How to read build variables in Source Generators

I used GitHub copilot to help me create a source generator that reads the schema of a database and generates C# ADO.net code that can call SQL Stored Procedures, Views and Functions in that database (https://github.com/TheJuanitoLearnsShow/Puppy.Ado.SourceGenerator). The connection string to the database is set on a build variable in the consuming csproj file. The problem is that copilot missed the step described in Microsoft’s Source Generator Cookbook . The missing step is to add a CompilerVisibleProperty element to an ItemGroup for each of the build variables you want the source generator to use.

For example, my source generator uses two build variables: DbGen_EnableLiveSchema and DbGen_ConnectionString, so they are defined in the PropertyGroup element in the consuming csproj file:

<DbGen_EnableLiveSchema>true</DbGen_EnableLiveSchema>
<DbGen_ConnectionString>Data Source=.\sqlExpress;Database=AutomatedTESTS_AdoGenerator_SampleDb;Integrated Security=True;TrustServerCertificate=True;</DbGen_ConnectionString>

In addition to the above, I have to add the corresponding CompilerVisibleProperty elements in that same csproj file to allow the source generator to read those variables via the AnalyzerConfigOptionsProvider’s GlobalOptions dictionary:

<ItemGroup>
    <CompilerVisibleProperty Include="DbGen_EnableLiveSchema" />
    <CompilerVisibleProperty Include="DbGen_ConnectionString" />
</ItemGroup>

C# code reading the variables:

    var options = context.AnalyzerConfigOptionsProvider.Select(
        (p, _) => new GeneratorOptions(p));
…
public GeneratorOptions(AnalyzerConfigOptionsProvider provider)
{
    var global = provider.GlobalOptions;
    global.TryGetValue("build_property.DbGen_EnableLiveSchema", out var enable);
    global.TryGetValue("build_property.DbGen_ConnectionString", out var conn);
    EnableLiveSchema = bool.TryParse(enable, out var b) && b;
    ConnectionString = conn;
}