From f62d92b900eac7d8603817ea65e95e08678ff840 Mon Sep 17 00:00:00 2001
From: Daniel Bevenius <daniel.bevenius@gmail.com>
Date: Mon, 6 Apr 2020 14:17:57 +0200
Subject: [PATCH] build: add --error-on-warn configure flag

This commit adds a configuration time flag named error-on-warn:
$ ./configure --help | grep -A1 error-on-warn
  --error-on-warn       Turn compiler warnings into errors for node core
                        sources.

The motivation for this is that CI jobs can use this flag to turn
warnings into errors.

PR-URL: https://github.com/nodejs/node/pull/32685
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Matheus Marchini <mat@mmarchini.me>
---
 common.gypi  | 10 +++++++++-
 configure.py |  6 ++++++
 node.gyp     |  6 ++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/common.gypi b/common.gypi
index fec140bbae983b..2ebabf8f80b38b 100644
--- a/common.gypi
+++ b/common.gypi
@@ -26,6 +26,7 @@
     'uv_library%': 'static_library',
 
     'clang%': 0,
+    'error_on_warn%': 'false',
 
     'openssl_fips%': '',
     'openssl_no_asm%': 0,
@@ -218,7 +219,14 @@
     # Forcibly disable -Werror.  We support a wide range of compilers, it's
     # simply not feasible to squelch all warnings, never mind that the
     # libraries in deps/ are not under our control.
-    'cflags!': ['-Werror'],
+    'conditions': [
+      [ 'error_on_warn=="false"', {
+        'cflags!': ['-Werror'],
+      }, '(_target_name!="<(node_lib_target_name)" or '
+          '_target_name!="<(node_core_target_name)")', {
+        'cflags!': ['-Werror'],
+      }],
+    ],
     'msvs_settings': {
       'VCCLCompilerTool': {
         'BufferSecurityCheck': 'true',
diff --git a/configure.py b/configure.py
index 2e7deb5a15ef11..ac26f62916cd06 100755
--- a/configure.py
+++ b/configure.py
@@ -117,6 +117,11 @@
     choices=valid_os,
     help='operating system to build for ({0})'.format(', '.join(valid_os)))
 
+parser.add_option('--error-on-warn',
+    action='store_true',
+    dest='error_on_warn',
+    help='Turn compiler warnings into errors for node core sources.')
+
 parser.add_option('--gdb',
     action='store_true',
     dest='gdb',
@@ -1018,6 +1023,7 @@ def configure_node(o):
   o['variables']['node_install_npm'] = b(not options.without_npm)
   o['variables']['debug_node'] = b(options.debug_node)
   o['default_configuration'] = 'Debug' if options.debug else 'Release'
+  o['variables']['error_on_warn'] = b(options.error_on_warn)
 
   host_arch = host_arch_win() if os.name == 'nt' else host_arch_cc()
   target_arch = options.dest_cpu or host_arch
diff --git a/node.gyp b/node.gyp
index 2f0f0f152ba8b3..3dadad15c9e193 100644
--- a/node.gyp
+++ b/node.gyp
@@ -376,6 +376,9 @@
       'msvs_disabled_warnings!': [4244],
 
       'conditions': [
+        [ 'error_on_warn=="true"', {
+          'cflags': ['-Werror'],
+        }],
         [ 'node_intermediate_lib_type=="static_library" and '
             'node_shared=="true" and OS=="aix"', {
           # For AIX, shared lib is linked by static lib and .exp. In the
@@ -750,6 +753,9 @@
       'msvs_disabled_warnings!': [4244],
 
       'conditions': [
+        [ 'error_on_warn=="true"', {
+          'cflags': ['-Werror'],
+        }],
         [ 'node_builtin_modules_path!=""', {
           'defines': [ 'NODE_BUILTIN_MODULES_PATH="<(node_builtin_modules_path)"' ]
         }],