diff --git a/src/inspector/inspector.cc b/src/inspector/inspector.cc
index 8fbd078..299c5fb 100644
--- a/src/inspector/inspector.cc
+++ b/src/inspector/inspector.cc
@@ -145,7 +145,7 @@
     entry_point.remapped_name = program_->Symbols().NameFor(func->symbol);
     entry_point.stage = func->PipelineStage();
 
-    auto wgsize = sem->workgroup_size();
+    auto wgsize = sem->WorkgroupSize();
     entry_point.workgroup_size_x = wgsize[0].value;
     entry_point.workgroup_size_y = wgsize[1].value;
     entry_point.workgroup_size_z = wgsize[2].value;
@@ -188,7 +188,7 @@
                           func->return_type_decorations);
     }
 
-    for (auto* var : sem->ReferencedModuleVariables()) {
+    for (auto* var : sem->TransitivelyReferencedGlobals()) {
       auto* decl = var->Declaration();
 
       auto name = program_->Symbols().NameFor(decl->symbol);
@@ -333,13 +333,13 @@
 
   size_t size = 0;
   auto* func_sem = program_->Sem().Get(func);
-  for (auto& ruv : func_sem->ReferencedUniformVariables()) {
+  for (auto& ruv : func_sem->TransitivelyReferencedUniformVariables()) {
     const sem::Struct* s = ruv.first->Type()->UnwrapRef()->As<sem::Struct>();
     if (s && s->IsBlockDecorated()) {
       size += s->Size();
     }
   }
-  for (auto& rsv : func_sem->ReferencedStorageBufferVariables()) {
+  for (auto& rsv : func_sem->TransitivelyReferencedStorageBufferVariables()) {
     const sem::Struct* s = rsv.first->Type()->UnwrapRef()->As<sem::Struct>();
     if (s) {
       size += s->Size();
@@ -389,7 +389,7 @@
   std::vector<ResourceBinding> result;
 
   auto* func_sem = program_->Sem().Get(func);
-  for (auto& ruv : func_sem->ReferencedUniformVariables()) {
+  for (auto& ruv : func_sem->TransitivelyReferencedUniformVariables()) {
     auto* var = ruv.first;
     auto binding_info = ruv.second;
 
@@ -437,7 +437,7 @@
   std::vector<ResourceBinding> result;
 
   auto* func_sem = program_->Sem().Get(func);
-  for (auto& rs : func_sem->ReferencedSamplerVariables()) {
+  for (auto& rs : func_sem->TransitivelyReferencedSamplerVariables()) {
     auto binding_info = rs.second;
 
     ResourceBinding entry;
@@ -461,7 +461,8 @@
   std::vector<ResourceBinding> result;
 
   auto* func_sem = program_->Sem().Get(func);
-  for (auto& rcs : func_sem->ReferencedComparisonSamplerVariables()) {
+  for (auto& rcs :
+       func_sem->TransitivelyReferencedComparisonSamplerVariables()) {
     auto binding_info = rcs.second;
 
     ResourceBinding entry;
@@ -502,7 +503,8 @@
 
   std::vector<ResourceBinding> result;
   auto* func_sem = program_->Sem().Get(func);
-  for (auto& ref : func_sem->ReferencedVariablesOfType(texture_type)) {
+  for (auto& ref :
+       func_sem->TransitivelyReferencedVariablesOfType(texture_type)) {
     auto* var = ref.first;
     auto binding_info = ref.second;
 
@@ -567,7 +569,7 @@
 
   uint32_t total_size = 0;
   auto* func_sem = program_->Sem().Get(func);
-  for (const sem::Variable* var : func_sem->ReferencedModuleVariables()) {
+  for (const sem::Variable* var : func_sem->TransitivelyReferencedGlobals()) {
     if (var->StorageClass() == ast::StorageClass::kWorkgroup) {
       auto* ty = var->Type()->UnwrapRef();
       uint32_t align = ty->Align();
@@ -678,7 +680,7 @@
 
   auto* func_sem = program_->Sem().Get(func);
   std::vector<ResourceBinding> result;
-  for (auto& rsv : func_sem->ReferencedStorageBufferVariables()) {
+  for (auto& rsv : func_sem->TransitivelyReferencedStorageBufferVariables()) {
     auto* var = rsv.first;
     auto binding_info = rsv.second;
 
@@ -717,8 +719,9 @@
   std::vector<ResourceBinding> result;
   auto* func_sem = program_->Sem().Get(func);
   auto referenced_variables =
-      multisampled_only ? func_sem->ReferencedMultisampledTextureVariables()
-                        : func_sem->ReferencedSampledTextureVariables();
+      multisampled_only
+          ? func_sem->TransitivelyReferencedMultisampledTextureVariables()
+          : func_sem->TransitivelyReferencedSampledTextureVariables();
   for (auto& ref : referenced_variables) {
     auto* var = ref.first;
     auto binding_info = ref.second;
@@ -757,7 +760,8 @@
 
   auto* func_sem = program_->Sem().Get(func);
   std::vector<ResourceBinding> result;
-  for (auto& ref : func_sem->ReferencedVariablesOfType<sem::StorageTexture>()) {
+  for (auto& ref :
+       func_sem->TransitivelyReferencedVariablesOfType<sem::StorageTexture>()) {
     auto* var = ref.first;
     auto binding_info = ref.second;
 
diff --git a/src/resolver/resolver.cc b/src/resolver/resolver.cc
index 6836f12..9664f00 100644
--- a/src/resolver/resolver.cc
+++ b/src/resolver/resolver.cc
@@ -3795,10 +3795,10 @@
   }
 
   auto remap_vars = [&sem](const std::vector<VariableInfo*>& in) {
-    std::vector<const sem::Variable*> out;
+    std::vector<const sem::GlobalVariable*> out;
     out.reserve(in.size());
     for (auto* info : in) {
-      out.emplace_back(sem.Get(info->declaration));
+      out.emplace_back(sem.Get<sem::GlobalVariable>(info->declaration));
     }
     return out;
   };
@@ -3818,9 +3818,8 @@
     auto* sem_func = builder_->create<sem::Function>(
         info->declaration, info->return_type, parameters,
         remap_vars(info->referenced_module_vars),
-        remap_vars(info->local_referenced_module_vars), info->return_statements,
-        info->callsites, ancestor_entry_points[func->symbol],
-        info->workgroup_size);
+        remap_vars(info->local_referenced_module_vars), info->callsites,
+        ancestor_entry_points[func->symbol], info->workgroup_size);
     func_info_to_sem_func.emplace(info, sem_func);
     sem.Add(func, sem_func);
   }
diff --git a/src/resolver/resolver_test.cc b/src/resolver/resolver_test.cc
index 198109f..ddf4d36 100644
--- a/src/resolver/resolver_test.cc
+++ b/src/resolver/resolver_test.cc
@@ -819,7 +819,7 @@
   EXPECT_EQ(func_sem->Parameters().size(), 0u);
   EXPECT_TRUE(func_sem->ReturnType()->Is<sem::Void>());
 
-  const auto& vars = func_sem->ReferencedModuleVariables();
+  const auto& vars = func_sem->TransitivelyReferencedGlobals();
   ASSERT_EQ(vars.size(), 3u);
   EXPECT_EQ(vars[0]->Declaration(), wg_var);
   EXPECT_EQ(vars[1]->Declaration(), sb_var);
@@ -856,7 +856,7 @@
   ASSERT_NE(func2_sem, nullptr);
   EXPECT_EQ(func2_sem->Parameters().size(), 0u);
 
-  const auto& vars = func2_sem->ReferencedModuleVariables();
+  const auto& vars = func2_sem->TransitivelyReferencedGlobals();
   ASSERT_EQ(vars.size(), 3u);
   EXPECT_EQ(vars[0]->Declaration(), wg_var);
   EXPECT_EQ(vars[1]->Declaration(), sb_var);
@@ -875,7 +875,7 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->ReferencedModuleVariables().size(), 0u);
+  EXPECT_EQ(func_sem->TransitivelyReferencedGlobals().size(), 0u);
   EXPECT_TRUE(func_sem->ReturnType()->Is<sem::Void>());
 }
 
@@ -890,7 +890,7 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->ReferencedModuleVariables().size(), 0u);
+  EXPECT_EQ(func_sem->TransitivelyReferencedGlobals().size(), 0u);
   EXPECT_TRUE(func_sem->ReturnType()->Is<sem::Void>());
 }
 
@@ -902,34 +902,10 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->ReferencedModuleVariables().size(), 0u);
+  EXPECT_EQ(func_sem->TransitivelyReferencedGlobals().size(), 0u);
   EXPECT_TRUE(func_sem->ReturnType()->Is<sem::Void>());
 }
 
-TEST_F(ResolverTest, Function_ReturnStatements) {
-  auto* var = Var("foo", ty.f32());
-
-  auto* ret_1 = Return(1.f);
-  auto* ret_foo = Return("foo");
-  auto* func = Func("my_func", ast::VariableList{}, ty.f32(),
-                    {
-                        Decl(var),
-                        If(true, Block(ret_1)),
-                        ret_foo,
-                    });
-
-  EXPECT_TRUE(r()->Resolve()) << r()->error();
-
-  auto* func_sem = Sem().Get(func);
-  ASSERT_NE(func_sem, nullptr);
-  EXPECT_EQ(func_sem->Parameters().size(), 0u);
-
-  EXPECT_EQ(func_sem->ReturnStatements().size(), 2u);
-  EXPECT_EQ(func_sem->ReturnStatements()[0], ret_1);
-  EXPECT_EQ(func_sem->ReturnStatements()[1], ret_foo);
-  EXPECT_TRUE(func_sem->ReturnType()->Is<sem::F32>());
-}
-
 TEST_F(ResolverTest, Function_CallSites) {
   auto* foo = Func("foo", ast::VariableList{}, ty.void_(), {});
 
@@ -964,12 +940,12 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->workgroup_size()[0].value, 1u);
-  EXPECT_EQ(func_sem->workgroup_size()[1].value, 1u);
-  EXPECT_EQ(func_sem->workgroup_size()[2].value, 1u);
-  EXPECT_EQ(func_sem->workgroup_size()[0].overridable_const, nullptr);
-  EXPECT_EQ(func_sem->workgroup_size()[1].overridable_const, nullptr);
-  EXPECT_EQ(func_sem->workgroup_size()[2].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].value, 1u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].value, 1u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].value, 1u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].overridable_const, nullptr);
 }
 
 TEST_F(ResolverTest, Function_WorkgroupSize_Literals) {
@@ -984,12 +960,12 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->workgroup_size()[0].value, 8u);
-  EXPECT_EQ(func_sem->workgroup_size()[1].value, 2u);
-  EXPECT_EQ(func_sem->workgroup_size()[2].value, 3u);
-  EXPECT_EQ(func_sem->workgroup_size()[0].overridable_const, nullptr);
-  EXPECT_EQ(func_sem->workgroup_size()[1].overridable_const, nullptr);
-  EXPECT_EQ(func_sem->workgroup_size()[2].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].value, 8u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].value, 2u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].value, 3u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].overridable_const, nullptr);
 }
 
 TEST_F(ResolverTest, Function_WorkgroupSize_Consts) {
@@ -1010,12 +986,12 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->workgroup_size()[0].value, 16u);
-  EXPECT_EQ(func_sem->workgroup_size()[1].value, 8u);
-  EXPECT_EQ(func_sem->workgroup_size()[2].value, 2u);
-  EXPECT_EQ(func_sem->workgroup_size()[0].overridable_const, nullptr);
-  EXPECT_EQ(func_sem->workgroup_size()[1].overridable_const, nullptr);
-  EXPECT_EQ(func_sem->workgroup_size()[2].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].value, 16u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].value, 8u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].value, 2u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].overridable_const, nullptr);
 }
 
 TEST_F(ResolverTest, Function_WorkgroupSize_Consts_NestedInitializer) {
@@ -1036,12 +1012,12 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->workgroup_size()[0].value, 8u);
-  EXPECT_EQ(func_sem->workgroup_size()[1].value, 4u);
-  EXPECT_EQ(func_sem->workgroup_size()[2].value, 1u);
-  EXPECT_EQ(func_sem->workgroup_size()[0].overridable_const, nullptr);
-  EXPECT_EQ(func_sem->workgroup_size()[1].overridable_const, nullptr);
-  EXPECT_EQ(func_sem->workgroup_size()[2].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].value, 8u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].value, 4u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].value, 1u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].overridable_const, nullptr);
 }
 
 TEST_F(ResolverTest, Function_WorkgroupSize_OverridableConsts) {
@@ -1062,12 +1038,12 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->workgroup_size()[0].value, 16u);
-  EXPECT_EQ(func_sem->workgroup_size()[1].value, 8u);
-  EXPECT_EQ(func_sem->workgroup_size()[2].value, 2u);
-  EXPECT_EQ(func_sem->workgroup_size()[0].overridable_const, width);
-  EXPECT_EQ(func_sem->workgroup_size()[1].overridable_const, height);
-  EXPECT_EQ(func_sem->workgroup_size()[2].overridable_const, depth);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].value, 16u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].value, 8u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].value, 2u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].overridable_const, width);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].overridable_const, height);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].overridable_const, depth);
 }
 
 TEST_F(ResolverTest, Function_WorkgroupSize_OverridableConsts_NoInit) {
@@ -1088,12 +1064,12 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->workgroup_size()[0].value, 0u);
-  EXPECT_EQ(func_sem->workgroup_size()[1].value, 0u);
-  EXPECT_EQ(func_sem->workgroup_size()[2].value, 0u);
-  EXPECT_EQ(func_sem->workgroup_size()[0].overridable_const, width);
-  EXPECT_EQ(func_sem->workgroup_size()[1].overridable_const, height);
-  EXPECT_EQ(func_sem->workgroup_size()[2].overridable_const, depth);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].value, 0u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].value, 0u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].value, 0u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].overridable_const, width);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].overridable_const, height);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].overridable_const, depth);
 }
 
 TEST_F(ResolverTest, Function_WorkgroupSize_Mixed) {
@@ -1112,12 +1088,12 @@
   auto* func_sem = Sem().Get(func);
   ASSERT_NE(func_sem, nullptr);
 
-  EXPECT_EQ(func_sem->workgroup_size()[0].value, 8u);
-  EXPECT_EQ(func_sem->workgroup_size()[1].value, 2u);
-  EXPECT_EQ(func_sem->workgroup_size()[2].value, 3u);
-  EXPECT_EQ(func_sem->workgroup_size()[0].overridable_const, nullptr);
-  EXPECT_EQ(func_sem->workgroup_size()[1].overridable_const, height);
-  EXPECT_EQ(func_sem->workgroup_size()[2].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].value, 8u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].value, 2u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].value, 3u);
+  EXPECT_EQ(func_sem->WorkgroupSize()[0].overridable_const, nullptr);
+  EXPECT_EQ(func_sem->WorkgroupSize()[1].overridable_const, height);
+  EXPECT_EQ(func_sem->WorkgroupSize()[2].overridable_const, nullptr);
 }
 
 TEST_F(ResolverTest, Expr_MemberAccessor_Struct) {
diff --git a/src/sem/function.cc b/src/sem/function.cc
index ac81698..070938b 100644
--- a/src/sem/function.cc
+++ b/src/sem/function.cc
@@ -28,35 +28,35 @@
 namespace tint {
 namespace sem {
 
-Function::Function(const ast::Function* declaration,
-                   Type* return_type,
-                   std::vector<Parameter*> parameters,
-                   std::vector<const Variable*> referenced_module_vars,
-                   std::vector<const Variable*> local_referenced_module_vars,
-                   std::vector<const ast::ReturnStatement*> return_statements,
-                   std::vector<const ast::CallExpression*> callsites,
-                   std::vector<Symbol> ancestor_entry_points,
-                   std::array<WorkgroupDimension, 3> workgroup_size)
+Function::Function(
+    const ast::Function* declaration,
+    Type* return_type,
+    std::vector<Parameter*> parameters,
+    std::vector<const GlobalVariable*> transitively_referenced_globals,
+    std::vector<const GlobalVariable*> directly_referenced_globals,
+    std::vector<const ast::CallExpression*> callsites,
+    std::vector<Symbol> ancestor_entry_points,
+    sem::WorkgroupSize workgroup_size)
     : Base(return_type, utils::ToConstPtrVec(parameters)),
       declaration_(declaration),
-      referenced_module_vars_(std::move(referenced_module_vars)),
-      local_referenced_module_vars_(std::move(local_referenced_module_vars)),
-      return_statements_(std::move(return_statements)),
+      workgroup_size_(std::move(workgroup_size)),
+      directly_referenced_globals_(std::move(directly_referenced_globals)),
+      transitively_referenced_globals_(
+          std::move(transitively_referenced_globals)),
       callsites_(callsites),
-      ancestor_entry_points_(std::move(ancestor_entry_points)),
-      workgroup_size_(std::move(workgroup_size)) {
+      ancestor_entry_points_(std::move(ancestor_entry_points)) {
   for (auto* parameter : parameters) {
     parameter->SetOwner(this);
   }
-}
+}  // namespace sem
 
 Function::~Function() = default;
 
 std::vector<std::pair<const Variable*, const ast::LocationDecoration*>>
-Function::ReferencedLocationVariables() const {
+Function::TransitivelyReferencedLocationVariables() const {
   std::vector<std::pair<const Variable*, const ast::LocationDecoration*>> ret;
 
-  for (auto* var : ReferencedModuleVariables()) {
+  for (auto* var : TransitivelyReferencedGlobals()) {
     for (auto* deco : var->Declaration()->decorations) {
       if (auto* location = deco->As<ast::LocationDecoration>()) {
         ret.push_back({var, location});
@@ -67,10 +67,11 @@
   return ret;
 }
 
-Function::VariableBindings Function::ReferencedUniformVariables() const {
+Function::VariableBindings Function::TransitivelyReferencedUniformVariables()
+    const {
   VariableBindings ret;
 
-  for (auto* var : ReferencedModuleVariables()) {
+  for (auto* var : TransitivelyReferencedGlobals()) {
     if (var->StorageClass() != ast::StorageClass::kUniform) {
       continue;
     }
@@ -82,10 +83,11 @@
   return ret;
 }
 
-Function::VariableBindings Function::ReferencedStorageBufferVariables() const {
+Function::VariableBindings
+Function::TransitivelyReferencedStorageBufferVariables() const {
   VariableBindings ret;
 
-  for (auto* var : ReferencedModuleVariables()) {
+  for (auto* var : TransitivelyReferencedGlobals()) {
     if (var->StorageClass() != ast::StorageClass::kStorage) {
       continue;
     }
@@ -98,10 +100,10 @@
 }
 
 std::vector<std::pair<const Variable*, const ast::BuiltinDecoration*>>
-Function::ReferencedBuiltinVariables() const {
+Function::TransitivelyReferencedBuiltinVariables() const {
   std::vector<std::pair<const Variable*, const ast::BuiltinDecoration*>> ret;
 
-  for (auto* var : ReferencedModuleVariables()) {
+  for (auto* var : TransitivelyReferencedGlobals()) {
     for (auto* deco : var->Declaration()->decorations) {
       if (auto* builtin = deco->As<ast::BuiltinDecoration>()) {
         ret.push_back({var, builtin});
@@ -112,28 +114,31 @@
   return ret;
 }
 
-Function::VariableBindings Function::ReferencedSamplerVariables() const {
-  return ReferencedSamplerVariablesImpl(ast::SamplerKind::kSampler);
-}
-
-Function::VariableBindings Function::ReferencedComparisonSamplerVariables()
+Function::VariableBindings Function::TransitivelyReferencedSamplerVariables()
     const {
-  return ReferencedSamplerVariablesImpl(ast::SamplerKind::kComparisonSampler);
+  return TransitivelyReferencedSamplerVariablesImpl(ast::SamplerKind::kSampler);
 }
 
-Function::VariableBindings Function::ReferencedSampledTextureVariables() const {
-  return ReferencedSampledTextureVariablesImpl(false);
+Function::VariableBindings
+Function::TransitivelyReferencedComparisonSamplerVariables() const {
+  return TransitivelyReferencedSamplerVariablesImpl(
+      ast::SamplerKind::kComparisonSampler);
 }
 
-Function::VariableBindings Function::ReferencedMultisampledTextureVariables()
-    const {
-  return ReferencedSampledTextureVariablesImpl(true);
+Function::VariableBindings
+Function::TransitivelyReferencedSampledTextureVariables() const {
+  return TransitivelyReferencedSampledTextureVariablesImpl(false);
 }
 
-Function::VariableBindings Function::ReferencedVariablesOfType(
+Function::VariableBindings
+Function::TransitivelyReferencedMultisampledTextureVariables() const {
+  return TransitivelyReferencedSampledTextureVariablesImpl(true);
+}
+
+Function::VariableBindings Function::TransitivelyReferencedVariablesOfType(
     const tint::TypeInfo& type_info) const {
   VariableBindings ret;
-  for (auto* var : ReferencedModuleVariables()) {
+  for (auto* var : TransitivelyReferencedGlobals()) {
     auto* unwrapped_type = var->Type()->UnwrapRef();
     if (unwrapped_type->TypeInfo().Is(type_info)) {
       if (auto binding_point = var->Declaration()->BindingPoint()) {
@@ -153,11 +158,11 @@
   return false;
 }
 
-Function::VariableBindings Function::ReferencedSamplerVariablesImpl(
+Function::VariableBindings Function::TransitivelyReferencedSamplerVariablesImpl(
     ast::SamplerKind kind) const {
   VariableBindings ret;
 
-  for (auto* var : ReferencedModuleVariables()) {
+  for (auto* var : TransitivelyReferencedGlobals()) {
     auto* unwrapped_type = var->Type()->UnwrapRef();
     auto* sampler = unwrapped_type->As<sem::Sampler>();
     if (sampler == nullptr || sampler->kind() != kind) {
@@ -171,11 +176,12 @@
   return ret;
 }
 
-Function::VariableBindings Function::ReferencedSampledTextureVariablesImpl(
+Function::VariableBindings
+Function::TransitivelyReferencedSampledTextureVariablesImpl(
     bool multisampled) const {
   VariableBindings ret;
 
-  for (auto* var : ReferencedModuleVariables()) {
+  for (auto* var : TransitivelyReferencedGlobals()) {
     auto* unwrapped_type = var->Type()->UnwrapRef();
     auto* texture = unwrapped_type->As<sem::Texture>();
     if (texture == nullptr) {
diff --git a/src/sem/function.h b/src/sem/function.h
index 18e4617..c10301d 100644
--- a/src/sem/function.h
+++ b/src/sem/function.h
@@ -20,23 +20,22 @@
 #include <vector>
 
 #include "src/ast/variable.h"
-#include "src/sem/call_target.h"
+#include "src/sem/call.h"
+#include "src/utils/unique_vector.h"
 
 namespace tint {
 
 // Forward declarations
 namespace ast {
-class BindingDecoration;
 class BuiltinDecoration;
-class CallExpression;
 class Function;
-class GroupDecoration;
 class LocationDecoration;
 class ReturnStatement;
 }  // namespace ast
 
 namespace sem {
 
+class Intrinsic;
 class Variable;
 
 /// WorkgroupDimension describes the size of a single dimension of an entry
@@ -49,6 +48,9 @@
   const ast::Variable* overridable_const = nullptr;
 };
 
+/// WorkgroupSize is a three-dimensional array of WorkgroupDimensions.
+using WorkgroupSize = std::array<WorkgroupDimension, 3>;
+
 /// Function holds the semantic information for function nodes.
 class Function : public Castable<Function, CallTarget> {
  public:
@@ -60,21 +62,19 @@
   /// @param declaration the ast::Function
   /// @param return_type the return type of the function
   /// @param parameters the parameters to the function
-  /// @param referenced_module_vars the referenced module variables
-  /// @param local_referenced_module_vars the locally referenced module
-  /// @param return_statements the function return statements
+  /// @param transitively_referenced_globals the referenced module variables
+  /// @param directly_referenced_globals the locally referenced module
   /// @param callsites the callsites of the function
   /// @param ancestor_entry_points the ancestor entry points
   /// @param workgroup_size the workgroup size
   Function(const ast::Function* declaration,
            Type* return_type,
            std::vector<Parameter*> parameters,
-           std::vector<const Variable*> referenced_module_vars,
-           std::vector<const Variable*> local_referenced_module_vars,
-           std::vector<const ast::ReturnStatement*> return_statements,
+           std::vector<const GlobalVariable*> transitively_referenced_globals,
+           std::vector<const GlobalVariable*> directly_referenced_globals,
            std::vector<const ast::CallExpression*> callsites,
            std::vector<Symbol> ancestor_entry_points,
-           std::array<WorkgroupDimension, 3> workgroup_size);
+           sem::WorkgroupSize workgroup_size);
 
   /// Destructor
   ~Function() override;
@@ -82,81 +82,78 @@
   /// @returns the ast::Function declaration
   const ast::Function* Declaration() const { return declaration_; }
 
-  /// Note: If this function calls other functions, the return will also include
-  /// all of the referenced variables from the callees.
-  /// @returns the referenced module variables
-  const std::vector<const Variable*>& ReferencedModuleVariables() const {
-    return referenced_module_vars_;
+  /// @returns the workgroup size {x, y, z} for the function.
+  const sem::WorkgroupSize& WorkgroupSize() const { return workgroup_size_; }
+
+  /// @returns all transitively referenced global variables
+  const utils::UniqueVector<const GlobalVariable*>&
+  TransitivelyReferencedGlobals() const {
+    return transitively_referenced_globals_;
   }
-  /// @returns the locally referenced module variables
-  const std::vector<const Variable*>& LocalReferencedModuleVariables() const {
-    return local_referenced_module_vars_;
-  }
-  /// @returns the return statements
-  const std::vector<const ast::ReturnStatement*> ReturnStatements() const {
-    return return_statements_;
-  }
+
   /// @returns the list of callsites of this function
   std::vector<const ast::CallExpression*> CallSites() const {
     return callsites_;
   }
-  /// @returns the ancestor entry points
+
+  /// @returns the names of the ancestor entry points
   const std::vector<Symbol>& AncestorEntryPoints() const {
     return ancestor_entry_points_;
   }
+
   /// Retrieves any referenced location variables
   /// @returns the <variable, decoration> pair.
   std::vector<std::pair<const Variable*, const ast::LocationDecoration*>>
-  ReferencedLocationVariables() const;
+  TransitivelyReferencedLocationVariables() const;
 
   /// Retrieves any referenced builtin variables
   /// @returns the <variable, decoration> pair.
   std::vector<std::pair<const Variable*, const ast::BuiltinDecoration*>>
-  ReferencedBuiltinVariables() const;
+  TransitivelyReferencedBuiltinVariables() const;
 
   /// Retrieves any referenced uniform variables. Note, the variables must be
   /// decorated with both binding and group decorations.
   /// @returns the referenced uniforms
-  VariableBindings ReferencedUniformVariables() const;
+  VariableBindings TransitivelyReferencedUniformVariables() const;
 
   /// Retrieves any referenced storagebuffer variables. Note, the variables
   /// must be decorated with both binding and group decorations.
   /// @returns the referenced storagebuffers
-  VariableBindings ReferencedStorageBufferVariables() const;
+  VariableBindings TransitivelyReferencedStorageBufferVariables() const;
 
   /// Retrieves any referenced regular Sampler variables. Note, the
   /// variables must be decorated with both binding and group decorations.
   /// @returns the referenced storagebuffers
-  VariableBindings ReferencedSamplerVariables() const;
+  VariableBindings TransitivelyReferencedSamplerVariables() const;
 
   /// Retrieves any referenced comparison Sampler variables. Note, the
   /// variables must be decorated with both binding and group decorations.
   /// @returns the referenced storagebuffers
-  VariableBindings ReferencedComparisonSamplerVariables() const;
+  VariableBindings TransitivelyReferencedComparisonSamplerVariables() const;
 
   /// Retrieves any referenced sampled textures variables. Note, the
   /// variables must be decorated with both binding and group decorations.
   /// @returns the referenced sampled textures
-  VariableBindings ReferencedSampledTextureVariables() const;
+  VariableBindings TransitivelyReferencedSampledTextureVariables() const;
 
   /// Retrieves any referenced multisampled textures variables. Note, the
   /// variables must be decorated with both binding and group decorations.
   /// @returns the referenced sampled textures
-  VariableBindings ReferencedMultisampledTextureVariables() const;
+  VariableBindings TransitivelyReferencedMultisampledTextureVariables() const;
 
   /// Retrieves any referenced variables of the given type. Note, the variables
   /// must be decorated with both binding and group decorations.
   /// @param type_info the type of the variables to find
   /// @returns the referenced variables
-  VariableBindings ReferencedVariablesOfType(
+  VariableBindings TransitivelyReferencedVariablesOfType(
       const tint::TypeInfo& type_info) const;
 
   /// Retrieves any referenced variables of the given type. Note, the variables
   /// must be decorated with both binding and group decorations.
   /// @returns the referenced variables
   template <typename T>
-  VariableBindings ReferencedVariablesOfType() const {
-    return ReferencedVariablesOfType(TypeInfo::Of<T>());
+  VariableBindings TransitivelyReferencedVariablesOfType() const {
+    return TransitivelyReferencedVariablesOfType(TypeInfo::Of<T>());
   }
 
   /// Checks if the given entry point is an ancestor
@@ -164,23 +161,21 @@
   /// @returns true if `sym` is an ancestor entry point of this function
   bool HasAncestorEntryPoint(Symbol sym) const;
 
-  /// @returns the workgroup size {x, y, z} for the function.
-  const std::array<WorkgroupDimension, 3>& workgroup_size() const {
-    return workgroup_size_;
-  }
-
  private:
-  VariableBindings ReferencedSamplerVariablesImpl(ast::SamplerKind kind) const;
-  VariableBindings ReferencedSampledTextureVariablesImpl(
+  VariableBindings TransitivelyReferencedSamplerVariablesImpl(
+      ast::SamplerKind kind) const;
+  VariableBindings TransitivelyReferencedSampledTextureVariablesImpl(
       bool multisampled) const;
 
   const ast::Function* const declaration_;
-  std::vector<const Variable*> const referenced_module_vars_;
-  std::vector<const Variable*> const local_referenced_module_vars_;
-  std::vector<const ast::ReturnStatement*> const return_statements_;
-  std::vector<const ast::CallExpression*> const callsites_;
-  std::vector<Symbol> const ancestor_entry_points_;
-  std::array<WorkgroupDimension, 3> workgroup_size_;
+  const sem::WorkgroupSize workgroup_size_;
+
+  utils::UniqueVector<const GlobalVariable*> directly_referenced_globals_;
+  utils::UniqueVector<const GlobalVariable*> transitively_referenced_globals_;
+  utils::UniqueVector<const Function*> transitively_called_functions_;
+  utils::UniqueVector<const Intrinsic*> directly_called_intrinsics_;
+  std::vector<const ast::CallExpression*> callsites_;
+  std::vector<Symbol> ancestor_entry_points_;
 };
 
 }  // namespace sem
diff --git a/src/transform/binding_remapper.cc b/src/transform/binding_remapper.cc
index 7689cba..f1ead01 100644
--- a/src/transform/binding_remapper.cc
+++ b/src/transform/binding_remapper.cc
@@ -64,7 +64,7 @@
       }
       auto* func = ctx.src->Sem().Get(func_ast);
       std::unordered_map<sem::BindingPoint, int> binding_point_counts;
-      for (auto* var : func->ReferencedModuleVariables()) {
+      for (auto* var : func->TransitivelyReferencedGlobals()) {
         if (auto binding_point = var->Declaration()->BindingPoint()) {
           BindingPoint from{binding_point.group->value,
                             binding_point.binding->value};
diff --git a/src/transform/module_scope_var_to_entry_point_param.cc b/src/transform/module_scope_var_to_entry_point_param.cc
index 891dc32..17076eb 100644
--- a/src/transform/module_scope_var_to_entry_point_param.cc
+++ b/src/transform/module_scope_var_to_entry_point_param.cc
@@ -98,7 +98,7 @@
       auto* func_sem = ctx.src->Sem().Get(func_ast);
 
       bool needs_processing = false;
-      for (auto* var : func_sem->ReferencedModuleVariables()) {
+      for (auto* var : func_sem->TransitivelyReferencedGlobals()) {
         if (var->StorageClass() != ast::StorageClass::kNone) {
           needs_processing = true;
           break;
@@ -155,7 +155,7 @@
         return workgroup_parameter_symbol;
       };
 
-      for (auto* var : func_sem->ReferencedModuleVariables()) {
+      for (auto* var : func_sem->TransitivelyReferencedGlobals()) {
         auto sc = var->StorageClass();
         if (sc == ast::StorageClass::kNone) {
           continue;
@@ -312,7 +312,7 @@
 
         // Add new arguments for any variables that are needed by the callee.
         // For entry points, pass non-handle types as pointers.
-        for (auto* target_var : target_sem->ReferencedModuleVariables()) {
+        for (auto* target_var : target_sem->TransitivelyReferencedGlobals()) {
           auto sc = target_var->StorageClass();
           if (sc == ast::StorageClass::kNone) {
             continue;
diff --git a/src/transform/single_entry_point.cc b/src/transform/single_entry_point.cc
index 531a1de..e03c962 100644
--- a/src/transform/single_entry_point.cc
+++ b/src/transform/single_entry_point.cc
@@ -63,7 +63,7 @@
 
   // Build set of referenced module-scope variables for faster lookups later.
   std::unordered_set<const ast::Variable*> referenced_vars;
-  for (auto* var : sem.Get(entry_point)->ReferencedModuleVariables()) {
+  for (auto* var : sem.Get(entry_point)->TransitivelyReferencedGlobals()) {
     referenced_vars.emplace(var->Declaration());
   }
 
diff --git a/src/transform/zero_init_workgroup_memory.cc b/src/transform/zero_init_workgroup_memory.cc
index 46fc32c..66176ef 100644
--- a/src/transform/zero_init_workgroup_memory.cc
+++ b/src/transform/zero_init_workgroup_memory.cc
@@ -121,7 +121,7 @@
     // Generate a list of statements to zero initialize each of the
     // workgroup storage variables used by `fn`. This will populate #statements.
     auto* func = sem.Get(fn);
-    for (auto* var : func->ReferencedModuleVariables()) {
+    for (auto* var : func->TransitivelyReferencedGlobals()) {
       if (var->StorageClass() == ast::StorageClass::kWorkgroup) {
         BuildZeroingStatements(
             var->Type()->UnwrapRef(), [&](uint32_t num_values) {
diff --git a/src/writer/glsl/generator_impl.cc b/src/writer/glsl/generator_impl.cc
index 8aa6d85..5a13b11 100644
--- a/src/writer/glsl/generator_impl.cc
+++ b/src/writer/glsl/generator_impl.cc
@@ -1756,7 +1756,7 @@
     auto out = line();
     if (func->PipelineStage() == ast::PipelineStage::kCompute) {
       // Emit the layout(local_size) attributes.
-      auto wgsize = func_sem->workgroup_size();
+      auto wgsize = func_sem->WorkgroupSize();
       out << "layout(";
       for (int i = 0; i < 3; i++) {
         if (i > 0) {
diff --git a/src/writer/hlsl/generator_impl.cc b/src/writer/hlsl/generator_impl.cc
index 631476c..12b3b0f 100644
--- a/src/writer/hlsl/generator_impl.cc
+++ b/src/writer/hlsl/generator_impl.cc
@@ -2580,7 +2580,7 @@
     auto out = line();
     if (func->PipelineStage() == ast::PipelineStage::kCompute) {
       // Emit the workgroup_size attribute.
-      auto wgsize = func_sem->workgroup_size();
+      auto wgsize = func_sem->WorkgroupSize();
       out << "[numthreads(";
       for (int i = 0; i < 3; i++) {
         if (i > 0) {
diff --git a/src/writer/spirv/builder.cc b/src/writer/spirv/builder.cc
index 71dc541..621838a 100644
--- a/src/writer/spirv/builder.cc
+++ b/src/writer/spirv/builder.cc
@@ -461,7 +461,7 @@
       Operand::String(builder_.Symbols().NameFor(func->symbol))};
 
   auto* func_sem = builder_.Sem().Get(func);
-  for (const auto* var : func_sem->ReferencedModuleVariables()) {
+  for (const auto* var : func_sem->TransitivelyReferencedGlobals()) {
     // For SPIR-V 1.3 we only output Input/output variables. If we update to
     // SPIR-V 1.4 or later this should be all variables.
     if (var->StorageClass() != ast::StorageClass::kInput &&
@@ -492,7 +492,7 @@
         spv::Op::OpExecutionMode,
         {Operand::Int(id), Operand::Int(SpvExecutionModeOriginUpperLeft)});
   } else if (func->PipelineStage() == ast::PipelineStage::kCompute) {
-    auto& wgsize = func_sem->workgroup_size();
+    auto& wgsize = func_sem->WorkgroupSize();
 
     // Check if the workgroup_size uses pipeline-overridable constants.
     if (wgsize[0].overridable_const || wgsize[1].overridable_const ||
@@ -553,7 +553,7 @@
     }
   }
 
-  for (auto builtin : func_sem->ReferencedBuiltinVariables()) {
+  for (auto builtin : func_sem->TransitivelyReferencedBuiltinVariables()) {
     if (builtin.second->builtin == ast::Builtin::kFragDepth) {
       push_execution_mode(
           spv::Op::OpExecutionMode,