Cleanup semantic analysis

Summary: AST mutators are an implementation detail of semantic analysis and are not supposed to be used directly. Remove them from the public API. This reduces the public API surface and prevents misuse.

Differential Revision: D63795762

fbshipit-source-id: e059217f1b1f10939766d2822ba9881b241881e3

thrift/compiler/compiler.cc

@@ -43,7 +43,6 @@
 #include <thrift/compiler/diagnostic.h>
 #include <thrift/compiler/generate/t_generator.h>
 #include <thrift/compiler/parse/parse_ast.h>
-#include <thrift/compiler/sema/ast_mutator.h>
 #include <thrift/compiler/sema/ast_validator.h>
 #include <thrift/compiler/sema/sema.h>
 #include <thrift/compiler/sema/sema_context.h>
@@ -773,9 +772,7 @@ std::unique_ptr<t_program_bundle> parse_and_mutate(
   // C++ codegen inserts an empty const if this is false. Other languages may
   // dynamically determine whether the schema const exists.
   if (gparams.inject_schema_const) {
-    mutator_context mctx;
-    mctx.bundle = program_bundle.get();
-    schema_mutator()(ctx, mctx, *program_bundle->root_program());
+    sema::add_schema(ctx, *program_bundle);
   }
 
   program_bundle->root_program()->set_include_prefix(
@@ -793,8 +790,8 @@ parse_and_mutate_program(
     parsing_params params,
     diagnostic_params dparams) {
   diagnostic_results results;
-  sema_context ctx(sm, results, std::move(dparams));
-  return {parse_ast(sm, ctx, filename, std::move(params)), results};
+  diagnostics_engine diags(sm, results, std::move(dparams));
+  return {parse_ast(sm, diags, filename, std::move(params)), results};
 }
 
 std::unique_ptr<t_program_bundle> parse_and_dump_diagnostics(
@@ -803,8 +800,8 @@ std::unique_ptr<t_program_bundle> parse_and_dump_diagnostics(
     parsing_params pparams,
     diagnostic_params dparams) {
   diagnostic_results results;
-  sema_context ctx(sm, results, std::move(dparams));
-  auto programs = parse_ast(sm, ctx, filename, std::move(pparams));
+  diagnostics_engine diags(sm, results, std::move(dparams));
+  auto programs = parse_ast(sm, diags, filename, std::move(pparams));
   for (const auto& diag : results.diagnostics()) {
     fmt::print(stderr, "{}\n", diag);
   }

thrift/compiler/parse/parse_ast.cc

@@ -36,7 +36,6 @@
 #include <thrift/compiler/diagnostic.h>
 #include <thrift/compiler/parse/lexer.h>
 #include <thrift/compiler/parse/parser.h>
-#include <thrift/compiler/sema/ast_mutator.h>
 #include <thrift/compiler/sema/sema.h>
 #include <thrift/compiler/source_location.h>
 
@@ -1095,6 +1094,9 @@ std::unique_ptr<t_program_bundle> parse_ast(
   } catch (const parsing_terminator&) {
     return {}; // Return a null program bundle if parsing failed.
   }
+  if (diags.has_errors()) {
+    return programs;
+  }
 
   sema_context ctx(
       diags.source_mgr(),
@@ -1103,21 +1105,7 @@ std::unique_ptr<t_program_bundle> parse_ast(
   if (sparams) {
     ctx.sema_parameters() = *sparams;
   }
-
-  // Resolve types in the root program.
-  if (!params.use_legacy_type_ref_resolution) {
-    type_ref_resolver().run(ctx, *programs);
-  }
-  std::string program_prefix = root_program.name() + ".";
-  for (t_placeholder_typedef& t :
-       root_program.scope()->placeholder_typedefs()) {
-    if (!t.resolve() && t.name().find(program_prefix) == 0) {
-      diags.error(t, "Type `{}` not defined.", t.name());
-    }
-  }
-  if (!diags.has_errors()) {
-    sema(params.use_legacy_type_ref_resolution).run(ctx, *programs);
-  }
+  sema(params.use_legacy_type_ref_resolution).run(ctx, *programs);
   return programs;
 }