Add support for handling line break in document attribute

src/bindgen/utilities.rs

@@ -272,8 +272,7 @@ impl SynAttributeHelpers for [syn::Attribute] {
                 })) = attr.parse_meta()
                 {
                     if path.is_ident("doc") {
-                        let text = content.value().trim_end().to_owned();
-                        comment.push(text);
+                        comment.extend(split_doc_attr(&content.value()));
                     }
                 }
             }
@@ -282,3 +281,15 @@ impl SynAttributeHelpers for [syn::Attribute] {
         comment
     }
 }
+
+fn split_doc_attr(input: &str) -> Vec<String> {
+    input
+        // Convert two newline (indicate "new paragraph") into two line break.
+        .replace("\n\n", "  \n  \n")
+        // Convert newline after two spaces (indicate "line break") into line break.
+        .split("  \n")
+        // Convert single newline (indicate hard-wrapped) into space.
+        .map(|s| s.replace('\n', " "))
+        .map(|s| s.trim_end().to_string())
+        .collect()
+}

tests/expectations/both/documentation_attr.c

@@ -0,0 +1,20 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/**
+ *With doc attr, each attr contribute to one line of document
+ *like this one with a new line character at its end
+ *and this one as well. So they are in the same paragraph
+ *
+ *Line ends with one new line should not break
+ *
+ *Line ends with two spaces and a new line
+ *should break to next line
+ *
+ *Line ends with two new lines
+ *
+ *Should break to next paragraph
+ */
+void root(void);

tests/expectations/both/documentation_attr.compat.c

@@ -0,0 +1,28 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+/**
+ *With doc attr, each attr contribute to one line of document
+ *like this one with a new line character at its end
+ *and this one as well. So they are in the same paragraph
+ *
+ *Line ends with one new line should not break
+ *
+ *Line ends with two spaces and a new line
+ *should break to next line
+ *
+ *Line ends with two new lines
+ *
+ *Should break to next paragraph
+ */
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/documentation_attr.c

@@ -0,0 +1,20 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/**
+ *With doc attr, each attr contribute to one line of document
+ *like this one with a new line character at its end
+ *and this one as well. So they are in the same paragraph
+ *
+ *Line ends with one new line should not break
+ *
+ *Line ends with two spaces and a new line
+ *should break to next line
+ *
+ *Line ends with two new lines
+ *
+ *Should break to next paragraph
+ */
+void root(void);

tests/expectations/documentation_attr.compat.c

@@ -0,0 +1,28 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+/**
+ *With doc attr, each attr contribute to one line of document
+ *like this one with a new line character at its end
+ *and this one as well. So they are in the same paragraph
+ *
+ *Line ends with one new line should not break
+ *
+ *Line ends with two spaces and a new line
+ *should break to next line
+ *
+ *Line ends with two new lines
+ *
+ *Should break to next paragraph
+ */
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/documentation_attr.cpp

@@ -0,0 +1,22 @@
+#include <cstdarg>
+#include <cstdint>
+#include <cstdlib>
+#include <new>
+
+extern "C" {
+
+///With doc attr, each attr contribute to one line of document
+///like this one with a new line character at its end
+///and this one as well. So they are in the same paragraph
+///
+///Line ends with one new line should not break
+///
+///Line ends with two spaces and a new line
+///should break to next line
+///
+///Line ends with two new lines
+///
+///Should break to next paragraph
+void root();
+
+} // extern "C"

tests/expectations/tag/documentation_attr.c

@@ -0,0 +1,20 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/**
+ *With doc attr, each attr contribute to one line of document
+ *like this one with a new line character at its end
+ *and this one as well. So they are in the same paragraph
+ *
+ *Line ends with one new line should not break
+ *
+ *Line ends with two spaces and a new line
+ *should break to next line
+ *
+ *Line ends with two new lines
+ *
+ *Should break to next paragraph
+ */
+void root(void);

tests/expectations/tag/documentation_attr.compat.c

@@ -0,0 +1,28 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+/**
+ *With doc attr, each attr contribute to one line of document
+ *like this one with a new line character at its end
+ *and this one as well. So they are in the same paragraph
+ *
+ *Line ends with one new line should not break
+ *
+ *Line ends with two spaces and a new line
+ *should break to next line
+ *
+ *Line ends with two new lines
+ *
+ *Should break to next paragraph
+ */
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/rust/documentation_attr.rs

@@ -0,0 +1,12 @@
+#[doc="With doc attr, each attr contribute to one line of document"]
+#[doc="like this one with a new line character at its end"]
+#[doc="and this one as well. So they are in the same paragraph"]
+#[doc=""]
+#[doc="Line ends with one new line\nshould not break"]
+#[doc=""]
+#[doc="Line ends with two spaces and a new line  \nshould break to next line"]
+#[doc=""]
+#[doc="Line ends with two new lines\n\nShould break to next paragraph"]
+#[no_mangle]
+pub extern "C" fn root() {
+}