CMake option to allow enabling experimental new pass manager by default

[phosek]

Summary

This CMake flag allows setting the default value for the -f[no]-experimental-new-pass-manager flag.

[chandlerc]

Just a question really.

clang/CMakeLists.txt

215 ↗

(On Diff #137844)

Does it make sense to put the word DEFAULT into the variable name? I don't feel strongly either way.

[phosek]

clang/CMakeLists.txt

215 ↗

(On Diff #137844)

I was following the ENABLE_X86_RELAX_RELOCATIONS above which is a similar flag in terms of its effect on the driver. Would you prefer ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER_BY_DEFAULT? It's more descriptive but also rather long.

[phosek]

Ping?

[chandlerc]

Meh, I think this is fine as-is.

CMakeLists.txt

 set(DEFAULT_SYSROOT "" CACHE PATH
   "Default <path> to all compiler invocations for --sysroot=<path>." )
 
 set(ENABLE_LINKER_BUILD_ID OFF CACHE BOOL "pass --build-id to ld")
 
 set(ENABLE_X86_RELAX_RELOCATIONS OFF CACHE BOOL
     "enable x86 relax relocations by default")
 
+set(ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER FALSE CACHE BOOL
+  "Enable the experimental new pass manager by default.")
+
 # TODO: verify the values against LangStandards.def?
 set(CLANG_DEFAULT_STD_C "" CACHE STRING
   "Default standard to use for C/ObjC code (IDENT from LangStandards.def, empty for platform default)")
 set(CLANG_DEFAULT_STD_CXX "" CACHE STRING
   "Default standard to use for C++/ObjC++ code (IDENT from LangStandards.def, empty for platform default)")
 
 set(CLANG_DEFAULT_LINKER "" CACHE STRING
   "Default linker to use (linker name or absolute path, empty for platform default)")

include/clang/Config/config.h.cmake

 #cmakedefine HOST_LINK_VERSION "${HOST_LINK_VERSION}"
 
 /* pass --build-id to ld */
 #cmakedefine ENABLE_LINKER_BUILD_ID
 
 /* enable x86 relax relocations by default */
 #cmakedefine01 ENABLE_X86_RELAX_RELOCATIONS
 
+/* Enable the experimental new pass manager by default */
+#cmakedefine01 ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER
+
 /* Enable each functionality of modules */
 #cmakedefine01 CLANG_ENABLE_ARCMT
 #cmakedefine01 CLANG_ENABLE_OBJC_REWRITER
 #cmakedefine01 CLANG_ENABLE_STATIC_ANALYZER
 
 #endif

lib/Driver/ToolChains/CommonArgs.cpp

if (Arg *A = getLastProfileSampleUseArg(Args)) {
     else
       CmdArgs.push_back(
           Args.MakeArgString(Twine("-plugin-opt=sample-profile=") + FName));
   }
 
   // Need this flag to turn on new pass manager via Gold plugin.
   if (Args.hasFlag(options::OPT_fexperimental_new_pass_manager,
                    options::OPT_fno_experimental_new_pass_manager,
-                   /* Default */ false)) {
+                   /* Default */ ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER)) {
     CmdArgs.push_back("-plugin-opt=new-pass-manager");
   }
 
 }
 
 void tools::addArchSpecificRPath(const ToolChain &TC, const ArgList &Args,
                                  ArgStringList &CmdArgs) {
   if (!Args.hasFlag(options::OPT_frtlib_add_rpath,

lib/Frontend/CompilerInvocation.cpp

if (Opts.OptimizationLevel > 0) {
         Opts.setInlining(CodeGenOptions::OnlyHintInlining);
       else
         Opts.setInlining(CodeGenOptions::OnlyAlwaysInlining);
     }
   }
 
   Opts.ExperimentalNewPassManager = Args.hasFlag(
       OPT_fexperimental_new_pass_manager, OPT_fno_experimental_new_pass_manager,
-      /* Default */ false);
+      /* Default */ ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER);
 
   Opts.DebugPassManager =
       Args.hasFlag(OPT_fdebug_pass_manager, OPT_fno_debug_pass_manager,
                    /* Default */ false);
 
   if (Arg *A = Args.getLastArg(OPT_fveclib)) {
     StringRef Name = A->getValue();
     if (Name == "Accelerate")