build: use `find_package(Python3)` if available

This is primarily motivated by the desire to move from Python2 to
Python3.  `PYTHON_EXECUTABLE` is ambiguous.  This explicitly identifies
the python interpreter in use.  Since the LLVM build seems to be able to
completed successfully with python3, use that across the build.  The old
path aliases `PYTHON_EXECUTABLE` to be treated as Python3.

3 files changed, 6 insertions, 6 deletions

diff --git a/clang/utils/perf-training/CMakeLists.txt b/clang/utils/perf-training/CMakeLists.txt
index 1f86122..172076f 100644
--- a/clang/utils/perf-training/CMakeLists.txt
+++ b/clang/utils/perf-training/CMakeLists.txt
@@ -23,7 +23,7 @@ if(LLVM_BUILD_INSTRUMENTED)
     )
 
   add_custom_target(clear-profraw
-    COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py clean ${CMAKE_CURRENT_BINARY_DIR} profraw
+    COMMAND "${Python3_EXECUTABLE}" ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py clean ${CMAKE_CURRENT_BINARY_DIR} profraw
     COMMENT "Clearing old profraw data")
 
   if(NOT LLVM_PROFDATA)
@@ -34,7 +34,7 @@ if(LLVM_BUILD_INSTRUMENTED)
     message(STATUS "To enable merging PGO data LLVM_PROFDATA has to point to llvm-profdata")
   else()
     add_custom_target(generate-profdata
-      COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py merge ${LLVM_PROFDATA} ${CMAKE_CURRENT_BINARY_DIR}/clang.profdata ${CMAKE_CURRENT_BINARY_DIR}
+      COMMAND "${Python3_EXECUTABLE}" ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py merge ${LLVM_PROFDATA} ${CMAKE_CURRENT_BINARY_DIR}/clang.profdata ${CMAKE_CURRENT_BINARY_DIR}
       COMMENT "Merging profdata"
       DEPENDS generate-profraw)
   endif()
@@ -55,7 +55,7 @@ if(APPLE AND DTRACE)
     )
 
   add_custom_target(clear-dtrace-logs
-    COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py clean ${CMAKE_CURRENT_BINARY_DIR} dtrace
+    COMMAND "${Python3_EXECUTABLE}" ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py clean ${CMAKE_CURRENT_BINARY_DIR} dtrace
     COMMENT "Clearing old dtrace data")
 
   if(NOT CLANG_ORDER_FILE)
@@ -63,7 +63,7 @@ if(APPLE AND DTRACE)
   endif()
 
   add_custom_target(generate-order-file
-    COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py gen-order-file --binary $<TARGET_FILE:clang> --output ${CLANG_ORDER_FILE} ${CMAKE_CURRENT_BINARY_DIR}
+    COMMAND "${Python3_EXECUTABLE}" ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py gen-order-file --binary $<TARGET_FILE:clang> --output ${CLANG_ORDER_FILE} ${CMAKE_CURRENT_BINARY_DIR}
     COMMENT "Generating order file"
     DEPENDS generate-dtrace-logs)
 endif()
diff --git a/clang/utils/perf-training/lit.site.cfg.in b/clang/utils/perf-training/lit.site.cfg.in
index 340a0e9..a1c6d6b 100644
--- a/clang/utils/perf-training/lit.site.cfg.in
+++ b/clang/utils/perf-training/lit.site.cfg.in
@@ -7,7 +7,7 @@ config.perf_helper_dir = "@CMAKE_CURRENT_SOURCE_DIR@"
 config.test_exec_root = "@CMAKE_CURRENT_BINARY_DIR@"
 config.test_source_root = "@CLANG_PGO_TRAINING_DATA@"
 config.target_triple = "@TARGET_TRIPLE@"
-config.python_exe = "@PYTHON_EXECUTABLE@"
+config.python_exe = "@Python3_EXECUTABLE@"
 
 # Support substitution of the tools and libs dirs with user parameters. This is
 # used when we can't determine the tool dir at configuration time.
diff --git a/clang/utils/perf-training/order-files.lit.site.cfg.in b/clang/utils/perf-training/order-files.lit.site.cfg.in
index 87406db..91f2b79 100644
--- a/clang/utils/perf-training/order-files.lit.site.cfg.in
+++ b/clang/utils/perf-training/order-files.lit.site.cfg.in
@@ -7,7 +7,7 @@ config.perf_helper_dir = "@CMAKE_CURRENT_SOURCE_DIR@"
 config.test_exec_root = "@CMAKE_CURRENT_BINARY_DIR@"
 config.test_source_root = "@CLANG_PGO_TRAINING_DATA@"
 config.target_triple = "@TARGET_TRIPLE@"
-config.python_exe = "@PYTHON_EXECUTABLE@"
+config.python_exe = "@Python3_EXECUTABLE@"
 
 # Support substitution of the tools and libs dirs with user parameters. This is
 # used when we can't determine the tool dir at configuration time.