1 files changed, 111 insertions, 0 deletions
diff --git a/src/bindgen/ir/documentation.rs b/src/bindgen/ir/documentation.rs
new file mode 100644
index 0000000..6822c0e
--- /dev/null
+++ b/src/bindgen/ir/documentation.rs
@@ -0,0 +1,111 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use std::io::Write;
+
+use crate::bindgen::config::{Config, DocumentationLength, DocumentationStyle, Language};
+use crate::bindgen::utilities::SynAttributeHelpers;
+use crate::bindgen::writer::{Source, SourceWriter};
+
+#[derive(Debug, Clone)]
+pub struct Documentation {
+    pub doc_comment: Vec<String>,
+}
+
+impl Documentation {
+    pub fn load(attrs: &[syn::Attribute]) -> Self {
+        let doc = attrs
+            .get_comment_lines()
+            .into_iter()
+            .filter(|x| !x.trim_start().starts_with("cbindgen:"))
+            .collect();
+
+        Documentation { doc_comment: doc }
+    }
+
+    pub fn simple(line: &str) -> Self {
+        Documentation {
+            doc_comment: vec![line.to_owned()],
+        }
+    }
+
+    pub fn none() -> Self {
+        Documentation {
+            doc_comment: Vec::new(),
+        }
+    }
+}
+
+impl Source for Documentation {
+    fn write<F: Write>(&self, config: &Config, out: &mut SourceWriter<F>) {
+        if self.doc_comment.is_empty() || !config.documentation {
+            return;
+        }
+
+        let end = match config.documentation_length {
+            DocumentationLength::Short => 1,
+            DocumentationLength::Full => self.doc_comment.len(),
+        };
+
+        // Cython uses Python-style comments, so `documentation_style` is not relevant.
+        if config.language == Language::Cython {
+            for line in &self.doc_comment[..end] {
+                write!(out, "#{}", line);
+                out.new_line();
+            }
+            return;
+        }
+
+        let style = match config.documentation_style {
+            DocumentationStyle::Auto if config.language == Language::C => DocumentationStyle::Doxy,
+            DocumentationStyle::Auto if config.language == Language::Cxx => DocumentationStyle::Cxx,
+            DocumentationStyle::Auto => DocumentationStyle::C, // Fallback if `Language` gets extended.
+            other => other,
+        };
+
+        // Following these documents for style conventions:
+        // https://en.wikibooks.org/wiki/C++_Programming/Code/Style_Conventions/Comments
+        // https://www.cs.cmu.edu/~410/doc/doxygen.html
+        match style {
+            DocumentationStyle::C => {
+                out.write("/*");
+                out.new_line();
+            }
+
+            DocumentationStyle::Doxy => {
+                out.write("/**");
+                out.new_line();
+            }
+
+            _ => (),
+        }
+
+        for line in &self.doc_comment[..end] {
+            match style {
+                DocumentationStyle::C => out.write(""),
+                DocumentationStyle::Doxy => out.write(" *"),
+                DocumentationStyle::C99 => out.write("//"),
+                DocumentationStyle::Cxx => out.write("///"),
+                DocumentationStyle::Auto => unreachable!(), // Auto case should always be covered
+            }
+
+            write!(out, "{}", line);
+            out.new_line();
+        }
+
+        match style {
+            DocumentationStyle::C => {
+                out.write(" */");
+                out.new_line();
+            }
+
+            DocumentationStyle::Doxy => {
+                out.write(" */");
+                out.new_line();
+            }
+
+            _ => (),
+        }
+    }
+}