let mut fmt = Cow::Borrowed(fmt); if self.tcx.sess.opts.unstable_opts.flatten_format_args { fmt = flatten_format_args(fmt); <del> fmt = inline_literals(fmt); </del> <ins> fmt = self.inline_literals(fmt); </ins> } expand_format_args(self, sp, &fmt, allow_const) } <ins> /// Try to convert a literal into an interned string fn try_inline_lit(&self, lit: token::Lit) -> Option<Symbol> { match LitKind::from_token_lit(lit) { Ok(LitKind::Str(s, _)) => Some(s), Ok(LitKind::Int(n, ty)) => { match ty { // unsuffixed integer literals are assumed to be i32's LitIntType::Unsuffixed => { (n <= i32::MAX as u128).then_some(Symbol::intern(&n.to_string())) } LitIntType::Signed(int_ty) => { let max_literal = self.int_ty_max(int_ty); (n <= max_literal).then_some(Symbol::intern(&n.to_string())) } LitIntType::Unsigned(uint_ty) => { let max_literal = self.uint_ty_max(uint_ty); (n <= max_literal).then_some(Symbol::intern(&n.to_string())) } } } _ => None, } } /// Get the maximum value of int_ty. It is platform-dependent due to the byte size of isize fn int_ty_max(&self, int_ty: IntTy) -> u128 { match int_ty { IntTy::Isize => self.tcx.data_layout.pointer_size.signed_int_max() as u128, IntTy::I8 => i8::MAX as u128, IntTy::I16 => i16::MAX as u128, IntTy::I32 => i32::MAX as u128, IntTy::I64 => i64::MAX as u128, IntTy::I128 => i128::MAX as u128, } } /// Get the maximum value of uint_ty. It is platform-dependent due to the byte size of usize fn uint_ty_max(&self, uint_ty: UintTy) -> u128 { match uint_ty { UintTy::Usize => self.tcx.data_layout.pointer_size.unsigned_int_max(), UintTy::U8 => u8::MAX as u128, UintTy::U16 => u16::MAX as u128, UintTy::U32 => u32::MAX as u128, UintTy::U64 => u64::MAX as u128, UintTy::U128 => u128::MAX as u128, } } /// Inline literals into the format string. /// /// Turns /// /// `format_args!("Hello, {}! {} {}", "World", 123, x)` /// /// into /// /// `format_args!("Hello, World! 123 {}", x)`. fn inline_literals<'fmt>(&self, mut fmt: Cow<'fmt, FormatArgs>) -> Cow<'fmt, FormatArgs> { let mut was_inlined = vec![false; fmt.arguments.all_args().len()]; let mut inlined_anything = false; for i in 0..fmt.template.len() { let FormatArgsPiece::Placeholder(placeholder) = &fmt.template[i] else { continue }; let Ok(arg_index) = placeholder.argument.index else { continue }; let mut literal = None; if let FormatTrait::Display = placeholder.format_trait && placeholder.format_options == Default::default() && let arg = fmt.arguments.all_args()[arg_index].expr.peel_parens_and_refs() && let ExprKind::Lit(lit) = arg.kind { literal = self.try_inline_lit(lit); } if let Some(literal) = literal { // Now we need to mutate the outer FormatArgs. // If this is the first time, this clones the outer FormatArgs. let fmt = fmt.to_mut(); // Replace the placeholder with the literal. fmt.template[i] = FormatArgsPiece::Literal(literal); was_inlined[arg_index] = true; inlined_anything = true; } } // Remove the arguments that were inlined. if inlined_anything { let fmt = fmt.to_mut(); let mut remove = was_inlined; // Don't remove anything that's still used. for_all_argument_indexes(&mut fmt.template, |index| remove[*index] = false); // Drop all the arguments that are marked for removal. let mut remove_it = remove.iter(); fmt.arguments.all_args_mut().retain(|_| remove_it.next() != Some(&true)); // Calculate the mapping of old to new indexes for the remaining arguments. let index_map: Vec<usize> = remove .into_iter() .scan(0, |i, remove| { let mapped = *i; *i += !remove as usize; Some(mapped) }) .collect(); // Correct the indexes that refer to arguments that have shifted position. for_all_argument_indexes(&mut fmt.template, |index| *index = index_map[*index]); } fmt } </ins> } /// Flattens nested `format_args!()` into one.