Allow option-env-unwrap within external macros

Author: krishna-veerareddy

clippy_lints/src/option_env_unwrap.rs

@@ -1,6 +1,5 @@
 use crate::utils::{is_direct_expn_of, span_lint_and_help};
 use if_chain::if_chain;
-use rustc::lint::in_external_macro;
 use rustc_lint::{EarlyContext, EarlyLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use syntax::ast::*;
@@ -36,7 +35,6 @@ declare_lint_pass!(OptionEnvUnwrap => [OPTION_ENV_UNWRAP]);
 impl EarlyLintPass for OptionEnvUnwrap {
     fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
         if_chain! {
-            if !in_external_macro(cx.sess, expr.span);
             if let ExprKind::MethodCall(path_segment, args) = &expr.kind;
             let method_name = path_segment.ident.as_str();
             if method_name == "expect" || method_name == "unwrap";

tests/ui/auxiliary/macro_rules.rs

@@ -46,3 +46,13 @@ macro_rules! take_external {
         std::mem::replace($s, Default::default())
     };
 }
+
+#[macro_export]
+macro_rules! option_env_unwrap_external {
+    ($env: expr) => {
+        option_env!($env).unwrap()
+    };
+    ($env: expr, $message: expr) => {
+        option_env!($env).expect($message)
+    };
+}

tests/ui/option_env_unwrap.rs

@@ -1,5 +1,9 @@
+// aux-build:macro_rules.rs
 #![warn(clippy::option_env_unwrap)]
 
+#[macro_use]
+extern crate macro_rules;
+
 macro_rules! option_env_unwrap {
     ($env: expr) => {
         option_env!($env).unwrap()
@@ -14,4 +18,6 @@ fn main() {
     let _ = option_env!("HOME").expect("environment variable HOME isn't set");
     let _ = option_env_unwrap!("HOME");
     let _ = option_env_unwrap!("HOME", "environment variable HOME isn't set");
+    let _ = option_env_unwrap_external!("HOME");
+    let _ = option_env_unwrap_external!("HOME", "environment variable HOME isn't set");
 }

tests/ui/option_env_unwrap.stderr

@@ -1,5 +1,5 @@
 error: this will panic at run-time if the environment variable doesn't exist at compile-time
-  --> $DIR/option_env_unwrap.rs:13:13
+  --> $DIR/option_env_unwrap.rs:17:13
    |
 LL |     let _ = option_env!("HOME").unwrap();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -8,15 +8,15 @@ LL |     let _ = option_env!("HOME").unwrap();
    = help: consider using the `env!` macro instead
 
 error: this will panic at run-time if the environment variable doesn't exist at compile-time
-  --> $DIR/option_env_unwrap.rs:14:13
+  --> $DIR/option_env_unwrap.rs:18:13
    |
 LL |     let _ = option_env!("HOME").expect("environment variable HOME isn't set");
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: consider using the `env!` macro instead
 
 error: this will panic at run-time if the environment variable doesn't exist at compile-time
-  --> $DIR/option_env_unwrap.rs:5:9
+  --> $DIR/option_env_unwrap.rs:9:9
    |
 LL |         option_env!($env).unwrap()
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -28,7 +28,7 @@ LL |     let _ = option_env_unwrap!("HOME");
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: this will panic at run-time if the environment variable doesn't exist at compile-time
-  --> $DIR/option_env_unwrap.rs:8:9
+  --> $DIR/option_env_unwrap.rs:12:9
    |
 LL |         option_env!($env).expect($message)
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -39,5 +39,23 @@ LL |     let _ = option_env_unwrap!("HOME", "environment variable HOME isn't set
    = help: consider using the `env!` macro instead
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 4 previous errors
+error: this will panic at run-time if the environment variable doesn't exist at compile-time
+  --> $DIR/option_env_unwrap.rs:21:13
+   |
+LL |     let _ = option_env_unwrap_external!("HOME");
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider using the `env!` macro instead
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: this will panic at run-time if the environment variable doesn't exist at compile-time
+  --> $DIR/option_env_unwrap.rs:22:13
+   |
+LL |     let _ = option_env_unwrap_external!("HOME", "environment variable HOME isn't set");
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider using the `env!` macro instead
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 6 previous errors