package main

import (
        "os"

        "github.com/hashicorp/hcl/v2"
        "github.com/hashicorp/hcl/v2/hclsyntax"
        "github.com/zclconf/go-cty/cty"
)

func main() {
        file, diags := hclsyntax.ParseConfig([]byte("foo = bar"), "main.tf", hcl.InitialPos)
        if diags.HasErrors() {
                panic(diags)
        }
        attrs, diags := file.Body.JustAttributes()
        if diags.HasErrors() {
                panic(diags)
        }
        expr := attrs["foo"].Expr
        ctx := &hcl.EvalContext{Variables: map[string]cty.Value{"bar": cty.StringVal("baz").Mark("x")}}

        diag := &hcl.Diagnostic{
                Severity:    hcl.DiagError,
                Summary:     "something went wrong",
                Subject:     expr.Range().Ptr(),
                Expression:  expr,
                EvalContext: ctx,
        }

        dwr := hcl.NewDiagnosticTextWriter(os.Stdout, map[string]*hcl.File{"main.tf": file}, 40, true)
        dwr.WriteDiagnostic(diag)
}