Only emit doc_include_without_cfg when include_str! is used

Author: GuillaumeGomez

clippy_lints/src/doc/include_in_doc_without_cfg.rs

@@ -21,8 +21,13 @@ pub fn check(cx: &LateContext<'_>, attrs: &[Attribute]) {
             // several lines.
             && let Some(start) = snippet.find('[')
             && let Some(end) = snippet.rfind(']')
+            && let snippet = &snippet[start + 1..end]
+            // We check that the expansion actually comes from `include_str!` and not just from
+            // another macro.
+            && let Some(sub_snippet) = snippet.trim().strip_prefix("doc")
+            && let Some(sub_snippet) = sub_snippet.trim().strip_prefix("=")
+            && sub_snippet.trim().starts_with("include_str!")
         {
-            let snippet = &snippet[start + 1..end];
             span_lint_and_sugg(
                 cx,
                 DOC_INCLUDE_WITHOUT_CFG,

tests/ui/doc/doc_include_without_cfg.fixed

@@ -8,6 +8,12 @@
 #![doc = "some doc"]
 //! more doc
 
+macro_rules! man_link {
+    ($a:literal, $b:literal) => {
+        concat!($a, $b)
+    };
+}
+
 // Should not lint!
 macro_rules! tst {
     ($(#[$attr:meta])*) => {
@@ -24,6 +30,7 @@ tst! {
 
 #[cfg_attr(doc, doc = include_str!("../approx_const.rs"))] //~ doc_include_without_cfg
 // Should not lint.
+#[doc = man_link!("bla", "blob")]
 #[cfg_attr(feature = "whatever", doc = include_str!("../approx_const.rs"))]
 #[cfg_attr(doc, doc = include_str!("../approx_const.rs"))]
 #[doc = "some doc"]

tests/ui/doc/doc_include_without_cfg.rs

@@ -8,6 +8,12 @@
 #![doc = "some doc"]
 //! more doc
 
+macro_rules! man_link {
+    ($a:literal, $b:literal) => {
+        concat!($a, $b)
+    };
+}
+
 // Should not lint!
 macro_rules! tst {
     ($(#[$attr:meta])*) => {
@@ -24,6 +30,7 @@ tst! {
 
 #[doc = include_str!("../approx_const.rs")] //~ doc_include_without_cfg
 // Should not lint.
+#[doc = man_link!("bla", "blob")]
 #[cfg_attr(feature = "whatever", doc = include_str!("../approx_const.rs"))]
 #[cfg_attr(doc, doc = include_str!("../approx_const.rs"))]
 #[doc = "some doc"]

tests/ui/doc/doc_include_without_cfg.stderr

@@ -8,7 +8,7 @@ LL | #![doc = include_str!("../approx_const.rs")]
    = help: to override `-D warnings` add `#[allow(clippy::doc_include_without_cfg)]`
 
 error: included a file in documentation unconditionally
-  --> tests/ui/doc/doc_include_without_cfg.rs:25:1
+  --> tests/ui/doc/doc_include_without_cfg.rs:31:1
    |
 LL | #[doc = include_str!("../approx_const.rs")]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `cfg_attr(doc, doc = "...")`: `#[cfg_attr(doc, doc = include_str!("../approx_const.rs"))]`