Auto merge of rust-lang#952 - mchlrhw:master, r=fitzgen

Add `bindgen::Builder::derive_copy`

Fixes rust-lang#948

Author: bors-servo

src/codegen/mod.rs

@@ -1493,7 +1493,9 @@ impl CodeGenerator for CompInfo {
             needs_default_impl = ctx.options().derive_default;
         }
 
-        if item.can_derive_copy(ctx) && !item.annotations().disallow_copy() {
+        if item.can_derive_copy(ctx) && !item.annotations().disallow_copy() &&
+            ctx.options().derive_copy
+        {
             derives.push("Copy");
             if used_template_params.is_some() {
                 // FIXME: This requires extra logic if you have a big array in a

src/lib.rs

@@ -253,6 +253,10 @@ impl Builder {
             output_vector.push("--no-layout-tests".into());
         }
 
+        if !self.options.derive_copy {
+            output_vector.push("--no-derive-copy".into());
+        }
+
         if !self.options.derive_debug {
             output_vector.push("--no-derive-debug".into());
         }
@@ -735,6 +739,12 @@ impl Builder {
         self
     }
 
+    /// Set whether `Copy` should be derived by default.
+    pub fn derive_copy(mut self, doit: bool) -> Self {
+        self.options.derive_copy = doit;
+        self
+    }
+
     /// Set whether `Debug` should be derived by default.
     pub fn derive_debug(mut self, doit: bool) -> Self {
         self.options.derive_debug = doit;
@@ -1104,6 +1114,10 @@ pub struct BindgenOptions {
     /// True if we should generate layout tests for generated structures.
     pub layout_tests: bool,
 
+    /// True if we should derive Copy trait implementations for C/C++ structures
+    /// and types.
+    pub derive_copy: bool,
+
     /// True if we should derive Debug trait implementations for C/C++ structures
     /// and types.
     pub derive_debug: bool,
@@ -1269,6 +1283,7 @@ impl Default for BindgenOptions {
             emit_ir: false,
             emit_ir_graphviz: None,
             layout_tests: true,
+            derive_copy: true,
             derive_debug: true,
             impl_debug: false,
             derive_default: false,

src/options.rs

@@ -61,6 +61,9 @@ where
             Arg::with_name("no-layout-tests")
                 .long("no-layout-tests")
                 .help("Avoid generating layout tests for any type."),
+            Arg::with_name("no-derive-copy")
+                .long("no-derive-copy")
+                .help("Avoid deriving Copy on any type."),
             Arg::with_name("no-derive-debug")
                 .long("no-derive-debug")
                 .help("Avoid deriving Debug on any type."),
@@ -311,6 +314,10 @@ where
         builder = builder.layout_tests(false);
     }
 
+    if matches.is_present("no-derive-copy") {
+        builder = builder.derive_copy(false);
+    }
+
     if matches.is_present("no-derive-debug") {
         builder = builder.derive_debug(false);
     }

tests/expectations/tests/do-not-derive-copy.rs

@@ -0,0 +1,28 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+#[repr(C)]
+#[derive(Debug, Default)]
+pub struct WouldBeCopyButWeAreNotDerivingCopy {
+    pub x: ::std::os::raw::c_int,
+}
+#[test]
+fn bindgen_test_layout_WouldBeCopyButWeAreNotDerivingCopy() {
+    assert_eq!(::std::mem::size_of::<WouldBeCopyButWeAreNotDerivingCopy>() ,
+               4usize , concat ! (
+               "Size of: " , stringify ! ( WouldBeCopyButWeAreNotDerivingCopy
+               ) ));
+    assert_eq! (::std::mem::align_of::<WouldBeCopyButWeAreNotDerivingCopy>() ,
+                4usize , concat ! (
+                "Alignment of " , stringify ! (
+                WouldBeCopyButWeAreNotDerivingCopy ) ));
+    assert_eq! (unsafe {
+                & ( * ( 0 as * const WouldBeCopyButWeAreNotDerivingCopy ) ) .
+                x as * const _ as usize } , 0usize , concat ! (
+                "Alignment of field: " , stringify ! (
+                WouldBeCopyButWeAreNotDerivingCopy ) , "::" , stringify ! ( x
+                ) ));
+}

tests/headers/do-not-derive-copy.hpp

@@ -0,0 +1,5 @@
+// bindgen-flags: --no-derive-copy
+
+class WouldBeCopyButWeAreNotDerivingCopy {
+    int x;
+};