[PATCH] D28077: [PM] Introduce options to enable the (still experimental) new pass manager, and a code path to use it.

[Mehdi AMINI via Phabricator via cfe-commits]

mehdi_amini accepted this revision.
mehdi_amini added a comment.
This revision is now accepted and ready to land.

LGTM! Exciting to see the new PM arriving in clang :)



================
Comment at: lib/CodeGen/BackendUtil.cpp:757
+  setCommandLineOpts();
+  cl::PrintOptionValues();
+
----------------
This is different from the legacy path, why?


================
Comment at: lib/CodeGen/BackendUtil.cpp:762
+  CreateTargetMachine(/*MustCreateTM*/ true);
+  TheModule->setDataLayout(TM->createDataLayout());
+
----------------
The legacy path accounts for the possibility of failing to create the TM

```
  CreateTargetMachine(UsesCodeGen);

  if (UsesCodeGen && !TM)
    return;
```


================
Comment at: lib/CodeGen/BackendUtil.cpp:831
+  // Now that we have all of the passes ready, run them.
+  MPM.run(*TheModule, MAM);
+
----------------
No need to wrap in a block with a `PrettyStackTraceString` like the legacy PM?


================
Comment at: test/Driver/clang_f_opts.c:475
+// RUN: %clang -### -fexperimental-new-pass-manager -fno-experimental-new-pass-manager %s 2>&1 | FileCheck --check-prefix=CHECK --check-prefix=CHECK-NO-NEW-PM %s
+// CHECK-NOT: argument unused
+// CHECK-NEW-PM: -fexperimental-new-pass-manager
----------------
Not critical, but using the "CHECK" prefix isn't nice in a file intended to be shared for multiple tests.


https://reviews.llvm.org/D28077