1 files changed, 595 insertions, 0 deletions
diff --git a/third_party/wasm2c/src/resolve-names.cc b/third_party/wasm2c/src/resolve-names.cc
new file mode 100644
index 0000000000..099a8e5754
--- /dev/null
+++ b/third_party/wasm2c/src/resolve-names.cc
@@ -0,0 +1,595 @@
+/*
+ * Copyright 2016 WebAssembly Community Group participants
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "src/resolve-names.h"
+
+#include <cassert>
+#include <cstdio>
+
+#include "src/cast.h"
+#include "src/expr-visitor.h"
+#include "src/ir.h"
+#include "src/wast-lexer.h"
+
+namespace wabt {
+
+namespace {
+
+class NameResolver : public ExprVisitor::DelegateNop {
+ public:
+  NameResolver(Script* script, Errors* errors);
+
+  Result VisitModule(Module* module);
+  Result VisitScript(Script* script);
+
+  // Implementation of ExprVisitor::DelegateNop.
+  Result BeginBlockExpr(BlockExpr*) override;
+  Result EndBlockExpr(BlockExpr*) override;
+  Result OnBrExpr(BrExpr*) override;
+  Result OnBrIfExpr(BrIfExpr*) override;
+  Result OnBrTableExpr(BrTableExpr*) override;
+  Result OnCallExpr(CallExpr*) override;
+  Result OnCallIndirectExpr(CallIndirectExpr*) override;
+  Result OnCatchExpr(TryExpr*, Catch*) override;
+  Result OnDelegateExpr(TryExpr*) override;
+  Result OnReturnCallExpr(ReturnCallExpr *) override;
+  Result OnReturnCallIndirectExpr(ReturnCallIndirectExpr*) override;
+  Result OnGlobalGetExpr(GlobalGetExpr*) override;
+  Result OnGlobalSetExpr(GlobalSetExpr*) override;
+  Result BeginIfExpr(IfExpr*) override;
+  Result EndIfExpr(IfExpr*) override;
+  Result OnLocalGetExpr(LocalGetExpr*) override;
+  Result OnLocalSetExpr(LocalSetExpr*) override;
+  Result OnLocalTeeExpr(LocalTeeExpr*) override;
+  Result BeginLoopExpr(LoopExpr*) override;
+  Result EndLoopExpr(LoopExpr*) override;
+  Result OnDataDropExpr(DataDropExpr*) override;
+  Result OnMemoryInitExpr(MemoryInitExpr*) override;
+  Result OnElemDropExpr(ElemDropExpr*) override;
+  Result OnTableCopyExpr(TableCopyExpr*) override;
+  Result OnTableInitExpr(TableInitExpr*) override;
+  Result OnTableGetExpr(TableGetExpr*) override;
+  Result OnTableSetExpr(TableSetExpr*) override;
+  Result OnTableGrowExpr(TableGrowExpr*) override;
+  Result OnTableSizeExpr(TableSizeExpr*) override;
+  Result OnTableFillExpr(TableFillExpr*) override;
+  Result OnRefFuncExpr(RefFuncExpr*) override;
+  Result BeginTryExpr(TryExpr*) override;
+  Result EndTryExpr(TryExpr*) override;
+  Result OnThrowExpr(ThrowExpr*) override;
+  Result OnRethrowExpr(RethrowExpr*) override;
+
+ private:
+  void PrintError(const Location* loc, const char* fmt, ...);
+  void PushLabel(const std::string& label);
+  void PopLabel();
+  void CheckDuplicateBindings(const BindingHash* bindings, const char* desc);
+  void PrintDuplicateBindingsError(const BindingHash::value_type&,
+                                   const BindingHash::value_type&,
+                                   const char* desc);
+  void ResolveLabelVar(Var* var);
+  void ResolveVar(const BindingHash* bindings, Var* var, const char* desc);
+  void ResolveFuncVar(Var* var);
+  void ResolveGlobalVar(Var* var);
+  void ResolveFuncTypeVar(Var* var);
+  void ResolveTableVar(Var* var);
+  void ResolveMemoryVar(Var* var);
+  void ResolveTagVar(Var* var);
+  void ResolveDataSegmentVar(Var* var);
+  void ResolveElemSegmentVar(Var* var);
+  void ResolveLocalVar(Var* var);
+  void ResolveBlockDeclarationVar(BlockDeclaration* decl);
+  void VisitFunc(Func* func);
+  void VisitExport(Export* export_);
+  void VisitGlobal(Global* global);
+  void VisitTag(Tag* tag);
+  void VisitElemSegment(ElemSegment* segment);
+  void VisitDataSegment(DataSegment* segment);
+  void VisitScriptModule(ScriptModule* script_module);
+  void VisitCommand(Command* command);
+
+  Errors* errors_ = nullptr;
+  Script* script_ = nullptr;
+  Module* current_module_ = nullptr;
+  Func* current_func_ = nullptr;
+  ExprVisitor visitor_;
+  std::vector<std::string> labels_;
+  Result result_ = Result::Ok;
+};
+
+NameResolver::NameResolver(Script* script, Errors* errors)
+    : errors_(errors),
+      script_(script),
+      visitor_(this) {}
+
+}  // end anonymous namespace
+
+void WABT_PRINTF_FORMAT(3, 4) NameResolver::PrintError(const Location* loc,
+                                                       const char* format,
+                                                       ...) {
+  result_ = Result::Error;
+  WABT_SNPRINTF_ALLOCA(buffer, length, format);
+  errors_->emplace_back(ErrorLevel::Error, *loc, buffer);
+}
+
+void NameResolver::PushLabel(const std::string& label) {
+  labels_.push_back(label);
+}
+
+void NameResolver::PopLabel() {
+  labels_.pop_back();
+}
+
+void NameResolver::CheckDuplicateBindings(const BindingHash* bindings,
+                                          const char* desc) {
+  bindings->FindDuplicates([this, desc](const BindingHash::value_type& a,
+                                        const BindingHash::value_type& b) {
+    PrintDuplicateBindingsError(a, b, desc);
+  });
+}
+
+void NameResolver::PrintDuplicateBindingsError(const BindingHash::value_type& a,
+                                               const BindingHash::value_type& b,
+                                               const char* desc) {
+  // Choose the location that is later in the file.
+  const Location& a_loc = a.second.loc;
+  const Location& b_loc = b.second.loc;
+  const Location& loc = a_loc.line > b_loc.line ? a_loc : b_loc;
+  PrintError(&loc, "redefinition of %s \"%s\"", desc, a.first.c_str());
+}
+
+void NameResolver::ResolveLabelVar(Var* var) {
+  if (var->is_name()) {
+    for (int i = labels_.size() - 1; i >= 0; --i) {
+      const std::string& label = labels_[i];
+      if (label == var->name()) {
+        var->set_index(labels_.size() - i - 1);
+        return;
+      }
+    }
+    PrintError(&var->loc, "undefined label variable \"%s\"",
+               var->name().c_str());
+  }
+}
+
+void NameResolver::ResolveVar(const BindingHash* bindings,
+                              Var* var,
+                              const char* desc) {
+  if (var->is_name()) {
+    Index index = bindings->FindIndex(*var);
+    if (index == kInvalidIndex) {
+      PrintError(&var->loc, "undefined %s variable \"%s\"", desc,
+                 var->name().c_str());
+      return;
+    }
+
+    var->set_index(index);
+  }
+}
+
+void NameResolver::ResolveFuncVar(Var* var) {
+  ResolveVar(&current_module_->func_bindings, var, "function");
+}
+
+void NameResolver::ResolveGlobalVar(Var* var) {
+  ResolveVar(&current_module_->global_bindings, var, "global");
+}
+
+void NameResolver::ResolveFuncTypeVar(Var* var) {
+  ResolveVar(&current_module_->type_bindings, var, "type");
+}
+
+void NameResolver::ResolveTableVar(Var* var) {
+  ResolveVar(&current_module_->table_bindings, var, "table");
+}
+
+void NameResolver::ResolveMemoryVar(Var* var) {
+  ResolveVar(&current_module_->memory_bindings, var, "memory");
+}
+
+void NameResolver::ResolveTagVar(Var* var) {
+  ResolveVar(&current_module_->tag_bindings, var, "tag");
+}
+
+void NameResolver::ResolveDataSegmentVar(Var* var) {
+  ResolveVar(&current_module_->data_segment_bindings, var, "data segment");
+}
+
+void NameResolver::ResolveElemSegmentVar(Var* var) {
+  ResolveVar(&current_module_->elem_segment_bindings, var, "elem segment");
+}
+
+void NameResolver::ResolveLocalVar(Var* var) {
+  if (var->is_name()) {
+    if (!current_func_) {
+      return;
+    }
+
+    Index index = current_func_->GetLocalIndex(*var);
+    if (index == kInvalidIndex) {
+      PrintError(&var->loc, "undefined local variable \"%s\"",
+                 var->name().c_str());
+      return;
+    }
+
+    var->set_index(index);
+  }
+}
+
+void NameResolver::ResolveBlockDeclarationVar(BlockDeclaration* decl) {
+  if (decl->has_func_type) {
+    ResolveFuncTypeVar(&decl->type_var);
+  }
+}
+
+Result NameResolver::BeginBlockExpr(BlockExpr* expr) {
+  PushLabel(expr->block.label);
+  ResolveBlockDeclarationVar(&expr->block.decl);
+  return Result::Ok;
+}
+
+Result NameResolver::EndBlockExpr(BlockExpr* expr) {
+  PopLabel();
+  return Result::Ok;
+}
+
+Result NameResolver::BeginLoopExpr(LoopExpr* expr) {
+  PushLabel(expr->block.label);
+  ResolveBlockDeclarationVar(&expr->block.decl);
+  return Result::Ok;
+}
+
+Result NameResolver::EndLoopExpr(LoopExpr* expr) {
+  PopLabel();
+  return Result::Ok;
+}
+
+Result NameResolver::OnBrExpr(BrExpr* expr) {
+  ResolveLabelVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnBrIfExpr(BrIfExpr* expr) {
+  ResolveLabelVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnBrTableExpr(BrTableExpr* expr) {
+  for (Var& target : expr->targets)
+    ResolveLabelVar(&target);
+  ResolveLabelVar(&expr->default_target);
+  return Result::Ok;
+}
+
+Result NameResolver::OnCallExpr(CallExpr* expr) {
+  ResolveFuncVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnCallIndirectExpr(CallIndirectExpr* expr) {
+  if (expr->decl.has_func_type) {
+    ResolveFuncTypeVar(&expr->decl.type_var);
+  }
+  ResolveTableVar(&expr->table);
+  return Result::Ok;
+}
+
+Result NameResolver::OnReturnCallExpr(ReturnCallExpr* expr) {
+  ResolveFuncVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnReturnCallIndirectExpr(ReturnCallIndirectExpr* expr) {
+  if (expr->decl.has_func_type) {
+    ResolveFuncTypeVar(&expr->decl.type_var);
+  }
+  ResolveTableVar(&expr->table);
+  return Result::Ok;
+}
+
+Result NameResolver::OnGlobalGetExpr(GlobalGetExpr* expr) {
+  ResolveGlobalVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnGlobalSetExpr(GlobalSetExpr* expr) {
+  ResolveGlobalVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::BeginIfExpr(IfExpr* expr) {
+  PushLabel(expr->true_.label);
+  ResolveBlockDeclarationVar(&expr->true_.decl);
+  return Result::Ok;
+}
+
+Result NameResolver::EndIfExpr(IfExpr* expr) {
+  PopLabel();
+  return Result::Ok;
+}
+
+Result NameResolver::OnLocalGetExpr(LocalGetExpr* expr) {
+  ResolveLocalVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnLocalSetExpr(LocalSetExpr* expr) {
+  ResolveLocalVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnLocalTeeExpr(LocalTeeExpr* expr) {
+  ResolveLocalVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnDataDropExpr(DataDropExpr* expr) {
+  ResolveDataSegmentVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnMemoryInitExpr(MemoryInitExpr* expr) {
+  ResolveDataSegmentVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnElemDropExpr(ElemDropExpr* expr) {
+  ResolveElemSegmentVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnTableCopyExpr(TableCopyExpr* expr) {
+  ResolveTableVar(&expr->dst_table);
+  ResolveTableVar(&expr->src_table);
+  return Result::Ok;
+}
+
+Result NameResolver::OnTableInitExpr(TableInitExpr* expr) {
+  ResolveElemSegmentVar(&expr->segment_index);
+  ResolveTableVar(&expr->table_index);
+  return Result::Ok;
+}
+
+Result NameResolver::OnTableGetExpr(TableGetExpr* expr) {
+  ResolveTableVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnTableSetExpr(TableSetExpr* expr) {
+  ResolveTableVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnTableGrowExpr(TableGrowExpr* expr) {
+  ResolveTableVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnTableSizeExpr(TableSizeExpr* expr) {
+  ResolveTableVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnTableFillExpr(TableFillExpr* expr) {
+  ResolveTableVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnRefFuncExpr(RefFuncExpr* expr) {
+  ResolveFuncVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::BeginTryExpr(TryExpr* expr) {
+  PushLabel(expr->block.label);
+  ResolveBlockDeclarationVar(&expr->block.decl);
+  return Result::Ok;
+}
+
+Result NameResolver::EndTryExpr(TryExpr*) {
+  PopLabel();
+  return Result::Ok;
+}
+
+Result NameResolver::OnCatchExpr(TryExpr*, Catch* catch_) {
+  if (!catch_->IsCatchAll()) {
+    ResolveTagVar(&catch_->var);
+  }
+  return Result::Ok;
+}
+
+Result NameResolver::OnDelegateExpr(TryExpr* expr) {
+  // Pop the label here as a try-delegate has no `end` instruction.
+  PopLabel();
+
+  // We resolve *after* popping the label in order to ensure that the
+  // delegate label starts counting after the current try-delegate.
+  ResolveLabelVar(&expr->delegate_target);
+
+  return Result::Ok;
+}
+
+Result NameResolver::OnThrowExpr(ThrowExpr* expr) {
+  ResolveTagVar(&expr->var);
+  return Result::Ok;
+}
+
+Result NameResolver::OnRethrowExpr(RethrowExpr* expr) {
+  // Note: the variable refers to corresponding (enclosing) catch, using the try
+  // block label for context.
+  ResolveLabelVar(&expr->var);
+  return Result::Ok;
+}
+
+void NameResolver::VisitFunc(Func* func) {
+  current_func_ = func;
+  if (func->decl.has_func_type) {
+    ResolveFuncTypeVar(&func->decl.type_var);
+  }
+
+  func->bindings.FindDuplicates(
+      [=](const BindingHash::value_type& a, const BindingHash::value_type& b) {
+        const char* desc =
+            (a.second.index < func->GetNumParams()) ? "parameter" : "local";
+        PrintDuplicateBindingsError(a, b, desc);
+      });
+
+  visitor_.VisitFunc(func);
+  current_func_ = nullptr;
+}
+
+void NameResolver::VisitExport(Export* export_) {
+  switch (export_->kind) {
+    case ExternalKind::Func:
+      ResolveFuncVar(&export_->var);
+      break;
+
+    case ExternalKind::Table:
+      ResolveTableVar(&export_->var);
+      break;
+
+    case ExternalKind::Memory:
+      ResolveMemoryVar(&export_->var);
+      break;
+
+    case ExternalKind::Global:
+      ResolveGlobalVar(&export_->var);
+      break;
+
+    case ExternalKind::Tag:
+      ResolveTagVar(&export_->var);
+      break;
+  }
+}
+
+void NameResolver::VisitGlobal(Global* global) {
+  visitor_.VisitExprList(global->init_expr);
+}
+
+void NameResolver::VisitTag(Tag* tag) {
+  if (tag->decl.has_func_type) {
+    ResolveFuncTypeVar(&tag->decl.type_var);
+  }
+}
+
+void NameResolver::VisitElemSegment(ElemSegment* segment) {
+  ResolveTableVar(&segment->table_var);
+  visitor_.VisitExprList(segment->offset);
+  for (ElemExpr& elem_expr : segment->elem_exprs) {
+    if (elem_expr.kind == ElemExprKind::RefFunc) {
+      ResolveFuncVar(&elem_expr.var);
+    }
+  }
+}
+
+void NameResolver::VisitDataSegment(DataSegment* segment) {
+  ResolveMemoryVar(&segment->memory_var);
+  visitor_.VisitExprList(segment->offset);
+}
+
+Result NameResolver::VisitModule(Module* module) {
+  current_module_ = module;
+  CheckDuplicateBindings(&module->elem_segment_bindings, "elem");
+  CheckDuplicateBindings(&module->func_bindings, "function");
+  CheckDuplicateBindings(&module->global_bindings, "global");
+  CheckDuplicateBindings(&module->type_bindings, "type");
+  CheckDuplicateBindings(&module->table_bindings, "table");
+  CheckDuplicateBindings(&module->memory_bindings, "memory");
+  CheckDuplicateBindings(&module->tag_bindings, "tag");
+
+  for (Func* func : module->funcs)
+    VisitFunc(func);
+  for (Export* export_ : module->exports)
+    VisitExport(export_);
+  for (Global* global : module->globals)
+    VisitGlobal(global);
+  for (Tag* tag : module->tags)
+    VisitTag(tag);
+  for (ElemSegment* elem_segment : module->elem_segments)
+    VisitElemSegment(elem_segment);
+  for (DataSegment* data_segment : module->data_segments)
+    VisitDataSegment(data_segment);
+  for (Var* start : module->starts)
+    ResolveFuncVar(start);
+  current_module_ = nullptr;
+  return result_;
+}
+
+void NameResolver::VisitScriptModule(ScriptModule* script_module) {
+  if (auto* tsm = dyn_cast<TextScriptModule>(script_module)) {
+    VisitModule(&tsm->module);
+  }
+}
+
+void NameResolver::VisitCommand(Command* command) {
+  switch (command->type) {
+    case CommandType::Module:
+      VisitModule(&cast<ModuleCommand>(command)->module);
+      break;
+
+    case CommandType::Action:
+    case CommandType::AssertReturn:
+    case CommandType::AssertTrap:
+    case CommandType::AssertExhaustion:
+    case CommandType::Register:
+      /* Don't resolve a module_var, since it doesn't really behave like other
+       * vars. You can't reference a module by index. */
+      break;
+
+    case CommandType::AssertMalformed:
+      /* Malformed modules should not be text; the whole point of this
+       * assertion is to test for malformed binary modules. */
+      break;
+
+    case CommandType::AssertInvalid: {
+      auto* assert_invalid_command = cast<AssertInvalidCommand>(command);
+      /* The module may be invalid because the names cannot be resolved; we
+       * don't want to print errors or fail if that's the case, but we still
+       * should try to resolve names when possible. */
+      Errors errors;
+      NameResolver new_resolver(script_, &errors);
+      new_resolver.VisitScriptModule(assert_invalid_command->module.get());
+      break;
+    }
+
+    case CommandType::AssertUnlinkable:
+      VisitScriptModule(cast<AssertUnlinkableCommand>(command)->module.get());
+      break;
+
+    case CommandType::AssertUninstantiable:
+      VisitScriptModule(
+          cast<AssertUninstantiableCommand>(command)->module.get());
+      break;
+  }
+}
+
+Result NameResolver::VisitScript(Script* script) {
+  for (const std::unique_ptr<Command>& command : script->commands)
+    VisitCommand(command.get());
+  return result_;
+}
+
+Result ResolveNamesModule(Module* module, Errors* errors) {
+  NameResolver resolver(nullptr, errors);
+  return resolver.VisitModule(module);
+}
+
+Result ResolveNamesScript(Script* script, Errors* errors) {
+  NameResolver resolver(script, errors);
+  return resolver.VisitScript(script);
+}
+
+}  // namespace wabt