From 979361d5fe11c716822b5636689f45a82b573140 Mon Sep 17 00:00:00 2001
From: Keeley Hammond <khammond@slack-corp.com>
Date: Wed, 6 Jul 2022 11:28:27 -0700
Subject: [PATCH] fix: add std=c++17 flag for e20+

---
 src/clang-fetcher.ts        | 7 +++++++
 src/module-type/node-gyp.ts | 4 ++++
 2 files changed, 11 insertions(+)

diff --git a/src/clang-fetcher.ts b/src/clang-fetcher.ts
index 8a6f624c..9ec61d45 100644
--- a/src/clang-fetcher.ts
+++ b/src/clang-fetcher.ts
@@ -2,6 +2,7 @@ import * as cp from 'child_process';
 import debug from 'debug';
 import * as fs from 'fs-extra';
 import * as path from 'path';
+import semver from 'semver';
 import * as tar from 'tar';
 import * as zlib from 'zlib';
 import { ELECTRON_GYP_DIR } from './constants';
@@ -36,10 +37,14 @@ export async function getClangEnvironmentVars(electronVersion: string, targetArc
   const clangDownloadDir = await downloadClangVersion(electronVersion);
 
   const clangDir = path.resolve(clangDownloadDir, 'bin');
+  const cxxflags = [];
   const clangArgs: string[] = [];
   if (process.platform === 'darwin') {
     clangArgs.push('-isysroot', getSDKRoot());
   }
+  if (semver.major(electronVersion) >= 20) {
+    cxxflags.push('-std=c++17');
+  }
 
   const gypArgs = [];
   if (process.platform === 'win32') {
@@ -56,6 +61,8 @@ export async function getClangEnvironmentVars(electronVersion: string, targetArc
     env: {
       CC: `"${path.resolve(clangDir, 'clang')}" ${clangArgs.join(' ')}`,
       CXX: `"${path.resolve(clangDir, 'clang++')}" ${clangArgs.join(' ')}`,
+      CFLAGS: `${cxxflags.join(' ')}`,
+      CXXFLAGS: `${cxxflags.join(' ')}`
     },
     args: gypArgs,
   }
diff --git a/src/module-type/node-gyp.ts b/src/module-type/node-gyp.ts
index d733c502..009896c2 100644
--- a/src/module-type/node-gyp.ts
+++ b/src/module-type/node-gyp.ts
@@ -89,6 +89,10 @@ export class NodeGyp extends NativeModule {
     let env: Record<string, string | undefined>;
     const extraNodeGypArgs: string[] = [];
 
+    if (semver.major(this.rebuilder.electronVersion) >= 20) {
+      process.env.CXXFLAGS = '-std=c++17';
+    }
+
     if (this.rebuilder.useElectronClang) {
       env = { ...process.env };
       const { env: clangEnv, args: clangArgs } = await getClangEnvironmentVars(this.rebuilder.electronVersion, this.rebuilder.arch);