chromium-116-compiler.patch

From 307a0f63dd9b118f4b8470ed3d7567e81fdb7a6d Mon Sep 17 00:00:00 2001
From: Mike Gilbert <floppym@gentoo.org>
Date: Thu, 15 Jun 2023 14:56:36 +0000
Subject: [PATCH] Disable various compiler configs

---
 build/config/compiler/BUILD.gn | 166 ++++-----------------------------
 1 file changed, 17 insertions(+), 149 deletions(-)

diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index d751ddb..6853f62 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -303,9 +303,6 @@ config("compiler") {
 
   configs += [
     # See the definitions below.
-    ":clang_revision",
-    ":rustc_revision",
-    ":compiler_cpu_abi",
     ":compiler_codegen",
     ":compiler_deterministic",
   ]
@@ -575,37 +572,6 @@ config("compiler") {
     ldflags += [ "-Wl,-z,keep-text-section-prefix" ]
   }
 
-  if (is_clang && !is_nacl && current_os != "zos") {
-    cflags += [ "-fcrash-diagnostics-dir=" + clang_diagnostic_dir ]
-    if (save_reproducers_on_lld_crash && use_lld) {
-      ldflags += [
-        "-fcrash-diagnostics=all",
-        "-fcrash-diagnostics-dir=" + clang_diagnostic_dir,
-      ]
-    }
-
-    # TODO(hans): Remove this once Clang generates better optimized debug info
-    # by default. https://crbug.com/765793
-    cflags += [
-      "-mllvm",
-      "-instcombine-lower-dbg-declare=0",
-    ]
-    if (!is_debug && use_thin_lto && is_a_target_toolchain) {
-      if (is_win) {
-        ldflags += [ "-mllvm:-instcombine-lower-dbg-declare=0" ]
-      } else {
-        ldflags += [ "-Wl,-mllvm,-instcombine-lower-dbg-declare=0" ]
-      }
-    }
-
-    # TODO(crbug.com/1235145): Investigate why/if this should be needed.
-    if (is_win) {
-      cflags += [ "/clang:-ffp-contract=off" ]
-    } else {
-      cflags += [ "-ffp-contract=off" ]
-    }
-  }
-
   # C11/C++11 compiler flags setup.
   # ---------------------------
   if (is_linux || is_chromeos || is_android || (is_nacl && is_clang) ||
@@ -759,14 +725,6 @@ config("compiler") {
       }
 
       ldflags += [ "-Wl,-mllvm,-import-instr-limit=$import_instr_limit" ]
-
-      if (!is_chromeos) {
-        # TODO(https://crbug.com/972449): turn on for ChromeOS when that
-        # toolchain has this flag.
-        # We only use one version of LLVM within a build so there's no need to
-        # upgrade debug info, which can be expensive since it runs the verifier.
-        ldflags += [ "-Wl,-mllvm,-disable-auto-upgrade-debug-info" ]
-      }
     }
 
     # TODO(https://crbug.com/1211155): investigate why this isn't effective on
@@ -968,17 +926,6 @@ config("compiler") {
     # `-nodefaultlibs` from the linker invocation from Rust, which would be used
     # to compile dylibs on Android, such as for constructing unit test APKs.
     "-Cdefault-linker-libraries",
-
-    # To make Rust .d files compatible with ninja
-    "-Zdep-info-omit-d-target",
-
-    # If a macro panics during compilation, show which macro and where it is
-    # defined.
-    "-Zmacro-backtrace",
-
-    # For deterministic builds, keep the local machine's current working
-    # directory from appearing in build outputs.
-    "-Zremap-cwd-prefix=.",
   ]
 
   if (!is_win || force_rustc_color_output) {
@@ -1452,46 +1399,6 @@ config("compiler_deterministic") {
     }
   }
 
-  # Makes builds independent of absolute file path.
-  if (is_clang && strip_absolute_paths_from_debug_symbols) {
-    # If debug option is given, clang includes $cwd in debug info by default.
-    # For such build, this flag generates reproducible obj files even we use
-    # different build directory like "out/feature_a" and "out/feature_b" if
-    # we build same files with same compile flag.
-    # Other paths are already given in relative, no need to normalize them.
-    if (is_nacl) {
-      # TODO(https://crbug.com/1231236): Use -ffile-compilation-dir= here.
-      cflags += [
-        "-Xclang",
-        "-fdebug-compilation-dir",
-        "-Xclang",
-        ".",
-      ]
-    } else {
-      # -ffile-compilation-dir is an alias for both -fdebug-compilation-dir=
-      # and -fcoverage-compilation-dir=.
-      cflags += [ "-ffile-compilation-dir=." ]
-      swiftflags += [ "-file-compilation-dir=." ]
-    }
-    if (!is_win) {
-      # We don't use clang -cc1as on Windows (yet? https://crbug.com/762167)
-      asmflags = [ "-Wa,-fdebug-compilation-dir,." ]
-    }
-
-    if (is_win && use_lld) {
-      if (symbol_level == 2 || (is_clang && using_sanitizer)) {
-        # Absolutize source file paths for PDB. Pass the real build directory
-        # if the pdb contains source-level debug information and if linker
-        # reproducibility is not critical.
-        ldflags += [ "/PDBSourcePath:" + rebase_path(root_build_dir) ]
-      } else {
-        # Use a fake fixed base directory for paths in the pdb to make the pdb
-        # output fully deterministic and independent of the build directory.
-        ldflags += [ "/PDBSourcePath:o:\fake\prefix" ]
-      }
-    }
-  }
-
   # Tells the compiler not to use absolute paths when passing the default
   # paths to the tools it invokes. We don't want this because we don't
   # really need it and it can mess up the goma cache entries.
@@ -1510,39 +1417,6 @@ config("compiler_deterministic") {
   }
 }
 
-config("clang_revision") {
-  if (is_clang && clang_base_path == default_clang_base_path) {
-    update_args = [
-      "--print-revision",
-      "--verify-version=$clang_version",
-    ]
-    if (llvm_force_head_revision) {
-      update_args += [ "--llvm-force-head-revision" ]
-    }
-    clang_revision = exec_script("//tools/clang/scripts/update.py",
-                                 update_args,
-                                 "trim string")
-
-    # This is here so that all files get recompiled after a clang roll and
-    # when turning clang on or off. (defines are passed via the command line,
-    # and build system rebuild things when their commandline changes). Nothing
-    # should ever read this define.
-    defines = [ "CR_CLANG_REVISION=\"$clang_revision\"" ]
-  }
-}
-
-config("rustc_revision") {
-  if (rustc_revision != "") {
-    # Similar to the above config, this is here so that all files get recompiled
-    # after a rustc roll. Nothing should ever read this cfg. This will not be
-    # set if a custom toolchain is used.
-    rustflags = [
-      "--cfg",
-      "cr_rustc_revision=\"$rustc_revision\"",
-    ]
-  }
-}
-
 config("compiler_arm_fpu") {
   if (current_cpu == "arm" && !is_ios && !is_nacl) {
     cflags = [ "-mfpu=$arm_fpu" ]
@@ -1842,7 +1716,7 @@ config("chromium_code") {
       defines = [ "_HAS_NODISCARD" ]
     }
   } else {
-    cflags = [ "-Wall" ]
+    cflags = []
     if (treat_warnings_as_errors) {
       cflags += [ "-Werror" ]
 
@@ -1851,10 +1725,6 @@ config("chromium_code") {
       # well.
       ldflags = [ "-Werror" ]
     }
-    if (is_clang) {
-      # Enable extra warnings for chromium_code when we control the compiler.
-      cflags += [ "-Wextra" ]
-    }
 
     if (treat_warnings_as_errors) {
       # Turn rustc warnings into the "deny" lint level, which produce compiler
@@ -1872,16 +1742,6 @@ config("chromium_code") {
       "__STDC_FORMAT_MACROS",
     ]
 
-    if (!is_debug && !using_sanitizer && current_cpu != "s390x" &&
-        current_cpu != "s390" && current_cpu != "ppc64" &&
-        current_cpu != "mips" && current_cpu != "mips64" &&
-        current_cpu != "riscv64" && current_cpu != "loong64") {
-      # Non-chromium code is not guaranteed to compile cleanly with
-      # _FORTIFY_SOURCE. Also, fortified build may fail when optimizations are
-      # disabled, so only do that for Release build.
-      defines += [ "_FORTIFY_SOURCE=2" ]
-    }
-
     if (is_apple) {
       cflags_objc = [ "-Wimplicit-retain-self" ]
       cflags_objcc = [ "-Wimplicit-retain-self" ]
@@ -2246,7 +2106,8 @@ config("default_stack_frames") {
 }
 
 # Default "optimization on" config.
-config("optimize") {
+config("optimize") { }
+config("xoptimize") {
   if (is_win) {
     if (chrome_pgo_phase != 2) {
       # Favor size over speed, /O1 must be before the common flags.
@@ -2305,7 +2166,8 @@ config("optimize") {
 }
 
 # Turn off optimizations.
-config("no_optimize") {
+config("no_optimize") { }
+config("xno_optimize") {
   if (is_win) {
     cflags = [
       "/Od",  # Disable optimization.
@@ -2345,7 +2207,8 @@ config("no_optimize") {
 # Turns up the optimization level. On Windows, this implies whole program
 # optimization and link-time code generation which is very expensive and should
 # be used sparingly.
-config("optimize_max") {
+config("optimize_max") { }
+config("xoptimize_max") {
   if (is_nacl && is_nacl_irt) {
     # The NaCl IRT is a special case and always wants its own config.
     # Various components do:
@@ -2378,7 +2241,8 @@ config("optimize_max") {
 #
 # TODO(crbug.com/621335) - rework how all of these configs are related
 # so that we don't need this disclaimer.
-config("optimize_speed") {
+config("optimize_speed") { }
+config("xoptimize_speed") {
   if (is_nacl && is_nacl_irt) {
     # The NaCl IRT is a special case and always wants its own config.
     # Various components do:
@@ -2404,7 +2268,8 @@ config("optimize_speed") {
   }
 }
 
-config("optimize_fuzzing") {
+config("optimize_fuzzing") { }
+config("xoptimize_fuzzing") {
   cflags = [ "-O1" ] + common_optimize_on_cflags
   rustflags = [ "-Copt-level=1" ]
   ldflags = common_optimize_on_ldflags
@@ -2529,7 +2394,8 @@ config("win_pdbaltpath") {
 }
 
 # Full symbols.
-config("symbols") {
+config("symbols") { }
+config("xsymbols") {
   rustflags = []
   if (is_win) {
     if (is_clang) {
@@ -2672,7 +2538,8 @@ config("symbols") {
 # Minimal symbols.
 # This config guarantees to hold symbol for stack trace which are shown to user
 # when crash happens in unittests running on buildbot.
-config("minimal_symbols") {
+config("minimal_symbols") { }
+config("xminimal_symbols") {
   rustflags = []
   if (is_win) {
     # Functions, files, and line tables only.
@@ -2757,7 +2624,8 @@ config("minimal_symbols") {
 # This configuration contains function names only. That is, the compiler is
 # told to not generate debug information and the linker then just puts function
 # names in the final debug information.
-config("no_symbols") {
+config("no_symbols") { }
+config("xno_symbols") {
   if (is_win) {
     ldflags = [ "/DEBUG" ]
 
-- 
2.39.3