From 98b24aa47f98d9c70d1e152228ac89dd41e0f637 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Thu, 4 Mar 2021 17:37:53 -0700
Subject: [PATCH] stage2: support environment variables for verbose options

The presence of ZIG_VERBOSE_LINK now enables --verbose-link.
The presence of ZIG_VERBOSE_CC now enables --verbose-cc.

These are useful when debugging usage of `zig cc` which does not have
CLI flags for these options, since they are not valid C compiler flags.
---
 src/main.zig | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/main.zig b/src/main.zig
index bfac976c5c..3b71379cb0 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -448,6 +448,15 @@ const Emit = union(enum) {
     }
 };
 
+fn optionalBoolEnvVar(arena: *Allocator, name: []const u8) !bool {
+    if (std.process.getEnvVarOwned(arena, name)) |value| {
+        return true;
+    } else |err| switch (err) {
+        error.EnvironmentVariableNotFound => return false,
+        else => |e| return e,
+    }
+}
+
 fn optionalStringEnvVar(arena: *Allocator, name: []const u8) !?[]const u8 {
     if (std.process.getEnvVarOwned(arena, name)) |value| {
         return value;
@@ -482,8 +491,8 @@ fn buildOutputType(
     var single_threaded = false;
     var function_sections = false;
     var watch = false;
-    var verbose_link = false;
-    var verbose_cc = false;
+    var verbose_link = try optionalBoolEnvVar(arena, "ZIG_VERBOSE_LINK");
+    var verbose_cc = try optionalBoolEnvVar(arena, "ZIG_VERBOSE_CC");
     var verbose_tokenize = false;
     var verbose_ast = false;
     var verbose_ir = false;