[BOLT] Combine two clang-bolt builders into one

Use BOLT.cmake and BOLT-PGO.cmake to run comprehensive
BOLT testing with Clang:
- `clang-bolt` instruments and optimizes 1st stage Clang built
with host GCC.
- `stage2-clang-bolt` uses optimized Clang to build 2nd stage
Clang (with PGO+LTO), then instruments/optimizes that binary.

This flow provides testing coverage of both clang-bolt-gcc
and clang-bolt-lto-pgo. BOLT is applied to GCC- and Clang-built
clang binary. Additionally, this extends BOLT testing by running
BOLT-optimized Clang to build 2nd stage Clang.

Reviewed By: gkistanova

Differential Revision: https://reviews.llvm.org/D142854

buildbot/osuosl/master/config/builders.py

@@ -2510,42 +2510,28 @@
                     is_nfc=True,
                     )},
 
-    {'name': "bolt-x86_64-ubuntu-clang-bolt-gcc",
+    {'name': "bolt-x86_64-ubuntu-clang",
     'tags': ["bolt"],
     'workernames':["bolt-worker"],
-    'builddir': "bolt-x86_64-ubuntu-clang-bolt-gcc",
+    'builddir': "bolt-x86_64-ubuntu-clang",
     'factory' : BOLTBuilder.getBOLTCmakeBuildFactory(
                     bolttests=False,
                     clean=True,
-                    depends_on_projects=['bolt', 'clang', 'llvm'],
-                    cache='clang/cmake/caches/BOLT.cmake',
+                    depends_on_projects=['bolt', 'clang', 'lld', 'llvm'],
+                    caches=[
+                        'clang/cmake/caches/BOLT.cmake',
+                        'clang/cmake/caches/BOLT-PGO.cmake',
+                    ],
                     targets=['clang-bolt'],
+                    checks=['stage2-clang-bolt'],
                     extra_configure_args=[
                         "-DCMAKE_C_COMPILER=gcc",
                         "-DCMAKE_CXX_COMPILER=g++",
                         "-DLLVM_APPEND_VC_REV=OFF",
                         "-DLLVM_CCACHE_BUILD=ON",
-                        "-DBOLT_LLD_EXE=/usr/bin/ld.lld",
-                        ],
-                    )},
-
-
-    {'name': "bolt-x86_64-ubuntu-clang-bolt-lto-pgo",
-    'tags': ["bolt"],
-    'workernames':["bolt-worker"],
-    'builddir': "bolt-x86_64-ubuntu-clang-bolt-lto-pgo",
-    'factory' : BOLTBuilder.getBOLTCmakeBuildFactory(
-                    bolttests=False,
-                    clean=True,
-                    depends_on_projects=['bolt', 'clang', 'lld', 'llvm'],
-                    cache='clang/cmake/caches/BOLT-PGO.cmake',
-                    targets=['stage2-clang-bolt'],
-                    extra_configure_args=[
-                        "-DLLVM_APPEND_VC_REV=OFF",
                         "-DLLVM_ENABLE_LLD=ON",
                         "-DBOOTSTRAP_LLVM_ENABLE_LLD=ON",
                         "-DBOOTSTRAP_BOOTSTRAP_LLVM_ENABLE_LLD=ON",
-                        "-DLLVM_CCACHE_BUILD=ON",
                         "-DBOOTSTRAP_LLVM_CCACHE_BUILD=ON",
                         "-DPGO_INSTRUMENT_LTO=Thin",
                         ],

zorg/buildbot/builders/BOLTBuilder.py

@@ -12,7 +12,7 @@ def getBOLTCmakeBuildFactory(
            is_nfc = False,
            targets = None,
            checks = None,
-           cache = None,
+           caches = None,
            extra_configure_args = None,
            env = None,
            depends_on_projects = None,
@@ -63,10 +63,9 @@ def getBOLTCmakeBuildFactory(
         ('-G',                      'Ninja'),
         ])
 
-    if cache:
-        CmakeCommand.applyRequiredOptions(extra_configure_args, [
-            ("-C", f"../{f.monorepo_dir}/{cache}"),
-            ])
+    if caches:
+        for cache in caches:
+            extra_configure_args += [f"-C../{f.monorepo_dir}/{cache}"]
 
     addCmakeSteps(
         f,