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Diffstat (limited to 'third_party/rust/bindgen/ir/var.rs')
| -rw-r--r-- | third_party/rust/bindgen/ir/var.rs | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/third_party/rust/bindgen/ir/var.rs b/third_party/rust/bindgen/ir/var.rs new file mode 100644 index 0000000000..c86742ff69 --- /dev/null +++ b/third_party/rust/bindgen/ir/var.rs @@ -0,0 +1,414 @@ +//! Intermediate representation of variables. + +use super::super::codegen::MacroTypeVariation; +use super::context::{BindgenContext, TypeId}; +use super::dot::DotAttributes; +use super::function::cursor_mangling; +use super::int::IntKind; +use super::item::Item; +use super::ty::{FloatKind, TypeKind}; +use crate::callbacks::MacroParsingBehavior; +use crate::clang; +use crate::clang::ClangToken; +use crate::parse::{ + ClangItemParser, ClangSubItemParser, ParseError, ParseResult, +}; +use cexpr; +use std::io; +use std::num::Wrapping; + +/// The type for a constant variable. +#[derive(Debug)] +pub enum VarType { + /// A boolean. + Bool(bool), + /// An integer. + Int(i64), + /// A floating point number. + Float(f64), + /// A character. + Char(u8), + /// A string, not necessarily well-formed utf-8. + String(Vec<u8>), +} + +/// A `Var` is our intermediate representation of a variable. +#[derive(Debug)] +pub struct Var { + /// The name of the variable. + name: String, + /// The mangled name of the variable. + mangled_name: Option<String>, + /// The type of the variable. + ty: TypeId, + /// The value of the variable, that needs to be suitable for `ty`. + val: Option<VarType>, + /// Whether this variable is const. + is_const: bool, +} + +impl Var { + /// Construct a new `Var`. + pub fn new( + name: String, + mangled_name: Option<String>, + ty: TypeId, + val: Option<VarType>, + is_const: bool, + ) -> Var { + assert!(!name.is_empty()); + Var { + name, + mangled_name, + ty, + val, + is_const, + } + } + + /// Is this variable `const` qualified? + pub fn is_const(&self) -> bool { + self.is_const + } + + /// The value of this constant variable, if any. + pub fn val(&self) -> Option<&VarType> { + self.val.as_ref() + } + + /// Get this variable's type. + pub fn ty(&self) -> TypeId { + self.ty + } + + /// Get this variable's name. + pub fn name(&self) -> &str { + &self.name + } + + /// Get this variable's mangled name. + pub fn mangled_name(&self) -> Option<&str> { + self.mangled_name.as_deref() + } +} + +impl DotAttributes for Var { + fn dot_attributes<W>( + &self, + _ctx: &BindgenContext, + out: &mut W, + ) -> io::Result<()> + where + W: io::Write, + { + if self.is_const { + writeln!(out, "<tr><td>const</td><td>true</td></tr>")?; + } + + if let Some(ref mangled) = self.mangled_name { + writeln!( + out, + "<tr><td>mangled name</td><td>{}</td></tr>", + mangled + )?; + } + + Ok(()) + } +} + +fn default_macro_constant_type(ctx: &BindgenContext, value: i64) -> IntKind { + if value < 0 || + ctx.options().default_macro_constant_type == + MacroTypeVariation::Signed + { + if value < i32::min_value() as i64 || value > i32::max_value() as i64 { + IntKind::I64 + } else if !ctx.options().fit_macro_constants || + value < i16::min_value() as i64 || + value > i16::max_value() as i64 + { + IntKind::I32 + } else if value < i8::min_value() as i64 || + value > i8::max_value() as i64 + { + IntKind::I16 + } else { + IntKind::I8 + } + } else if value > u32::max_value() as i64 { + IntKind::U64 + } else if !ctx.options().fit_macro_constants || + value > u16::max_value() as i64 + { + IntKind::U32 + } else if value > u8::max_value() as i64 { + IntKind::U16 + } else { + IntKind::U8 + } +} + +/// Parses tokens from a CXCursor_MacroDefinition pointing into a function-like +/// macro, and calls the func_macro callback. +fn handle_function_macro( + cursor: &clang::Cursor, + callbacks: &dyn crate::callbacks::ParseCallbacks, +) { + let is_closing_paren = |t: &ClangToken| { + // Test cheap token kind before comparing exact spellings. + t.kind == clang_sys::CXToken_Punctuation && t.spelling() == b")" + }; + let tokens: Vec<_> = cursor.tokens().iter().collect(); + if let Some(boundary) = tokens.iter().position(is_closing_paren) { + let mut spelled = tokens.iter().map(ClangToken::spelling); + // Add 1, to convert index to length. + let left = spelled.by_ref().take(boundary + 1); + let left = left.collect::<Vec<_>>().concat(); + if let Ok(left) = String::from_utf8(left) { + let right: Vec<_> = spelled.collect(); + callbacks.func_macro(&left, &right); + } + } +} + +impl ClangSubItemParser for Var { + fn parse( + cursor: clang::Cursor, + ctx: &mut BindgenContext, + ) -> Result<ParseResult<Self>, ParseError> { + use cexpr::expr::EvalResult; + use cexpr::literal::CChar; + use clang_sys::*; + match cursor.kind() { + CXCursor_MacroDefinition => { + for callbacks in &ctx.options().parse_callbacks { + match callbacks.will_parse_macro(&cursor.spelling()) { + MacroParsingBehavior::Ignore => { + return Err(ParseError::Continue); + } + MacroParsingBehavior::Default => {} + } + + if cursor.is_macro_function_like() { + handle_function_macro(&cursor, callbacks.as_ref()); + // We handled the macro, skip macro processing below. + return Err(ParseError::Continue); + } + } + + let value = parse_macro(ctx, &cursor); + + let (id, value) = match value { + Some(v) => v, + None => return Err(ParseError::Continue), + }; + + assert!(!id.is_empty(), "Empty macro name?"); + + let previously_defined = ctx.parsed_macro(&id); + + // NB: It's important to "note" the macro even if the result is + // not an integer, otherwise we might loose other kind of + // derived macros. + ctx.note_parsed_macro(id.clone(), value.clone()); + + if previously_defined { + let name = String::from_utf8(id).unwrap(); + warn!("Duplicated macro definition: {}", name); + return Err(ParseError::Continue); + } + + // NOTE: Unwrapping, here and above, is safe, because the + // identifier of a token comes straight from clang, and we + // enforce utf8 there, so we should have already panicked at + // this point. + let name = String::from_utf8(id).unwrap(); + let (type_kind, val) = match value { + EvalResult::Invalid => return Err(ParseError::Continue), + EvalResult::Float(f) => { + (TypeKind::Float(FloatKind::Double), VarType::Float(f)) + } + EvalResult::Char(c) => { + let c = match c { + CChar::Char(c) => { + assert_eq!(c.len_utf8(), 1); + c as u8 + } + CChar::Raw(c) => { + assert!(c <= ::std::u8::MAX as u64); + c as u8 + } + }; + + (TypeKind::Int(IntKind::U8), VarType::Char(c)) + } + EvalResult::Str(val) => { + let char_ty = Item::builtin_type( + TypeKind::Int(IntKind::U8), + true, + ctx, + ); + for callbacks in &ctx.options().parse_callbacks { + callbacks.str_macro(&name, &val); + } + (TypeKind::Pointer(char_ty), VarType::String(val)) + } + EvalResult::Int(Wrapping(value)) => { + let kind = ctx + .options() + .last_callback(|c| c.int_macro(&name, value)) + .unwrap_or_else(|| { + default_macro_constant_type(ctx, value) + }); + + (TypeKind::Int(kind), VarType::Int(value)) + } + }; + + let ty = Item::builtin_type(type_kind, true, ctx); + + Ok(ParseResult::New( + Var::new(name, None, ty, Some(val), true), + Some(cursor), + )) + } + CXCursor_VarDecl => { + let name = cursor.spelling(); + if name.is_empty() { + warn!("Empty constant name?"); + return Err(ParseError::Continue); + } + + let ty = cursor.cur_type(); + + // TODO(emilio): do we have to special-case constant arrays in + // some other places? + let is_const = ty.is_const() || + ([CXType_ConstantArray, CXType_IncompleteArray] + .contains(&ty.kind()) && + ty.elem_type() + .map_or(false, |element| element.is_const())); + + let ty = match Item::from_ty(&ty, cursor, None, ctx) { + Ok(ty) => ty, + Err(e) => { + assert!( + matches!(ty.kind(), CXType_Auto | CXType_Unexposed), + "Couldn't resolve constant type, and it \ + wasn't an nondeductible auto type or unexposed \ + type!" + ); + return Err(e); + } + }; + + // Note: Ty might not be totally resolved yet, see + // tests/headers/inner_const.hpp + // + // That's fine because in that case we know it's not a literal. + let canonical_ty = ctx + .safe_resolve_type(ty) + .and_then(|t| t.safe_canonical_type(ctx)); + + let is_integer = canonical_ty.map_or(false, |t| t.is_integer()); + let is_float = canonical_ty.map_or(false, |t| t.is_float()); + + // TODO: We could handle `char` more gracefully. + // TODO: Strings, though the lookup is a bit more hard (we need + // to look at the canonical type of the pointee too, and check + // is char, u8, or i8 I guess). + let value = if is_integer { + let kind = match *canonical_ty.unwrap().kind() { + TypeKind::Int(kind) => kind, + _ => unreachable!(), + }; + + let mut val = cursor.evaluate().and_then(|v| v.as_int()); + if val.is_none() || !kind.signedness_matches(val.unwrap()) { + val = get_integer_literal_from_cursor(&cursor); + } + + val.map(|val| { + if kind == IntKind::Bool { + VarType::Bool(val != 0) + } else { + VarType::Int(val) + } + }) + } else if is_float { + cursor + .evaluate() + .and_then(|v| v.as_double()) + .map(VarType::Float) + } else { + cursor + .evaluate() + .and_then(|v| v.as_literal_string()) + .map(VarType::String) + }; + + let mangling = cursor_mangling(ctx, &cursor); + let var = Var::new(name, mangling, ty, value, is_const); + + Ok(ParseResult::New(var, Some(cursor))) + } + _ => { + /* TODO */ + Err(ParseError::Continue) + } + } + } +} + +/// Try and parse a macro using all the macros parsed until now. +fn parse_macro( + ctx: &BindgenContext, + cursor: &clang::Cursor, +) -> Option<(Vec<u8>, cexpr::expr::EvalResult)> { + use cexpr::expr; + + let cexpr_tokens = cursor.cexpr_tokens(); + + let parser = expr::IdentifierParser::new(ctx.parsed_macros()); + + match parser.macro_definition(&cexpr_tokens) { + Ok((_, (id, val))) => Some((id.into(), val)), + _ => None, + } +} + +fn parse_int_literal_tokens(cursor: &clang::Cursor) -> Option<i64> { + use cexpr::expr; + use cexpr::expr::EvalResult; + + let cexpr_tokens = cursor.cexpr_tokens(); + + // TODO(emilio): We can try to parse other kinds of literals. + match expr::expr(&cexpr_tokens) { + Ok((_, EvalResult::Int(Wrapping(val)))) => Some(val), + _ => None, + } +} + +fn get_integer_literal_from_cursor(cursor: &clang::Cursor) -> Option<i64> { + use clang_sys::*; + let mut value = None; + cursor.visit(|c| { + match c.kind() { + CXCursor_IntegerLiteral | CXCursor_UnaryOperator => { + value = parse_int_literal_tokens(&c); + } + CXCursor_UnexposedExpr => { + value = get_integer_literal_from_cursor(&c); + } + _ => (), + } + if value.is_some() { + CXChildVisit_Break + } else { + CXChildVisit_Continue + } + }); + value +} |