Struct rustc_builtin_macros::assert::context::Context

pub(super) struct Context<'cx, 'a> {
    best_case_captures: Vec<Stmt>,
    capture_decls: Vec<Capture>,
    cx: &'cx ExtCtxt<'a>,
    fmt_string: String,
    is_consumed: bool,
    local_bind_decls: Vec<Stmt>,
    paths: FxHashSet<Ident>,
    span: Span,
}

Fields

best_case_captures: Vec<Stmt>

capture_decls: Vec<Capture>

cx: &'cx ExtCtxt<'a>

fmt_string: String

is_consumed: bool

local_bind_decls: Vec<Stmt>

paths: FxHashSet<Ident>

span: Span

Implementations

impl<'cx, 'a> Context<'cx, 'a>

pub(super) fn new(cx: &'cx ExtCtxt<'a>, span: Span) -> Self

pub(super) fn build(self, cond_expr: P<Expr>, panic_path: Path) -> P<Expr>

Builds the whole assert! expression. For example, let elem = 1; assert!(elem == 1); expands to:

#![feature(generic_assert_internals)]
let elem = 1;
{
  #[allow(unused_imports)]
  use ::core::asserting::{TryCaptureGeneric, TryCapturePrintable};
  let mut __capture0 = ::core::asserting::Capture::new();
  let __local_bind0 = &elem;
  if !(
    *{
      (&::core::asserting::Wrapper(__local_bind0)).try_capture(&mut __capture0);
      __local_bind0
    } == 1
  ) {
    panic!("Assertion failed: elem == 1\nWith captures:\n  elem = {:?}", __capture0)
  }
}

fn build_initial_imports(&self) -> Stmt

Initial trait imports

use ::core::asserting::{ … };

fn build_unlikely(&self, cond_expr: P<Expr>) -> P<Expr>

Takes the conditional expression of assert! and then wraps it inside unlikely

fn build_panic(&self, expr_str: &str, panic_path: Path) -> P<Expr>

The necessary custom panic!(...) expression.

panic!( “Assertion failed: … \n With expansion: …”, __capture0, … );

fn manage_cond_expr(&mut self, expr: &mut P<Expr>)

Recursive function called until cond_expr and fmt_str are fully modified.

See Self::manage_initial_capture and Self::manage_try_capture

fn manage_initial_capture(&mut self, expr: &mut P<Expr>, path_ident: Ident)

Pushes the top-level declarations and modifies expr to try capturing variables.

fmt_str, the formatting string used for debugging, is constructed to show possible captured variables.

fn manage_try_capture( &mut self, capture: Ident, curr_capture_idx: usize, expr: &mut P<Expr> )

Tries to copy __local_bindN into __captureN.

*{ (&Wrapper(__local_bindN)).try_capture(&mut __captureN); __local_bindN }

fn with_is_consumed_management( &mut self, curr_is_consumed: bool, f: impl FnOnce(&mut Self) )

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 152 bytes