From 417a90d2eec59318142189fce10edfe1ee1411a4 Mon Sep 17 00:00:00 2001
From: dan sinclair <dsinclair@chromium.org>
Date: Mon, 6 Apr 2020 21:07:41 +0000
Subject: [PATCH] Add stub definitions to the type determiner.

This adds enough infrastructure to type determiner to start building
out the statement and expression determination.

Bug: tint:5
Change-Id: I5e095cf652b5e3358e6fbabd66dd703348950857
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/18826
Reviewed-by: David Neto <dneto@google.com>
---
 src/type_determiner.cc | 56 +++++++++++++++++++++++++++++++++++++++++-
 src/type_determiner.h  | 30 ++++++++++++++++++----
 2 files changed, 80 insertions(+), 6 deletions(-)

diff --git a/src/type_determiner.cc b/src/type_determiner.cc
index 8abece1024..4e8a0465f5 100644
--- a/src/type_determiner.cc
+++ b/src/type_determiner.cc
@@ -23,8 +23,62 @@ TypeDeterminer::TypeDeterminer(Context* ctx) : ctx_(*ctx) {
 
 TypeDeterminer::~TypeDeterminer() = default;
 
-bool TypeDeterminer::Determine(ast::Module*) {
+bool TypeDeterminer::Determine(ast::Module* mod) {
+  for (const auto& var : mod->global_variables()) {
+    variable_stack_.set_global(var->name(), var.get());
+  }
+
+  for (const auto& func : mod->functions()) {
+    name_to_function_[func->name()] = func.get();
+  }
+
+  if (!DetermineFunctions(mod->functions())) {
+    return false;
+  }
   return true;
 }
 
+bool TypeDeterminer::DetermineFunctions(const ast::FunctionList& funcs) {
+  for (const auto& func : funcs) {
+    if (!DetermineFunction(func.get())) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool TypeDeterminer::DetermineFunction(ast::Function* func) {
+  variable_stack_.push_scope();
+  if (!DetermineResultType(func->body())) {
+    return false;
+  }
+  variable_stack_.pop_scope();
+
+  return true;
+}
+
+bool TypeDeterminer::DetermineResultType(const ast::StatementList& stmts) {
+  for (const auto& stmt : stmts) {
+    if (!DetermineResultType(stmt.get())) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool TypeDeterminer::DetermineResultType(ast::Statement*) {
+  error_ = "unknown statement type for type determination";
+  return false;
+}
+
+bool TypeDeterminer::DetermineResultType(ast::Expression* expr) {
+  // This is blindly called above, so in some cases the expression won't exist.
+  if (!expr) {
+    return true;
+  }
+
+  error_ = "unknown expression for type determination";
+  return false;
+}
+
 }  // namespace tint
diff --git a/src/type_determiner.h b/src/type_determiner.h
index b43f923096..2bfba85798 100644
--- a/src/type_determiner.h
+++ b/src/type_determiner.h
@@ -38,14 +38,34 @@ class TypeDeterminer {
   explicit TypeDeterminer(Context* ctx);
   ~TypeDeterminer();
 
-  /// Runs the type determiner
-  /// @param module the module to update with typing information
-  /// @returns true if the type determiner was successful
-  bool Determine(ast::Module* module);
-
   /// @returns error messages from the type determiner
   const std::string& error() { return error_; }
 
+  /// Runs the type determiner
+  /// @param mod the module to update with typing information
+  /// @returns true if the type determiner was successful
+  bool Determine(ast::Module* mod);
+  /// Determines type information for functions
+  /// @param funcs the functions to check
+  /// @returns true if the determination was successful
+  bool DetermineFunctions(const ast::FunctionList& funcs);
+  /// Determines type information for a function
+  /// @param func the function to check
+  /// @returns true if the determination was successful
+  bool DetermineFunction(ast::Function* func);
+  /// Determines type information for a set of statements
+  /// @param stmts the statements to check
+  /// @returns true if the determination was successful
+  bool DetermineResultType(const ast::StatementList& stmts);
+  /// Determines type information for a statement
+  /// @param stmt the statement to check
+  /// @returns true if the determination was successful
+  bool DetermineResultType(ast::Statement* stmt);
+  /// Determines type information for an expression
+  /// @param expr the expression to check
+  /// @returns true if the determination was successful
+  bool DetermineResultType(ast::Expression* expr);
+
  private:
   Context& ctx_;
   std::string error_;