Backed out changeset 9f805dc435b5 (bug 1839832) as requested by glandium for causing shippable build bustages. CLOSED TREE

build/moz.configure/lto-pgo.configure

@@ -79,16 +79,9 @@ def pgo_profile_path(path, pgo_use, profdata, build_env):
 set_config("PGO_PROFILE_PATH", pgo_profile_path)
 
 
-pgo_temporal = c_compiler.try_compile(
-    flags=["-fprofile-generate", "-mllvm", "-pgo-temporal-instrumentation"],
-    check_msg="whether the C compiler supports temporal instrumentation",
-    when="--enable-profile-generate",
-)
-
-
-@depends(c_compiler, pgo_profile_path, target_is_windows, pgo_temporal)
+@depends(c_compiler, pgo_profile_path, target_is_windows)
 @imports("multiprocessing")
-def pgo_flags(compiler, profdata, target_is_windows, pgo_temporal):
+def pgo_flags(compiler, profdata, target_is_windows):
     if compiler.type == "gcc":
         return namespace(
             gen_cflags=["-fprofile-generate"],
@@ -106,9 +99,6 @@ def pgo_flags(compiler, profdata, target_is_windows, pgo_temporal):
             gen_ldflags = ["-fprofile-generate"]
 
         gen_cflags = [prefix + "-fprofile-generate"]
-        if pgo_temporal:
-            gen_cflags += ["-mllvm", "-pgo-temporal-instrumentation"]
-
         if target_is_windows:
             # native llvm-profdata.exe on Windows can't read profile data
             # if name compression is enabled (which cross-compiling enables

config/makefiles/rust.mk

@@ -269,9 +269,7 @@ endif
 # In PROFILE_GEN_CFLAGS, they look like "-mllvm foo", and we want "-C llvm-args=foo", so first turn
 # "-mllvm foo" into "-mllvm:foo" so that it becomes a unique argument, that we can then filter for,
 # excluding other flags, and then turn into the right string.
-#
-# Remove -mllvm -pgo-temporal-instrumentation as long as it's not supported by rustc.
-rust_pgo_flags += $(patsubst -mllvm:%,-C llvm-args=%,$(filter-out -mllvm:-pgo-temporal-instrumentation,$(filter -mllvm:%,$(subst -mllvm ,-mllvm:,$(PROFILE_GEN_CFLAGS)))))
+rust_pgo_flags += $(patsubst -mllvm:%,-C llvm-args=%,$(filter -mllvm:%,$(subst -mllvm ,-mllvm:,$(PROFILE_GEN_CFLAGS))))
 else # MOZ_PROFILE_USE
 rust_pgo_flags := -C profile-use=$(PGO_PROFILE_PATH)
 endif