Bootstrap enzyme tblgen (rust-lang#730)

* Bootstrap enzyme tblgen

* Update .packaging/build_tarballs.jl

* Fix tablgen exe

* only set tblgen if empty

* Fix

* Update .packaging/build_tarballs.jl

Co-authored-by: Valentin Churavy <vchuravy@users.noreply.github.com>

Co-authored-by: William S. Moses <gh@wsmoses.com>

.packaging/build_tarballs.jl

@@ -38,13 +38,14 @@ NATIVE_CMAKE_FLAGS+=(-DBC_LOAD_FLAGS="-target ${target} --sysroot=/opt/${target}
 
 cmake -B build-native -S enzyme -GNinja "${NATIVE_CMAKE_FLAGS[@]}"
 
-# Only build blasheaders (and eventually tblgen)
-ninja -C build-native -j ${nproc} blasheaders
+# Only build blasheaders and tblgen
+ninja -C build-native -j ${nproc} blasheaders enzyme-tblgen
 
 # 2. Cross-compile
 CMAKE_FLAGS=()
 CMAKE_FLAGS+=(-DENZYME_EXTERNAL_SHARED_LIB=ON)
 CMAKE_FLAGS+=(-DBC_LOAD_HEADER=`pwd`/build-native/BCLoad/gsl/blas_headers.h)
+CMAKE_FLAGS+=(-DEnzyme_TABLEGEN_EXE=`pwd`/build-native/tools/enzyme-tblgen/enzyme-tblgen)
 CMAKE_FLAGS+=(-DENZYME_CLANG=OFF)
 # RelWithDebInfo for decent performance, with debugability
 CMAKE_FLAGS+=(-DCMAKE_BUILD_TYPE=RelWithDebInfo)

enzyme/Enzyme/CMakeLists.txt

@@ -2,7 +2,9 @@
 #  set(LLVM_LINK_COMPONENTS Core Support)
 #endif()
 
-set(Enzyme_TABLEGEN_EXE enzyme-tblgen)
+if ("${Enzyme_TABLEGEN_EXE}" STREQUAL "")
+  set(Enzyme_TABLEGEN_EXE enzyme-tblgen)
+endif()
 
 get_target_property(TBL_LINKED_LIBS LLVMSupport INTERFACE_LINK_LIBRARIES)
 list(REMOVE_ITEM TBL_LINKED_LIBS "ZLIB::ZLIB")