From 4bd7b07d2fecfcdc8aa57e41b9fc6497780a7c88 Mon Sep 17 00:00:00 2001
From: Rasmus Eneman <rasmus@eneman.eu>
Date: Sat, 24 Aug 2019 01:09:50 +0200
Subject: [PATCH] Add support for adding "using namespace" statements

---
 src/bindgen/bindings.rs                |  8 ++++++++
 src/bindgen/config.rs                  |  3 +++
 tests/expectations/both/using.c        |  6 ++++++
 tests/expectations/both/using.compat.c | 16 ++++++++++++++++
 tests/expectations/tag/using.c         |  6 ++++++
 tests/expectations/tag/using.compat.c  | 16 ++++++++++++++++
 tests/expectations/using.c             |  6 ++++++
 tests/expectations/using.compat.c      | 16 ++++++++++++++++
 tests/expectations/using.cpp           | 12 ++++++++++++
 tests/rust/using.rs                    |  3 +++
 tests/rust/using.toml                  |  1 +
 11 files changed, 93 insertions(+)
 create mode 100644 tests/expectations/both/using.c
 create mode 100644 tests/expectations/both/using.compat.c
 create mode 100644 tests/expectations/tag/using.c
 create mode 100644 tests/expectations/tag/using.compat.c
 create mode 100644 tests/expectations/using.c
 create mode 100644 tests/expectations/using.compat.c
 create mode 100644 tests/expectations/using.cpp
 create mode 100644 tests/rust/using.rs
 create mode 100644 tests/rust/using.toml

diff --git a/src/bindgen/bindings.rs b/src/bindgen/bindings.rs
index aec45d0..b857764 100644
--- a/src/bindgen/bindings.rs
+++ b/src/bindgen/bindings.rs
@@ -217,6 +217,14 @@ impl Bindings {
             }
 
             if self.config.language == Language::Cxx || self.config.cpp_compat {
+                if let Some(ref using) = self.config.using {
+                    for namespace in using {
+                        out.new_line();
+                        write!(out, "using namespace {};", namespace);
+                    }
+                    out.new_line();
+                }
+
                 out.new_line();
                 out.write("extern \"C\" {");
                 out.new_line();
diff --git a/src/bindgen/config.rs b/src/bindgen/config.rs
index c1f6ec0..aa0d18f 100644
--- a/src/bindgen/config.rs
+++ b/src/bindgen/config.rs
@@ -621,6 +621,8 @@ pub struct Config {
     pub namespace: Option<String>,
     /// An optional list of namespaces. Only applicable when language="C++"
     pub namespaces: Option<Vec<String>>,
+    /// An optional list of namespaces to ddeclare as using. Only applicable when language="C++"
+    pub using: Option<Vec<String>>,
     /// The style to use for braces
     pub braces: Braces,
     /// The preferred length of a line, used for auto breaking function arguments
@@ -672,6 +674,7 @@ impl Default for Config {
             no_includes: false,
             namespace: None,
             namespaces: None,
+            using: None,
             braces: Braces::SameLine,
             line_length: 100,
             tab_width: 2,
diff --git a/tests/expectations/both/using.c b/tests/expectations/both/using.c
new file mode 100644
index 0000000..376246e
--- /dev/null
+++ b/tests/expectations/both/using.c
@@ -0,0 +1,6 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+void root(void);
diff --git a/tests/expectations/both/using.compat.c b/tests/expectations/both/using.compat.c
new file mode 100644
index 0000000..5659475
--- /dev/null
+++ b/tests/expectations/both/using.compat.c
@@ -0,0 +1,16 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+using namespace std;
+
+extern "C" {
+#endif // __cplusplus
+
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus
diff --git a/tests/expectations/tag/using.c b/tests/expectations/tag/using.c
new file mode 100644
index 0000000..376246e
--- /dev/null
+++ b/tests/expectations/tag/using.c
@@ -0,0 +1,6 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+void root(void);
diff --git a/tests/expectations/tag/using.compat.c b/tests/expectations/tag/using.compat.c
new file mode 100644
index 0000000..5659475
--- /dev/null
+++ b/tests/expectations/tag/using.compat.c
@@ -0,0 +1,16 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+using namespace std;
+
+extern "C" {
+#endif // __cplusplus
+
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus
diff --git a/tests/expectations/using.c b/tests/expectations/using.c
new file mode 100644
index 0000000..376246e
--- /dev/null
+++ b/tests/expectations/using.c
@@ -0,0 +1,6 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+void root(void);
diff --git a/tests/expectations/using.compat.c b/tests/expectations/using.compat.c
new file mode 100644
index 0000000..5659475
--- /dev/null
+++ b/tests/expectations/using.compat.c
@@ -0,0 +1,16 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+using namespace std;
+
+extern "C" {
+#endif // __cplusplus
+
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus
diff --git a/tests/expectations/using.cpp b/tests/expectations/using.cpp
new file mode 100644
index 0000000..cd881fa
--- /dev/null
+++ b/tests/expectations/using.cpp
@@ -0,0 +1,12 @@
+#include <cstdarg>
+#include <cstdint>
+#include <cstdlib>
+#include <new>
+
+using namespace std;
+
+extern "C" {
+
+void root();
+
+} // extern "C"
diff --git a/tests/rust/using.rs b/tests/rust/using.rs
new file mode 100644
index 0000000..03de69f
--- /dev/null
+++ b/tests/rust/using.rs
@@ -0,0 +1,3 @@
+#[no_mangle]
+pub extern "C" fn root() {
+}
diff --git a/tests/rust/using.toml b/tests/rust/using.toml
new file mode 100644
index 0000000..986e255
--- /dev/null
+++ b/tests/rust/using.toml
@@ -0,0 +1 @@
+using = ["std"]
\ No newline at end of file