Added pragma once option. Issue #510

docs.md

@@ -335,6 +335,10 @@ trailer = "/* Text to put at the end of the generated file */"
 # default: doesn't emit an include guard
 include_guard = "mozilla_wr_bindings_h"
 
+# Whether to add a `#pragma once` guard 
+# default: doesn't emit a `#pragma once`
+pragma_once = true
+
 # An optional string of text to output between major sections of the generated
 # file as a warning against manual editing
 #

src/bindgen/bindings.rs

@@ -133,6 +133,11 @@ impl Bindings {
             write!(out, "#define {}", f);
             out.new_line();
         }
+        if self.config.pragma_once {
+            out.new_line_if_not_start();
+            write!(out, "#pragma once");
+            out.new_line();
+        }
         if self.config.include_version {
             out.new_line_if_not_start();
             write!(

src/bindgen/builder.rs

@@ -72,6 +72,12 @@ impl Builder {
         self
     }
 
+    #[allow(unused)]
+    pub fn with_pragma_once(mut self, pragma_once: bool) -> Builder {
+        self.config.pragma_once = pragma_once;
+        self
+    }
+
     #[allow(unused)]
     pub fn with_autogen_warning<S: AsRef<str>>(mut self, autogen_warning: S) -> Builder {
         self.config.autogen_warning = Some(String::from(autogen_warning.as_ref()));

src/bindgen/config.rs

@@ -705,6 +705,8 @@ pub struct Config {
     pub trailer: Option<String>,
     /// Optional name to use for an include guard
     pub include_guard: Option<String>,
+    /// Add a `#pragma once` guard
+    pub pragma_once: bool,
     /// Generates no includes at all. Overrides all other include options
     ///
     /// This option is useful when using cbindgen with tools such as python's cffi which
@@ -768,6 +770,7 @@ impl Default for Config {
             sys_includes: Vec::new(),
             trailer: None,
             include_guard: None,
+            pragma_once: false,
             autogen_warning: None,
             include_version: false,
             no_includes: false,

template.toml

@@ -15,6 +15,7 @@ language = "C++"
 # header = "/* Text to put at the beginning of the generated file. Probably a license. */"
 # trailer = "/* Text to put at the end of the generated file */"
 # include_guard = "my_bindings_h"
+# pragma_once = true
 # autogen_warning = "/* Warning, this file is autogenerated by cbindgen. Don't modify this manually. */"
 include_version = false
 # namespace = "my_namespace"

tests/expectations/both/pragma_once.c

@@ -0,0 +1 @@
+#include "pragma_once.h"

tests/expectations/both/pragma_once.compat.c

@@ -0,0 +1 @@
+#include "pragma_once.compat.h"

tests/expectations/both/pragma_once.compat.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/both/pragma_once.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void root(void);

tests/expectations/pragma_once.c

@@ -0,0 +1 @@
+#include "pragma_once.h"

tests/expectations/pragma_once.compat.c

@@ -0,0 +1 @@
+#include "pragma_once.compat.h"

tests/expectations/pragma_once.compat.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/pragma_once.cpp

@@ -0,0 +1 @@
+#include "pragma_once.hpp"

tests/expectations/pragma_once.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void root(void);

tests/expectations/pragma_once.hpp

@@ -0,0 +1,7 @@
+#pragma once
+
+extern "C" {
+
+void root();
+
+} // extern "C"

tests/expectations/tag/pragma_once.c

@@ -0,0 +1 @@
+#include "pragma_once.h"

tests/expectations/tag/pragma_once.compat.c

@@ -0,0 +1 @@
+#include "pragma_once.compat.h"

tests/expectations/tag/pragma_once.compat.h

@@ -0,0 +1,11 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+void root(void);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

tests/expectations/tag/pragma_once.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void root(void);

tests/rust/pragma_once.header.rs

@@ -0,0 +1,3 @@
+#[no_mangle]
+pub extern "C" fn root() {
+}

tests/rust/pragma_once.header.toml

@@ -0,0 +1,2 @@
+pragma_once = true
+no_includes = true

tests/testing-helpers.h

@@ -1,5 +1,5 @@
 #ifndef testing_helpers_h
-#define  testing_helpers_h
+#define testing_helpers_h
 
 // This is a helper file to easily add static_asserts to C / C++ tests.
 

tests/tests.rs

@@ -1,6 +1,7 @@
 extern crate cbindgen;
 
 use cbindgen::*;
+use std::io::Write;
 use std::path::Path;
 use std::process::Command;
 use std::{env, fs, str};
@@ -154,9 +155,44 @@ fn run_compile_test(
         }
     };
 
-    output.push(format!("{}.{}", name, ext));
+    let header_suffix = ".header";
+    let header_position = name.rfind(&header_suffix);
+    let is_header = header_position.is_some();
+
+    let source_file = format!(
+        "{}.{}",
+        if is_header {
+            &name[0..header_position.unwrap()]
+        } else {
+            name
+        },
+        &ext
+    );
+    output.push(&source_file);
+
+    if is_header {
+        let header_ext = match output.extension().unwrap().to_str().unwrap().as_ref() {
+            "cpp" => "hpp",
+            "c" => "h",
+            _ => "",
+        };
+        let mut ofile = fs::File::create(output.as_path()).expect("unable to create surce file");
+        output.set_extension(header_ext);
+        let source_file_content = format!(
+            "#include \"{}\"\n",
+            output.file_name().unwrap().to_str().unwrap()
+        );
+        ofile
+            .write(source_file_content.as_bytes())
+            .expect("unable to write source file content");
+    }
 
     run_cbindgen(cbindgen_path, path, &output, language, cpp_compat, style);
+
+    if is_header {
+        output.set_file_name(source_file);
+    }
+
     compile(&output, &tests_path, tmp_dir, language, style);
 
     if language == Language::C && cpp_compat {