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use std::collections::hash_map::Entry;
use syn::parse;
use syn::Token;
use quote::quote;
use proc_macro_error::emit_error;
use crate::common::{Stmt, Size, delimited};
use crate::arch;
use crate::DynasmContext;
use crate::parse_helpers::ParseOptExt;
pub(crate) fn evaluate_directive(invocation_context: &mut DynasmContext, stmts: &mut Vec<Stmt>, input: parse::ParseStream) -> parse::Result<()> {
let directive: syn::Ident = input.parse()?;
match directive.to_string().as_str() {
"arch" => {
let arch: syn::Ident = input.parse()?;
if let Some(a) = arch::from_str(arch.to_string().as_str()) {
invocation_context.current_arch = a;
} else {
emit_error!(arch, "Unknown architecture '{}'", arch);
}
},
"feature" => {
let mut features = Vec::new();
let ident: syn::Ident = input.parse()?;
features.push(ident);
while input.peek(Token![,]) {
let _: Token![,] = input.parse()?;
let ident: syn::Ident = input.parse()?;
features.push(ident);
}
if features.len() == 1 && features[0] == "none" {
features.pop();
}
invocation_context.current_arch.set_features(&features);
},
"byte" => directive_const(invocation_context, stmts, input, Size::BYTE)?,
"word" => directive_const(invocation_context, stmts, input, Size::WORD)?,
"dword" => directive_const(invocation_context, stmts, input, Size::DWORD)?,
"qword" => directive_const(invocation_context, stmts, input, Size::QWORD)?,
"bytes" => {
let iterator: syn::Expr = input.parse()?;
stmts.push(Stmt::ExprExtend(delimited(iterator)));
},
"align" => {
let value: syn::Expr = input.parse()?;
let with = if input.peek(Token![,]) {
let _: Token![,] = input.parse()?;
let with: syn::Expr = input.parse()?;
delimited(with)
} else {
let with = invocation_context.current_arch.default_align();
delimited(quote!(#with))
};
stmts.push(Stmt::Align(delimited(value), with));
},
"alias" => {
let alias = input.parse::<syn::Ident>()?;
let _: Token![,] = input.parse()?;
let reg = input.parse::<syn::Ident>()?;
let alias_name = alias.to_string();
match invocation_context.aliases.entry(alias_name) {
Entry::Occupied(_) => {
emit_error!(alias, "Duplicate alias definition, alias '{}' was already defined", alias);
},
Entry::Vacant(v) => {
v.insert(reg.to_string());
}
}
},
d => {
emit_error!(directive, "unknown directive '{}'", d);
skip_until_semicolon(input);
}
}
Ok(())
}
fn directive_const(invocation_context: &mut DynasmContext, stmts: &mut Vec<Stmt>, input: parse::ParseStream, size: Size) -> parse::Result<()> {
if input.is_empty() || input.peek(Token![;]) {
return Ok(())
}
if let Some(jump) = input.parse_opt()? {
invocation_context.current_arch.handle_static_reloc(stmts, jump, size);
} else {
let expr: syn::Expr = input.parse()?;
stmts.push(Stmt::ExprSigned(delimited(expr), size));
}
while input.peek(Token![,]) {
let _: Token![,] = input.parse()?;
if let Some(jump) = input.parse_opt()? {
invocation_context.current_arch.handle_static_reloc(stmts, jump, size);
} else {
let expr: syn::Expr = input.parse()?;
stmts.push(Stmt::ExprSigned(delimited(expr), size));
}
}
Ok(())
}
fn skip_until_semicolon(input: parse::ParseStream) {
let _ = input.step(|cursor| {
let mut rest = *cursor;
while let Some((tt, next)) = rest.token_tree() {
match tt {
::proc_macro2::TokenTree::Punct(ref punct) if punct.as_char() == ';' => {
return Ok(((), rest));
}
_ => rest = next,
}
}
Ok(((), rest))
});
}