Add support for SourceGenerators

dotnet/nuget_repo.bzl

@@ -23,9 +23,6 @@ def _nuget_repo_impl(ctx):
   if r.return_code != 0:
     print(r.stdout)
     fail("nuget_repository failed with exit code " + repr(r.return_code) + "\n\n" + r.stderr)
-
-  ctx.file("BUILD", r"""
-)""")
 
 nuget_repo = repository_rule(
     _nuget_repo_impl,

dotnet/private/actions/assembly.bzl

@@ -49,6 +49,10 @@ def _make_runner_arglist(dotnet, deps, transitive_analyzers, resources, output,
         args.add(dotnet.analyzer_ruleset, format = "/ruleset:%s")
         args.add(dotnet.analyzer_config, format = "/analyzerconfig:%s")
         args.add_all(dotnet.analyzer_additionalfiles, format_each = "/additionalfile:%s")
+    else:
+        for a in transitive_analyzers.to_list():
+            if a.path.endswith("SourceGenerator.dll") or a.path.endswith("SourceGeneration.dll"):
+                args.add(a, format = "/analyzer:%s")
 
     args.add_all(resources, format_each = "/resource:%s", map_each = _map_resource)
     args.add_all(deps, format_each = "/reference:%s")
@@ -101,6 +105,8 @@ def emit_assembly_core(
     # files could contain spaces. therefore quote
     runner_args.add_all(all_srcs, format_each = '"%s"')
 
+    runner_args.add("/analyzer:external/nuget/newtonsoft.json/current/lib/netstandard2.0/Newtonsoft.Json.dll")
+
     runner_args.use_param_file("@%s", use_always = True)
     runner_args.set_param_file_format("multiline")
 
@@ -140,7 +146,7 @@ def emit_assembly_core(
         unused_refs = dotnet.declare_file(dotnet, path = name + ".unused")
         dotnet.actions.run(
             # ensure propsfile is build when this action runs by making it an input
-            inputs = depset(direct = [paramfile, propsfile] + resource_files, transitive = [all_srcs, transitive_refs]),
+            inputs = depset(direct = [paramfile, propsfile] + resource_files, transitive = [all_srcs, transitive_refs, transitive_analyzers]),
             input_manifests = input_manifests,
             outputs = outputs + [unused_refs],
             executable = server,
@@ -167,6 +173,23 @@ def emit_assembly_core(
             ),
         )
 
+    if out and out.endswith("SourceGenerator.dll"):
+        transitive_analyzers = depset(direct = [result], transitive = [a[DotnetLibrary].transitive_analyzers for a in deps])
+
+        return DotnetLibrary(
+            name = dotnet.label.name if not name else name,
+            label = dotnet.label,
+            analyzer = result,
+            transitive_analyzers = transitive_analyzers,
+            deps = [],
+            result = None,
+            ref_result = None,
+            runfiles = depset(),
+            transitive_refs = depset(),
+            transitive = depset(),
+            output_groups = [OutputGroupInfo(targets = [propsfile])] if propsfile else [],
+        )
+
     return dotnet.new_library(
         dotnet = dotnet,
         name = name,

dotnet/private/rules/binary.bzl

@@ -18,6 +18,17 @@ load(
 )
 load("@bazel_skylib//lib:paths.bzl", "paths")
 
+def _framework_transition_impl(settings, attr):
+  if Label("@nuget//netstandard.library") in attr.deps:
+    return {"@nuget//:framework" : "netstandard2.0"}
+  return settings
+
+framework_transition = transition(
+  implementation = _framework_transition_impl,
+  inputs = ["@nuget//:framework"],
+  outputs = ["@nuget//:framework"]
+)
+
 # DotnetContext, DotnetLibrary
 def create_launcher(dotnet, library, shim = None):
     launch_target = shim if shim else library.result
@@ -92,10 +103,10 @@ def _rule_impl(ctx):
     if ctx.attr._target_type == "exe":
         shim = create_shim_exe(ctx, assembly.result)
         result.append(create_launcher(dotnet, assembly, shim))
-    else:
+    elif assembly.result or assembly.analyzer:
         # always output a DefaultInfo with a file so directly building this target will trigger actions
         result.append(DefaultInfo(
-            files = depset([assembly.result]),
+            files = depset([assembly.result or assembly.analyzer]),
         ))
 
     return result
@@ -106,7 +117,10 @@ def _rule(target_type,
     return rule(
         _rule_impl,
         attrs = {
-            "deps": attr.label_list(providers = [DotnetLibrary]),
+            "_allowlist_function_transition": attr.label(
+              default = "@bazel_tools//tools/allowlists/function_transition_allowlist"
+            ),
+            "deps": attr.label_list(providers = [DotnetLibrary], cfg = framework_transition),
             "resources": attr.label_list(providers = [DotnetResourceList]),
             "srcs": attr.label_list(allow_files = [".cs"]),
             "out": attr.string(),

tools/server/Program.cs

@@ -117,6 +117,11 @@ string ScopePath(string path)
 </CSCReference>
 ");
                     }
+                    else if (line.StartsWith("/analyzer:") && (line.EndsWith("SourceGenerator.dll") || line.EndsWith("SourceGeneration.dll")))
+                    {
+                        var analyzerPath = line.Substring(10).Replace('/', '\\');
+                        sb.Append($"<Analyzer Include=\"{ScopePath(analyzerPath)}\" />\n\n");
+                    }
                 }
 
                 // obj/....csproj.bazel.props file