--- build/config/compiler/BUILD.gn.orig	2025-01-27 17:37:37 UTC
+++ build/config/compiler/BUILD.gn
@@ -199,7 +199,7 @@ declare_args() {
   # This greatly reduces the size of debug builds, at the cost of
   # debugging information which is required by some specialized
   # debugging tools.
-  simple_template_names = is_clang && !is_nacl && !is_win && !is_apple
+  simple_template_names = is_clang && !is_nacl && !is_win && !is_apple && !is_bsd
 }
 
 declare_args() {
@@ -256,13 +256,16 @@ config("no_unresolved_symbols") {
 # Compiler instrumentation can introduce dependencies in DSOs to symbols in
 # the executable they are loaded into, so they are unresolved at link-time.
 config("no_unresolved_symbols") {
-  if (!using_sanitizer &&
+  if (!using_sanitizer && !is_bsd &&
       (is_linux || is_chromeos || is_android || is_fuchsia)) {
     ldflags = [
       "-Wl,-z,defs",
       "-Wl,--as-needed",
     ]
   }
+  if (current_cpu == "x86" && is_openbsd) {
+    ldflags = [ "-Wl,-z,notext", "-Wl,--strip-all" ]
+  }
 }
 
 # compiler ---------------------------------------------------------------------
@@ -509,6 +512,10 @@ config("compiler") {
     }
   }
 
+  if (is_openbsd) {
+    ldflags += [ "-Wl,-z,wxneeded" ]
+  }
+
   # Linux-specific compiler flags setup.
   # ------------------------------------
   if (use_icf && (!is_apple || use_lld)) {
@@ -568,7 +575,7 @@ config("compiler") {
     ldflags += [ "-Wl,-z,keep-text-section-prefix" ]
   }
 
-  if (is_clang && !is_nacl) {
+  if (is_clang && !is_nacl && !is_bsd) {
     cflags += [ "-fcrash-diagnostics-dir=" + clang_diagnostic_dir ]
     if (save_reproducers_on_lld_crash && use_lld) {
       ldflags += [
@@ -1241,7 +1248,7 @@ config("compiler_cpu_abi") {
         ]
       }
     } else if (current_cpu == "arm") {
-      if (is_clang && !is_android && !is_nacl && !is_chromeos_device) {
+      if (is_clang && !is_android && !is_nacl && !is_chromeos_device && !is_bsd) {
         cflags += [ "--target=arm-linux-gnueabihf" ]
         ldflags += [ "--target=arm-linux-gnueabihf" ]
       }
@@ -1256,7 +1263,7 @@ config("compiler_cpu_abi") {
       }
     } else if (current_cpu == "arm64") {
       if (is_clang && !is_android && !is_nacl && !is_fuchsia &&
-          !is_chromeos_device) {
+          !is_chromeos_device && !is_bsd) {
         cflags += [ "--target=aarch64-linux-gnu" ]
         ldflags += [ "--target=aarch64-linux-gnu" ]
       }
@@ -1590,7 +1597,7 @@ config("compiler_deterministic") {
     # 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) {
+    if (is_nacl || is_bsd) {
       # TODO(https://crbug.com/1231236): Use -ffile-compilation-dir= here.
       cflags += [
         "-Xclang",
@@ -1648,7 +1655,7 @@ config("clang_revision") {
 }
 
 config("clang_revision") {
-  if (is_clang && clang_base_path == default_clang_base_path &&
+  if (is_clang && !is_bsd && clang_base_path == default_clang_base_path &&
       current_os != "zos") {
     update_args = [
       "--print-revision",
@@ -1972,9 +1979,6 @@ config("default_warnings") {
       cflags += [
         # TODO(crbug.com/330524456): -Wcast-function-type is under -Wextra now.
         "-Wno-cast-function-type",
-
-        # TODO(crbug.com/40284799): Fix and re-enable.
-        "-Wno-thread-safety-reference-return",
       ]
 
       cflags_cc += [
@@ -2761,7 +2765,7 @@ config("afdo") {
 # There are some targeted places that AFDO regresses, so we provide a separate
 # config to allow AFDO to be disabled per-target.
 config("afdo") {
-  if (is_clang) {
+  if (is_clang && !is_bsd) {
     cflags = []
     if (clang_emit_debug_info_for_profiling) {
       # Add the following flags to generate debug info for profiling.
@@ -2788,7 +2792,7 @@ config("afdo") {
       cflags += [ "-Wno-backend-plugin" ]
       inputs = [ _clang_sample_profile ]
     }
-  } else if (auto_profile_path != "" && is_a_target_toolchain) {
+  } else if (auto_profile_path != "" && is_a_target_toolchain && !is_bsd) {
     cflags = [ "-fauto-profile=${auto_profile_path}" ]
     inputs = [ auto_profile_path ]
   }
@@ -2965,7 +2969,7 @@ config("symbols") {
     cflags += [ "-gomit-unreferenced-methods" ]
   }
 
-  if (is_clang && (!is_nacl || is_nacl_saigo)) {
+  if (is_clang && (!is_nacl || is_nacl_saigo) && !is_bsd) {
     if (is_apple) {
       # TODO(crbug.com/40117949): Investigate missing debug info on mac.
       # Make sure we don't use constructor homing on mac.