Improve docs on nightly builds, such as our own hosted docs

Author: TheDan64

.travis.yml

@@ -193,7 +193,7 @@ matrix:
         - export PATH=/usr/lib/llvm-10/bin/:$HOME/.local/bin:$PATH
         - export LLVM_PATH=/usr/share/llvm-10/cmake/
       script:
-        - cargo doc --no-default-features --features "target-all,llvm10-0" --color=always
+        - cargo doc --no-default-features --features "target-all,llvm10-0,nightly" --color=always
         - echo '<meta http-equiv="refresh" content="1; url=inkwell/index.html">' > target/doc/index.html
       rust: nightly
       name: "GitHub IO Documentation Deployment"

Cargo.toml

@@ -79,6 +79,7 @@ target-all = [
     "target-riscv"
 ]
 experimental = ["static-alloc"]
+nightly = ["inkwell_internals/nightly"]
 
 [dependencies]
 either = "1.5"

internal_macros/Cargo.toml

@@ -15,3 +15,6 @@ proc-macro2 = "1.0"
 
 [lib]
 proc-macro = true
+
+[features]
+nightly = []

internal_macros/src/lib.rs

@@ -179,7 +179,7 @@ impl Parse for ParenthesizedFeatureSet {
 }
 
 /// Handler for parsing of TokenStreams from macro input
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 struct FeatureSet(std::vec::IntoIter<&'static str>, Option<Error>);
 impl Default for FeatureSet {
     fn default() -> Self {
@@ -307,8 +307,20 @@ pub fn llvm_versions(attribute_args: TokenStream, attributee: TokenStream) -> To
         return features.into_compile_error();
     }
 
+    // Add nightly only doc cfgs to improve documentation on nightly builds
+    // such as our own hosted docs.
+    let doc = if cfg!(feature = "nightly") {
+        let features2 = features.clone();
+        quote! {
+            #[doc(cfg(any(#(feature = #features2),*)))]
+        }
+    } else {
+        quote! {}
+    };
+
     let q = quote! {
         #[cfg(any(#(feature = #features),*))]
+        #doc
         #folded
     };
 

src/lib.rs

@@ -9,6 +9,7 @@
 //! * Most functions which take a string slice as input may possibly panic in the unlikely event that a c style string cannot be created based on it. (IE if your slice already has a null byte in it)
 
 #![deny(missing_debug_implementations)]
+#![cfg_attr(feature = "nightly", feature(doc_cfg))]
 
 #[macro_use]
 extern crate inkwell_internals;