update main BUILD.gns

arm/build/config/compiler/BUILD.gn

@@ -1,4 +1,4 @@
-# Copyright 2023 The Chromium Authors and Alex313031
+# Copyright 2024 The Chromium Authors and Alex313031
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -19,6 +19,7 @@ import("//build/config/rust.gni")
 import("//build/config/ui.gni")
 import("//build/config/unwind.gni")
 import("//build/toolchain/cc_wrapper.gni")
+import("//build/toolchain/cros/cros_config.gni")
 import("//build/toolchain/goma.gni")
 import("//build/toolchain/rbe.gni")
 import("//build/toolchain/toolchain.gni")
@@ -74,6 +75,9 @@ declare_args() {
   # Whether to enable LLVM's Polly optimizations. See https://polly.llvm.org/
   use_polly = false
 
+  # Whether to use Raspberry Pi specific optimizations.
+  is_raspi = false
+
   # Enable fatal linker warnings. Building Chromium with certain versions
   # of binutils can cause linker warning.
   fatal_linker_warnings = true
@@ -135,6 +139,11 @@ declare_args() {
       (is_chromeos || is_android || is_win || is_linux || is_mac ||
        (is_ios && use_lld)) && is_official_build
 
+  # Whether to enable thin lto incremental builds.
+  # See: https://clang.llvm.org/docs/ThinLTO.html#incremental
+  # The cache can lead to non-determinism: https://crbug.com/1486045
+  thin_lto_enable_cache = false
+
   # Initialize all local variables with a pattern. This flag will fill
   # uninitialized floating-point types (and 32-bit pointers) with 0xFF and the
   # rest with 0xAA. This makes behavior of uninitialized memory bugs consistent,
@@ -489,6 +498,11 @@ config("compiler") {
       asmflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
       cflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
     }
+
+    # dsymutil is not available in the system, on bots, for rustc to call. Our
+    # linker_driver.py script runs dsymutil itself, which is set to be the
+    # linker for Rust targets as well.
+    rustflags += [ "-Csplit-debuginfo=unpacked" ]
   }
 
   # Linux/Android/Fuchsia common flags setup.
@@ -619,6 +633,24 @@ config("compiler") {
       }
     }
 
+    # TODO(crbug.com/1488374): This causes binary size growth and potentially
+    # other problems.
+    # TODO(crbug.com/1491036): This isn't supported by Cronet's mainline llvm version.
+    if (default_toolchain != "//build/toolchain/cros:target" &&
+        !llvm_android_mainline) {
+      cflags += [
+        "-mllvm",
+        "-split-threshold-for-reg-with-hint=0",
+      ]
+      if (use_thin_lto && is_a_target_toolchain) {
+        if (is_win) {
+          ldflags += [ "-mllvm:-split-threshold-for-reg-with-hint=0" ]
+        } else {
+          ldflags += [ "-Wl,-mllvm,-split-threshold-for-reg-with-hint=0" ]
+        }
+      }
+    }
+
     # TODO(crbug.com/1235145): Investigate why/if this should be needed.
     if (is_win) {
       cflags += [ "/clang:-ffp-contract=fast" ]
@@ -675,8 +707,7 @@ config("compiler") {
     }
   } else if (is_win) {
     cflags_c += [ "/std:c11" ]
-    if ((defined(use_cxx17) && use_cxx17) ||
+    if (defined(use_cxx17) && use_cxx17) {
-        (!is_clang && defined(msvc_use_cxx17) && msvc_use_cxx17)) {
       cflags_cc += [ "/std:c++17" ]
     } else {
       cflags_cc += [ "/std:c++20" ]
@@ -723,9 +754,26 @@ config("compiler") {
       "-fsplit-lto-unit",
     ]
 
+    if (thin_lto_enable_cache) {
       # Limit the size of the ThinLTO cache to the lesser of 10% of
       # available disk space, 40GB and 100000 files.
-    # cache_policy = "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_policy =
+          "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_dir = rebase_path("$root_out_dir/thinlto-cache", root_build_dir)
+      if (is_win) {
+        ldflags += [
+          "/lldltocache:$cache_dir",
+          "/lldltocachepolicy:$cache_policy",
+        ]
+      } else {
+        if (is_apple) {
+          ldflags += [ "-Wl,-cache_path_lto,$cache_dir" ]
+        } else {
+          ldflags += [ "-Wl,--thinlto-cache-dir=$cache_dir" ]
+        }
+        ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
+      }
+    }
 
     # An import limit of 30 has better performance (per speedometer) and lower
     # binary size than the default setting of 100.
@@ -740,9 +788,6 @@ config("compiler") {
         "-mllvm:-import-hot-multiplier=15",
         "-mllvm:-import-cold-multiplier=2",
         "-mllvm:-disable-auto-upgrade-debug-info",
-        # "/lldltocache:" +
-        #    rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-        # "/lldltocachepolicy:$cache_policy",
       ]
     } else {
       ldflags += [ "-flto=thin" ]
@@ -756,18 +801,6 @@ config("compiler") {
       # TODO(thakis): Check if '=0' (that is, number of cores, instead
       # of "all" which means number of hardware threads) is faster.
       ldflags += [ "-Wl,--thinlto-jobs=all" ]
-      if (is_apple) {
-        ldflags += [
-          "-Wl,-cache_path_lto," +
-              rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-          "-Wcrl,object_path_lto",
-        ]
-      } else {
-        ldflags +=
-            [ "-Wl,-O3" ]
-      }
-
-      # ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
 
       if (is_chromeos) {
         # ARM was originally set lower than x86 to keep the size
@@ -783,6 +816,10 @@ config("compiler") {
 
       ldflags += [ "-Wl,-mllvm,-import-instr-limit=$import_instr_limit" ]
 
+      if (is_apple) {
+        ldflags += [ "-Wcrl,object_path_lto" ]
+      }
+
       if (!is_chromeos) {
         # TODO(https://crbug.com/972449): turn on for ChromeOS when that
         # toolchain has this flag.
@@ -832,6 +869,9 @@ config("compiler") {
   if (compiler_timing) {
     if (is_clang && !is_nacl) {
       cflags += [ "-ftime-trace" ]
+      if (use_lld && is_mac) {
+        ldflags += [ "-Wl,--time-trace" ]
+      }
     } else if (is_win) {
       cflags += [
         # "Documented" here:
@@ -1145,11 +1185,16 @@ config("compiler_cpu_abi") {
       cflags += [
         "-m64",
         "-O3",
+        "-msse3",
+        "-mssse3",
+        "-msse4",
+        "-msse4.1",
+        "-msse4.2",
         "-mavx",
         "-maes",
         "-mpclmul",
       ]
-      ldflags += [ "-m64", "-Wl,-O3", "-mavx", "-maes", "-mpclmul", "-Wl,-mllvm,-import-instr-limit=30", "-Wl,-mllvm,-import-hot-multiplier=15", "-Wl,-mllvm,-import-cold-multiplier=2", ]
+      ldflags += [ "-m64", "-Wl,-O3", "-msse3", "-mssse3", "-msse4", "-msse4.1", "-msse4.2", "-mavx", "-maes", "-mpclmul", "-Wl,-mllvm,-import-instr-limit=30", "-Wl,-mllvm,-import-hot-multiplier=15", "-Wl,-mllvm,-import-cold-multiplier=2", ]
     } else if (current_cpu == "x86") {
       cflags += [ "-m32" ]
       ldflags += [ "-m32", "-Wl,-O3", "-msse3", ]
@@ -1858,14 +1903,6 @@ config("default_warnings") {
         "-Wno-ignored-pragma-optimize",
       ]
 
-      if (llvm_force_head_revision && !is_nacl && enable_precompiled_headers &&
-          !is_win) {
-        cflags += [
-          # TODO(crbug.com/1486799) Find a long-term solution.
-          "-Wno-deprecated-include-gch",
-        ]
-      }
-
       if (!is_nacl) {
         cflags += [
           # TODO(crbug.com/1343975) Evaluate and possibly enable.
@@ -1876,6 +1913,18 @@ config("default_warnings") {
 
           # TODO(crbug.com/1412713) Evaluate and possibly enable.
           "-Wno-deprecated-this-capture",
+
+          # TODO(https://crbug.com/1491833): Fix and re-enable.
+          "-Wno-invalid-offsetof",
+
+          # TODO(crbug.com/1494809): Evaluate and possibly enable.
+          "-Wno-vla-extension",
+
+          # TODO(https://crbug.com/1490607): Fix and re-enable.
+          "-Wno-thread-safety-reference-return",
+
+          # TODO(crbug.com/1495100): Evaluate and possibly enable.
+          "-Wno-delayed-template-parsing-in-cxx20",
         ]
       }
     }
@@ -1976,9 +2025,10 @@ config("chromium_code") {
       # disabled, so only do that for Release build.
       fortify_level = "2"
 
-      # ChromeOS supports a high-quality _FORTIFY_SOURCE=3 implementation
+      # ChromeOS's toolchain supports a high-quality _FORTIFY_SOURCE=3
-      # with a few custom glibc patches. Use that if it's available.
+      # implementation with a few custom glibc patches. Use that if it's
-      if (is_chromeos_ash) {
+      # available.
+      if (is_chromeos_device && !lacros_use_chromium_toolchain) {
         fortify_level = "3"
       }
       defines += [ "_FORTIFY_SOURCE=" + fortify_level ]
@@ -2281,6 +2331,10 @@ if (is_win) {
     "-Xclang", "-O3",
   ]
 
+  if (current_cpu == "arm64") {
+    common_optimize_on_ldflags += [ "-march=armv8-a+simd", ]
+  }
+
   common_optimize_on_ldflags += [
   ]
 
@@ -2313,10 +2367,22 @@ if (is_win) {
   common_optimize_on_cflags = []
   common_optimize_on_ldflags = []
 
+  if (current_cpu == "arm64") {
+    common_optimize_on_cflags += [ "-march=armv8-a+simd", ]
+  }
+
+  if (is_raspi == true) {
+    common_optimize_on_cflags += [ "-mtune=cortex-a72", ]
+  }
+
   common_optimize_on_cflags += [
     "-O3",
   ]
 
+  if (current_cpu == "arm64") {
+    common_optimize_on_ldflags += [ "-march=armv8-a+simd", ]
+  }
+
   common_optimize_on_ldflags += [
     "-Wl,-O3",
   ]

arm/raspi/raspi_args.gn

@@ -4,6 +4,7 @@ google_default_client_secret = ""
 target_os = "linux"
 target_cpu = "arm64"
 v8_target_cpu = "arm64"
+is_raspi = true
 # sysroot = "/home/alex/chromium/src/build/linux/debian_bullseye_arm64-sysroot"
 arm_version = 8
 arm_arch = "armv8-a"

other/AVX2/build/config/compiler/BUILD.gn

@@ -1,4 +1,4 @@
-# Copyright 2023 The Chromium Authors and Alex313031
+# Copyright 2024 The Chromium Authors and Alex313031
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -19,6 +19,7 @@ import("//build/config/rust.gni")
 import("//build/config/ui.gni")
 import("//build/config/unwind.gni")
 import("//build/toolchain/cc_wrapper.gni")
+import("//build/toolchain/cros/cros_config.gni")
 import("//build/toolchain/goma.gni")
 import("//build/toolchain/rbe.gni")
 import("//build/toolchain/toolchain.gni")
@@ -135,6 +136,11 @@ declare_args() {
       (is_chromeos || is_android || is_win || is_linux || is_mac ||
        (is_ios && use_lld)) && is_official_build
 
+  # Whether to enable thin lto incremental builds.
+  # See: https://clang.llvm.org/docs/ThinLTO.html#incremental
+  # The cache can lead to non-determinism: https://crbug.com/1486045
+  thin_lto_enable_cache = false
+
   # Initialize all local variables with a pattern. This flag will fill
   # uninitialized floating-point types (and 32-bit pointers) with 0xFF and the
   # rest with 0xAA. This makes behavior of uninitialized memory bugs consistent,
@@ -489,6 +495,11 @@ config("compiler") {
       asmflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
       cflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
     }
+
+    # dsymutil is not available in the system, on bots, for rustc to call. Our
+    # linker_driver.py script runs dsymutil itself, which is set to be the
+    # linker for Rust targets as well.
+    rustflags += [ "-Csplit-debuginfo=unpacked" ]
   }
 
   # Linux/Android/Fuchsia common flags setup.
@@ -619,6 +630,24 @@ config("compiler") {
       }
     }
 
+    # TODO(crbug.com/1488374): This causes binary size growth and potentially
+    # other problems.
+    # TODO(crbug.com/1491036): This isn't supported by Cronet's mainline llvm version.
+    if (default_toolchain != "//build/toolchain/cros:target" &&
+        !llvm_android_mainline) {
+      cflags += [
+        "-mllvm",
+        "-split-threshold-for-reg-with-hint=0",
+      ]
+      if (use_thin_lto && is_a_target_toolchain) {
+        if (is_win) {
+          ldflags += [ "-mllvm:-split-threshold-for-reg-with-hint=0" ]
+        } else {
+          ldflags += [ "-Wl,-mllvm,-split-threshold-for-reg-with-hint=0" ]
+        }
+      }
+    }
+
     # TODO(crbug.com/1235145): Investigate why/if this should be needed.
     if (is_win) {
       cflags += [ "/clang:-ffp-contract=fast" ]
@@ -675,8 +704,7 @@ config("compiler") {
     }
   } else if (is_win) {
     cflags_c += [ "/std:c11" ]
-    if ((defined(use_cxx17) && use_cxx17) ||
+    if (defined(use_cxx17) && use_cxx17) {
-        (!is_clang && defined(msvc_use_cxx17) && msvc_use_cxx17)) {
       cflags_cc += [ "/std:c++17" ]
     } else {
       cflags_cc += [ "/std:c++20" ]
@@ -723,9 +751,26 @@ config("compiler") {
       "-fsplit-lto-unit",
     ]
 
+    if (thin_lto_enable_cache) {
       # Limit the size of the ThinLTO cache to the lesser of 10% of
       # available disk space, 40GB and 100000 files.
-    # cache_policy = "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_policy =
+          "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_dir = rebase_path("$root_out_dir/thinlto-cache", root_build_dir)
+      if (is_win) {
+        ldflags += [
+          "/lldltocache:$cache_dir",
+          "/lldltocachepolicy:$cache_policy",
+        ]
+      } else {
+        if (is_apple) {
+          ldflags += [ "-Wl,-cache_path_lto,$cache_dir" ]
+        } else {
+          ldflags += [ "-Wl,--thinlto-cache-dir=$cache_dir" ]
+        }
+        ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
+      }
+    }
 
     # An import limit of 30 has better performance (per speedometer) and lower
     # binary size than the default setting of 100.
@@ -740,9 +785,6 @@ config("compiler") {
         "-mllvm:-import-hot-multiplier=15",
         "-mllvm:-import-cold-multiplier=2",
         "-mllvm:-disable-auto-upgrade-debug-info",
-        # "/lldltocache:" +
-        #    rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-        # "/lldltocachepolicy:$cache_policy",
       ]
     } else {
       ldflags += [ "-flto=thin" ]
@@ -756,18 +798,6 @@ config("compiler") {
       # TODO(thakis): Check if '=0' (that is, number of cores, instead
       # of "all" which means number of hardware threads) is faster.
       ldflags += [ "-Wl,--thinlto-jobs=all" ]
-      if (is_apple) {
-        ldflags += [
-          "-Wl,-cache_path_lto," +
-              rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-          "-Wcrl,object_path_lto",
-        ]
-      } else {
-        ldflags +=
-            [ "-Wl,-O3" ]
-      }
-
-      # ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
 
       if (is_chromeos) {
         # ARM was originally set lower than x86 to keep the size
@@ -783,6 +813,10 @@ config("compiler") {
 
       ldflags += [ "-Wl,-mllvm,-import-instr-limit=$import_instr_limit" ]
 
+      if (is_apple) {
+        ldflags += [ "-Wcrl,object_path_lto" ]
+      }
+
       if (!is_chromeos) {
         # TODO(https://crbug.com/972449): turn on for ChromeOS when that
         # toolchain has this flag.
@@ -828,6 +862,9 @@ config("compiler") {
   if (compiler_timing) {
     if (is_clang && !is_nacl) {
       cflags += [ "-ftime-trace" ]
+      if (use_lld && is_mac) {
+        ldflags += [ "-Wl,--time-trace" ]
+      }
     } else if (is_win) {
       cflags += [
         # "Documented" here:
@@ -1854,14 +1891,6 @@ config("default_warnings") {
         "-Wno-ignored-pragma-optimize",
       ]
 
-      if (llvm_force_head_revision && !is_nacl && enable_precompiled_headers &&
-          !is_win) {
-        cflags += [
-          # TODO(crbug.com/1486799) Find a long-term solution.
-          "-Wno-deprecated-include-gch",
-        ]
-      }
-
       if (!is_nacl) {
         cflags += [
           # TODO(crbug.com/1343975) Evaluate and possibly enable.
@@ -1872,6 +1901,18 @@ config("default_warnings") {
 
           # TODO(crbug.com/1412713) Evaluate and possibly enable.
           "-Wno-deprecated-this-capture",
+
+          # TODO(https://crbug.com/1491833): Fix and re-enable.
+          "-Wno-invalid-offsetof",
+
+          # TODO(crbug.com/1494809): Evaluate and possibly enable.
+          "-Wno-vla-extension",
+
+          # TODO(https://crbug.com/1490607): Fix and re-enable.
+          "-Wno-thread-safety-reference-return",
+
+          # TODO(crbug.com/1495100): Evaluate and possibly enable.
+          "-Wno-delayed-template-parsing-in-cxx20",
         ]
       }
     }
@@ -1972,9 +2013,10 @@ config("chromium_code") {
       # disabled, so only do that for Release build.
       fortify_level = "2"
 
-      # ChromeOS supports a high-quality _FORTIFY_SOURCE=3 implementation
+      # ChromeOS's toolchain supports a high-quality _FORTIFY_SOURCE=3
-      # with a few custom glibc patches. Use that if it's available.
+      # implementation with a few custom glibc patches. Use that if it's
-      if (is_chromeos_ash) {
+      # available.
+      if (is_chromeos_device && !lacros_use_chromium_toolchain) {
         fortify_level = "3"
       }
       defines += [ "_FORTIFY_SOURCE=" + fortify_level ]

other/CrOS/build/config/compiler/BUILD.gn

@@ -1,4 +1,4 @@
-# Copyright 2023 The Chromium Authors and Alex313031
+# Copyright 2024 The Chromium Authors and Alex313031
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -19,6 +19,7 @@ import("//build/config/rust.gni")
 import("//build/config/ui.gni")
 import("//build/config/unwind.gni")
 import("//build/toolchain/cc_wrapper.gni")
+import("//build/toolchain/cros/cros_config.gni")
 import("//build/toolchain/goma.gni")
 import("//build/toolchain/rbe.gni")
 import("//build/toolchain/toolchain.gni")
@@ -135,6 +136,11 @@ declare_args() {
       (is_chromeos || is_android || is_win || is_linux || is_mac ||
        (is_ios && use_lld)) && is_official_build
 
+  # Whether to enable thin lto incremental builds.
+  # See: https://clang.llvm.org/docs/ThinLTO.html#incremental
+  # The cache can lead to non-determinism: https://crbug.com/1486045
+  thin_lto_enable_cache = false
+
   # Initialize all local variables with a pattern. This flag will fill
   # uninitialized floating-point types (and 32-bit pointers) with 0xFF and the
   # rest with 0xAA. This makes behavior of uninitialized memory bugs consistent,
@@ -489,6 +495,11 @@ config("compiler") {
       asmflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
       cflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
     }
+
+    # dsymutil is not available in the system, on bots, for rustc to call. Our
+    # linker_driver.py script runs dsymutil itself, which is set to be the
+    # linker for Rust targets as well.
+    rustflags += [ "-Csplit-debuginfo=unpacked" ]
   }
 
   # Linux/Android/Fuchsia common flags setup.
@@ -619,6 +630,24 @@ config("compiler") {
       }
     }
 
+    # TODO(crbug.com/1488374): This causes binary size growth and potentially
+    # other problems.
+    # TODO(crbug.com/1491036): This isn't supported by Cronet's mainline llvm version.
+    if (default_toolchain != "//build/toolchain/cros:target" &&
+        !llvm_android_mainline) {
+      cflags += [
+        "-mllvm",
+        "-split-threshold-for-reg-with-hint=0",
+      ]
+      if (use_thin_lto && is_a_target_toolchain) {
+        if (is_win) {
+          ldflags += [ "-mllvm:-split-threshold-for-reg-with-hint=0" ]
+        } else {
+          ldflags += [ "-Wl,-mllvm,-split-threshold-for-reg-with-hint=0" ]
+        }
+      }
+    }
+
     # TODO(crbug.com/1235145): Investigate why/if this should be needed.
     if (is_win) {
       cflags += [ "/clang:-ffp-contract=off" ]
@@ -675,8 +704,7 @@ config("compiler") {
     }
   } else if (is_win) {
     cflags_c += [ "/std:c11" ]
-    if ((defined(use_cxx17) && use_cxx17) ||
+    if (defined(use_cxx17) && use_cxx17) {
-        (!is_clang && defined(msvc_use_cxx17) && msvc_use_cxx17)) {
       cflags_cc += [ "/std:c++17" ]
     } else {
       cflags_cc += [ "/std:c++20" ]
@@ -723,9 +751,26 @@ config("compiler") {
       "-fsplit-lto-unit",
     ]
 
+    if (thin_lto_enable_cache) {
       # Limit the size of the ThinLTO cache to the lesser of 10% of
       # available disk space, 40GB and 100000 files.
-    # cache_policy = "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_policy =
+          "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_dir = rebase_path("$root_out_dir/thinlto-cache", root_build_dir)
+      if (is_win) {
+        ldflags += [
+          "/lldltocache:$cache_dir",
+          "/lldltocachepolicy:$cache_policy",
+        ]
+      } else {
+        if (is_apple) {
+          ldflags += [ "-Wl,-cache_path_lto,$cache_dir" ]
+        } else {
+          ldflags += [ "-Wl,--thinlto-cache-dir=$cache_dir" ]
+        }
+        ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
+      }
+    }
 
     # An import limit of 30 has better performance (per speedometer) and lower
     # binary size than the default setting of 100.
@@ -740,9 +785,6 @@ config("compiler") {
         "-mllvm:-import-hot-multiplier=15",
         "-mllvm:-import-cold-multiplier=2",
         "-mllvm:-disable-auto-upgrade-debug-info",
-        # "/lldltocache:" +
-        #    rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-        # "/lldltocachepolicy:$cache_policy",
       ]
     } else {
       ldflags += [ "-flto=thin" ]
@@ -756,18 +798,6 @@ config("compiler") {
       # TODO(thakis): Check if '=0' (that is, number of cores, instead
       # of "all" which means number of hardware threads) is faster.
       ldflags += [ "-Wl,--thinlto-jobs=all" ]
-      if (is_apple) {
-        ldflags += [
-          "-Wl,-cache_path_lto," +
-              rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-          "-Wcrl,object_path_lto",
-        ]
-      } else {
-        ldflags +=
-            [ "-Wl,-O3" ]
-      }
-
-      # ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
 
       if (is_chromeos) {
         # ARM was originally set lower than x86 to keep the size
@@ -783,6 +813,10 @@ config("compiler") {
 
       ldflags += [ "-Wl,-mllvm,-import-instr-limit=$import_instr_limit" ]
 
+      if (is_apple) {
+        ldflags += [ "-Wcrl,object_path_lto" ]
+      }
+
       if (!is_chromeos) {
         # TODO(https://crbug.com/972449): turn on for ChromeOS when that
         # toolchain has this flag.
@@ -828,6 +862,9 @@ config("compiler") {
   if (compiler_timing) {
     if (is_clang && !is_nacl) {
       cflags += [ "-ftime-trace" ]
+      if (use_lld && is_mac) {
+        ldflags += [ "-Wl,--time-trace" ]
+      }
     } else if (is_win) {
       cflags += [
         # "Documented" here:
@@ -1141,9 +1178,12 @@ config("compiler_cpu_abi") {
       cflags += [
         "-m64",
         "-O3",
+        "-msse3",
+        "-mssse3",
+        "-msse4",
         "-msse4.1",
       ]
-      ldflags += [ "-m64", "-Wl,-O3", "-msse4.1", ]
+      ldflags += [ "-m64", "-Wl,-O3", "-msse3", "-mssse3", "-msse4", "-msse4.1", ]
     } else if (current_cpu == "x86") {
       cflags += [ "-m32" ]
       ldflags += [ "-m32", "-Wl,-O3", "-msse3", ]
@@ -1852,14 +1892,6 @@ config("default_warnings") {
         "-Wno-ignored-pragma-optimize",
       ]
 
-      if (llvm_force_head_revision && !is_nacl && enable_precompiled_headers &&
-          !is_win) {
-        cflags += [
-          # TODO(crbug.com/1486799) Find a long-term solution.
-          "-Wno-deprecated-include-gch",
-        ]
-      }
-
       if (!is_nacl) {
         cflags += [
           # TODO(crbug.com/1343975) Evaluate and possibly enable.
@@ -1870,6 +1902,18 @@ config("default_warnings") {
 
           # TODO(crbug.com/1412713) Evaluate and possibly enable.
           "-Wno-deprecated-this-capture",
+
+          # TODO(https://crbug.com/1491833): Fix and re-enable.
+          "-Wno-invalid-offsetof",
+
+          # TODO(crbug.com/1494809): Evaluate and possibly enable.
+          "-Wno-vla-extension",
+
+          # TODO(https://crbug.com/1490607): Fix and re-enable.
+          "-Wno-thread-safety-reference-return",
+
+          # TODO(crbug.com/1495100): Evaluate and possibly enable.
+          "-Wno-delayed-template-parsing-in-cxx20",
         ]
       }
     }
@@ -1970,9 +2014,10 @@ config("chromium_code") {
       # disabled, so only do that for Release build.
       fortify_level = "2"
 
-      # ChromeOS supports a high-quality _FORTIFY_SOURCE=3 implementation
+      # ChromeOS's toolchain supports a high-quality _FORTIFY_SOURCE=3
-      # with a few custom glibc patches. Use that if it's available.
+      # implementation with a few custom glibc patches. Use that if it's
-      if (is_chromeos_ash) {
+      # available.
+      if (is_chromeos_device && !lacros_use_chromium_toolchain) {
         fortify_level = "3"
       }
       defines += [ "_FORTIFY_SOURCE=" + fortify_level ]
@@ -2284,6 +2329,9 @@ if (is_win) {
     "-mllvm", "-enable-dfa-jump-thread",
     "/O2",
     "/clang:-O3",
+    "/clang:-msse3",
+    "/clang:-mssse3",
+    "/clang:-msse4",
     "/clang:-msse4.1",
     "-Xclang", "-O3",
   ]
@@ -2342,6 +2390,7 @@ if (is_win) {
   ]
 
   common_optimize_on_ldflags += [
+    "-Wl,-mllvm,-freroll-loops",
     "-Wl,-mllvm,-enable-gvn-hoist",
     "-Wl,-mllvm,-import-instr-limit=30", "-Wl,-mllvm,-import-hot-multiplier=15", "-Wl,-mllvm,-import-cold-multiplier=2",
     "-Wl,-O3",

other/SSE3/build/config/compiler/BUILD.gn

@@ -1,4 +1,4 @@
-# Copyright 2023 The Chromium Authors and Alex313031
+# Copyright 2024 The Chromium Authors and Alex313031
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -19,6 +19,7 @@ import("//build/config/rust.gni")
 import("//build/config/ui.gni")
 import("//build/config/unwind.gni")
 import("//build/toolchain/cc_wrapper.gni")
+import("//build/toolchain/cros/cros_config.gni")
 import("//build/toolchain/goma.gni")
 import("//build/toolchain/rbe.gni")
 import("//build/toolchain/toolchain.gni")
@@ -135,6 +136,11 @@ declare_args() {
       (is_chromeos || is_android || is_win || is_linux || is_mac ||
        (is_ios && use_lld)) && is_official_build
 
+  # Whether to enable thin lto incremental builds.
+  # See: https://clang.llvm.org/docs/ThinLTO.html#incremental
+  # The cache can lead to non-determinism: https://crbug.com/1486045
+  thin_lto_enable_cache = false
+
   # Initialize all local variables with a pattern. This flag will fill
   # uninitialized floating-point types (and 32-bit pointers) with 0xFF and the
   # rest with 0xAA. This makes behavior of uninitialized memory bugs consistent,
@@ -489,6 +495,11 @@ config("compiler") {
       asmflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
       cflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
     }
+
+    # dsymutil is not available in the system, on bots, for rustc to call. Our
+    # linker_driver.py script runs dsymutil itself, which is set to be the
+    # linker for Rust targets as well.
+    rustflags += [ "-Csplit-debuginfo=unpacked" ]
   }
 
   # Linux/Android/Fuchsia common flags setup.
@@ -619,6 +630,24 @@ config("compiler") {
       }
     }
 
+    # TODO(crbug.com/1488374): This causes binary size growth and potentially
+    # other problems.
+    # TODO(crbug.com/1491036): This isn't supported by Cronet's mainline llvm version.
+    if (default_toolchain != "//build/toolchain/cros:target" &&
+        !llvm_android_mainline) {
+      cflags += [
+        "-mllvm",
+        "-split-threshold-for-reg-with-hint=0",
+      ]
+      if (use_thin_lto && is_a_target_toolchain) {
+        if (is_win) {
+          ldflags += [ "-mllvm:-split-threshold-for-reg-with-hint=0" ]
+        } else {
+          ldflags += [ "-Wl,-mllvm,-split-threshold-for-reg-with-hint=0" ]
+        }
+      }
+    }
+
     # TODO(crbug.com/1235145): Investigate why/if this should be needed.
     if (is_win) {
       cflags += [ "/clang:-ffp-contract=off" ]
@@ -675,8 +704,7 @@ config("compiler") {
     }
   } else if (is_win) {
     cflags_c += [ "/std:c11" ]
-    if ((defined(use_cxx17) && use_cxx17) ||
+    if (defined(use_cxx17) && use_cxx17) {
-        (!is_clang && defined(msvc_use_cxx17) && msvc_use_cxx17)) {
       cflags_cc += [ "/std:c++17" ]
     } else {
       cflags_cc += [ "/std:c++20" ]
@@ -723,9 +751,26 @@ config("compiler") {
       "-fsplit-lto-unit",
     ]
 
+    if (thin_lto_enable_cache) {
       # Limit the size of the ThinLTO cache to the lesser of 10% of
       # available disk space, 40GB and 100000 files.
-    # cache_policy = "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_policy =
+          "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_dir = rebase_path("$root_out_dir/thinlto-cache", root_build_dir)
+      if (is_win) {
+        ldflags += [
+          "/lldltocache:$cache_dir",
+          "/lldltocachepolicy:$cache_policy",
+        ]
+      } else {
+        if (is_apple) {
+          ldflags += [ "-Wl,-cache_path_lto,$cache_dir" ]
+        } else {
+          ldflags += [ "-Wl,--thinlto-cache-dir=$cache_dir" ]
+        }
+        ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
+      }
+    }
 
     # An import limit of 30 has better performance (per speedometer) and lower
     # binary size than the default setting of 100.
@@ -740,9 +785,6 @@ config("compiler") {
         "-mllvm:-import-hot-multiplier=15",
         "-mllvm:-import-cold-multiplier=2",
         "-mllvm:-disable-auto-upgrade-debug-info",
-        # "/lldltocache:" +
-        #    rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-        # "/lldltocachepolicy:$cache_policy",
       ]
     } else {
       ldflags += [ "-flto=thin" ]
@@ -756,18 +798,6 @@ config("compiler") {
       # TODO(thakis): Check if '=0' (that is, number of cores, instead
       # of "all" which means number of hardware threads) is faster.
       ldflags += [ "-Wl,--thinlto-jobs=all" ]
-      if (is_apple) {
-        ldflags += [
-          "-Wl,-cache_path_lto," +
-              rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-          "-Wcrl,object_path_lto",
-        ]
-      } else {
-        ldflags +=
-            [ "-Wl,-O3" ]
-      }
-
-      # ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
 
       if (is_chromeos) {
         # ARM was originally set lower than x86 to keep the size
@@ -783,6 +813,10 @@ config("compiler") {
 
       ldflags += [ "-Wl,-mllvm,-import-instr-limit=$import_instr_limit" ]
 
+      if (is_apple) {
+        ldflags += [ "-Wcrl,object_path_lto" ]
+      }
+
       if (!is_chromeos) {
         # TODO(https://crbug.com/972449): turn on for ChromeOS when that
         # toolchain has this flag.
@@ -828,6 +862,9 @@ config("compiler") {
   if (compiler_timing) {
     if (is_clang && !is_nacl) {
       cflags += [ "-ftime-trace" ]
+      if (use_lld && is_mac) {
+        ldflags += [ "-Wl,--time-trace" ]
+      }
     } else if (is_win) {
       cflags += [
         # "Documented" here:
@@ -1852,14 +1889,6 @@ config("default_warnings") {
         "-Wno-ignored-pragma-optimize",
       ]
 
-      if (llvm_force_head_revision && !is_nacl && enable_precompiled_headers &&
-          !is_win) {
-        cflags += [
-          # TODO(crbug.com/1486799) Find a long-term solution.
-          "-Wno-deprecated-include-gch",
-        ]
-      }
-
       if (!is_nacl) {
         cflags += [
           # TODO(crbug.com/1343975) Evaluate and possibly enable.
@@ -1870,6 +1899,18 @@ config("default_warnings") {
 
           # TODO(crbug.com/1412713) Evaluate and possibly enable.
           "-Wno-deprecated-this-capture",
+
+          # TODO(https://crbug.com/1491833): Fix and re-enable.
+          "-Wno-invalid-offsetof",
+
+          # TODO(crbug.com/1494809): Evaluate and possibly enable.
+          "-Wno-vla-extension",
+
+          # TODO(https://crbug.com/1490607): Fix and re-enable.
+          "-Wno-thread-safety-reference-return",
+
+          # TODO(crbug.com/1495100): Evaluate and possibly enable.
+          "-Wno-delayed-template-parsing-in-cxx20",
         ]
       }
     }
@@ -1970,9 +2011,10 @@ config("chromium_code") {
       # disabled, so only do that for Release build.
       fortify_level = "2"
 
-      # ChromeOS supports a high-quality _FORTIFY_SOURCE=3 implementation
+      # ChromeOS's toolchain supports a high-quality _FORTIFY_SOURCE=3
-      # with a few custom glibc patches. Use that if it's available.
+      # implementation with a few custom glibc patches. Use that if it's
-      if (is_chromeos_ash) {
+      # available.
+      if (is_chromeos_device && !lacros_use_chromium_toolchain) {
         fortify_level = "3"
       }
       defines += [ "_FORTIFY_SOURCE=" + fortify_level ]

src/build/config/compiler/BUILD.gn

@@ -1,4 +1,4 @@
-# Copyright 2023 The Chromium Authors and Alex313031
+# Copyright 2024 The Chromium Authors and Alex313031
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
@@ -19,6 +19,7 @@ import("//build/config/rust.gni")
 import("//build/config/ui.gni")
 import("//build/config/unwind.gni")
 import("//build/toolchain/cc_wrapper.gni")
+import("//build/toolchain/cros/cros_config.gni")
 import("//build/toolchain/goma.gni")
 import("//build/toolchain/rbe.gni")
 import("//build/toolchain/toolchain.gni")
@@ -135,6 +136,11 @@ declare_args() {
       (is_chromeos || is_android || is_win || is_linux || is_mac ||
        (is_ios && use_lld)) && is_official_build
 
+  # Whether to enable thin lto incremental builds.
+  # See: https://clang.llvm.org/docs/ThinLTO.html#incremental
+  # The cache can lead to non-determinism: https://crbug.com/1486045
+  thin_lto_enable_cache = false
+
   # Initialize all local variables with a pattern. This flag will fill
   # uninitialized floating-point types (and 32-bit pointers) with 0xFF and the
   # rest with 0xAA. This makes behavior of uninitialized memory bugs consistent,
@@ -489,6 +495,11 @@ config("compiler") {
       asmflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
       cflags += [ "-femit-dwarf-unwind=no-compact-unwind" ]
     }
+
+    # dsymutil is not available in the system, on bots, for rustc to call. Our
+    # linker_driver.py script runs dsymutil itself, which is set to be the
+    # linker for Rust targets as well.
+    rustflags += [ "-Csplit-debuginfo=unpacked" ]
   }
 
   # Linux/Android/Fuchsia common flags setup.
@@ -619,6 +630,24 @@ config("compiler") {
       }
     }
 
+    # TODO(crbug.com/1488374): This causes binary size growth and potentially
+    # other problems.
+    # TODO(crbug.com/1491036): This isn't supported by Cronet's mainline llvm version.
+    if (default_toolchain != "//build/toolchain/cros:target" &&
+        !llvm_android_mainline) {
+      cflags += [
+        "-mllvm",
+        "-split-threshold-for-reg-with-hint=0",
+      ]
+      if (use_thin_lto && is_a_target_toolchain) {
+        if (is_win) {
+          ldflags += [ "-mllvm:-split-threshold-for-reg-with-hint=0" ]
+        } else {
+          ldflags += [ "-Wl,-mllvm,-split-threshold-for-reg-with-hint=0" ]
+        }
+      }
+    }
+
     # TODO(crbug.com/1235145): Investigate why/if this should be needed.
     if (is_win) {
       cflags += [ "/clang:-ffp-contract=off" ]
@@ -675,8 +704,7 @@ config("compiler") {
     }
   } else if (is_win) {
     cflags_c += [ "/std:c11" ]
-    if ((defined(use_cxx17) && use_cxx17) ||
+    if (defined(use_cxx17) && use_cxx17) {
-        (!is_clang && defined(msvc_use_cxx17) && msvc_use_cxx17)) {
       cflags_cc += [ "/std:c++17" ]
     } else {
       cflags_cc += [ "/std:c++20" ]
@@ -723,9 +751,26 @@ config("compiler") {
       "-fsplit-lto-unit",
     ]
 
+    if (thin_lto_enable_cache) {
       # Limit the size of the ThinLTO cache to the lesser of 10% of
       # available disk space, 40GB and 100000 files.
-    # cache_policy = "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_policy =
+          "cache_size=10%:cache_size_bytes=40g:cache_size_files=100000"
+      cache_dir = rebase_path("$root_out_dir/thinlto-cache", root_build_dir)
+      if (is_win) {
+        ldflags += [
+          "/lldltocache:$cache_dir",
+          "/lldltocachepolicy:$cache_policy",
+        ]
+      } else {
+        if (is_apple) {
+          ldflags += [ "-Wl,-cache_path_lto,$cache_dir" ]
+        } else {
+          ldflags += [ "-Wl,--thinlto-cache-dir=$cache_dir" ]
+        }
+        ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
+      }
+    }
 
     # An import limit of 30 has better performance (per speedometer) and lower
     # binary size than the default setting of 100.
@@ -740,9 +785,6 @@ config("compiler") {
         "-mllvm:-import-hot-multiplier=15",
         "-mllvm:-import-cold-multiplier=2",
         "-mllvm:-disable-auto-upgrade-debug-info",
-        # "/lldltocache:" +
-        #    rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-        # "/lldltocachepolicy:$cache_policy",
       ]
     } else {
       ldflags += [ "-flto=thin" ]
@@ -756,18 +798,6 @@ config("compiler") {
       # TODO(thakis): Check if '=0' (that is, number of cores, instead
       # of "all" which means number of hardware threads) is faster.
       ldflags += [ "-Wl,--thinlto-jobs=all" ]
-      if (is_apple) {
-        ldflags += [
-          "-Wl,-cache_path_lto," +
-              rebase_path("$root_out_dir/thinlto-cache", root_build_dir),
-          "-Wcrl,object_path_lto",
-        ]
-      } else {
-        ldflags +=
-            [ "-Wl,-O3" ]
-      }
-
-      # ldflags += [ "-Wl,--thinlto-cache-policy=$cache_policy" ]
 
       if (is_chromeos) {
         # ARM was originally set lower than x86 to keep the size
@@ -783,6 +813,10 @@ config("compiler") {
 
       ldflags += [ "-Wl,-mllvm,-import-instr-limit=$import_instr_limit" ]
 
+      if (is_apple) {
+        ldflags += [ "-Wcrl,object_path_lto" ]
+      }
+
       if (!is_chromeos) {
         # TODO(https://crbug.com/972449): turn on for ChromeOS when that
         # toolchain has this flag.
@@ -828,6 +862,9 @@ config("compiler") {
   if (compiler_timing) {
     if (is_clang && !is_nacl) {
       cflags += [ "-ftime-trace" ]
+      if (use_lld && is_mac) {
+        ldflags += [ "-Wl,--time-trace" ]
+      }
     } else if (is_win) {
       cflags += [
         # "Documented" here:
@@ -1062,11 +1099,11 @@ config("thinlto_optimize_default") {
     if (is_win) {
       ldflags = [ "/opt:lldlto=" + lto_opt_level ]
       ldflags += [ "-mllvm:-enable-pre=false", ]
-      # ldflags += [ "-opt:lldltocgo=" + lto_opt_level ]
+      ldflags += [ "-opt:lldltocgo=" + lto_opt_level ]
     } else {
       ldflags = [ "-Wl,--lto-O" + lto_opt_level ]
       ldflags += [ "-Wl,--lto-CGO" + lto_opt_level ]
-      # ldflags += [ "-Wl,-mllvm,-enable-pre=false", ]
+      ldflags += [ "-Wl,-mllvm,-enable-pre=false", ]
     }
 
     if (toolchain_supports_rust_thin_lto) {
@@ -1100,11 +1137,11 @@ config("thinlto_optimize_max") {
     if (is_win) {
       ldflags = [ "/opt:lldlto=" + lto_opt_level ]
       ldflags += [ "-mllvm:-enable-pre=false", ]
-      # ldflags += [ "-opt:lldltocgo=" + lto_opt_level ]
+      ldflags += [ "-opt:lldltocgo=" + lto_opt_level ]
     } else {
       ldflags = [ "-Wl,--lto-O" + lto_opt_level ]
       ldflags += [ "-Wl,--lto-CGO" + lto_opt_level ]
-      # ldflags += [ "-Wl,-mllvm,-enable-pre=false", ]
+      ldflags += [ "-Wl,-mllvm,-enable-pre=false", ]
     }
 
     if (toolchain_supports_rust_thin_lto) {
@@ -1146,11 +1183,11 @@ config("compiler_cpu_abi") {
         "-msse4",
         "-msse4.1",
         "-msse4.2",
-        "-mavx",
-        "-maes",
         "-mpclmul",
+        "-maes",
+        "-mavx",
       ]
-      ldflags += [ "-m64", "-Wl,-O3", "-msse3", "-mssse3", "-msse4", "-msse4.1", "-msse4.2", "-mavx", "-maes", "-mpclmul", "-Wl,-mllvm,-import-instr-limit=30", "-Wl,-mllvm,-import-hot-multiplier=15", "-Wl,-mllvm,-import-cold-multiplier=2", ]
+      ldflags += [ "-m64", "-Wl,-O3", "-msse3", "-mssse3", "-msse4", "-msse4.1", "-msse4.2", "-mpclmul", "-maes", "-mavx", "-Wl,-mllvm,-import-instr-limit=30", "-Wl,-mllvm,-import-hot-multiplier=15", "-Wl,-mllvm,-import-cold-multiplier=2", ]
     } else if (current_cpu == "x86") {
       cflags += [ "-m32" ]
       ldflags += [ "-m32", "-Wl,-O3", "-msse3", ]
@@ -1859,14 +1896,6 @@ config("default_warnings") {
         "-Wno-ignored-pragma-optimize",
       ]
 
-      if (llvm_force_head_revision && !is_nacl && enable_precompiled_headers &&
-          !is_win) {
-        cflags += [
-          # TODO(crbug.com/1486799) Find a long-term solution.
-          "-Wno-deprecated-include-gch",
-        ]
-      }
-
       if (!is_nacl) {
         cflags += [
           # TODO(crbug.com/1343975) Evaluate and possibly enable.
@@ -1877,6 +1906,18 @@ config("default_warnings") {
 
           # TODO(crbug.com/1412713) Evaluate and possibly enable.
           "-Wno-deprecated-this-capture",
+
+          # TODO(https://crbug.com/1491833): Fix and re-enable.
+          "-Wno-invalid-offsetof",
+
+          # TODO(crbug.com/1494809): Evaluate and possibly enable.
+          "-Wno-vla-extension",
+
+          # TODO(https://crbug.com/1490607): Fix and re-enable.
+          "-Wno-thread-safety-reference-return",
+
+          # TODO(crbug.com/1495100): Evaluate and possibly enable.
+          "-Wno-delayed-template-parsing-in-cxx20",
         ]
       }
     }
@@ -1977,9 +2018,10 @@ config("chromium_code") {
       # disabled, so only do that for Release build.
       fortify_level = "2"
 
-      # ChromeOS supports a high-quality _FORTIFY_SOURCE=3 implementation
+      # ChromeOS's toolchain supports a high-quality _FORTIFY_SOURCE=3
-      # with a few custom glibc patches. Use that if it's available.
+      # implementation with a few custom glibc patches. Use that if it's
-      if (is_chromeos_ash) {
+      # available.
+      if (is_chromeos_device && !lacros_use_chromium_toolchain) {
         fortify_level = "3"
       }
       defines += [ "_FORTIFY_SOURCE=" + fortify_level ]