Add compat_build option

Make it easier to fork the versioned lld compat packages, so this
work doesn't have to be redone for every release.

lld.spec

@@ -1,4 +1,5 @@
 %bcond_without check
+%bcond_with compat_build
 
 #global rc_ver 1
 %global lld_srcdir lld-%{maj_ver}.%{min_ver}.%{patch_ver}%{?rc_ver:rc%{rc_ver}}.src
@@ -6,11 +7,23 @@
 %global min_ver 0
 %global patch_ver 5
 
+%if %{with compat_build}
+%global pkg_name lld%{maj_ver}
+%global install_prefix %{_libdir}/llvm%{maj_ver}
+%global install_includedir %{install_prefix}/include
+%global install_libdir %{install_prefix}/lib
+%else
+%global pkg_name lld
+%global install_prefix /usr
+%global install_includedir %{_includedir}
+%global install_libdir %{_libdir}
+%endif
+
 # Don't include unittests in automatic generation of provides or requires.
 %global __provides_exclude_from ^%{_libdir}/lld/.*$
 %global __requires_exclude ^libgtest.*$
 
-Name:		lld
+Name:		%{pkg_name}
 Version:	%{maj_ver}.%{min_ver}.%{patch_ver}%{?rc_ver:~rc%{rc_ver}}
 Release:	4%{?dist}
 Summary:	The LLVM Linker
@@ -20,8 +33,10 @@ URL:		http://llvm.org
 Source0:	https://github.com/llvm/llvm-project/releases/download/llvmorg-%{maj_ver}.%{min_ver}.%{patch_ver}%{?rc_ver:-rc%{rc_ver}}/%{lld_srcdir}.tar.xz
 Source1:	https://github.com/llvm/llvm-project/releases/download/llvmorg-%{maj_ver}.%{min_ver}.%{patch_ver}%{?rc_ver:-rc%{rc_ver}}/%{lld_srcdir}.tar.xz.sig
 Source2:	tstellar-gpg-key.asc
+%if %{without compat_build}
 Source3:	run-lit-tests
 Source4:	lit.lld-test.cfg.py
+%endif
 
 ExcludeArch:	s390x
 
@@ -37,15 +52,19 @@ BuildRequires:	gcc
 BuildRequires:	gcc-c++
 BuildRequires:	cmake
 BuildRequires:	ninja-build
+%if %{with compat_build}
+BuildRequires:	llvm%{maj_ver}-devel = %{version}
+%else
 BuildRequires:	llvm-devel = %{version}
 BuildRequires:	llvm-test = %{version}
+BuildRequires:	llvm-googletest = %{version}
+%endif
 BuildRequires:	ncurses-devel
 BuildRequires:	zlib-devel
 
 # For make check:
 BuildRequires:	python3-rpm-macros
 BuildRequires:	python3-lit
-BuildRequires:	llvm-googletest = %{version}
 
 # For gpg source verification
 BuildRequires:	gnupg2
@@ -53,17 +72,19 @@ BuildRequires:	gnupg2
 Requires(post): %{_sbindir}/update-alternatives
 Requires(preun): %{_sbindir}/update-alternatives
 
-Requires: lld-libs = %{version}-%{release}
+Requires: %{name}-libs = %{version}-%{release}
 
 %description
 The LLVM project linker.
 
 %package devel
 Summary:	Libraries and header files for LLD
-Requires: lld-libs%{?_isa} = %{version}-%{release}
+Requires: %{name}-libs%{?_isa} = %{version}-%{release}
+%if %{without compat_build}
 # lld tools are referenced in the cmake files, so we need to add lld as a
 # dependency.
 Requires: %{name}%{?_isa} = %{version}-%{release}
+%endif
 
 %description devel
 This package contains library and header files needed to develop new native
@@ -75,6 +96,7 @@ Summary:	LLD shared libraries
 %description libs
 Shared libraries for LLD.
 
+%if %{without compat_build}
 %package test
 Summary: LLD regression tests
 Requires:	%{name}%{?_isa} = %{version}-%{release}
@@ -84,11 +106,20 @@ Requires:	lld-libs = %{version}-%{release}
 
 %description test
 LLVM regression tests.
+%endif
 
 %prep
 %{gpgverify} --keyring='%{SOURCE2}' --signature='%{SOURCE1}' --data='%{SOURCE0}'
 %autosetup -n %{lld_srcdir} -p2
 
+%if %{with compat_build}
+# For compat builds, we don't want to build the actual lld binary. While there is an
+# LLD_BUILD_TOOLS cmake option, it is incomplete in various ways (e.g. still leaves install
+# targets and symlinks), so instead skip the tools/lld build entirely.
+# We can't simply delete the binaries after the fact, because this would leave checks for
+# their existence in the cmake exports.
+sed 's/add_subdirectory(tools\/lld)//' -i CMakeLists.txt
+%endif
 
 %build
 
@@ -98,28 +129,36 @@ LLVM regression tests.
 %cmake \
 	-GNinja \
 	-DCMAKE_BUILD_TYPE=RelWithDebInfo \
+	-DCMAKE_INSTALL_PREFIX=%{install_prefix} \
 	-DLLVM_LINK_LLVM_DYLIB:BOOL=ON \
 	-DLLVM_DYLIB_COMPONENTS="all" \
 	-DCMAKE_SKIP_RPATH:BOOL=ON \
 	-DPYTHON_EXECUTABLE=%{__python3} \
+%if %{with compat_build}
+	-DLLVM_INCLUDE_TESTS=OFF \
+%else
 	-DLLVM_INCLUDE_TESTS=ON \
-	-DLLVM_MAIN_SRC_DIR=%{_datadir}/llvm/src \
 	-DLLVM_EXTERNAL_LIT=%{_bindir}/lit \
 	-DLLVM_LIT_ARGS="-sv \
 	--path %{_libdir}/llvm" \
 %if 0%{?__isa_bits} == 64
-	-DLLVM_LIBDIR_SUFFIX=64
+	-DLLVM_LIBDIR_SUFFIX=64 \
 %else
-	-DLLVM_LIBDIR_SUFFIX=
+	-DLLVM_LIBDIR_SUFFIX= \
 %endif
+%endif
+	-DLLVM_MAIN_SRC_DIR=%{_datadir}/llvm/src
 
 %cmake_build
 
+%if %{without compat_build}
 # Build the unittests so we can install them.
 %cmake_build --target lld-test-depends
+%endif
 
 %install
 
+%if %{without compat_build}
 %global lit_cfg test/%{_arch}.site.cfg.py
 %global lit_unit_cfg test/Unit/%{_arch}.site.cfg.py
 %global lit_lld_test_cfg_install_path %{_datadir}/lld/lit.lld-test.cfg.py
@@ -154,13 +193,15 @@ rm -rf `find %{buildroot}%{_libdir}/lld/ -iname '*make*'`
 
 # Install gtest libraries
 cp %{__cmake_builddir}/%{_lib}/libgtest*so* %{buildroot}%{_libdir}/lld/
+%endif
 
 # Install libraries and binaries
 %cmake_install
 
 # This is generated by Patch1 during build and (probably) must be removed afterward
-rm %{buildroot}%{_includedir}/mach-o/compact_unwind_encoding.h
+rm %{buildroot}%{install_includedir}/mach-o/compact_unwind_encoding.h
 
+%if %{without compat_build}
 # Required when using update-alternatives:
 # https://docs.fedoraproject.org/en-US/packaging-guidelines/Alternatives/
 touch %{buildroot}%{_bindir}/ld
@@ -172,9 +213,11 @@ touch %{buildroot}%{_bindir}/ld
 if [ $1 -eq 0 ] ; then
   %{_sbindir}/update-alternatives --remove ld %{_bindir}/ld.lld
 fi
+%endif
 
 %check
 
+%if %{without compat_build}
 # armv7lhl tests disabled because of arm issue, see https://koji.fedoraproject.org/koji/taskinfo?taskID=33660162
 %ifnarch %{arm}
 %if %{with check}
@@ -183,7 +226,9 @@ fi
 %endif
 
 %ldconfig_scriptlets libs
+%endif
 
+%if %{without compat_build}
 %files
 %license LICENSE.TXT
 %ghost %{_bindir}/ld
@@ -191,15 +236,17 @@ fi
 %{_bindir}/ld.lld
 %{_bindir}/ld64.lld
 %{_bindir}/wasm-ld
+%endif
 
 %files devel
-%{_includedir}/lld
+%{install_includedir}/lld
-%{_libdir}/liblld*.so
+%{install_libdir}/liblld*.so
-%{_libdir}/cmake/lld/
+%{install_libdir}/cmake/lld/
 
 %files libs
-%{_libdir}/liblld*.so.*
+%{install_libdir}/liblld*.so.*
 
+%if %{without compat_build}
 %files test
 %{_libexecdir}/tests/lld/
 %{_libdir}/lld/
@@ -207,6 +254,7 @@ fi
 %{_datadir}/lld/src/%{_arch}.site.cfg.py
 %{_datadir}/lld/src/%{_arch}.Unit.site.cfg.py
 %{_datadir}/lld/lit.lld-test.cfg.py
+%endif
 
 %changelog
 * Tue Aug 09 2022 Nikita Popov <npopov@redhat.com> - 14.0.5-4