add write_bindings to LanguageBackend for more flexible LB impls

src/bindgen/bindings.rs

@@ -16,7 +16,7 @@ use crate::bindgen::ir::{
     Constant, Function, ItemContainer, ItemMap, Path as BindgenPath, Static, Struct, Type, Typedef,
 };
 use crate::bindgen::language_backend::{
-    CLikeLanguageBackend, CythonLanguageBackend, LanguageBackend, NamespaceOperation,
+    CLikeLanguageBackend, CythonLanguageBackend, LanguageBackend,
 };
 use crate::bindgen::writer::SourceWriter;
 
@@ -28,10 +28,10 @@ pub struct Bindings {
     struct_map: ItemMap<Struct>,
     typedef_map: ItemMap<Typedef>,
     struct_fileds_memo: RefCell<HashMap<BindgenPath, Rc<Vec<String>>>>,
-    globals: Vec<Static>,
-    constants: Vec<Constant>,
-    items: Vec<ItemContainer>,
-    functions: Vec<Function>,
+    pub globals: Vec<Static>,
+    pub constants: Vec<Constant>,
+    pub items: Vec<ItemContainer>,
+    pub functions: Vec<Function>,
     source_files: Vec<path::PathBuf>,
     /// Bindings are generated by a recursive call to cbindgen
     /// and shouldn't do anything when written anywhere.
@@ -202,142 +202,25 @@ impl Bindings {
     pub fn write<F: Write>(&self, file: F) {
         match self.config.language {
             Language::Cxx | Language::C => {
-                self.write_with_backend(file, &CLikeLanguageBackend::new(&self.config))
+                self.write_with_backend(file, &mut CLikeLanguageBackend::new(&self.config))
             }
             Language::Cython => {
-                self.write_with_backend(file, &CythonLanguageBackend::new(&self.config))
+                self.write_with_backend(file, &mut CythonLanguageBackend::new(&self.config))
             }
         }
     }
 
     pub fn write_with_backend<F: Write, LB: LanguageBackend>(
         &self,
         file: F,
-        language_backend: &LB,
+        language_backend: &mut LB,
     ) {
         if self.noop {
             return;
         }
 
         let mut out = SourceWriter::new(file, self);
 
-        language_backend.write_headers(&mut out);
-
-        language_backend.open_close_namespaces(NamespaceOperation::Open, &mut out);
-
-        for constant in &self.constants {
-            if constant.uses_only_primitive_types() {
-                out.new_line_if_not_start();
-                constant.write(&self.config, language_backend, &mut out, None);
-                out.new_line();
-            }
-        }
-
-        for item in &self.items {
-            if item
-                .deref()
-                .annotations()
-                .bool("no-export")
-                .unwrap_or(false)
-            {
-                continue;
-            }
-
-            out.new_line_if_not_start();
-            match *item {
-                ItemContainer::Constant(..) => unreachable!(),
-                ItemContainer::Static(..) => unreachable!(),
-                ItemContainer::Enum(ref x) => language_backend.write_enum(&mut out, x),
-                ItemContainer::Struct(ref x) => language_backend.write_struct(&mut out, x),
-                ItemContainer::Union(ref x) => language_backend.write_union(&mut out, x),
-                ItemContainer::OpaqueItem(ref x) => language_backend.write_opaque_item(&mut out, x),
-                ItemContainer::Typedef(ref x) => language_backend.write_type_def(&mut out, x),
-            }
-            out.new_line();
-        }
-
-        for constant in &self.constants {
-            if !constant.uses_only_primitive_types() {
-                out.new_line_if_not_start();
-                constant.write(&self.config, language_backend, &mut out, None);
-                out.new_line();
-            }
-        }
-
-        if !self.functions.is_empty() || !self.globals.is_empty() {
-            if self.config.cpp_compatible_c() {
-                out.new_line_if_not_start();
-                out.write("#ifdef __cplusplus");
-            }
-
-            if self.config.language == Language::Cxx {
-                if let Some(ref using_namespaces) = self.config.using_namespaces {
-                    for namespace in using_namespaces {
-                        out.new_line();
-                        write!(out, "using namespace {};", namespace);
-                    }
-                    out.new_line();
-                }
-            }
-
-            if self.config.language == Language::Cxx || self.config.cpp_compatible_c() {
-                out.new_line();
-                out.write("extern \"C\" {");
-                out.new_line();
-            }
-
-            if self.config.cpp_compatible_c() {
-                out.write("#endif // __cplusplus");
-                out.new_line();
-            }
-
-            for global in &self.globals {
-                out.new_line_if_not_start();
-                language_backend.write_static(&mut out, global);
-                out.new_line();
-            }
-
-            for function in &self.functions {
-                out.new_line_if_not_start();
-                language_backend.write_function(&mut out, function);
-                out.new_line();
-            }
-
-            if self.config.cpp_compatible_c() {
-                out.new_line();
-                out.write("#ifdef __cplusplus");
-            }
-
-            if self.config.language == Language::Cxx || self.config.cpp_compatible_c() {
-                out.new_line();
-                out.write("} // extern \"C\"");
-                out.new_line();
-            }
-
-            if self.config.cpp_compatible_c() {
-                out.write("#endif // __cplusplus");
-                out.new_line();
-            }
-        }
-
-        if self.config.language == Language::Cython
-            && self.globals.is_empty()
-            && self.constants.is_empty()
-            && self.items.is_empty()
-            && self.functions.is_empty()
-        {
-            out.write("pass");
-        }
-
-        language_backend.open_close_namespaces(NamespaceOperation::Close, &mut out);
-
-        language_backend.write_footers(&mut out);
-        if let Some(ref f) = self.config.trailer {
-            out.new_line_if_not_start();
-            write!(out, "{}", f);
-            if !f.ends_with('\n') {
-                out.new_line();
-            }
-        }
+        language_backend.write_bindings(&mut out, self);
     }
 }

src/bindgen/cdecl.rs

@@ -194,7 +194,7 @@ impl CDecl {
 
     fn write<F: Write, LB: LanguageBackend>(
         &self,
-        language_backend: &LB,
+        language_backend: &mut LB,
         out: &mut SourceWriter<F>,
         ident: Option<&str>,
         config: &Config,
@@ -305,7 +305,7 @@ impl CDecl {
                     }
 
                     fn write_vertical<F: Write, LB: LanguageBackend>(
-                        language_backend: &LB,
+                        language_backend: &mut LB,
                         out: &mut SourceWriter<F>,
                         config: &Config,
                         args: &[(Option<String>, CDecl)],
@@ -327,7 +327,7 @@ impl CDecl {
                     }
 
                     fn write_horizontal<F: Write, LB: LanguageBackend>(
-                        language_backend: &LB,
+                        language_backend: &mut LB,
                         out: &mut SourceWriter<F>,
                         config: &Config,
                         args: &[(Option<String>, CDecl)],
@@ -372,7 +372,7 @@ impl CDecl {
 }
 
 pub fn write_func<F: Write, LB: LanguageBackend>(
-    language_backend: &LB,
+    language_backend: &mut LB,
     out: &mut SourceWriter<F>,
     f: &Function,
     layout: Layout,
@@ -382,7 +382,7 @@ pub fn write_func<F: Write, LB: LanguageBackend>(
 }
 
 pub fn write_field<F: Write, LB: LanguageBackend>(
-    language_backend: &LB,
+    language_backend: &mut LB,
     out: &mut SourceWriter<F>,
     t: &Type,
     ident: &str,
@@ -392,7 +392,7 @@ pub fn write_field<F: Write, LB: LanguageBackend>(
 }
 
 pub fn write_type<F: Write, LB: LanguageBackend>(
-    language_backend: &LB,
+    language_backend: &mut LB,
     out: &mut SourceWriter<F>,
     t: &Type,
     config: &Config,

src/bindgen/ir/constant.rs

@@ -595,7 +595,7 @@ impl Constant {
     pub fn write_declaration<F: Write, LB: LanguageBackend>(
         &self,
         config: &Config,
-        language_backend: &LB,
+        language_backend: &mut LB,
         out: &mut SourceWriter<F>,
         associated_to_struct: &Struct,
     ) {
@@ -617,7 +617,7 @@ impl Constant {
     pub fn write<F: Write, LB: LanguageBackend>(
         &self,
         config: &Config,
-        language_backend: &LB,
+        language_backend: &mut LB,
         out: &mut SourceWriter<F>,
         associated_to_struct: Option<&Struct>,
     ) {

src/bindgen/ir/enumeration.rs

@@ -637,11 +637,11 @@ impl Enum {
     pub(crate) fn write_tag_enum<
         F: Write,
         LB: LanguageBackend,
-        WV: Fn(&LB, &mut SourceWriter<F>, &EnumVariant),
+        WV: Fn(&mut LB, &mut SourceWriter<F>, &EnumVariant),
     >(
         &self,
         config: &Config,
-        language_backend: &LB,
+        language_backend: &mut LB,
         out: &mut SourceWriter<F>,
         size: Option<&str>,
         write_variant: WV,
@@ -809,7 +809,7 @@ impl Enum {
     pub(crate) fn write_variant_defs<F: Write, LB: LanguageBackend>(
         &self,
         config: &Config,
-        language_backend: &LB, // TODO probably need only one of Config/LanguageBackend
+        language_backend: &mut LB, // TODO probably need only one of Config/LanguageBackend
         out: &mut SourceWriter<F>,
     ) {
         for variant in &self.variants {
@@ -870,11 +870,11 @@ impl Enum {
     pub(crate) fn write_variant_fields<
         F: Write,
         LB: LanguageBackend,
-        WF: Fn(&LB, &mut SourceWriter<F>, &Field),
+        WF: Fn(&mut LB, &mut SourceWriter<F>, &Field),
     >(
         &self,
         config: &Config,
-        language_backend: &LB,
+        language_backend: &mut LB,
         out: &mut SourceWriter<F>,
         inline_tag_field: bool,
         write_field: WF,
@@ -933,7 +933,7 @@ impl Enum {
     fn write_derived_functions_enum<F: Write, LB: LanguageBackend>(
         &self,
         config: &Config,
-        language_backend: &LB,
+        language_backend: &mut LB,
         out: &mut SourceWriter<F>,
     ) {
         let has_data = self.tag.is_some();
@@ -1089,11 +1089,11 @@ impl Enum {
     pub(crate) fn write_derived_functions_data<
         F: Write,
         LB: LanguageBackend,
-        WF: Fn(&LB, &mut SourceWriter<F>, &Field),
+        WF: Fn(&mut LB, &mut SourceWriter<F>, &Field),
     >(
         &self,
         config: &Config,
-        language_backend: &LB,
+        language_backend: &mut LB,
         out: &mut SourceWriter<F>,
         tag_name: &str,
         write_field: WF,

src/bindgen/ir/generic_path.rs

@@ -97,7 +97,7 @@ impl GenericParams {
 
     pub(crate) fn write_internal<F: Write, LB: LanguageBackend>(
         &self,
-        language_backend: &LB,
+        language_backend: &mut LB,
         config: &Config,
         out: &mut SourceWriter<F>,
         with_default: bool,
@@ -130,7 +130,7 @@ impl GenericParams {
 
     pub fn write_with_default<F: Write, LB: LanguageBackend>(
         &self,
-        language_backend: &LB,
+        language_backend: &mut LB,
         config: &Config,
         out: &mut SourceWriter<F>,
     ) {