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

src/asmjs/asm-typer.cc

Index: src/asmjs/asm-typer.cc
diff --git a/src/asmjs/asm-typer.cc b/src/asmjs/asm-typer.cc
index 2b0b91a5568ff8b9081cbbb7db21b03309815d94..b16845ad14d64d289cfb2940278b5b70254bd637 100644
--- a/src/asmjs/asm-typer.cc
+++ b/src/asmjs/asm-typer.cc
@@ -19,14 +19,19 @@
 #include "src/globals.h"
 #include "src/utils.h"
 
+#define FAIL_LINE(line, msg)                                   \
+  do {                                                         \
+    base::OS::SNPrintF(error_message_, sizeof(error_message_), \
+                       "asm: line %d: %s", (line) + 1, msg);   \
+    return AsmType::None();                                    \
+  } while (false)
+
 #define FAIL(node, msg)                                        \
   do {                                                         \
     int line = node->position() == kNoSourcePosition           \
                    ? -1                                        \
                    : script_->GetLineNumber(node->position()); \
-    base::OS::SNPrintF(error_message_, sizeof(error_message_), \
-                       "asm: line %d: %s", line + 1, msg);     \
-    return AsmType::None();                                    \
+    FAIL_LINE(line, msg);                                      \
   } while (false)
 
 #define RECURSE(call)                                             \
@@ -91,6 +96,51 @@ Statement* AsmTyper::FlattenedStatements::Next() {
 }
 
 // ----------------------------------------------------------------------------
+// Implementation of AsmTyper::SourceLayoutTracker
+
+bool AsmTyper::SourceLayoutTracker::IsValid() const {
+  const Section* kAllSections[] = {&use_asm_, &globals_, &functions_, &tables_,
+                                   &exports_};
+  for (size_t ii = 0; ii < arraysize(kAllSections); ++ii) {
+    const auto& curr_section = *kAllSections[ii];
+    for (size_t jj = ii + 1; jj < arraysize(kAllSections); ++jj) {
+      if (curr_section.OverlapsWith(*kAllSections[jj])) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+void AsmTyper::SourceLayoutTracker::Section::AddNewElement(
+    const AstNode& node) {
+  const int node_pos = node.position();
+  if (start_ == kNoSourcePosition) {
+    start_ = node_pos;
+  } else {
+    start_ = std::max(start_, node_pos);
+  }
+  if (end_ == kNoSourcePosition) {
+    end_ = node_pos;
+  } else {
+    end_ = std::max(end_, node_pos);
+  }
+}
+
+bool AsmTyper::SourceLayoutTracker::Section::OverlapsWith(

[titzer, 2016/11/29 14:57:37]

This check is actually stricter than OverlapsWith; it is that this section is
actually starts and ends before {other}.

Different name?

[bradn, 2016/11/29 22:09:06]

Actually this is too strict.
It happens to work because other parts of validation prescribe the ordering, but
it's clear to just have this check for overlap.
Changed the comparison instead.

[bradn, 2016/11/29 23:30:02]

Actually this is not overlap, renaming.

+    const Section& other) const {
+  if (start_ == kNoSourcePosition) {
+    DCHECK_EQ(end_, kNoSourcePosition);
+    return false;
+  }
+  if (other.start_ == kNoSourcePosition) {
+    DCHECK_EQ(other.end_, kNoSourcePosition);
+    return false;
+  }
+  return other.start_ < end_ || other.end_ < start_;
+}
+
+// ----------------------------------------------------------------------------
 // Implementation of AsmTyper::VariableInfo
 
 AsmTyper::VariableInfo* AsmTyper::VariableInfo::ForSpecialSymbol(
@@ -112,10 +162,10 @@ AsmTyper::VariableInfo* AsmTyper::VariableInfo::Clone(Zone* zone) const {
   return new_var_info;
 }
 
-void AsmTyper::VariableInfo::FirstForwardUseIs(VariableProxy* var) {
-  DCHECK(first_forward_use_ == nullptr);
+void AsmTyper::VariableInfo::FirstForwardUseIs(int source_location) {
+  DCHECK(source_location_ == -1);
   missing_definition_ = true;
-  first_forward_use_ = var;
+  source_location_ = source_location;
 }
 
 // ----------------------------------------------------------------------------
@@ -137,9 +187,11 @@ AsmTyper::AsmTyper(Isolate* isolate, Zone* zone, Script* script,
       local_scope_(ZoneHashMap::kDefaultHashMapCapacity,
                    ZoneAllocationPolicy(zone)),
       stack_limit_(isolate->stack_guard()->real_climit()),
-      node_types_(zone_),
+      module_node_types_(zone_),
+      function_node_types_(zone_),
       fround_type_(AsmType::FroundType(zone_)),
-      ffi_type_(AsmType::FFIType(zone_)) {
+      ffi_type_(AsmType::FFIType(zone_)),
+      function_pointer_tables_(zone_) {
   InitializeStdlib();
 }
 
@@ -345,7 +397,9 @@ AsmTyper::VariableInfo* AsmTyper::Lookup(Variable* variable) const {
 }
 
 void AsmTyper::AddForwardReference(VariableProxy* proxy, VariableInfo* info) {
-  info->FirstForwardUseIs(proxy);
+  info->FirstForwardUseIs(proxy->position() == kNoSourcePosition
+                              ? -1
+                              : script_->GetLineNumber(proxy->position()));
   forward_definitions_.push_back(info);
 }
 
@@ -390,13 +444,22 @@ bool AsmTyper::AddLocal(Variable* variable, VariableInfo* info) {
 
 void AsmTyper::SetTypeOf(AstNode* node, AsmType* type) {
   DCHECK_NE(type, AsmType::None());
-  DCHECK(node_types_.find(node) == node_types_.end());
-  node_types_.insert(std::make_pair(node, type));
+  if (in_function_) {
+    DCHECK(function_node_types_.find(node) == function_node_types_.end());
+    function_node_types_.insert(std::make_pair(node, type));
+  } else {
+    DCHECK(module_node_types_.find(node) == module_node_types_.end());
+    module_node_types_.insert(std::make_pair(node, type));
+  }
 }
 
 AsmType* AsmTyper::TypeOf(AstNode* node) const {
-  auto node_type_iter = node_types_.find(node);
-  if (node_type_iter != node_types_.end()) {
+  auto node_type_iter = function_node_types_.find(node);
+  if (node_type_iter != function_node_types_.end()) {
+    return node_type_iter->second;
+  }
+  node_type_iter = module_node_types_.find(node);
+  if (node_type_iter != module_node_types_.end()) {
     return node_type_iter->second;
   }
 
@@ -434,12 +497,34 @@ AsmTyper::StandardMember AsmTyper::VariableAsStandardMember(Variable* var) {
 }
 
 bool AsmTyper::Validate() {
-  if (!AsmType::None()->IsExactly(ValidateModule(root_))) {
+  return ValidateBeforeFunctionsPhase() &&
+         !AsmType::None()->IsExactly(ValidateModuleFunctions(root_)) &&
+         ValidateAfterFunctionsPhase();
+}
+
+bool AsmTyper::ValidateBeforeFunctionsPhase() {
+  if (!AsmType::None()->IsExactly(ValidateModuleBeforeFunctionsPhase(root_))) {
     return true;
   }
   return false;
 }
 
+bool AsmTyper::ValidateInnerFunction(FunctionDeclaration* fun_decl) {
+  if (!AsmType::None()->IsExactly(ValidateModuleFunction(fun_decl))) {
+    return true;
+  }
+  return false;
+}
+
+bool AsmTyper::ValidateAfterFunctionsPhase() {
+  if (!AsmType::None()->IsExactly(ValidateModuleAfterFunctionsPhase(root_))) {
+    return true;
+  }
+  return false;
+}
+
+void AsmTyper::ClearFunctionNodeTypes() { function_node_types_.clear(); }
+
 namespace {
 bool IsUseAsmDirective(Statement* first_statement) {
   ExpressionStatement* use_asm = first_statement->AsExpressionStatement();
@@ -477,89 +562,7 @@ Assignment* ExtractInitializerExpression(Statement* statement) {
 }  // namespace
 
 // 6.1 ValidateModule
-namespace {
-// SourceLayoutTracker keeps track of the start and end positions of each
-// section in the asm.js source. The sections should not overlap, otherwise the
-// asm.js source is invalid.
-class SourceLayoutTracker {
- public:
-  SourceLayoutTracker() = default;
-
-  bool IsValid() const {
-    const Section* kAllSections[] = {&use_asm_, &globals_, &functions_,
-                                     &tables_, &exports_};
-    for (size_t ii = 0; ii < arraysize(kAllSections); ++ii) {
-      const auto& curr_section = *kAllSections[ii];
-      for (size_t jj = ii + 1; jj < arraysize(kAllSections); ++jj) {
-        if (curr_section.OverlapsWith(*kAllSections[jj])) {
-          return false;
-        }
-      }
-    }
-    return true;
-  }
-
-  void AddUseAsm(const AstNode& node) { use_asm_.AddNewElement(node); }
-
-  void AddGlobal(const AstNode& node) { globals_.AddNewElement(node); }
-
-  void AddFunction(const AstNode& node) { functions_.AddNewElement(node); }
-
-  void AddTable(const AstNode& node) { tables_.AddNewElement(node); }
-
-  void AddExport(const AstNode& node) { exports_.AddNewElement(node); }
-
- private:
-  class Section {
-   public:
-    Section() = default;
-    Section(const Section&) = default;
-    Section& operator=(const Section&) = default;
-
-    void AddNewElement(const AstNode& node) {
-      const int node_pos = node.position();
-      if (start_ == kNoSourcePosition) {
-        start_ = node_pos;
-      } else {
-        start_ = std::max(start_, node_pos);
-      }
-      if (end_ == kNoSourcePosition) {
-        end_ = node_pos;
-      } else {
-        end_ = std::max(end_, node_pos);
-      }
-    }
-
-    bool OverlapsWith(const Section& other) const {
-      if (start_ == kNoSourcePosition) {
-        DCHECK_EQ(end_, kNoSourcePosition);
-        return false;
-      }
-      if (other.start_ == kNoSourcePosition) {
-        DCHECK_EQ(other.end_, kNoSourcePosition);
-        return false;
-      }
-      return other.start_ < end_ || other.end_ < start_;
-    }
-
-   private:
-    int start_ = kNoSourcePosition;
-    int end_ = kNoSourcePosition;
-  };
-
-  Section use_asm_;
-  Section globals_;
-  Section functions_;
-  Section tables_;
-  Section exports_;
-
-  DISALLOW_COPY_AND_ASSIGN(SourceLayoutTracker);
-};
-}  // namespace
-
-AsmType* AsmTyper::ValidateModule(FunctionLiteral* fun) {
-  SourceLayoutTracker source_layout;
-
+AsmType* AsmTyper::ValidateModuleBeforeFunctionsPhase(FunctionLiteral* fun) {
   DeclarationScope* scope = fun->scope();
   if (!scope->is_function_scope()) FAIL(fun, "Not at function scope.");
   if (!ValidAsmIdentifier(fun->name()))
@@ -594,7 +597,6 @@ AsmType* AsmTyper::ValidateModule(FunctionLiteral* fun) {
     }
   }
 
-  ZoneVector<Assignment*> function_pointer_tables(zone_);
   FlattenedStatements iter(zone_, fun->body());
   auto* use_asm_directive = iter.Next();
   if (use_asm_directive == nullptr) {
@@ -616,8 +618,8 @@ AsmType* AsmTyper::ValidateModule(FunctionLiteral* fun) {
   if (!IsUseAsmDirective(use_asm_directive)) {
     FAIL(fun, "Missing \"use asm\".");
   }
-  source_layout.AddUseAsm(*use_asm_directive);
-  ReturnStatement* module_return = nullptr;
+  source_layout_.AddUseAsm(*use_asm_directive);
+  module_return_ = nullptr;
 
   // *VIOLATION* The spec states that globals should be followed by function
   // declarations, which should be followed by function pointer tables, followed
@@ -627,40 +629,57 @@ AsmType* AsmTyper::ValidateModule(FunctionLiteral* fun) {
     if (auto* assign = ExtractInitializerExpression(current)) {
       if (assign->value()->IsArrayLiteral()) {
         // Save function tables for later validation.
-        function_pointer_tables.push_back(assign);
+        function_pointer_tables_.push_back(assign);
       } else {
         RECURSE(ValidateGlobalDeclaration(assign));
-        source_layout.AddGlobal(*assign);
+        source_layout_.AddGlobal(*assign);
       }
       continue;
     }
 
     if (auto* current_as_return = current->AsReturnStatement()) {
-      if (module_return != nullptr) {
+      if (module_return_ != nullptr) {
         FAIL(fun, "Multiple export statements.");
       }
-      module_return = current_as_return;
-      source_layout.AddExport(*module_return);
+      module_return_ = current_as_return;
+      source_layout_.AddExport(*module_return_);
       continue;
     }
 
     FAIL(current, "Invalid top-level statement in asm.js module.");
   }
 
+  return AsmType::Int();  // Any type that is not AsmType::None();
+}
+
+AsmType* AsmTyper::ValidateModuleFunction(FunctionDeclaration* fun_decl) {
+  RECURSE(ValidateFunction(fun_decl));
+  source_layout_.AddFunction(*fun_decl);
+
+  return AsmType::Int();  // Any type that is not AsmType::None();
+}
+
+AsmType* AsmTyper::ValidateModuleFunctions(FunctionLiteral* fun) {
+  DeclarationScope* scope = fun->scope();
   Declaration::List* decls = scope->declarations();
   for (Declaration* decl : *decls) {
     if (FunctionDeclaration* fun_decl = decl->AsFunctionDeclaration()) {
-      RECURSE(ValidateFunction(fun_decl));
-      source_layout.AddFunction(*fun_decl);
+      RECURSE(ValidateModuleFunction(fun_decl));
       continue;
     }
   }
 
-  for (auto* function_table : function_pointer_tables) {
+  return AsmType::Int();  // Any type that is not AsmType::None();
+}
+
+AsmType* AsmTyper::ValidateModuleAfterFunctionsPhase(FunctionLiteral* fun) {
+  for (auto* function_table : function_pointer_tables_) {
     RECURSE(ValidateFunctionTable(function_table));
-    source_layout.AddTable(*function_table);
+    source_layout_.AddTable(*function_table);
   }
 
+  DeclarationScope* scope = fun->scope();
+  Declaration::List* decls = scope->declarations();
   for (Declaration* decl : *decls) {
     if (decl->IsFunctionDeclaration()) {
       continue;
@@ -682,20 +701,20 @@ AsmType* AsmTyper::ValidateModule(FunctionLiteral* fun) {
   }
 
   // 6.2 ValidateExport
-  if (module_return == nullptr) {
+  if (module_return_ == nullptr) {
     FAIL(fun, "Missing asm.js module export.");
   }
 
   for (auto* forward_def : forward_definitions_) {
     if (forward_def->missing_definition()) {
-      FAIL(forward_def->first_forward_use(),
-           "Missing definition for forward declared identifier.");
+      FAIL_LINE(forward_def->source_location(),
+                "Missing definition for forward declared identifier.");
     }
   }
 
-  RECURSE(ValidateExport(module_return));
+  RECURSE(ValidateExport(module_return_));
 
-  if (!source_layout.IsValid()) {
+  if (!source_layout_.IsValid()) {
     FAIL(fun, "Invalid asm.js source code layout.");
   }