Method verify_inst_arg

cranelift/codegen/src/verifier/mod.rs:1004–1093

(
        &self,
        loc_inst: Inst,
        v: Value,
        errors: &mut VerifierErrors,
    )

    }

    fn verify_inst_arg(
        &self,
        loc_inst: Inst,
        v: Value,
        errors: &mut VerifierErrors,
    ) -> VerifierStepResult {
        self.verify_value(loc_inst, v, errors)?;

        let dfg = &self.func.dfg;
        let loc_block = self
            .func
            .layout
            .inst_block(loc_inst)
            .expect("Instruction not in layout.");
        let is_reachable = self.expected_domtree.is_reachable(loc_block);

        // SSA form
        match dfg.value_def(v) {
            ValueDef::Result(def_inst, _) => {
                // Value is defined by an instruction that exists.
                if !dfg.inst_is_valid(def_inst) {
                    return errors.fatal((
                        loc_inst,
                        self.context(loc_inst),
                        format!("{v} is defined by invalid instruction {def_inst}"),
                    ));
                }
                // Defining instruction is inserted in a block.
                if self.func.layout.inst_block(def_inst) == None {
                    return errors.fatal((
                        loc_inst,
                        self.context(loc_inst),
                        format!("{v} is defined by {def_inst} which has no block"),
                    ));
                }
                // Defining instruction dominates the instruction that uses the value.
                if is_reachable {
                    if !self
                        .expected_domtree
                        .dominates(def_inst, loc_inst, &self.func.layout)
                    {
                        return errors.fatal((
                            loc_inst,
                            self.context(loc_inst),
                            format!("uses value {v} from non-dominating {def_inst}"),
                        ));
                    }
                    if def_inst == loc_inst {
                        return errors.fatal((
                            loc_inst,
                            self.context(loc_inst),
                            format!("uses value {v} from itself"),
                        ));
                    }
                }
            }
            ValueDef::Param(block, _) => {
                // Value is defined by an existing block.