[wasm] asm.js - Parse and convert asm.js to wasm a function at a time.

src/asmjs/asm-wasm-builder.cc

Index: src/asmjs/asm-wasm-builder.cc
diff --git a/src/asmjs/asm-wasm-builder.cc b/src/asmjs/asm-wasm-builder.cc
index 60bdd9a5a8473311ae54c694fd1ec53783f33e63..c4e64352b914e5e927bb35696a53768abbac5d9d 100644
--- a/src/asmjs/asm-wasm-builder.cc
+++ b/src/asmjs/asm-wasm-builder.cc
@@ -19,6 +19,9 @@
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/codegen.h"
+#include "src/compiler.h"
+#include "src/isolate.h"
+#include "src/parsing/parse-info.h"
 
 namespace v8 {
 namespace internal {
@@ -42,8 +45,8 @@ struct ForeignVariable {
 
 class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
  public:
-  AsmWasmBuilderImpl(Isolate* isolate, Zone* zone, FunctionLiteral* literal,
-                     AsmTyper* typer)
+  AsmWasmBuilderImpl(Isolate* isolate, Zone* zone, Script* script,
+                     FunctionLiteral* literal, AsmTyper* typer)
       : local_variables_(ZoneHashMap::kDefaultHashMapCapacity,
                          ZoneAllocationPolicy(zone)),
         functions_(ZoneHashMap::kDefaultHashMapCapacity,
@@ -56,12 +59,13 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
         literal_(literal),
         isolate_(isolate),
         zone_(zone),
+        script_(script),
         typer_(typer),
+        typer_failed_(false),
         breakable_blocks_(zone),
         foreign_variables_(zone),
         init_function_(nullptr),
         foreign_init_function_(nullptr),
-        next_table_index_(0),
         function_tables_(ZoneHashMap::kDefaultHashMapCapacity,
                          ZoneAllocationPolicy(zone)),
         imported_function_table_(this) {
@@ -108,10 +112,21 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
     return ret;
   }
 
-  void Build() {
+  bool Build() {
     InitializeInitFunction();
-    RECURSE(VisitFunctionLiteral(literal_));
+    if (!typer_->ValidatePhase1of2()) {
+      return false;
+    }
+    DCHECK(!HasStackOverflow());
+    VisitFunctionLiteral(literal_);
+    if (HasStackOverflow()) {
+      return false;
+    }
+    if (typer_failed_) {
+      return false;
+    }
     BuildForeignInitFunction();
+    return true;
   }
 
   void VisitVariableDeclaration(VariableDeclaration* decl) {}
@@ -119,9 +134,40 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
   void VisitFunctionDeclaration(FunctionDeclaration* decl) {
     DCHECK_EQ(kModuleScope, scope_);
     DCHECK_NULL(current_function_builder_);
+    bool had_body;
+    i::Zone zone(isolate_->allocator());
+    if (decl->fun()->body() == nullptr) {
+      Handle<SharedFunctionInfo> shared =

[titzer, 2016/10/07 12:56:59]

Do we really need a shared function info here? Seems wasteful.

[bradn, 2016/11/25 09:19:36]

A large number of places in the parser assume a SharedFunctionInfo in the case
you're parsing one function.
Added a TODO to refactor to avoid needing this.

+          i::Compiler::NewSharedFunctionInfoFromLiteral(
+              isolate_, decl->fun(), handle(script_, isolate_));
+      shared->set_is_toplevel(false);
+      i::ParseInfo info(&zone, handle(script_, isolate_));
+      info.set_shared_info(shared);
+      info.set_language_mode(decl->fun()->scope()->language_mode());
+      info.set_lazy(true);
+      info.set_allow_lazy_parsing(false);
+      info.set_script_scope(decl->fun()->scope());
+      if (!i::Compiler::ParseAndAnalyze(&info)) {
+        typer_failed_ = true;
+        return;
+      }
+      FunctionLiteral* func = info.literal();
+      DCHECK_NOT_NULL(func);
+      decl->fun()->set_body(func->body());
+      had_body = false;
+    } else {
+      had_body = true;
+    }
+    if (!typer_->ValidateInnerFunction(decl)) {
+      typer_failed_ = true;
+      return;
+    }
     current_function_builder_ = LookupOrInsertFunction(decl->proxy()->var());
     scope_ = kFuncScope;
     RECURSE(Visit(decl->fun()));
+    if (!had_body) {
+      decl->fun()->set_body(nullptr);
+    }
     scope_ = kModuleScope;
     current_function_builder_ = nullptr;
     local_variables_.Clear();
@@ -135,6 +181,7 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
         continue;
       }
       RECURSE(Visit(stmt));
+      if (typer_failed_) break;
       if (stmt->IsJump()) break;
     }
   }
@@ -454,8 +501,13 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
         UNREACHABLE();
       }
     }
-    RECURSE(VisitStatements(expr->body()));
-    RECURSE(VisitDeclarations(scope->declarations()));
+    if (scope_ == kFuncScope) {

[titzer, 2016/10/07 12:56:59]

Why do we need to do the declarations after for a func scope?

[bradn, 2016/11/25 09:19:36]

No good reason.
Both should be declarations then statements (in the new traversal).
Changed.

+      RECURSE(VisitStatements(expr->body()));
+      RECURSE(VisitDeclarations(scope->declarations()));
+    } else {
+      RECURSE(VisitDeclarations(scope->declarations()));
+      RECURSE(VisitStatements(expr->body()));
+    }
   }
 
   void VisitNativeFunctionLiteral(NativeFunctionLiteral* expr) {
@@ -637,6 +689,11 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
   void VisitRegExpLiteral(RegExpLiteral* expr) { UNREACHABLE(); }
 
   void VisitObjectLiteral(ObjectLiteral* expr) {
+    if (!typer_->ValidatePhase2of2()) {
+      typer_failed_ = true;
+      return;
+    }
+
     ZoneList<ObjectLiteralProperty*>* props = expr->properties();
     for (int i = 0; i < props->length(); ++i) {
       ObjectLiteralProperty* prop = props->at(i);
@@ -669,10 +726,22 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
     current_function_builder_ = nullptr;
   }
 
-  void AddFunctionTable(VariableProxy* table, ArrayLiteral* funcs) {
-    auto* func_tbl_type = typer_->TypeOf(funcs)->AsFunctionTableType();
-    DCHECK_NOT_NULL(func_tbl_type);
-    auto* func_type = func_tbl_type->signature()->AsFunctionType();
+  struct FunctionTableIndices : public ZoneObject {
+    uint32_t start_index;
+    uint32_t signature_index;
+  };
+
+  FunctionTableIndices* LookupOrAddFunctionTable(VariableProxy* table,
+                                                 Property* p) {
+    FunctionTableIndices* indices = LookupFunctionTable(table->var());
+    if (indices != nullptr) {
+      // Already setup.
+      return indices;
+    }
+    indices = new (zone()) FunctionTableIndices();
+    auto* func_type = typer_->TypeOf(p)->AsFunctionType();
+    auto* func_table_type = typer_->TypeOf(p->obj()->AsVariableProxy()->var())
+                                ->AsFunctionTableType();
     const auto& arguments = func_type->Arguments();
     LocalType return_type = TypeFrom(func_type->ReturnType());
     FunctionSig::Builder sig(zone(), return_type == kAstStmt ? 0 : 1,
@@ -684,38 +753,37 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
       sig.AddParam(TypeFrom(arg));
     }
     uint32_t signature_index = builder_->AddSignature(sig.Build());
-    InsertFunctionTable(table->var(), next_table_index_, signature_index);
-    next_table_index_ += funcs->values()->length();
-    for (int i = 0; i < funcs->values()->length(); ++i) {
-      VariableProxy* func = funcs->values()->at(i)->AsVariableProxy();
-      DCHECK_NOT_NULL(func);
-      builder_->AddIndirectFunction(
-          LookupOrInsertFunction(func->var())->func_index());
-    }
-  }
-
-  struct FunctionTableIndices : public ZoneObject {
-    uint32_t start_index;
-    uint32_t signature_index;
-  };
-
-  void InsertFunctionTable(Variable* v, uint32_t start_index,
-                           uint32_t signature_index) {
-    FunctionTableIndices* container = new (zone()) FunctionTableIndices();
-    container->start_index = start_index;
-    container->signature_index = signature_index;
+    indices->start_index =
+        builder_->AllocateIndirectFunctions(func_table_type->length());
+    indices->signature_index = signature_index;
     ZoneHashMap::Entry* entry = function_tables_.LookupOrInsert(
-        v, ComputePointerHash(v), ZoneAllocationPolicy(zone()));
-    entry->value = container;
+        table->var(), ComputePointerHash(table->var()),
+        ZoneAllocationPolicy(zone()));
+    entry->value = indices;
+    return indices;
   }
 
   FunctionTableIndices* LookupFunctionTable(Variable* v) {
     ZoneHashMap::Entry* entry =
         function_tables_.Lookup(v, ComputePointerHash(v));
-    DCHECK_NOT_NULL(entry);
+    if (entry == nullptr) {
+      return nullptr;
+    }
     return reinterpret_cast<FunctionTableIndices*>(entry->value);
   }
 
+  void PopulateFunctionTable(VariableProxy* table, ArrayLiteral* funcs) {
+    FunctionTableIndices* indices = LookupFunctionTable(table->var());
+    DCHECK_NOT_NULL(indices);
+    for (int i = 0; i < funcs->values()->length(); ++i) {
+      VariableProxy* func = funcs->values()->at(i)->AsVariableProxy();
+      DCHECK_NOT_NULL(func);
+      builder_->SetIndirectFunction(
+          indices->start_index + i,
+          LookupOrInsertFunction(func->var())->func_index());
+    }
+  }
+
   class ImportedFunctionTable {
    private:
     class ImportedFunctionIndices : public ZoneObject {
@@ -736,20 +804,33 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
                  ZoneAllocationPolicy(builder->zone())),
           builder_(builder) {}
 
-    void AddImport(Variable* v, const char* name, int name_length) {
-      ImportedFunctionIndices* indices = new (builder_->zone())
-          ImportedFunctionIndices(name, name_length, builder_->zone());
+    ImportedFunctionIndices* LookupOrInsertImport(Variable* v) {
       auto* entry = table_.LookupOrInsert(
           v, ComputePointerHash(v), ZoneAllocationPolicy(builder_->zone()));
-      entry->value = indices;
+      ImportedFunctionIndices* indices;
+      if (entry->value == nullptr) {
+        indices = new (builder_->zone())
+            ImportedFunctionIndices(nullptr, 0, builder_->zone());
+        entry->value = indices;
+      } else {
+        indices = reinterpret_cast<ImportedFunctionIndices*>(entry->value);
+      }
+      return indices;
+    }
+
+    void SetImportName(Variable* v, const char* name, int name_length) {
+      auto* indices = LookupOrInsertImport(v);
+      indices->name_ = name;
+      indices->name_length_ = name_length;
+      for (auto i : indices->signature_to_index_) {
+        builder_->builder_->SetImportName(i.second, indices->name_,
+                                          indices->name_length_);
+      }
     }
 
     // Get a function's index (or allocate if new).
-    uint32_t LookupOrInsertImport(Variable* v, FunctionSig* sig) {
-      ZoneHashMap::Entry* entry = table_.Lookup(v, ComputePointerHash(v));
-      DCHECK_NOT_NULL(entry);
-      ImportedFunctionIndices* indices =
-          reinterpret_cast<ImportedFunctionIndices*>(entry->value);
+    uint32_t LookupOrInsertImportUse(Variable* v, FunctionSig* sig) {
+      auto* indices = LookupOrInsertImport(v);
       WasmModuleBuilder::SignatureMap::iterator pos =
           indices->signature_to_index_.find(sig);
       if (pos != indices->signature_to_index_.end()) {
@@ -910,7 +991,7 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
           if (typer_->TypeOf(target)->AsFFIType() != nullptr) {
             const AstRawString* name =
                 prop->key()->AsLiteral()->AsRawPropertyName();
-            imported_function_table_.AddImport(
+            imported_function_table_.SetImportName(
                 target->var(), reinterpret_cast<const char*>(name->raw_data()),
                 name->length());
           }
@@ -919,14 +1000,10 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
         return;
       }
       ArrayLiteral* funcs = expr->value()->AsArrayLiteral();
-      if (funcs != nullptr &&
-          typer_->TypeOf(funcs)
-              ->AsFunctionTableType()
-              ->signature()
-              ->AsFunctionType()) {
+      if (funcs != nullptr) {
         VariableProxy* target = expr->target()->AsVariableProxy();
         DCHECK_NOT_NULL(target);
-        AddFunctionTable(target, funcs);
+        PopulateFunctionTable(target, funcs);
         // Only add to the function table. No init needed.
         return;
       }
@@ -1361,7 +1438,7 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
           for (int i = 0; i < args->length(); ++i) {
             sig.AddParam(TypeOf(args->at(i)));
           }
-          uint32_t index = imported_function_table_.LookupOrInsertImport(
+          uint32_t index = imported_function_table_.LookupOrInsertImportUse(
               vp->var(), sig.Build());
           VisitCallArgs(expr);
           current_function_builder_->Emit(kExprCallFunction);
@@ -1382,7 +1459,7 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
         DCHECK_NOT_NULL(p);
         VariableProxy* var = p->obj()->AsVariableProxy();
         DCHECK_NOT_NULL(var);
-        FunctionTableIndices* indices = LookupFunctionTable(var->var());
+        FunctionTableIndices* indices = LookupOrAddFunctionTable(var, p);
         Visit(p->key());  // TODO(titzer): should use RECURSE()
 
         // We have to use a temporary for the correct order of evaluation.
@@ -1727,6 +1804,9 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
     for (int i = 0; i < decls->length(); ++i) {
       Declaration* decl = decls->at(i);
       RECURSE(Visit(decl));
+      if (typer_failed_) {
+        return;
+      }
     }
   }
 
@@ -1854,7 +1934,9 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
   FunctionLiteral* literal_;
   Isolate* isolate_;
   Zone* zone_;
+  Script* script_;
   AsmTyper* typer_;
+  bool typer_failed_;
   ZoneVector<std::pair<BreakableStatement*, bool>> breakable_blocks_;
   ZoneVector<ForeignVariable> foreign_variables_;
   WasmFunctionBuilder* init_function_;
@@ -1869,15 +1951,21 @@ class AsmWasmBuilderImpl final : public AstVisitor<AsmWasmBuilderImpl> {
   DISALLOW_COPY_AND_ASSIGN(AsmWasmBuilderImpl);
 };
 
-AsmWasmBuilder::AsmWasmBuilder(Isolate* isolate, Zone* zone,
-                               FunctionLiteral* literal, AsmTyper* typer)
-    : isolate_(isolate), zone_(zone), literal_(literal), typer_(typer) {}
+AsmWasmBuilder::AsmWasmBuilder(Isolate* isolate, Zone* zone, Script* script,
+                               FunctionLiteral* literal)
+    : isolate_(isolate),
+      zone_(zone),
+      script_(script),
+      literal_(literal),
+      typer_(isolate, zone, script, literal) {}
 
 // TODO(aseemgarg): probably should take zone (to write wasm to) as input so
 // that zone in constructor may be thrown away once wasm module is written.
 ZoneBuffer* AsmWasmBuilder::Run(i::Handle<i::FixedArray>* foreign_args) {
-  AsmWasmBuilderImpl impl(isolate_, zone_, literal_, typer_);
-  impl.Build();
+  AsmWasmBuilderImpl impl(isolate_, zone_, script_, literal_, &typer_);
+  if (!impl.Build()) {
+    return nullptr;
+  }
   *foreign_args = impl.GetForeignArgs();
   ZoneBuffer* buffer = new (zone_) ZoneBuffer(zone_);
   impl.builder_->WriteTo(*buffer);