diff options
Diffstat (limited to 'src/bindgen/cdecl.rs')
| -rw-r--r-- | src/bindgen/cdecl.rs | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/src/bindgen/cdecl.rs b/src/bindgen/cdecl.rs new file mode 100644 index 0000000..a9c5a0f --- /dev/null +++ b/src/bindgen/cdecl.rs @@ -0,0 +1,372 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +use std::io::Write; + +use crate::bindgen::config::Layout; +use crate::bindgen::declarationtyperesolver::DeclarationType; +use crate::bindgen::ir::{ConstExpr, Function, GenericArgument, Type}; +use crate::bindgen::writer::{ListType, SourceWriter}; +use crate::bindgen::{Config, Language}; + +// This code is for translating Rust types into C declarations. +// See Section 6.7, Declarations, in the C standard for background. +// http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf + +enum CDeclarator { + Ptr { + is_const: bool, + is_nullable: bool, + is_ref: bool, + }, + Array(String), + Func { + args: Vec<(Option<String>, CDecl)>, + layout: Layout, + never_return: bool, + }, +} + +impl CDeclarator { + fn is_ptr(&self) -> bool { + matches!(self, CDeclarator::Ptr { .. } | CDeclarator::Func { .. }) + } +} + +struct CDecl { + type_qualifers: String, + type_name: String, + type_generic_args: Vec<GenericArgument>, + declarators: Vec<CDeclarator>, + type_ctype: Option<DeclarationType>, + deprecated: Option<String>, +} + +impl CDecl { + fn new() -> CDecl { + CDecl { + type_qualifers: String::new(), + type_name: String::new(), + type_generic_args: Vec::new(), + declarators: Vec::new(), + type_ctype: None, + deprecated: None, + } + } + + fn from_type(t: &Type, config: &Config) -> CDecl { + let mut cdecl = CDecl::new(); + cdecl.build_type(t, false, config); + cdecl + } + + fn from_func_arg(t: &Type, array_length: Option<&str>, config: &Config) -> CDecl { + let mut cdecl = CDecl::new(); + let length = match array_length { + Some(l) => l, + None => return CDecl::from_type(t, config), + }; + let (ty, is_const) = match t { + Type::Ptr { ty, is_const, .. } => (ty, is_const), + _ => unreachable!( + "Should never have an array length for a non pointer type {:?}", + t + ), + }; + let ptr_as_array = Type::Array(ty.clone(), ConstExpr::Value(length.to_string())); + cdecl.build_type(&ptr_as_array, *is_const, config); + cdecl + } + + fn from_func(f: &Function, layout: Layout, config: &Config) -> CDecl { + let mut cdecl = CDecl::new(); + cdecl.build_func(f, layout, config); + cdecl + } + + fn build_func(&mut self, f: &Function, layout: Layout, config: &Config) { + let args = f + .args + .iter() + .map(|arg| { + ( + arg.name.clone(), + CDecl::from_func_arg(&arg.ty, arg.array_length.as_deref(), config), + ) + }) + .collect(); + self.declarators.push(CDeclarator::Func { + args, + layout, + never_return: f.never_return, + }); + self.deprecated = f.annotations.deprecated.clone(); + self.build_type(&f.ret, false, config); + } + + fn build_type(&mut self, t: &Type, is_const: bool, config: &Config) { + match t { + Type::Path(ref generic) => { + if is_const { + assert!( + self.type_qualifers.is_empty(), + "error generating cdecl for {:?}", + t + ); + self.type_qualifers = "const".to_owned(); + } + + assert!( + self.type_name.is_empty(), + "error generating cdecl for {:?}", + t + ); + self.type_name = generic.export_name().to_owned(); + assert!( + self.type_generic_args.is_empty(), + "error generating cdecl for {:?}", + t + ); + self.type_generic_args = generic.generics().to_owned(); + self.type_ctype = generic.ctype().cloned(); + } + Type::Primitive(ref p) => { + if is_const { + assert!( + self.type_qualifers.is_empty(), + "error generating cdecl for {:?}", + t + ); + self.type_qualifers = "const".to_owned(); + } + + assert!( + self.type_name.is_empty(), + "error generating cdecl for {:?}", + t + ); + self.type_name = p.to_repr_c(config).to_string(); + } + Type::Ptr { + ref ty, + is_nullable, + is_const: ptr_is_const, + is_ref, + } => { + self.declarators.push(CDeclarator::Ptr { + is_const, + is_nullable: *is_nullable, + is_ref: *is_ref, + }); + self.build_type(ty, *ptr_is_const, config); + } + Type::Array(ref t, ref constant) => { + let len = constant.as_str().to_owned(); + self.declarators.push(CDeclarator::Array(len)); + self.build_type(t, is_const, config); + } + Type::FuncPtr { + ref ret, + ref args, + is_nullable: _, + never_return, + } => { + let args = args + .iter() + .map(|(ref name, ref ty)| (name.clone(), CDecl::from_type(ty, config))) + .collect(); + self.declarators.push(CDeclarator::Ptr { + is_const: false, + is_nullable: true, + is_ref: false, + }); + self.declarators.push(CDeclarator::Func { + args, + layout: config.function.args.clone(), + never_return: *never_return, + }); + self.build_type(ret, false, config); + } + } + } + + fn write<F: Write>(&self, out: &mut SourceWriter<F>, ident: Option<&str>, config: &Config) { + // Write the type-specifier and type-qualifier first + if !self.type_qualifers.is_empty() { + write!(out, "{} ", self.type_qualifers); + } + + if config.language != Language::Cython { + if let Some(ref ctype) = self.type_ctype { + write!(out, "{} ", ctype.to_str()); + } + } + + write!(out, "{}", self.type_name); + + if !self.type_generic_args.is_empty() { + out.write("<"); + out.write_horizontal_source_list(&self.type_generic_args, ListType::Join(", ")); + out.write(">"); + } + + // When we have an identifier, put a space between the type and the declarators + if ident.is_some() { + out.write(" "); + } + + // Write the left part of declarators before the identifier + let mut iter_rev = self.declarators.iter().rev().peekable(); + + #[allow(clippy::while_let_on_iterator)] + while let Some(declarator) = iter_rev.next() { + let next_is_pointer = iter_rev.peek().map_or(false, |x| x.is_ptr()); + + match *declarator { + CDeclarator::Ptr { + is_const, + is_nullable, + is_ref, + } => { + out.write(if is_ref { "&" } else { "*" }); + if is_const { + out.write("const "); + } + if !is_nullable && !is_ref && config.language != Language::Cython { + if let Some(attr) = &config.pointer.non_null_attribute { + write!(out, "{} ", attr); + } + } + } + CDeclarator::Array(..) => { + if next_is_pointer { + out.write("("); + } + } + CDeclarator::Func { .. } => { + if next_is_pointer { + out.write("("); + } + } + } + } + + // Write the identifier + if let Some(ident) = ident { + write!(out, "{}", ident); + } + + // Write the right part of declarators after the identifier + let mut iter = self.declarators.iter(); + let mut last_was_pointer = false; + + #[allow(clippy::while_let_on_iterator)] + while let Some(declarator) = iter.next() { + match *declarator { + CDeclarator::Ptr { .. } => { + last_was_pointer = true; + } + CDeclarator::Array(ref constant) => { + if last_was_pointer { + out.write(")"); + } + write!(out, "[{}]", constant); + + last_was_pointer = false; + } + CDeclarator::Func { + ref args, + ref layout, + never_return, + } => { + if last_was_pointer { + out.write(")"); + } + + out.write("("); + if args.is_empty() && config.language == Language::C { + out.write("void"); + } + + fn write_vertical<F: Write>( + out: &mut SourceWriter<F>, + config: &Config, + args: &[(Option<String>, CDecl)], + ) { + let align_length = out.line_length_for_align(); + out.push_set_spaces(align_length); + for (i, (arg_ident, arg_ty)) in args.iter().enumerate() { + if i != 0 { + out.write(","); + out.new_line(); + } + + // Convert &Option<String> to Option<&str> + let arg_ident = arg_ident.as_ref().map(|x| x.as_ref()); + + arg_ty.write(out, arg_ident, config); + } + out.pop_tab(); + } + + fn write_horizontal<F: Write>( + out: &mut SourceWriter<F>, + config: &Config, + args: &[(Option<String>, CDecl)], + ) { + for (i, (arg_ident, arg_ty)) in args.iter().enumerate() { + if i != 0 { + out.write(", "); + } + + // Convert &Option<String> to Option<&str> + let arg_ident = arg_ident.as_ref().map(|x| x.as_ref()); + + arg_ty.write(out, arg_ident, config); + } + } + + match layout { + Layout::Vertical => write_vertical(out, config, args), + Layout::Horizontal => write_horizontal(out, config, args), + Layout::Auto => { + if !out.try_write( + |out| write_horizontal(out, config, args), + config.line_length, + ) { + write_vertical(out, config, args) + } + } + } + out.write(")"); + + if never_return && config.language != Language::Cython { + if let Some(ref no_return_attr) = config.function.no_return { + out.write_fmt(format_args!(" {}", no_return_attr)); + } + } + + last_was_pointer = true; + } + } + } + } +} + +pub fn write_func<F: Write>( + out: &mut SourceWriter<F>, + f: &Function, + layout: Layout, + config: &Config, +) { + CDecl::from_func(f, layout, config).write(out, Some(f.path().name()), config); +} + +pub fn write_field<F: Write>(out: &mut SourceWriter<F>, t: &Type, ident: &str, config: &Config) { + CDecl::from_type(t, config).write(out, Some(ident), config); +} + +pub fn write_type<F: Write>(out: &mut SourceWriter<F>, t: &Type, config: &Config) { + CDecl::from_type(t, config).write(out, None, config); +} |