From c63d1faefb2dbe4406ca01ac445a2b28d1aca0b5 Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Thu, 12 Nov 2020 15:39:14 +0100
Subject: [PATCH] Generate doc cfg attributes for more beautiful docs

---
 src/codegen/general.rs       | 14 +++++++++++---
 src/codegen/sys/functions.rs |  5 +++++
 src/codegen/sys/statics.rs   |  1 +
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/codegen/general.rs b/src/codegen/general.rs
index 7201b72c1..63de4a0e0 100644
--- a/src/codegen/general.rs
+++ b/src/codegen/general.rs
@@ -51,6 +51,11 @@ pub fn uses(w: &mut dyn Write, env: &Env, imports: &Imports) -> Result<()> {
                 "#[cfg(any({},feature = \"dox\"))]",
                 scope.constraints.join(", ")
             )?;
+            writeln!(
+                w,
+                "#[cfg_attr(feature = \"dox\", doc(cfg({})))]",
+                scope.constraints.join(", ")
+            )?;
         }
 
         version_condition(w, env, scope.version, false, 0)?;
@@ -517,7 +522,8 @@ pub fn version_condition_string(
         Some(v) if v > env.config.min_cfg_version => {
             let comment = if commented { "//" } else { "" };
             Some(format!(
-                "{}{}#[cfg(any({}, feature = \"dox\"))]",
+                "{0}{1}#[cfg(any({2}, feature = \"dox\"))]\n\
+                 {0}{1}#[cfg_attr(feature = \"dox\", doc(cfg({2})))]",
                 tabs(indent),
                 comment,
                 v.to_cfg()
@@ -536,7 +542,8 @@ pub fn not_version_condition(
     if let Some(v) = version {
         let comment = if commented { "//" } else { "" };
         let s = format!(
-            "{}{}#[cfg(any(not({}), feature = \"dox\"))]",
+            "{0}{1}#[cfg(any(not({2}), feature = \"dox\"))]\n\
+             {0}{1}#[cfg_attr(feature = \"dox\", doc(cfg(not({2}))))]",
             tabs(indent),
             comment,
             v.to_cfg()
@@ -587,7 +594,8 @@ pub fn cfg_condition_string(
         Some(v) => {
             let comment = if commented { "//" } else { "" };
             Some(format!(
-                "{}{}#[cfg(any({}, feature = \"dox\"))]",
+                "{0}{1}#[cfg(any({2}, feature = \"dox\"))]\n\
+                 {0}{1}#[cfg_attr(feature = \"dox\", doc(cfg({2})))]",
                 tabs(indent),
                 comment,
                 v
diff --git a/src/codegen/sys/functions.rs b/src/codegen/sys/functions.rs
index 6dce6a259..53d4d1b97 100644
--- a/src/codegen/sys/functions.rs
+++ b/src/codegen/sys/functions.rs
@@ -254,6 +254,11 @@ fn generate_object_funcs(
         // since we work with gir-files from Linux, some function names need to be adjusted
         if is_windows_utf8 {
             writeln!(w, "    {}#[cfg(any(windows, feature = \"dox\"))]", comment)?;
+            writeln!(
+                w,
+                "    {}#[cfg_attr(feature = \"dox\", doc(cfg(windows)))]",
+                comment
+            )?;
             writeln!(w, "    {}pub fn {}_utf8{};", comment, name, sig)?;
             version_condition(w, env, version, commented, 1)?;
         }
diff --git a/src/codegen/sys/statics.rs b/src/codegen/sys/statics.rs
index e3a59bb5b..fa9ab9488 100644
--- a/src/codegen/sys/statics.rs
+++ b/src/codegen/sys/statics.rs
@@ -6,6 +6,7 @@ pub fn begin(w: &mut dyn Write) -> Result<()> {
         "",
         "#![allow(non_camel_case_types, non_upper_case_globals, non_snake_case)]",
         "#![allow(clippy::approx_constant, clippy::type_complexity, clippy::unreadable_literal)]",
+        "#![cfg_attr(feature = \"dox\", feature(doc_cfg))]",
         "",
         "extern crate libc;",
     ];