--- ./build/config/compiler/BUILD.gn.orig
+++ ./build/config/compiler/BUILD.gn
@@ -658,22 +658,6 @@
       }
     }
 
-    # TODO(crbug.com/40283598): This causes binary size growth and potentially
-    # other problems.
-    if (default_toolchain != "//build/toolchain/cros:target") {
-      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/40192287): Investigate why/if this should be needed.
     if (is_win) {
       cflags += [ "/clang:-ffp-contract=off" ]
@@ -1273,8 +1257,8 @@
     # simplicity we always explicitly set the architecture.
     if (current_cpu == "x64") {
       if (is_clang && !is_android && !is_fuchsia && !is_chromeos_device) {
-        cflags += [ "--target=x86_64-unknown-linux-gnu" ]
-        ldflags += [ "--target=x86_64-unknown-linux-gnu" ]
+        cflags += [ "--target=x86_64-alpine-linux-musl" ]
+        ldflags += [ "--target=x86_64-alpine-linux-musl" ]
       } else {
         cflags += [ "-m64" ]
         ldflags += [ "-m64" ]
@@ -1282,8 +1266,8 @@
       cflags += [ "-msse3" ]
     } else if (current_cpu == "x86") {
       if (is_clang && !is_android && !is_chromeos_device) {
-        cflags += [ "--target=i386-unknown-linux-gnu" ]
-        ldflags += [ "--target=i386-unknown-linux-gnu" ]
+        cflags += [ "--target=i586-alpine-linux-musl" ]
+        ldflags += [ "--target=i586-alpine-linux-musl" ]
       } else {
         cflags += [ "-m32" ]
         ldflags += [ "-m32" ]
@@ -1294,8 +1278,8 @@
       ]
     } else if (current_cpu == "arm") {
       if (is_clang && !is_android && !is_chromeos_device) {
-        cflags += [ "--target=arm-linux-gnueabihf" ]
-        ldflags += [ "--target=arm-linux-gnueabihf" ]
+        cflags += [ "--target=armv7-alpine-linux-musleabihf" ]
+        ldflags += [ "--target=armv7-alpine-linux-musleabihf" ]
       }
       cflags += [
         "-march=$arm_arch",
@@ -1306,8 +1290,8 @@
       }
     } else if (current_cpu == "arm64") {
       if (is_clang && !is_android && !is_fuchsia && !is_chromeos_device) {
-        cflags += [ "--target=aarch64-linux-gnu" ]
-        ldflags += [ "--target=aarch64-linux-gnu" ]
+        cflags += [ "--target=aarch64-alpine-linux-musl" ]
+        ldflags += [ "--target=aarch64-alpine-linux-musl" ]
       }
     } else if (current_cpu == "mipsel") {
       ldflags += [ "-Wl,--hash-style=sysv" ]
@@ -1551,22 +1535,22 @@
           ldflags += [ "-maix64" ]
         }
       } else if (is_clang) {
-        cflags += [ "--target=powerpc64le-unknown-linux-gnu" ]
-        ldflags += [ "--target=powerpc64le-unknown-linux-gnu" ]
+        cflags += [ "--target=powerpc64le-alpine-linux-musl" ]
+        ldflags += [ "--target=powerpc64le-alpine-linux-musl" ]
       } else {
         cflags += [ "-m64" ]
         ldflags += [ "-m64" ]
       }
     } else if (current_cpu == "riscv64") {
       if (is_clang && !is_android) {
-        cflags += [ "--target=riscv64-linux-gnu" ]
-        ldflags += [ "--target=riscv64-linux-gnu" ]
+        cflags += [ "--target=riscv64-alpine-linux-musl" ]
+        ldflags += [ "--target=riscv64-alpine-linux-musl" ]
       }
       cflags += [ "-mabi=lp64d" ]
     } else if (current_cpu == "loong64") {
       if (is_clang) {
-        cflags += [ "--target=loongarch64-linux-gnu" ]
-        ldflags += [ "--target=loongarch64-linux-gnu" ]
+        cflags += [ "--target=loongarch64-alpine-linux-musl" ]
+        ldflags += [ "--target=loongarch64-alpine-linux-musl" ]
       }
       cflags += [
         "-mabi=lp64d",
@@ -1574,8 +1558,8 @@
       ]
     } else if (current_cpu == "s390x") {
       if (is_clang) {
-        cflags += [ "--target=s390x-unknown-linux-gnu" ]
-        ldflags += [ "--target=s390x-unknown-linux-gnu" ]
+        cflags += [ "--target=s390x-alpine-linux-musl" ]
+        ldflags += [ "--target=s390x-alpine-linux-musl" ]
       }
       cflags += [ "-m64" ]
       ldflags += [ "-m64" ]
@@ -2274,7 +2258,7 @@
       defines = [ "_HAS_NODISCARD" ]
     }
   } else {
-    cflags = [ "-Wall" ]
+    cflags = []
     if (is_clang) {
       # Enable extra warnings for chromium_code when we control the compiler.
       cflags += [ "-Wextra" ]
--- ./build/config/rust.gni.orig
+++ ./build/config/rust.gni
@@ -178,11 +178,11 @@
 rust_abi_target = ""
 if (is_linux || is_chromeos) {
   if (current_cpu == "arm64") {
-    rust_abi_target = "aarch64-unknown-linux-gnu"
+    rust_abi_target = "aarch64-alpine-linux-musl"
   } else if (current_cpu == "x86") {
-    rust_abi_target = "i686-unknown-linux-gnu"
+    rust_abi_target = "i586-alpine-linux-musl"
   } else if (current_cpu == "x64") {
-    rust_abi_target = "x86_64-unknown-linux-gnu"
+    rust_abi_target = "x86_64-alpine-linux-musl"
   } else if (current_cpu == "arm") {
     if (arm_float_abi == "hard") {
       float_suffix = "hf"
@@ -200,25 +200,21 @@
       # The thumbv7 vs. armv7 distinction is for legacy reasons and both
       # targets in fact target Thumb, see:
       # https://github.com/rust-lang/rust/issues/44722
-      if (arm_use_neon) {
-        rust_abi_target = "thumbv7neon-unknown-linux-gnueabi" + float_suffix
-      } else {
-        rust_abi_target = "armv7-unknown-linux-gnueabi" + float_suffix
-      }
+      rust_abi_target = "armv7-alpine-linux-musleabi" + float_suffix
     } else {
-      rust_abi_target = "arm-unknown-linux-gnueabi" + float_suffix
+      rust_abi_target = "armv6-alpine-linux-musleabi" + float_suffix
     }
   } else if (current_cpu == "riscv64") {
-    rust_abi_target = "riscv64gc-unknown-linux-gnu"
+    rust_abi_target = "riscv64-alpine-linux-musl"
   } else if (current_cpu == "ppc64") {
-    rust_abi_target = "powerpc64le-unknown-linux-gnu"
+    rust_abi_target = "powerpc64le-alpine-linux-musl"
   } else if (current_cpu == "s390x") {
-    rust_abi_target = "s390x-unknown-linux-gnu"
+    rust_abi_target = "s390x-alpine-linux-musl"
   } else if (current_cpu == "loong64") {
-    rust_abi_target = "loongarch64-unknown-linux-gnu"
+    rust_abi_target = "loongarch64-alpine-linux-musl"
   } else {
     # Best guess for other future platforms.
-    rust_abi_target = current_cpu + "-unknown-linux-gnu"
+    rust_abi_target = current_cpu + "-alpine-linux-musl"
   }
 } else if (is_android) {
   import("//build/config/android/abi.gni")
--- ./build/config/clang/BUILD.gn.orig
+++ ./build/config/clang/BUILD.gn
@@ -207,22 +207,23 @@
           assert(false)  # Unhandled cpu type
         }
       } else if (is_linux || is_chromeos) {
+        _dir = "linux"
         if (current_cpu == "x64") {
-          _dir = "x86_64-unknown-linux-gnu"
+          _suffix = "-x86_64"
         } else if (current_cpu == "x86") {
-          _dir = "i386-unknown-linux-gnu"
+          _suffix = "-i386"
         } else if (current_cpu == "arm") {
-          _dir = "armv7-unknown-linux-gnueabihf"
+          _suffix = "-armhf"
         } else if (current_cpu == "arm64") {
-          _dir = "aarch64-unknown-linux-gnu"
+          _suffix = "-aarch64"
         } else if (current_cpu == "loong64") {
-          _dir = "loongarch64-unknown-linux-gnu"
+          _suffix = "-loongarch64"
         } else if (current_cpu == "riscv64") {
-          _dir = "riscv64-unknown-linux-gnu"
+          _suffix = "-riscv64"
         } else if (current_cpu == "ppc64") {
-          _dir = "ppc64le-unknown-linux-gnu"
+          _suffix = "-powerpc64le"
         } else if (current_cpu == "s390x") {
-          _dir = "s390x-unknown-linux-gnu"
+          _suffix = "-s390x"
         } else {
           assert(false)  # Unhandled cpu type
         }