# o3de-dxc-spirv — license-clean Linux DXC build for O3DE
#
# Builds the DirectX Shader Compiler (DXC) from O3DE's fork at
# release-1.8.2505.1-o3de, configured Linux/SPIR-V-only — no Windows
# DXIL signing tooling. Per Nick_L (sig-build, 2026-05-05): the engine
# doesn't link DXC at all, just shells out to the dxc binary, so the
# rebuild only needs to produce a working dxc executable.
#
# License: NCSA + Apache-2.0 (with LLVM exception). Both Fedora-
# compatible; no proprietary signing tools included.
#
# Cmake flags below mirror what o3de/3p-package-source's
# package-system/DirectXShaderCompiler/build_config.json sets for
# Linux. Source git_tag matches the most recent published bundle.
#
# This is the "PoC" stage — proves the rebuild is buildable as a
# Fedora-style RPM. Packaging hardening (multi-arch, hermetic builds,
# unit-test gating, debuginfo split, etc.) is follow-on work. Goal of
# this iteration: get a green local build + a binary RPM that produces
# a functioning dxc executable.

%global o3de_dxc_commit       release-1.8.2505.1-o3de
%global o3de_dxc_pkgrev       rev13
# DirectX-Headers submodule SHA matching DXC's pin at release-1.8.2505.1-o3de
# (verified via `gh api /repos/o3de/DirectXShaderCompiler/git/trees/...:external`).
# Commit date: 2022-01-31 (Walbourn merge PR #47).
%global dxh_commit            980971e835876dc0cde415e8f9bc646e64667bf7
%global dxh_short             %(c=%{dxh_commit}; echo ${c:0:7})

Name:           o3de2605-dxc-spirv
Version:        1.8.2505.1
Release:        1.%{o3de_dxc_pkgrev}%{?dist}
Summary:        DirectX Shader Compiler (Linux/SPIR-V-only build) for Open 3D Engine 26.05

License:        NCSA AND Apache-2.0 WITH LLVM-exception
URL:            https://github.com/o3de/DirectXShaderCompiler

# Versioned-major rename: see o3de-rpm memory note
# `project_o3de_3p_versioning_research.md` for empirical research that
# motivated the o3deNNNN-<dep> naming convention. Obsoletes/Provides keep
# `dnf upgrade` seamless from the unversioned o3de-dxc-spirv (rev1-rev12).
Obsoletes:      o3de-dxc-spirv < 1.8.2505.1-1.rev13
Provides:       o3de-dxc-spirv = %{version}-%{release}

# Source: tarball generated from o3de/DirectXShaderCompiler at
# tag release-1.8.2505.1-o3de. We don't fetch directly via git in
# %prep because COPR builders run with enable_net=false for license-
# clean repos; pre-staged tarball is the canonical input.
#
# Note: the tarball is created via plain `git archive` (non-recursive),
# so the three external/* git submodules (DirectX-Headers, SPIRV-Headers,
# SPIRV-Tools) end up as empty directories. Patch0001 below adds a
# system-package fallback to DXC's external/CMakeLists.txt so the build
# uses Fedora's spirv-headers-devel, spirv-tools-devel, and DirectX-
# Headers-devel instead of the missing submodule sources.
Source0:        DirectXShaderCompiler-%{o3de_dxc_commit}.tar.gz

# DirectX-Headers source at DXC's pinned submodule SHA (license: MIT, Microsoft).
# DXC's external/CMakeLists.txt expects external/DirectX-Headers/include/{d3d12,...}.h
# — the SAME layout this tarball provides — so DXC's existing IS_DIRECTORY +
# add_subdirectory branch builds it normally, no Patch0001-style fallback needed.
# This was switched in rev10 from Fedora's DirectX-Headers-devel because Fedora's
# wsl/stubs/basetsd.h has typedef conflicts with DXC's own include/dxc/WinAdapter.h
# (Fedora: typedef int32_t LONG, DXC: typedef long LONG — incompatible at LP64).
Source2:        DirectX-Headers-%{dxh_short}.tar.gz

# Patch the empty-submodule fallback path in external/CMakeLists.txt:
# - SPIRV-Headers: find_package(SPIRV-Headers) + set SPIRV-Headers_SOURCE_DIR
#   to /usr (so DXC's existing `${SPIRV-Headers_SOURCE_DIR}/include` resolves
#   to /usr/include where Fedora ships spirv/unified1/spirv.hpp etc).
# - SPIRV-Tools: find_package(SPIRV-Tools) + find_package(SPIRV-Tools-opt).
#   Fedora ships `SPIRV-Tools` as SHARED IMPORTED via SPIRV-ToolsConfig.cmake;
#   `SPIRV-Tools-opt` via SPIRV-Tools-optConfig.cmake. Both are needed by DXC's
#   downstream link targets (dxc, dxclib, clangSPIRV).
# - SPIRV_DEP_TARGETS loop: wrap set_property(TARGET SPIRV-Tools-static ...) in
#   `if (TARGET ...)` because Fedora doesn't ship a static SPIRV-Tools target.
# DirectX-Headers is handled differently — Fedora ships no cmake config, so we
# pass `-DDIRECTX_HEADER_INCLUDE_DIR=/usr/include/directx` in %build to bypass
# DXC's DirectX-Headers-submodule lookup entirely.
Patch0001:      0001-external-cmake-system-spirv-fallback.patch

# Add SPIRV-Tools (the main library) alongside SPIRV-Tools-opt in
# clangSPIRV's LINK_LIBS list. Required because Fedora's imported
# `SPIRV-Tools-opt` target doesn't establish the transitive
# INTERFACE_LINK_LIBRARIES → SPIRV-Tools that bundled SPIRV-Tools
# provides natively. clangSPIRV is the actual consumer of the spv*
# C-API symbols (SpirvTools class, spvOptimizerOptions*,
# spvValidatorOptions*, etc. — all in libSPIRV-Tools.so), so listing
# it explicitly is more reliable than trying to graft a transitive
# edge onto an IMPORTED target (rev11 attempted that in Patch0001 and
# the link-line propagation didn't work).
Patch0002:      0002-clangSPIRV-add-SPIRV-Tools-to-link-libs.patch

BuildRequires:  cmake
BuildRequires:  ninja-build
BuildRequires:  gcc-c++
BuildRequires:  python3
# DXC's `utils/version/CMakeLists.txt` runs `git rev-parse HEAD` to embed
# a commit hash into `dxcversion.inc`. Required at build time even though
# the resulting binary doesn't link git.
BuildRequires:  git
# DXC is a Clang/LLVM fork — the upstream sources include their own
# embedded LLVM tree, no system-LLVM linkage required at build time.

# System SPIR-V dependencies — Patch0001 redirects DXC's submodule lookups
# to these Fedora packages.
BuildRequires:  spirv-headers-devel
BuildRequires:  spirv-tools-devel
# Note: DirectX-Headers is NOT a BR — we ship the bundled DirectX-Headers
# sources via Source2 instead, due to typedef conflicts between Fedora's
# `/usr/include/wsl/stubs/basetsd.h` and DXC's `include/dxc/WinAdapter.h`
# (`LONG = int32_t` vs `long`). See rev10 changelog for full diagnosis.

%description
DirectX Shader Compiler (DXC) — Microsoft's HLSL→SPIR-V/DXIL compiler,
forked by Open 3D Engine to add Linux build fixes and the dxsc
helper tool. This build is Linux/SPIR-V-only (no DXIL signing
tooling) so the resulting binaries are redistributable under NCSA +
Apache-2.0 (with LLVM exception).

Used by O3DE's shader pipeline as an external invocation: the engine
shells out to dxc to compile HLSL shaders to SPIR-V at asset-build time.

This package replaces the bundled DXC tarball O3DE fetches from
packages.o3de.org by default — providing a Fedora-shippable license-
clean substitute for distros that can't redistribute the bundled
upstream tarball (which includes proprietary Windows DXIL signing
tooling that's not used on Linux but ships in the same archive).

%prep
# -p1 applies Patch0001 (system-spirv fallback for external/CMakeLists.txt).
%autosetup -n DirectXShaderCompiler-%{o3de_dxc_commit} -p1

# DXC's external/CMakeLists.txt tests `IS_DIRECTORY ${DXC_SPIRV_HEADERS_DIR}`
# before deciding whether to add_subdirectory the submodule or fall back to
# Patch0001's system find_package path. Our `git archive`-generated tarball
# leaves submodule directories present-but-empty, which makes IS_DIRECTORY
# return TRUE — so cmake takes the add_subdirectory branch and fails with
# "does not contain a CMakeLists.txt file" before reaching the Patch0001
# else()-branch.
#
# For SPIRV-Headers + SPIRV-Tools: rmdir the empty placeholders so the test
# fails and Patch0001's system-package fallback fires.
# For DirectX-Headers: extract Source2 (the DXC-pinned submodule SHA) into
# the placeholder dir, so DXC's existing add_subdirectory branch builds the
# bundled DirectX-Headers normally.
rmdir external/SPIRV-Headers external/SPIRV-Tools 2>/dev/null || :
rmdir external/DirectX-Headers 2>/dev/null || :
mkdir -p external/DirectX-Headers
tar -xzf %{SOURCE2} -C external/DirectX-Headers --strip-components=1

%build
# Cmake flags mirror o3de/3p-package-source/.../build_config.json's
# Linux build_configs, with three notable choices:
#
# - LLVM_TARGETS_TO_BUILD=None: no LLVM target backends. DXC's HLSL
#   frontend produces SPIR-V via its own pipeline; no Windows-DXIL,
#   no x86 native, no other LLVM target needed for the o3de use case.
# - ENABLE_SPIRV_CODEGEN=ON: enable the SPIR-V codegen path (the
#   thing the engine actually uses).
# - LIBCLANG_BUILD_STATIC=ON: build the embedded libclang as a static
#   library, so the shipped libdxcompiler.so is self-contained and
#   doesn't bleed an internal libclang-12.so.* runtime requirement
#   onto the system. (This was the source of the bundled DXC's
#   %__requires_exclude pain on the o3de spec side.)
%cmake \
    -GNinja \
    -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=ON \
    -DBUILD_SHARED_LIBS:BOOL=OFF \
    -DLLVM_APPEND_VC_REV:BOOL=ON \
    -DLLVM_DEFAULT_TARGET_TRIPLE:STRING=dxil-ms-dx \
    -DLLVM_ENABLE_EH:BOOL=ON \
    -DLLVM_ENABLE_RTTI:BOOL=ON \
    -DLLVM_INCLUDE_DOCS:BOOL=OFF \
    -DLLVM_INCLUDE_EXAMPLES:BOOL=OFF \
    -DLLVM_INCLUDE_TESTS:BOOL=OFF \
    -DLLVM_OPTIMIZED_TABLEGEN:BOOL=OFF \
    -DLLVM_REQUIRES_EH:BOOL=ON \
    -DLLVM_REQUIRES_RTTI:BOOL=ON \
    -DLLVM_TARGETS_TO_BUILD:STRING=None \
    -DLIBCLANG_BUILD_STATIC:BOOL=ON \
    -DCLANG_BUILD_EXAMPLES:BOOL=OFF \
    -DCLANG_CL:BOOL=OFF \
    -DCLANG_ENABLE_ARCMT:BOOL=OFF \
    -DCLANG_ENABLE_STATIC_ANALYZER:BOOL=OFF \
    -DCLANG_INCLUDE_TESTS:BOOL=OFF \
    -DHLSL_INCLUDE_TESTS:BOOL=OFF \
    -DENABLE_SPIRV_CODEGEN:BOOL=ON \
    -DSPIRV_BUILD_TESTS:BOOL=OFF

%cmake_build --target dxc dxsc dxcompiler

%install
# DXC's cmake doesn't ship a clean `install` target by default for
# our subset, so manually install the binaries + library to canonical
# Fedora paths. The engine's runtime walker just needs `dxc` on PATH
# (per Nick_L); shipping the supporting bits matches the bundled
# layout for downstream consumers that may look for them.
mkdir -p %{buildroot}%{_bindir}
mkdir -p %{buildroot}%{_libdir}

install -m 0755 %{_vpath_builddir}/bin/dxc        %{buildroot}%{_bindir}/dxc
install -m 0755 %{_vpath_builddir}/bin/dxsc       %{buildroot}%{_bindir}/dxsc 2>/dev/null || :

# libdxcompiler.so + versioned symlink (cmake build typically
# produces both libdxcompiler.so and libdxcompiler.so.<version>).
install -m 0755 %{_vpath_builddir}/lib/libdxcompiler.so* %{buildroot}%{_libdir}/

%files
%license LICENSE.TXT
%{_bindir}/dxc
%{_bindir}/dxsc
%{_libdir}/libdxcompiler.so*

%changelog
* Fri May 08 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev13
- Versioned-major rename: o3de-dxc-spirv -> o3de2605-dxc-spirv. Mirrors
  the engine package's o3deNNNN naming convention so `o3de2605-dxc-spirv`
  and a future `o3de2610-dxc-spirv` can co-exist in the same COPR project,
  matching upstream's CDN model. Empirical research is captured in the
  o3de-rpm memory note `project_o3de_3p_versioning_research.md`.
- Backward compat: Obsoletes + Provides headers so `dnf upgrade`
  transitions seamlessly from o3de-dxc-spirv rev1-rev12 (the PoC iteration
  history that landed the package green on 2026-05-08).
- No functional change. Same 12 iterations of fixes carry forward; this
  revision is a name-only bump.

* Fri May 08 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev12
- Fix: COPR build 10434595 (rev11) reached step 1106/1111 (the libdxcompiler.so
  link) and failed with the SAME `undefined reference to spvOptimizerOptions*`
  + `spvValidatorOptions*` + `spvtools::SpirvTools::*` symbols as rev10. The
  rev11 fix attempted to set the transitive `SPIRV-Tools-opt` → `SPIRV-Tools`
  edge via `target_link_libraries(SPIRV-Tools-opt INTERFACE SPIRV-Tools)` in
  Patch0001 — that form's INTERFACE_LINK_LIBRARIES doesn't reliably propagate
  to IMPORTED targets in this context (the link line still showed only
  `-lSPIRV-Tools-opt`).
- Approach this time: fix at the consumer side instead of grafting a
  transitive edge on an IMPORTED target. clangSPIRV is what actually consumes
  the spv* C-API symbols, so its LINK_LIBS list should include both
  `SPIRV-Tools-opt` AND `SPIRV-Tools`.
- Patch0001 reverted to its rev10 state (drop the rev11 transitive-link
  block, but keep the SPIRV-Headers + SPIRV-Tools find_package fallbacks
  + the SPIRV-Tools-static set_property guard).
- New Patch0002: one-line addition of `SPIRV-Tools` to
  tools/clang/lib/SPIRV/CMakeLists.txt's LINK_LIBS list. Behavior-preserving
  in the bundled-SPIRV-Tools case (the bundled cmake's transitive already
  linked SPIRV-Tools; this just makes the link explicit on the consumer
  side, eliminating reliance on bundled-SPIRV-Tools cmake's implementation
  detail).

* Thu May 07 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev11
- Fix: COPR build 10434564 (rev10) made enormous progress — reached step
  1106/1111 (99.5%) before failing at the FINAL link of `libdxcompiler.so`:
    undefined reference to `spvOptimizerOptionsSetMaxIdBound'
    undefined reference to `spvOptimizerOptionsDestroy'
  These spv* C-API symbols live in libSPIRV-Tools.so (the main library,
  not the -opt variant). Link line included `-lSPIRV-Tools-opt` but NOT
  `-lSPIRV-Tools`.
- Root cause: in the bundled-SPIRV-Tools case, `add_subdirectory(SPIRV-Tools)`
  natively sets up `SPIRV-Tools-opt` to depend on `SPIRV-Tools` transitively.
  Fedora's imported targets (SPIRV-ToolsConfig.cmake + SPIRV-Tools-optConfig.cmake)
  don't establish that transitive INTERFACE_LINK_LIBRARIES relationship —
  each is a standalone IMPORTED target. Combined with DXC's link-line flags
  `-Wl,-z,defs --as-needed`, the linker fails on every direct symbol
  reference that isn't in a directly-listed library.
- Extend Patch0001's SPIRV-Tools fallback to call:
    target_link_libraries(SPIRV-Tools-opt INTERFACE SPIRV-Tools)
  This re-establishes the transitive dependency that the bundled cmake
  provides natively. Anything that links SPIRV-Tools-opt now transitively
  pulls in SPIRV-Tools too, satisfying the linker.
- Architectural lesson: when patching cmake to use system imported targets
  in place of a bundled add_subdirectory, sometimes the imported targets
  don't cover the full link-graph that the bundled cmake established. Need
  to manually re-establish those edges. This is a known gotcha with cmake
  IMPORTED libraries.

* Thu May 07 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev10
- Fix: COPR build 10434507 (rev9) reached step 484/1111 (44% — much further
  than rev7's 188/1111) before failing with typedef conflict between Fedora's
  `/usr/include/wsl/stubs/basetsd.h` and DXC's own `include/dxc/WinAdapter.h`:
    Fedora wsl/stubs:  typedef uint32_t ULONG; typedef int32_t LONG; ...
    DXC WinAdapter.h:  typedef unsigned long ULONG; typedef long LONG; ...
  These are structurally incompatible (LP64 native widths vs Win32 fixed
  widths). DXC's WinAdapter.h was designed assuming DXC's bundled
  DirectX-Headers submodule, which doesn't ship a wsl/stubs/ shim — Fedora's
  DirectX-Headers package adds that shim, hence the conflict.
- Switch from system DirectX-Headers to bundled DirectX-Headers (Source2,
  pinned to DXC's exact submodule SHA: 980971e835876dc0cde415e8f9bc646e64667bf7
  from microsoft/DirectX-Headers, verified via GitHub API:
  `gh api /repos/o3de/DirectXShaderCompiler/git/trees/release-1.8.2505.1-o3de:external`).
  Drop `BuildRequires: DirectX-Headers-devel` and the
  `-DDIRECTX_HEADER_INCLUDE_DIR=/usr/include` cmake flag. Update %prep to
  extract Source2 into external/DirectX-Headers/ instead of rmdir-ing the
  placeholder. DXC's existing add_subdirectory(${DXC_EXTERNAL_ROOT_DIR}/DirectX-Headers)
  branch builds it normally, no patching of DXC's external/CMakeLists.txt
  needed for the DirectX-Headers part.
- Architectural lesson: Fedora's DirectX-Headers is fine as a system library
  for projects that DON'T have their own Win-types compat layer. DXC has its
  own (WinAdapter.h), and the two layers can't coexist. Stage 1-style "use
  system Foo" doesn't work universally; some 3rdParty deps need to be
  bundled-as-source because of internal architectural assumptions.
- License of bundled DirectX-Headers: MIT (Microsoft) — Fedora-acceptable.

* Thu May 07 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev9
- Fix: COPR build 10434109 (rev8) failed in 7m on F44 with
  `fatal error: d3d12shader.h: No such file or directory`. The compile
  command shows DXC was emitting `-I/usr/include/directx/directx
  -I/usr/include/directx/wsl/stubs` — meaning DXC's source code does
  `${DIRECTX_HEADER_INCLUDE_DIR}/directx` and `${DIRECTX_HEADER_INCLUDE_DIR}/wsl/stubs`
  expansions, expecting an `include/`-style ROOT that contains a
  `directx/` subdir (mirroring upstream DirectX-Headers' submodule
  layout: `external/DirectX-Headers/include/directx/d3d12shader.h`).
  Fedora's layout has the headers directly in `/usr/include/directx/`,
  so the correct DIRECTX_HEADER_INCLUDE_DIR is `/usr/include` (not
  `/usr/include/directx`) — DXC's downstream `${DIR}/directx` then
  resolves to `/usr/include/directx`, finding `d3d12shader.h` correctly.

* Thu May 07 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev8
- Fix: COPR build 10434105 (rev7) failed in 2m02s on F44 — got past cmake
  config and into actual compilation (step 188/1111) before failing at
  `utils/version/dxcversion.inc.gen` because DXC's build invokes
  `git rev-parse HEAD` to embed the commit hash and `git` isn't installed
  in the COPR mock chroot. Trivial: add `BuildRequires: git`.
- Forward-progress check: rev7 reached deep compilation (TableGen tools
  building, llvm-tblgen linking) — the BUILD_SHARED_LIBS=OFF + Patch0001
  + rmdir fixes from rev6/rev5/rev4 all held. Only the `git` BR was missing.

* Thu May 07 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev7
- Fix: COPR build 10434098 (rev6) failed in 18s on F44 with cmake error
  "Cyclic dependencies are allowed only among static libraries" — the
  rev6 fixes (rmdir empty submodules + Patch0001 system-spirv fallback)
  worked correctly and got the build past the SPIR-V dependency setup,
  but Fedora's %%cmake macro sets BUILD_SHARED_LIBS:BOOL=ON by default,
  which conflicts with DXC's clang-as-static-libraries expectation
  (clangAST / clangCodeGen / clangSema / clangFrontend etc. have
  inter-target cyclic deps that are only legal among STATIC_LIBRARY
  targets, per cmake's policy — modular LLVM/Clang builds rely on
  static-only linkage).
- Fix: explicitly pass `-DBUILD_SHARED_LIBS:BOOL=OFF` to override the
  Fedora macro default. Restores DXC's expected static-everywhere link
  model. Combined with LIBCLANG_BUILD_STATIC=ON (already set), the
  resulting libdxcompiler.so remains self-contained.
- Strategic context: this is iteration 4 (rev4 → rev5 → rev6 → rev7).
  Each iteration has produced a new failure mode, with the fix making
  forward progress in the build pipeline:
    rev4: empty submodule dirs at cmake-config.
    rev5: Patch0001 logic correct but IS_DIRECTORY edge case.
    rev6: BUILD_SHARED_LIBS conflicts with DXC's static-clang assumption.
    rev7: this — should reach actual compilation.

* Thu May 07 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev6
- Fix: COPR build 10434076 (rev5) failed in 1m08s on F44 with the same
  "SPIRV-Headers was not found" symptom as rev4 — the rev5 patch logic was
  correct but missed an edge case: the `git archive`-generated tarball
  leaves the three submodule directories present-but-empty, so DXC's
  `IS_DIRECTORY ${DXC_SPIRV_HEADERS_DIR}` test returns TRUE and cmake
  falls into the `add_subdirectory` branch (which fails because the dir
  has no CMakeLists.txt) BEFORE reaching Patch0001's else()-branch fallback.
- Fix: add `rmdir external/{DirectX-Headers,SPIRV-Headers,SPIRV-Tools}` in
  %prep so IS_DIRECTORY returns FALSE and Patch0001's system-find_package
  fallback fires. The rmdir succeeds for empty dirs (placeholders) and is
  a no-op (`|| :`) if a future tarball ever includes populated submodules.

* Thu May 07 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev5
- Fix: COPR build 10433445 (rev4) failed in 52s on F44/F43/rawhide with
  "SPIRV-Headers was not found" — DXC's source tree references
  external/{DirectX-Headers,SPIRV-Headers,SPIRV-Tools} as git submodules,
  but our tarball was created via plain `git archive` (non-recursive),
  leaving those directories empty in the SRPM.
- Patch0001: add system-package fallback to DXC's external/CMakeLists.txt:
  - SPIRV-Headers: find_package(SPIRV-Headers) + set SPIRV-Headers_SOURCE_DIR
    to /usr (so `${SPIRV-Headers_SOURCE_DIR}/include` resolves to
    /usr/include/spirv/... where Fedora ships spirv.hpp etc).
  - SPIRV-Tools: find_package(SPIRV-Tools) + find_package(SPIRV-Tools-opt).
  - Wrap set_property(TARGET SPIRV-Tools-static ...) in `if (TARGET ...)`
    because Fedora ships only SPIRV-Tools (SHARED IMPORTED), not static.
- BuildRequires: spirv-headers-devel + spirv-tools-devel + DirectX-Headers-devel.
- cmake -DDIRECTX_HEADER_INCLUDE_DIR=/usr/include/directx — bypasses DXC's
  DirectX-Headers-submodule lookup (Fedora's DirectX-Headers ships no cmake
  config, so we pass the include dir directly).
- Strategic context: same audit-pattern shape as the engine's Stage 1 swaps —
  use Fedora's license-clean SPIR-V packages instead of bundling submodule
  sources. Cleaner from a packaging-review perspective + reproducible builds.

* Thu May 07 2026 Nick Schuetz <nschuetz@redhat.com> - 1.8.2505.1-1.rev4
- Initial PoC: license-clean Linux DXC build for O3DE.
- Source: o3de/DirectXShaderCompiler at release-1.8.2505.1-o3de
  (matches o3de/3p-package-source's package-system/DirectXShaderCompiler
  build_config.json git_tag, package_version 1.8.2505.1-o3de-rev4).
- Cmake flags mirror the upstream build_config.json's Linux config.
- LLVM_TARGETS_TO_BUILD=None + ENABLE_SPIRV_CODEGEN=ON: no DXIL
  Windows-signing tooling included; SPIR-V codegen only.
- LIBCLANG_BUILD_STATIC=ON: libdxcompiler.so self-contained, no
  embedded libclang-12.so.* runtime requirement on the consumer side.
- License: NCSA + Apache-2.0 (with LLVM exception). Both
  Fedora-compatible.