Basic compiler infra

compiler/rustc_builtin_macros/src/assert/context.rs

@@ -0,0 +1,44 @@
+use rustc_ast::{ptr::P, Expr, Path};
+use rustc_expand::base::ExtCtxt;
+use rustc_span::Span;
+
+pub(super) struct Context<'cx, 'a> {
+    cx: &'cx ExtCtxt<'a>,
+    span: Span,
+}
+
+impl<'cx, 'a> Context<'cx, 'a> {
+    pub(super) fn new(cx: &'cx ExtCtxt<'a>, span: Span) -> Self {
+        Self { cx, span }
+    }
+
+    /// Builds the whole `assert!` expression.
+    ///
+    /// {
+    ///    use ::core::asserting::{ ... };
+    ///
+    ///    let mut __capture0 = Capture::new();
+    ///    ...
+    ///    ...
+    ///    ...
+    ///
+    ///    if !{
+    ///       ...
+    ///       ...
+    ///       ...
+    ///    } {
+    ///        panic!(
+    ///            "Assertion failed: ... \n With expansion: ...",
+    ///            __capture0,
+    ///            ...
+    ///            ...
+    ///            ...
+    ///        );
+    ///    }
+    /// }
+    pub(super) fn build(self, _cond_expr: P<Expr>, _panic_path: Path) -> P<Expr> {
+        let Self { cx, span, .. } = self;
+        let stmts = Vec::new();
+        cx.expr_block(cx.block(span, stmts))
+    }
+}