public UnityResource(string name)
{
Name = name;
VersionRange = UnityVersionRange.FromFilename(name);
}
// Guess which header file(s) correspond to the given metadata+binary.
// Note that this may match multiple headers due to structural changes between versions
// that are not reflected in the metadata version.
public static List <UnityHeaders> GuessHeadersForBinary(Il2CppBinary binary)
{
List <UnityResource> typeHeaders = new List <UnityResource>();
foreach (var r in GetAllTypeHeaders())
{
var metadataVersion = GetMetadataVersionFromFilename(r.Name);
if (metadataVersion != binary.Image.Version)
{
continue;
}
if (metadataVersion == 21)
{
/* Special version logic for metadata version 21 based on the Il2CppMetadataRegistration.fieldOffsets field */
var headerFieldOffsetsArePointers = r.VersionRange.Min.CompareTo("5.3.7") >= 0 && r.VersionRange.Min.CompareTo("5.4.0") != 0;
var binaryFieldOffsetsArePointers = binary.FieldOffsets == null;
if (headerFieldOffsetsArePointers != binaryFieldOffsetsArePointers)
{
continue;
}
}
typeHeaders.Add(r);
}
// Get total range of selected headers
// Sort is needed because 5.x.x comes before 20xx.x.x in the resource list
typeHeaders = typeHeaders.OrderBy(x => x.VersionRange).ToList();
var totalRange = new UnityVersionRange(typeHeaders.First().VersionRange.Min, typeHeaders.Last().VersionRange.Max);
// Get all API versions in this range
var apis = GetAllAPIHeaders().Where(a => a.VersionRange.Intersect(totalRange) != null).ToList();
// Get the API exports for the binary
var exports = binary.GetAPIExports();
// No il2cpp exports? Just return the earliest version from the header range
// The API version may be incorrect but should be a subset of the real API and won't cause C++ compile errors
if (!exports.Any())
{
Console.WriteLine("No IL2CPP API exports found in binary - IL2CPP APIs will be unavailable in C++ project");
return(typeHeaders.Select(t => new UnityHeaders(t,
apis.Last(a => a.VersionRange.Intersect(t.VersionRange) != null))).ToList());
}
// Go through all of the possible API versions and see how closely they match the binary
// Note: if apis.Count == 1, we can't actually narrow down the version range further,
// but we still need to check that the APIs actually exist in the binary
var apiMatches = new List <UnityResource>();
foreach (var api in apis)
{
var apiFunctionList = GetFunctionNamesFromAPIHeaderText(api.GetText());
// Every single function in the API list must be an export for a match
if (!apiFunctionList.Except(exports.Keys).Any())
{
apiMatches.Add(api);
}
}
if (apiMatches.Any())
{
// Intersect all API ranges with all header ranges to produce final list of possible ranges
Console.WriteLine("IL2CPP API discovery was successful");
return(typeHeaders.SelectMany(
t => apiMatches.Where(a => t.VersionRange.Intersect(a.VersionRange) != null)
.Select(a => new UnityHeaders(t, a))).ToList());
}
// None of the possible API versions match the binary
// Select the oldest API version from the group - C++ project compilation will fail
Console.WriteLine("No exact match for IL2CPP APIs found in binary - IL2CPP API availability in C++ project will be partial");
return(typeHeaders.Select(t => new UnityHeaders(t,
apis.Last(a => a.VersionRange.Intersect(t.VersionRange) != null))).ToList());
}
