js78/trunk/0001-Fixes-for-LTO-PGO-support.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: "Jan Alexander Steffens (heftig)" <jan.steffens@gmail.com>
   3 Date: Tue, 17 Nov 2020 22:45:47 +0100
   4 Subject: [PATCH] Fixes for LTO+PGO support
   5
   6 Cherry-picked from Firefox Nightly.
   7 ---
   8  build/moz.configure/lto-pgo.configure |  7 +++++--
   9  config/makefiles/rust.mk              | 21 +++++++++++++++++----
  10  2 files changed, 22 insertions(+), 6 deletions(-)
  11
  12 diff --git a/build/moz.configure/lto-pgo.configure b/build/moz.configure/lto-pgo.configure
  13 index 366c6691f7d1..e5342a037ee9 100644
  14 --- a/build/moz.configure/lto-pgo.configure
  15 +++ b/build/moz.configure/lto-pgo.configure
  16 @@ -229,7 +229,10 @@ def lto(value, c_compiler, ld64_known_good, target, instrumented_build):
  17              # instruction sets.
  18          else:
  19              num_cores = multiprocessing.cpu_count()
  20 -            cflags.append("-flto")
  21 +            if len(value) and value[0].lower() == 'full':
  22 +                cflags.append("-flto")
  23 +            else:
  24 +                cflags.append("-flto=thin")
  25              cflags.append("-flifetime-dse=1")
  26
  27              ldflags.append("-flto=%s" % num_cores)
  28 @@ -258,6 +261,6 @@ set_config('MOZ_LTO', lto.enabled)
  29  set_define('MOZ_LTO', lto.enabled)
  30  set_config('MOZ_LTO_CFLAGS', lto.cflags)
  31  set_config('MOZ_LTO_LDFLAGS', lto.ldflags)
  32 -set_config('MOZ_LTO_RUST', lto.rust_lto)
  33 +set_config('MOZ_LTO_RUST_CROSS', lto.rust_lto)
  34  add_old_configure_assignment('MOZ_LTO_CFLAGS', lto.cflags)
  35  add_old_configure_assignment('MOZ_LTO_LDFLAGS', lto.ldflags)
  36 diff --git a/config/makefiles/rust.mk b/config/makefiles/rust.mk
  37 index f4475054f897..f19dfbc72fad 100644
  38 --- a/config/makefiles/rust.mk
  39 +++ b/config/makefiles/rust.mk
  40 @@ -59,17 +59,19 @@ cargo_rustc_flags = $(CARGO_RUSTCFLAGS)
  41  ifndef DEVELOPER_OPTIONS
  42  ifndef MOZ_DEBUG_RUST
  43  # Enable link-time optimization for release builds, but not when linking
  44 -# gkrust_gtest.
  45 +# gkrust_gtest. And not when doing cross-language LTO.
  46 +ifndef MOZ_LTO_RUST_CROSS
  47  ifeq (,$(findstring gkrust_gtest,$(RUST_LIBRARY_FILE)))
  48  cargo_rustc_flags += -Clto
  49  endif
  50  # Versions of rust >= 1.45 need -Cembed-bitcode=yes for all crates when
  51  # using -Clto.
  52  ifeq (,$(filter 1.38.% 1.39.% 1.40.% 1.41.% 1.42.% 1.43.% 1.44.%,$(RUSTC_VERSION)))
  53  RUSTFLAGS += -Cembed-bitcode=yes
  54  endif
  55  endif
  56  endif
  57 +endif
  58
  59  ifdef CARGO_INCREMENTAL
  60  export CARGO_INCREMENTAL
  61 @@ -195,10 +197,19 @@ target_rust_ltoable := force-cargo-library-build
  62  target_rust_nonltoable := force-cargo-test-run force-cargo-library-check $(foreach b,build check,force-cargo-program-$(b))
  63
  64  ifdef MOZ_PGO_RUST
  65 -rust_pgo_flags := $(if $(MOZ_PROFILE_GENERATE),-C profile-generate=$(topobjdir)) $(if $(MOZ_PROFILE_USE),-C profile-use=$(PGO_PROFILE_PATH))
  66 +ifdef MOZ_PROFILE_GENERATE
  67 +rust_pgo_flags := -C profile-generate=$(topobjdir)
  68 +# The C compiler may be passed extra llvm flags for PGO that we also want to pass to rust as well.
  69 +# In PROFILE_GEN_CFLAGS, they look like "-mllvm foo", and we want "-C llvm-args=foo", so first turn
  70 +# "-mllvm foo" into "-mllvm:foo" so that it becomes a unique argument, that we can then filter for,
  71 +# excluding other flags, and then turn into the right string.
  72 +rust_pgo_flags += $(patsubst -mllvm:%,-C llvm-args=%,$(filter -mllvm:%,$(subst -mllvm ,-mllvm:,$(PROFILE_GEN_CFLAGS))))
  73 +else # MOZ_PROFILE_USE
  74 +rust_pgo_flags := -C profile-use=$(PGO_PROFILE_PATH)
  75 +endif
  76  endif
  77
  78 -$(target_rust_ltoable): RUSTFLAGS:=$(rustflags_override) $(rustflags_sancov) $(RUSTFLAGS) $(if $(MOZ_LTO_RUST),-Clinker-plugin-lto) $(rust_pgo_flags)
  79 +$(target_rust_ltoable): RUSTFLAGS:=$(rustflags_override) $(rustflags_sancov) $(RUSTFLAGS) $(if $(MOZ_LTO_RUST_CROSS),-Clinker-plugin-lto) $(rust_pgo_flags)
  80  $(target_rust_nonltoable): RUSTFLAGS:=$(rustflags_override) $(rustflags_sancov) $(RUSTFLAGS)
  81
  82  TARGET_RECIPES := $(target_rust_ltoable) $(target_rust_nonltoable)
  83 @@ -312,17 +323,19 @@ $(RUST_LIBRARY_FILE): force-cargo-library-build
  84  # When we are building in --enable-release mode; we add an additional check to confirm
  85  # that we are not importing any networking-related functions in rust code. This reduces
  86  # the chance of proxy bypasses originating from rust code.
  87 -# The check only works when rust code is built with -Clto.
  88 +# The check only works when rust code is built with -Clto but without MOZ_LTO_RUST_CROSS.
  89  # Sanitizers and sancov also fail because compiler-rt hooks network functions.
  90  ifndef MOZ_PROFILE_GENERATE
  91  ifeq ($(OS_ARCH), Linux)
  92  ifeq (,$(rustflags_sancov)$(MOZ_ASAN)$(MOZ_TSAN)$(MOZ_UBSAN))
  93 +ifndef MOZ_LTO_RUST_CROSS
  94  ifneq (,$(filter -Clto,$(cargo_rustc_flags)))
  95         $(call py_action,check_binary,--target --networking $@)
  96  endif
  97  endif
  98  endif
  99  endif
 100 +endif
 101
 102  force-cargo-library-check:
 103         $(call CARGO_CHECK) --lib $(cargo_target_flag) $(rust_features_flag)