Method verify_global_values

cranelift/codegen/src/verifier/mod.rs:331–418

Check for: - cycles in the global value declarations. - use of 'vmctx' when no special parameter declares it.

(&self, errors: &mut VerifierErrors)

    //  - cycles in the global value declarations.
    //  - use of 'vmctx' when no special parameter declares it.
    fn verify_global_values(&self, errors: &mut VerifierErrors) -> VerifierStepResult {
        let mut cycle_seen = false;
        let mut seen = SparseSet::new();

        'gvs: for gv in self.func.global_values.keys() {
            seen.clear();
            seen.insert(gv);

            let mut cur = gv;
            loop {
                match self.func.global_values[cur] {
                    ir::GlobalValueData::Load { base, .. }
                    | ir::GlobalValueData::IAddImm { base, .. } => {
                        if seen.insert(base).is_some() {
                            if !cycle_seen {
                                errors.report((
                                    gv,
                                    format!("global value cycle: {}", DisplayList(seen.as_slice())),
                                ));
                                // ensures we don't report the cycle multiple times
                                cycle_seen = true;
                            }
                            continue 'gvs;
                        }

                        cur = base;
                    }
                    _ => break,
                }
            }

            match self.func.global_values[gv] {
                ir::GlobalValueData::VMContext { .. } => {
                    if self
                        .func
                        .special_param(ir::ArgumentPurpose::VMContext)
                        .is_none()
                    {
                        errors.report((gv, format!("undeclared vmctx reference {gv}")));
                    }
                }
                ir::GlobalValueData::IAddImm {
                    base, global_type, ..
                } => {
                    if !global_type.is_int() {
                        errors.report((
                            gv,
                            format!("iadd_imm global value with non-int type {global_type}"),
                        ));
                    } else if let Some(isa) = self.isa {
                        let base_type = self.func.global_values[base].global_type(isa);
                        if global_type != base_type {
                            errors.report((
                                gv,
                                format!(
                                    "iadd_imm type {global_type} differs from operand type {base_type}"
                                ),
                            ));