rust-langGH-1090: Integration tests

integration test: document the GH issue

integration test (macro): same order in impl as the trait for consistency

integration test: move each setup into its own function, just to save face

inline static func integration test

Author: amanjeev

bindgen-integration/build.rs

@@ -28,21 +28,14 @@ impl ParseCallbacks for MacroCallback {
         MacroParsingBehavior::Default
     }
 
-    fn item_name(&self, original_item_name: &str) -> Option<String> {
-        if original_item_name.starts_with("my_prefixed_") {
-            Some(
-                original_item_name
-                    .trim_start_matches("my_prefixed_")
-                    .to_string(),
-            )
-        } else if original_item_name.starts_with("MY_PREFIXED_") {
-            Some(
-                original_item_name
-                    .trim_start_matches("MY_PREFIXED_")
-                    .to_string(),
-            )
-        } else {
-            None
+    fn int_macro(&self, name: &str, _value: i64) -> Option<IntKind> {
+        match name {
+            "TESTMACRO_CUSTOMINTKIND_PATH" => Some(IntKind::Custom {
+                name: "crate::MacroInteger",
+                is_signed: true,
+            }),
+
+            _ => None,
         }
     }
 
@@ -67,17 +60,6 @@ impl ParseCallbacks for MacroCallback {
         }
     }
 
-    fn int_macro(&self, name: &str, _value: i64) -> Option<IntKind> {
-        match name {
-            "TESTMACRO_CUSTOMINTKIND_PATH" => Some(IntKind::Custom {
-                name: "crate::MacroInteger",
-                is_signed: true,
-            }),
-
-            _ => None,
-        }
-    }
-
     fn func_macro(&self, name: &str, value: &[&[u8]]) {
         match name {
             "TESTMACRO_NONFUNCTIONAL" => {
@@ -122,6 +104,24 @@ impl ParseCallbacks for MacroCallback {
         }
     }
 
+    fn item_name(&self, original_item_name: &str) -> Option<String> {
+        if original_item_name.starts_with("my_prefixed_") {
+            Some(
+                original_item_name
+                    .trim_start_matches("my_prefixed_")
+                    .to_string(),
+            )
+        } else if original_item_name.starts_with("MY_PREFIXED_") {
+            Some(
+                original_item_name
+                    .trim_start_matches("MY_PREFIXED_")
+                    .to_string(),
+            )
+        } else {
+            None
+        }
+    }
+
     // Test the "custom derives" capability by adding `PartialEq` to the `Test` struct.
     fn add_derives(&self, info: &DeriveInfo<'_>) -> Vec<String> {
         if info.name == "Test" {
@@ -149,7 +149,7 @@ impl Drop for MacroCallback {
     }
 }
 
-fn main() {
+fn setup_macro_test() {
     cc::Build::new()
         .cpp(true)
         .file("cpp/Test.cc")
@@ -204,3 +204,46 @@ fn main() {
         "including stub via include dir must produce correct dep path",
     );
 }
+
+fn setup_extern_test() {
+    // GH-1090: https://github.com/rust-lang/rust-bindgen/issues/1090
+    cc::Build::new()
+        .cpp(true)
+        .file("cpp/extern.c")
+        .include("include")
+        .compile("libextern.a");
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+    let out_rust_file = out_path.join("extern.rs");
+    let out_rust_file_relative = out_rust_file
+        .strip_prefix(std::env::current_dir().unwrap().parent().unwrap())
+        .unwrap();
+    let out_dep_file = out_path.join("extern.d");
+
+    let bindings = Builder::default()
+        .rustfmt_bindings(false)
+        .header("cpp/extern.h")
+        .clang_args(&["-x", "c++", "-I", "include"])
+        .depfile(out_rust_file_relative.display().to_string(), &out_dep_file)
+        .generate_extern_functions(true)
+        .generate()
+        .expect("Unable to generate extern bindings");
+
+    bindings
+        .write_to_file(&out_rust_file)
+        .expect("Couldn't write bindings!");
+    let observed_deps =
+        std::fs::read_to_string(out_dep_file).expect("Couldn't read depfile!");
+    let expected_deps = format!(
+        "{}: /tmp/bindgen/extern.hpp cpp/extern.h include/extern_stub.h",
+        out_rust_file_relative.display()
+    );
+    assert_eq!(
+        observed_deps, expected_deps,
+        "including stub via include dir must produce correct dep path",
+    );
+}
+
+fn main() {
+    setup_macro_test();
+    setup_extern_test();
+}

bindgen-integration/cpp/extern.c

@@ -0,0 +1,4 @@
+#include "extern.h"
+
+int foo__extern() { return foo(); }
+int bar__extern() { return bar(); }

bindgen-integration/cpp/extern.h

@@ -0,0 +1,4 @@
+#include "extern_stub.h" // this bad path is made valid by a `-I include` clang arg
+
+int foo__extern();
+int bar__extern();

bindgen-integration/include/extern_stub.h

@@ -0,0 +1,9 @@
+static inline int foo() {
+    return 11;
+}
+static int bar() {
+    return 1;
+}
+inline int baz() {
+    return 2;
+}

bindgen-integration/src/lib.rs

@@ -4,6 +4,10 @@ mod bindings {
     include!(concat!(env!("OUT_DIR"), "/test.rs"));
 }
 
+mod extern_bindings {
+    include!(concat!(env!("OUT_DIR"), "/extern.rs"));
+}
+
 use std::ffi::CStr;
 use std::mem;
 use std::os::raw::c_int;
@@ -286,3 +290,15 @@ fn test_custom_derive() {
     assert!(meter < lightyear);
     assert!(meter > micron);
 }
+
+#[test]
+fn test_extern_bindings() {
+    // GH-1090: https://github.com/rust-lang/rust-bindgen/issues/1090
+    unsafe {
+        let f = extern_bindings::foo();
+        assert_eq!(11, f);
+
+        let b = extern_bindings::bar();
+        assert_eq!(1, b);
+    }
+}