[CMake] Support generation of linker order files using dtrace

Summary:
This patch extends the lit-based perf-training tooling supplied for PGO data generation to also generate linker order files using dtrace.

This patch should work on any system that has dtrace. If CMake can find the dtrace tool it will generate a target 'generate-order-file' which will run the per-training tests wrapped by dtrace to capture function entries. There are several algorithms implemented for sorting the order files which can be experimented with for best performance. The dtrace wrapper also supports bot oneshot and pid probes.

The perf-helper.py changes to support order file construction are ported from internal changes by ddunbar; he gets all the credit for the hard work here, I just copy and pasted.

Note: I've tested these patches on FreeBSD and OS X 10.10.

Reviewers: ddunbar, bogner, silvas

Subscribers: llvm-commits, emaste

Differential Revision: http://reviews.llvm.org/D16134

llvm-svn: 257934

Author: Chris Bieneman

clang/utils/perf-training/CMakeLists.txt

@@ -1,24 +1,24 @@
-if(LLVM_BUILD_INSTRUMENTED)
-  if (CMAKE_CFG_INTDIR STREQUAL ".")
-    set(LLVM_BUILD_MODE ".")
-  else ()
-    set(LLVM_BUILD_MODE "%(build_mode)s")
-  endif ()
+if (CMAKE_CFG_INTDIR STREQUAL ".")
+  set(LLVM_BUILD_MODE ".")
+else ()
+  set(LLVM_BUILD_MODE "%(build_mode)s")
+endif ()
 
-  string(REPLACE ${CMAKE_CFG_INTDIR} ${LLVM_BUILD_MODE} CLANG_TOOLS_DIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
+string(REPLACE ${CMAKE_CFG_INTDIR} ${LLVM_BUILD_MODE} CLANG_TOOLS_DIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
 
+if(LLVM_BUILD_INSTRUMENTED)
   configure_lit_site_cfg(
     ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
-    ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg
+    ${CMAKE_CURRENT_BINARY_DIR}/pgo-data/lit.site.cfg
     )
 
   add_lit_testsuite(generate-profraw "Generating clang PGO data"
-    ${CMAKE_CURRENT_BINARY_DIR}
+    ${CMAKE_CURRENT_BINARY_DIR}/pgo-data/
     DEPENDS clang clear-profraw
     )
 
   add_custom_target(clear-profraw
-    COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py clean ${CMAKE_CURRENT_BINARY_DIR}
+    COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py clean ${CMAKE_CURRENT_BINARY_DIR} profraw
     COMMENT "Clearing old profraw data")
 
   if(NOT LLVM_PROFDATA)
@@ -34,3 +34,26 @@ if(LLVM_BUILD_INSTRUMENTED)
     COMMENT "Merging profdata"
     DEPENDS generate-profraw)
 endif()
+
+find_program(DTRACE dtrace)
+if(DTRACE)
+  configure_lit_site_cfg(
+    ${CMAKE_CURRENT_SOURCE_DIR}/order-files.lit.site.cfg.in
+    ${CMAKE_CURRENT_BINARY_DIR}/order-files/lit.site.cfg
+    )
+
+  add_lit_testsuite(generate-dtrace-logs "Generating clang dtrace data"
+    ${CMAKE_CURRENT_BINARY_DIR}/order-files/
+    DEPENDS clang clear-dtrace-logs
+    )
+
+  add_custom_target(clear-dtrace-logs
+    COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py clean ${CMAKE_CURRENT_BINARY_DIR} dtrace
+    COMMENT "Clearing old dtrace data")
+
+
+  add_custom_target(generate-order-file
+    COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/perf-helper.py gen-order-file --binary $<TARGET_FILE:clang> --output ${CMAKE_CURRENT_BINARY_DIR}/clang.order ${CMAKE_CURRENT_BINARY_DIR}
+    COMMENT "Generating order file"
+    DEPENDS generate-dtrace-logs)
+endif()

clang/utils/perf-training/order-files.lit.cfg

@@ -0,0 +1,39 @@
+# -*- Python -*-
+
+from lit import Test
+import lit.formats
+import lit.util
+import os
+
+def getSysrootFlagsOnDarwin(config, lit_config):
+    # On Darwin, support relocatable SDKs by providing Clang with a
+    # default system root path.
+    if 'darwin' in config.target_triple:
+        try:
+            out = lit.util.capture(['xcrun', '--show-sdk-path']).strip()
+            res = 0
+        except OSError:
+            res = -1
+        if res == 0 and out:
+            sdk_path = out
+            lit_config.note('using SDKROOT: %r' % sdk_path)
+            return '-isysroot %s' % sdk_path
+    return ''
+
+sysroot_flags = getSysrootFlagsOnDarwin(config, lit_config)
+
+config.clang = os.path.realpath(lit.util.which('clang', config.clang_tools_dir)).replace('\\', '/')
+
+config.name = 'Clang Perf Training'
+config.suffixes = ['.c', '.cpp', '.m', '.mm', '.cu', '.ll', '.cl', '.s', '.S', '.modulemap']
+
+dtrace_wrapper = '%s %s/perf-helper.py dtrace' % (config.python_exe, config.test_source_root)
+
+use_lit_shell = os.environ.get("LIT_USE_INTERNAL_SHELL")
+config.test_format = lit.formats.ShTest(use_lit_shell == "0")
+config.substitutions.append( ('%clang_cpp', ' %s %s --driver-mode=cpp %s ' % (dtrace_wrapper, config.clang, sysroot_flags)))
+config.substitutions.append( ('%clang_cc1', ' %s %s -cc1 %s ' % (dtrace_wrapper, config.clang, sysroot_flags)))
+config.substitutions.append( ('%clang', ' %s %s %s ' % (dtrace_wrapper, config.clang, sysroot_flags) ) )
+config.substitutions.append( ('%test_root', config.test_exec_root ) )
+
+

clang/utils/perf-training/order-files.lit.site.cfg.in

@@ -0,0 +1,21 @@
+import sys
+
+## Autogenerated by LLVM/Clang configuration.
+# Do not edit!
+config.clang_tools_dir = "@CLANG_TOOLS_DIR@"
+config.test_exec_root = "@CMAKE_CURRENT_BINARY_DIR@"
+config.test_source_root = "@CMAKE_CURRENT_SOURCE_DIR@"
+config.target_triple = "@TARGET_TRIPLE@"
+config.python_exe = "@PYTHON_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.
+try:
+    config.clang_tools_dir = config.clang_tools_dir % lit_config.params
+except KeyError:
+    e = sys.exc_info()[1]
+    key, = e.args
+    lit_config.fatal("unable to find %r parameter, use '--param=%s=VALUE'" % (key,key))
+
+# Let the main config do the real work.
+lit_config.load_config(config, "@CLANG_SOURCE_DIR@/utils/perf-training/order-files.lit.cfg")