From 6ea200c1dce192e9b8525b178dcd8effc88655e3 Mon Sep 17 00:00:00 2001
From: klzgrad <kizdiv@gmail.com>
Date: Tue, 19 May 2020 23:42:14 +0800
Subject: [PATCH] build: Support ARM -mcpu= flag

---
 src/build/config/arm.gni           | 2 ++
 src/build/config/compiler/BUILD.gn | 8 ++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/build/config/arm.gni b/src/build/config/arm.gni
index 29434eba92..7b6e40f8ee 100644
--- a/src/build/config/arm.gni
+++ b/src/build/config/arm.gni
@@ -41,6 +41,8 @@ if (current_cpu == "arm" || v8_current_cpu == "arm") {
     # Thumb is a reduced instruction set available on some ARM processors that
     # has increased code density.
     arm_use_thumb = true
+
+    arm_cpu = ""
   }
 
   assert(arm_float_abi == "" || arm_float_abi == "hard" ||
diff --git a/src/build/config/compiler/BUILD.gn b/src/build/config/compiler/BUILD.gn
index cbeeed60e9..930b86ea02 100644
--- a/src/build/config/compiler/BUILD.gn
+++ b/src/build/config/compiler/BUILD.gn
@@ -762,7 +762,7 @@ config("compiler_cpu_abi") {
         ]
       }
     } else if (current_cpu == "arm") {
-      if (is_clang && !is_android && !is_nacl) {
+      if (is_clang && !is_android && !is_nacl && custom_toolchain == "") {
         cflags += [ "--target=arm-linux-gnueabihf" ]
         ldflags += [ "--target=arm-linux-gnueabihf" ]
       }
@@ -771,12 +771,16 @@ config("compiler_cpu_abi") {
           "-march=$arm_arch",
           "-mfloat-abi=$arm_float_abi",
         ]
+        if (arm_cpu != "") {
+          cflags += [ "-mcpu=$arm_cpu" ]
+        }
+        ldflags += [ "-mfloat-abi=$arm_float_abi" ]
       }
       if (arm_tune != "") {
         cflags += [ "-mtune=$arm_tune" ]
       }
     } else if (current_cpu == "arm64") {
-      if (is_clang && !is_android && !is_nacl && !is_fuchsia) {
+      if (is_clang && !is_android && !is_nacl && !is_fuchsia && custom_toolchain == "") {
         cflags += [ "--target=aarch64-linux-gnu" ]
         ldflags += [ "--target=aarch64-linux-gnu" ]
       }