimes.extend(["libcxx", "libcxxabi"])
-            else:
-                projects.extend(["libcxx", "libcxxabi"])
+        if "compiler-rt=runtime" in spec:
+            runtimes.append("compiler-rt")
+        elif "compiler-rt=project" in spec:
+            projects.append("compiler-rt")
+        if "libcxx=runtime" in spec:
+            runtimes.extend(["libcxx", "libcxxabi"])
+        elif "libcxx=project" in spec:
+            projects.extend(["libcxx", "libcxxabi"])
         if "+mlir" in spec:
             projects.append("mlir")
-        if "+internal_unwind" in spec:
-            if self.spec.satisfies("@15.0.0:"):
-                runtimes.append("libunwind")
-            else:
-                projects.append("libunwind")
+        if "libunwind=runtime" in spec:
+            runtimes.append("libunwind")
+        elif "libunwind=project" in spec:
+            projects.append("libunwind")
         if "+polly" in spec:
             projects.append("polly")
             cmake_args.append(define("LINK_POLLY_INTO_TOOLS", True))
@@ -718,7 +864,7 @@ class Llvm(CMakePackage, CudaPackage):
 
         cmake_args.append(define("LLVM_TARGETS_TO_BUILD", get_llvm_targets_to_build(spec)))
 
-        cmake_args.append(from_variant("LIBOMP_TSAN_SUPPORT", "omp_tsan"))
+        cmake_args.append(from_variant("LIBOMP_TSAN_SUPPORT", "libomp_tsan"))
 
         if self.compiler.name == "gcc":
             cmake_args.append(define("GCC_INSTALL_PREFIX", self.compiler.prefix))
@@ -746,7 +892,7 @@ class Llvm(CMakePackage, CudaPackage):
         define = self.define
 
         # unnecessary if we build openmp via LLVM_ENABLE_RUNTIMES
-        if "+cuda ~omp_as_runtime" in self.spec:
+        if "+cuda openmp=project" in self.spec:
             ompdir = "build-bootstrapped-omp"
             prefix_paths = spack.build_environment.get_cmake_prefix_path(self)
             prefix_paths.append(str(spec.prefix))