codegen: Deal with overloads in method code generation.

Fixes #2019

Author: emilio

src/codegen/mod.rs

@@ -422,37 +422,36 @@ trait CodeGenerator {
     /// Extra information from the caller.
     type Extra;
 
+    /// Extra information returned to the caller.
+    type Return;
+
     fn codegen<'a>(
         &self,
         ctx: &BindgenContext,
         result: &mut CodegenResult<'a>,
         extra: &Self::Extra,
-    );
+    ) -> Self::Return;
 }
 
-impl CodeGenerator for Item {
-    type Extra = ();
-
-    fn codegen<'a>(
+impl Item {
+    fn process_before_codegen(
         &self,
         ctx: &BindgenContext,
-        result: &mut CodegenResult<'a>,
-        _extra: &(),
-    ) {
+        result: &mut CodegenResult,
+    ) -> bool {
         if !self.is_enabled_for_codegen(ctx) {
-            return;
+            return false;
         }
 
         if self.is_blocklisted(ctx) || result.seen(self.id()) {
             debug!(
-                "<Item as CodeGenerator>::codegen: Ignoring hidden or seen: \
+                "<Item as CodeGenerator>::process_before_codegen: Ignoring hidden or seen: \
                  self = {:?}",
                 self
             );
-            return;
+            return false;
         }
 
-        debug!("<Item as CodeGenerator>::codegen: self = {:?}", self);
         if !ctx.codegen_items().contains(&self.id()) {
             // TODO(emilio, #453): Figure out what to do when this happens
             // legitimately, we could track the opaque stuff and disable the
@@ -461,6 +460,24 @@ impl CodeGenerator for Item {
         }
 
         result.set_seen(self.id());
+        true
+    }
+}
+
+impl CodeGenerator for Item {
+    type Extra = ();
+    type Return = ();
+
+    fn codegen<'a>(
+        &self,
+        ctx: &BindgenContext,
+        result: &mut CodegenResult<'a>,
+        _extra: &(),
+    ) {
+        debug!("<Item as CodeGenerator>::codegen: self = {:?}", self);
+        if !self.process_before_codegen(ctx, result) {
+            return;
+        }
 
         match *self.kind() {
             ItemKind::Module(ref module) => {
@@ -481,6 +498,7 @@ impl CodeGenerator for Item {
 
 impl CodeGenerator for Module {
     type Extra = Item;
+    type Return = ();
 
     fn codegen<'a>(
         &self,
@@ -572,6 +590,8 @@ impl CodeGenerator for Module {
 
 impl CodeGenerator for Var {
     type Extra = Item;
+    type Return = ();
+
     fn codegen<'a>(
         &self,
         ctx: &BindgenContext,
@@ -698,6 +718,7 @@ impl CodeGenerator for Var {
 
 impl CodeGenerator for Type {
     type Extra = Item;
+    type Return = ();
 
     fn codegen<'a>(
         &self,
@@ -1004,6 +1025,7 @@ impl<'a> Vtable<'a> {
 
 impl<'a> CodeGenerator for Vtable<'a> {
     type Extra = Item;
+    type Return = ();
 
     fn codegen<'b>(
         &self,
@@ -1048,6 +1070,7 @@ impl<'a> TryToRustTy for Vtable<'a> {
 
 impl CodeGenerator for TemplateInstantiation {
     type Extra = Item;
+    type Return = ();
 
     fn codegen<'a>(
         &self,
@@ -1664,6 +1687,7 @@ impl<'a> FieldCodegen<'a> for Bitfield {
 
 impl CodeGenerator for CompInfo {
     type Extra = Item;
+    type Return = ();
 
     fn codegen<'a>(
         &self,
@@ -2261,13 +2285,15 @@ impl MethodCodegen for Method {
 
         // First of all, output the actual function.
         let function_item = ctx.resolve_item(self.signature());
-        if function_item.is_blocklisted(ctx) {
-            // We shouldn't emit a method declaration if the function is blocklisted
+        if !function_item.process_before_codegen(ctx, result) {
             return;
         }
-        function_item.codegen(ctx, result, &());
-
         let function = function_item.expect_function();
+        let times_seen = function.codegen(ctx, result, &function_item);
+        let times_seen = match times_seen {
+            Some(seen) => seen,
+            None => return,
+        };
         let signature_item = ctx.resolve_item(function.signature());
         let mut name = match self.kind() {
             MethodKind::Constructor => "new".into(),
@@ -2302,7 +2328,11 @@ impl MethodCodegen for Method {
             name.push_str(&count.to_string());
         }
 
-        let function_name = ctx.rust_ident(function_item.canonical_name(ctx));
+        let mut function_name = function_item.canonical_name(ctx);
+        if times_seen > 0 {
+            write!(&mut function_name, "{}", times_seen).unwrap();
+        }
+        let function_name = ctx.rust_ident(function_name);
         let mut args = utils::fnsig_arguments(ctx, signature);
         let mut ret = utils::fnsig_return_ty(ctx, signature);
 
@@ -2808,6 +2838,7 @@ impl<'a> EnumBuilder<'a> {
 
 impl CodeGenerator for Enum {
     type Extra = Item;
+    type Return = ();
 
     fn codegen<'a>(
         &self,
@@ -3731,19 +3762,23 @@ impl TryToRustTy for FunctionSig {
 impl CodeGenerator for Function {
     type Extra = Item;
 
+    /// If we've actually generated the symbol, the number of times we've seen
+    /// it.
+    type Return = Option<u32>;
+
     fn codegen<'a>(
         &self,
         ctx: &BindgenContext,
         result: &mut CodegenResult<'a>,
         item: &Item,
-    ) {
+    ) -> Self::Return {
         debug!("<Function as CodeGenerator>::codegen: item = {:?}", item);
         debug_assert!(item.is_enabled_for_codegen(ctx));
 
         // We can't currently do anything with Internal functions so just
         // avoid generating anything for them.
         match self.linkage() {
-            Linkage::Internal => return,
+            Linkage::Internal => return None,
             Linkage::External => {}
         }
 
@@ -3753,7 +3788,7 @@ impl CodeGenerator for Function {
             FunctionKind::Method(ref method_kind)
                 if method_kind.is_pure_virtual() =>
             {
-                return;
+                return None;
             }
             _ => {}
         }
@@ -3763,7 +3798,7 @@ impl CodeGenerator for Function {
         // instantiations is open ended and we have no way of knowing which
         // monomorphizations actually exist.
         if !item.all_template_params(ctx).is_empty() {
-            return;
+            return None;
         }
 
         let name = self.name();
@@ -3776,7 +3811,7 @@ impl CodeGenerator for Function {
             // TODO: Maybe warn here if there's a type/argument mismatch, or
             // something?
             if result.seen_function(seen_symbol_name) {
-                return;
+                return None;
             }
             result.saw_function(seen_symbol_name);
         }
@@ -3803,21 +3838,14 @@ impl CodeGenerator for Function {
             attributes.push(attributes::doc(comment));
         }
 
-        // Handle overloaded functions by giving each overload its own unique
-        // suffix.
-        let times_seen = result.overload_number(&canonical_name);
-        if times_seen > 0 {
-            write!(&mut canonical_name, "{}", times_seen).unwrap();
-        }
-
         let abi = match signature.abi() {
             Abi::ThisCall if !ctx.options().rust_features().thiscall_abi => {
                 warn!("Skipping function with thiscall ABI that isn't supported by the configured Rust target");
-                return;
+                return None;
             }
             Abi::Win64 if signature.is_variadic() => {
                 warn!("Skipping variadic function with Win64 ABI that isn't supported");
-                return;
+                return None;
             }
             Abi::Unknown(unknown_abi) => {
                 panic!(
@@ -3828,6 +3856,13 @@ impl CodeGenerator for Function {
             abi => abi,
         };
 
+        // Handle overloaded functions by giving each overload its own unique
+        // suffix.
+        let times_seen = result.overload_number(&canonical_name);
+        if times_seen > 0 {
+            write!(&mut canonical_name, "{}", times_seen).unwrap();
+        }
+
         let link_name = mangled_name.unwrap_or(name);
         if !utils::names_will_be_identical_after_mangling(
             &canonical_name,
@@ -3878,6 +3913,7 @@ impl CodeGenerator for Function {
         } else {
             result.push(tokens);
         }
+        Some(times_seen)
     }
 }
 
@@ -3933,6 +3969,7 @@ fn objc_method_codegen(
 
 impl CodeGenerator for ObjCInterface {
     type Extra = Item;
+    type Return = ();
 
     fn codegen<'a>(
         &self,

tests/expectations/tests/issue-2019.rs

@@ -0,0 +1,73 @@
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
+
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct A {
+    pub a: ::std::os::raw::c_int,
+}
+#[test]
+fn bindgen_test_layout_A() {
+    assert_eq!(
+        ::std::mem::size_of::<A>(),
+        4usize,
+        concat!("Size of: ", stringify!(A))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<A>(),
+        4usize,
+        concat!("Alignment of ", stringify!(A))
+    );
+    assert_eq!(
+        unsafe { &(*(::std::ptr::null::<A>())).a as *const _ as usize },
+        0usize,
+        concat!("Offset of field: ", stringify!(A), "::", stringify!(a))
+    );
+}
+extern "C" {
+    #[link_name = "\u{1}_ZN1A4makeEv"]
+    pub fn make() -> A;
+}
+impl A {
+    #[inline]
+    pub unsafe fn make() -> A {
+        make()
+    }
+}
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct B {
+    pub b: ::std::os::raw::c_int,
+}
+#[test]
+fn bindgen_test_layout_B() {
+    assert_eq!(
+        ::std::mem::size_of::<B>(),
+        4usize,
+        concat!("Size of: ", stringify!(B))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<B>(),
+        4usize,
+        concat!("Alignment of ", stringify!(B))
+    );
+    assert_eq!(
+        unsafe { &(*(::std::ptr::null::<B>())).b as *const _ as usize },
+        0usize,
+        concat!("Offset of field: ", stringify!(B), "::", stringify!(b))
+    );
+}
+extern "C" {
+    #[link_name = "\u{1}_ZN1B4makeEv"]
+    pub fn make1() -> B;
+}
+impl B {
+    #[inline]
+    pub unsafe fn make() -> B {
+        make1()
+    }
+}

tests/headers/issue-2019.hpp

@@ -0,0 +1,10 @@
+// bindgen-flags: --disable-nested-struct-naming
+
+struct A {
+    static A make();
+    int a;
+};
+struct B {
+    static B make();
+    int b;
+};