Add type determiner infrastructure.

This CL adds the Context object, variable ScopeStack and a Function map
into the type determiner.

The sample app is also updated to verify the module produced before
passing to the type determiner.

Bug: tint:5
Change-Id: Ib4af4e4305ee8a306f48e1bd328eaf3ad006fd9a
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/18823
Reviewed-by: David Neto <dneto@google.com>

samples/main.cc

diff --git a/samples/main.cc b/samples/main.cc
index b4af202..4fc31a4 100644
--- a/samples/main.cc
+++ b/samples/main.cc
@@ -292,22 +292,27 @@
     return 1;
   }
 
-  auto module = reader->module();
+  auto mod = reader->module();
   if (options.dump_ast) {
-    std::cout << std::endl << module.to_str() << std::endl;
+    std::cout << std::endl << mod.to_str() << std::endl;
   }
   if (options.parse_only) {
     return 1;
   }
 
-  tint::TypeDeterminer td;
-  if (!td.Determine(&module)) {
+  if (!mod.IsValid()) {
+    std::cerr << "Invalid module generated..." << std::endl;
+    return 1;
+  }
+
+  tint::TypeDeterminer td(&ctx);
+  if (!td.Determine(&mod)) {
     std::cerr << td.error() << std::endl;
     return 1;
   }
 
   tint::Validator v;
-  if (!v.Validate(module)) {
+  if (!v.Validate(mod)) {
     std::cerr << v.error() << std::endl;
     return 1;
   }
@@ -316,14 +321,13 @@
 
 #if TINT_BUILD_SPV_WRITER
   if (options.format == Format::kSpirv || options.format == Format::kSpvAsm) {
-    writer =
-        std::make_unique<tint::writer::spirv::Generator>(std::move(module));
+    writer = std::make_unique<tint::writer::spirv::Generator>(std::move(mod));
   }
 #endif  // TINT_BUILD_SPV_WRITER
 
 #if TINT_BUILD_WGSL_WRITER
   if (options.format == Format::kWgsl) {
-    writer = std::make_unique<tint::writer::wgsl::Generator>(std::move(module));
+    writer = std::make_unique<tint::writer::wgsl::Generator>(std::move(mod));
   }
 #endif  // TINT_BUILD_WGSL_WRITER
 

src/type_determiner.cc

diff --git a/src/type_determiner.cc b/src/type_determiner.cc
index 0faf0af..8abece1 100644
--- a/src/type_determiner.cc
+++ b/src/type_determiner.cc
@@ -16,7 +16,10 @@
 
 namespace tint {
 
-TypeDeterminer::TypeDeterminer() = default;
+TypeDeterminer::TypeDeterminer(Context* ctx) : ctx_(*ctx) {
+  // TODO(dsinclair): Temporary usage to avoid compiler warning
+  static_cast<void>(ctx_.type_mgr());
+}
 
 TypeDeterminer::~TypeDeterminer() = default;
 

src/type_determiner.h

diff --git a/src/type_determiner.h b/src/type_determiner.h
index 8f2062e..b43f923 100644
--- a/src/type_determiner.h
+++ b/src/type_determiner.h
@@ -16,16 +16,26 @@
 #define SRC_TYPE_DETERMINER_H_
 
 #include <string>
+#include <unordered_map>
 
 #include "src/ast/module.h"
+#include "src/context.h"
+#include "src/scope_stack.h"
 
 namespace tint {
+namespace ast {
+
+class Function;
+class Variable;
+
+}  // namespace ast
 
 /// Determines types for all items in the given tint module
 class TypeDeterminer {
  public:
   /// Constructor
-  TypeDeterminer();
+  /// @param ctx the tint context
+  explicit TypeDeterminer(Context* ctx);
   ~TypeDeterminer();
 
   /// Runs the type determiner
@@ -37,7 +47,10 @@
   const std::string& error() { return error_; }
 
  private:
+  Context& ctx_;
   std::string error_;
+  ScopeStack<ast::Variable*> variable_stack_;
+  std::unordered_map<std::string, ast::Function*> name_to_function_;
 };
 
 }  // namespace tint