rename function; hide more cross-compile details in functions

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c704578..fe5e182 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -226,15 +226,16 @@
 add_subdirectory(build_tools/third_party/vulkan_extensionlayer EXCLUDE_FROM_ALL)
 
 if(CMAKE_CROSSCOMPILING)
-  iree_build_host_executable(flatc BUILDONLY)
+  iree_declare_host_excutable(flatc BUILDONLY)
   # Set the FLATBUFFERS_FLATC_EXECUTABLE. It controls where to find the flatc
   # binary in BuildFlatBuffers().
-  iree_get_host_exectuable_path(flatc FLATBUFFERS_FLATC_EXECUTABLE)
+  iree_get_executable_path(flatc FLATBUFFERS_FLATC_EXECUTABLE)
   # Add a custom target to copy the flatc to the binary directory.
   add_custom_target(iree_host_flatc
     COMMAND "${CMAKE_COMMAND}" -E copy_if_different
       "${IREE_HOST_BINARY_ROOT}/third_party/flatbuffers/flatc" "${IREE_HOST_BINARY_ROOT}/bin"
     DEPENDS iree_host_build_flatc
+    COMMENT "Installing host flatc..."
   )
 endif()
 

build_tools/cmake/flatbuffer_cc_library.cmake

diff --git a/build_tools/cmake/flatbuffer_cc_library.cmake b/build_tools/cmake/flatbuffer_cc_library.cmake
index 71219b9..d3ffd5e 100644
--- a/build_tools/cmake/flatbuffer_cc_library.cmake
+++ b/build_tools/cmake/flatbuffer_cc_library.cmake
@@ -106,7 +106,7 @@
   )
 
   if(CMAKE_CROSSCOMPILING)
-    iree_get_host_exectuable_path(flatc _FLATC_PATH)
+    # Additionally depend on the flatc binary to drive compiling it.
     add_dependencies("${_NAME}_gen" iree_host_flatc)
   endif()
 

build_tools/cmake/iree_bytecode_module.cmake

diff --git a/build_tools/cmake/iree_bytecode_module.cmake b/build_tools/cmake/iree_bytecode_module.cmake
index fa79ecf..8003b7d 100644
--- a/build_tools/cmake/iree_bytecode_module.cmake
+++ b/build_tools/cmake/iree_bytecode_module.cmake
@@ -59,12 +59,7 @@
     set(_TRANSLATE_TOOL "iree-translate")
   endif()
 
-  if (CMAKE_CROSSCOMPILING)
-    iree_get_host_exectuable_path(${_TRANSLATE_TOOL} _TRANSLATE_TOOL_EXECUTABLE)
-  else()
-    # Resolve the executable binary path from the target name.
-    set(_TRANSLATE_TOOL_EXECUTABLE $<TARGET_FILE:${_TRANSLATE_TOOL}>)
-  endif()
+  iree_get_executable_path(${_TRANSLATE_TOOL} _TRANSLATE_TOOL_EXECUTABLE)
 
   set(_ARGS "${_FLAGS}")
   list(APPEND _ARGS "${CMAKE_CURRENT_SOURCE_DIR}/${_RULE_SRC}")

build_tools/cmake/iree_cc_binary.cmake

diff --git a/build_tools/cmake/iree_cc_binary.cmake b/build_tools/cmake/iree_cc_binary.cmake
index 211b809..d7384aa 100644
--- a/build_tools/cmake/iree_cc_binary.cmake
+++ b/build_tools/cmake/iree_cc_binary.cmake
@@ -71,6 +71,10 @@
   endif()
 
   if(_RULE_HOSTONLY AND CMAKE_CROSSCOMPILING)
+    # The binary is marked as host only. We need to declare the rules for
+    # generating them under host configuration so cross-compiling towards
+    # target we can still have this binary.
+    iree_declare_host_excutable(_RULE_NAME)
     return()
   endif()
 

build_tools/cmake/iree_cc_embed_data.cmake

diff --git a/build_tools/cmake/iree_cc_embed_data.cmake b/build_tools/cmake/iree_cc_embed_data.cmake
index 7852dc5..40fd0c0 100644
--- a/build_tools/cmake/iree_cc_embed_data.cmake
+++ b/build_tools/cmake/iree_cc_embed_data.cmake
@@ -79,12 +79,7 @@
     list(APPEND _ARGS "${SRC}")
   endforeach(SRC)
 
-  if (CMAKE_CROSSCOMPILING)
-    iree_get_host_exectuable_path(generate_cc_embed_data _EXE_PATH)
-  else()
-    # Resolve the executable binary path from the target name.
-    set(_EXE_PATH $<TARGET_FILE:generate_cc_embed_data>)
-  endif()
+  iree_get_executable_path(generate_cc_embed_data _EXE_PATH)
 
   add_custom_command(
     OUTPUT "${_RULE_H_FILE_OUTPUT}" "${_RULE_CC_FILE_OUTPUT}"

build_tools/cmake/iree_copts.cmake

diff --git a/build_tools/cmake/iree_copts.cmake b/build_tools/cmake/iree_copts.cmake
index fbc40e7..f66a7c9 100644
--- a/build_tools/cmake/iree_copts.cmake
+++ b/build_tools/cmake/iree_copts.cmake
@@ -143,12 +143,10 @@
   ${PROJECT_BINARY_DIR}/third_party/llvm-project/llvm/tools/mlir/include
 )
 
-if(CMAKE_CROSSCOMPILING)
-  iree_get_host_exectuable_path(iree-tblgen IREE_TABLEGEN_EXE)
-else()
-  set(MLIR_TABLEGEN_EXE mlir-tblgen)
-  set(IREE_TABLEGEN_EXE iree-tblgen)
-endif()
+set(MLIR_TABLEGEN_EXE mlir-tblgen)
+# iree-tblgen is not defined using the add_tablegen mechanism as other TableGen
+# tools in LLVM.
+iree_get_executable_path(iree-tblgen IREE_TABLEGEN_EXE)
 
 #-------------------------------------------------------------------------------
 # Third party: tensorflow

build_tools/cmake/iree_cross_compile.cmake

diff --git a/build_tools/cmake/iree_cross_compile.cmake b/build_tools/cmake/iree_cross_compile.cmake
index 8f7d9fa..5bed987 100644
--- a/build_tools/cmake/iree_cross_compile.cmake
+++ b/build_tools/cmake/iree_cross_compile.cmake
@@ -130,18 +130,6 @@
   endif()
 endfunction()
 
-# iree_get_host_executable_path
-#
-# Gets the path to a host executable.
-#
-# Paramters:
-# - target: the target to build on host.
-# - output_path_var: variable name for receiving the path to the built target.
-function(iree_get_host_exectuable_path target output_path_var)
-  set(output_path "${IREE_HOST_BINARY_ROOT}/bin/${target}")
-  set(${output_path_var} "${output_path}" PARENT_SCOPE)
-endfunction()
-
 # iree_host_install
 #
 # Defines custom commands and targets for installing the given `target`. The
@@ -160,7 +148,7 @@
     set(prefix_option -DCMAKE_INSTALL_PREFIX="${_RULE_PREFIX}")
   endif()
 
-  iree_get_host_exectuable_path(${target} output_path)
+  iree_get_executable_path(${target} output_path)
 
   add_custom_command(
     OUTPUT ${output_path}
@@ -174,7 +162,7 @@
   add_custom_target(iree_host_install_${target} DEPENDS ${output_path})
 endfunction()
 
-# iree_build_host_executable
+# iree_declare_host_excutable
 #
 # Generates custom commands and targets for building and installing a tool on
 # host for cross-compilation.
@@ -183,10 +171,10 @@
 # - target: the target to build on host.
 # - BUILDONLY: only generates commands for building the target.
 # - DEPENDS: any additional dependencies for the target.
-function(iree_build_host_executable target)
+function(iree_declare_host_excutable target)
   cmake_parse_arguments(_RULE "BUILDONLY" "" "DEPENDS" ${ARGN})
 
-  iree_get_host_exectuable_path(${target} output_path)
+  iree_get_executable_path(${target} output_path)
 
   iree_get_build_command(${target} ${IREE_HOST_BINARY_ROOT} build_cmd)
 

build_tools/cmake/iree_macros.cmake

diff --git a/build_tools/cmake/iree_macros.cmake b/build_tools/cmake/iree_macros.cmake
index 4929146..9fa6697 100644
--- a/build_tools/cmake/iree_macros.cmake
+++ b/build_tools/cmake/iree_macros.cmake
@@ -72,6 +72,28 @@
   set(${PACKAGE_DIR} ${_PACKAGE_DIR} PARENT_SCOPE)
 endfunction()
 
+# iree_get_executable_path
+#
+# Gets the path to an executable in a cross-compilation-aware way. This is
+# meant to be used for binaries that are used to generate source files and
+# can only be built on host.
+#
+# Paramters:
+# - target: the target to build on host.
+# - output_path_var: variable name for receiving the path to the built target.
+function(iree_get_executable_path target output_path_var)
+  if(CMAKE_CROSSCOMPILING)
+    # The target is defined in the CMake invocation for host. We don't have
+    # access to the target; relying on the path here.
+    set(output_path "${IREE_HOST_BINARY_ROOT}/bin/${target}")
+    set(${output_path_var} "${output_path}" PARENT_SCOPE)
+  else()
+    # The target is defined in this CMake invocation. We can query the location
+    # directly from CMake.
+    set(${output_path_var} "$<TARGET_FILE:${target}>" PARENT_SCOPE)
+  endif()
+endfunction()
+
 #-------------------------------------------------------------------------------
 # select()-like Evaluation
 #-------------------------------------------------------------------------------

build_tools/embed_data/CMakeLists.txt

diff --git a/build_tools/embed_data/CMakeLists.txt b/build_tools/embed_data/CMakeLists.txt
index 3f9410e..4efad40 100644
--- a/build_tools/embed_data/CMakeLists.txt
+++ b/build_tools/embed_data/CMakeLists.txt
@@ -13,19 +13,19 @@
 # limitations under the License.
 
 if(CMAKE_CROSSCOMPILING)
-  iree_build_host_executable(generate_cc_embed_data)
+  iree_declare_host_excutable(generate_cc_embed_data)
 else()
   add_executable(generate_cc_embed_data)
-target_sources(generate_cc_embed_data PRIVATE generate_cc_embed_data.cc)
-set_target_properties(generate_cc_embed_data PROPERTIES OUTPUT_NAME generate_cc_embed_data)
+  target_sources(generate_cc_embed_data PRIVATE generate_cc_embed_data.cc)
+  set_target_properties(generate_cc_embed_data PROPERTIES OUTPUT_NAME generate_cc_embed_data)
 
-target_link_libraries(generate_cc_embed_data
-  absl::flags
-  absl::flags_parse
-  absl::strings
-  absl::time
-)
-install(TARGETS generate_cc_embed_data
-        COMPONENT generate_cc_embed_data
-        RUNTIME DESTINATION bin)
+  target_link_libraries(generate_cc_embed_data
+    absl::flags
+    absl::flags_parse
+    absl::strings
+    absl::time
+  )
+  install(TARGETS generate_cc_embed_data
+          COMPONENT generate_cc_embed_data
+          RUNTIME DESTINATION bin)
 endif()

iree/tools/CMakeLists.txt

diff --git a/iree/tools/CMakeLists.txt b/iree/tools/CMakeLists.txt
index 00c9c6e..c881b4c 100644
--- a/iree/tools/CMakeLists.txt
+++ b/iree/tools/CMakeLists.txt
@@ -104,10 +104,6 @@
   )
 endif()
 
-if(CMAKE_CROSSCOMPILING)
-  iree_build_host_executable(iree-tblgen)
-endif()
-
 if(${IREE_BUILD_COMPILER})
   iree_cc_library(
     NAME
@@ -388,12 +384,6 @@
     iree::vm::variant_list
 )
 
-if(CMAKE_CROSSCOMPILING)
-  iree_build_host_executable(iree-opt)
-  iree_build_host_executable(iree-run-mlir)
-  iree_build_host_executable(iree-translate)
-endif()
-
 if(${IREE_ENABLE_LLVM})
   add_custom_target(IreeFileCheck ALL
     COMMAND ${CMAKE_COMMAND} -E create_symlink ${CMAKE_CURRENT_SOURCE_DIR}/IreeFileCheck.sh IreeFileCheck