[hlsl-writer] Add CallExpression.

This Cl adds support for call expressions into the HLSL backend.

Bug: tint:7
Change-Id: Id07e3d95e745aa016a658c3ec5d099f74f21a80e
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/26781
Commit-Queue: dan sinclair <dsinclair@chromium.org>
Reviewed-by: David Neto <dneto@google.com>

BUILD.gn

@@ -1063,6 +1063,7 @@ source_set("tint_unittests_hlsl_writer_src") {
     "src/writer/hlsl/generator_impl_binary_test.cc",
     "src/writer/hlsl/generator_impl_block_test.cc",
     "src/writer/hlsl/generator_impl_break_test.cc",
+    "src/writer/hlsl/generator_impl_call_test.cc",
     "src/writer/hlsl/generator_impl_case_test.cc",
     "src/writer/hlsl/generator_impl_constructor_test.cc",
     "src/writer/hlsl/generator_impl_continue_test.cc",

src/CMakeLists.txt

@@ -574,6 +574,7 @@ if (${TINT_BUILD_HLSL_WRITER})
     writer/hlsl/generator_impl_binary_test.cc
     writer/hlsl/generator_impl_block_test.cc
     writer/hlsl/generator_impl_break_test.cc
+    writer/hlsl/generator_impl_call_test.cc
     writer/hlsl/generator_impl_case_test.cc
     writer/hlsl/generator_impl_constructor_test.cc
     writer/hlsl/generator_impl_continue_test.cc

src/writer/hlsl/generator_impl.cc

@@ -19,12 +19,15 @@
 #include "src/ast/assignment_statement.h"
 #include "src/ast/binary_expression.h"
 #include "src/ast/bool_literal.h"
+#include "src/ast/call_expression.h"
+#include "src/ast/call_statement.h"
 #include "src/ast/case_statement.h"
 #include "src/ast/decorated_variable.h"
 #include "src/ast/else_statement.h"
 #include "src/ast/float_literal.h"
 #include "src/ast/identifier_expression.h"
 #include "src/ast/if_statement.h"
+#include "src/ast/intrinsic.h"
 #include "src/ast/loop_statement.h"
 #include "src/ast/member_accessor_expression.h"
 #include "src/ast/return_statement.h"
@@ -318,6 +321,72 @@ bool GeneratorImpl::EmitBreak(ast::BreakStatement*) {
   return true;
 }
 
+bool GeneratorImpl::EmitCall(ast::CallExpression* expr) {
+  if (!expr->func()->IsIdentifier()) {
+    error_ = "invalid function name";
+    return 0;
+  }
+
+  auto* ident = expr->func()->AsIdentifier();
+  if (!ident->has_path() && ast::intrinsic::IsIntrinsic(ident->name())) {
+    error_ = "Intrinsics not supported in HLSL backend.";
+    return false;
+  }
+
+  if (!ident->has_path()) {
+    auto name = ident->name();
+    auto it = ep_func_name_remapped_.find(current_ep_name_ + "_" + name);
+    if (it != ep_func_name_remapped_.end()) {
+      name = it->second;
+    }
+
+    auto* func = module_->FindFunctionByName(ident->name());
+    if (func == nullptr) {
+      error_ = "Unable to find function: " + name;
+      return false;
+    }
+
+    out_ << name << "(";
+
+    bool first = true;
+    if (has_referenced_in_var_needing_struct(func)) {
+      auto var_name = current_ep_var_name(VarType::kIn);
+      if (!var_name.empty()) {
+        out_ << var_name;
+        first = false;
+      }
+    }
+    if (has_referenced_out_var_needing_struct(func)) {
+      auto var_name = current_ep_var_name(VarType::kOut);
+      if (!var_name.empty()) {
+        if (!first) {
+          out_ << ", ";
+        }
+        first = false;
+        out_ << var_name;
+      }
+    }
+
+    const auto& params = expr->params();
+    for (const auto& param : params) {
+      if (!first) {
+        out_ << ", ";
+      }
+      first = false;
+
+      if (!EmitExpression(param.get())) {
+        return false;
+      }
+    }
+
+    out_ << ")";
+  } else {
+    error_ = "Imported functions not supported in HLSL backend.";
+    return false;
+  }
+  return true;
+}
+
 bool GeneratorImpl::EmitCase(ast::CaseStatement* stmt) {
   make_indent();
 
@@ -436,6 +505,9 @@ bool GeneratorImpl::EmitExpression(ast::Expression* expr) {
   if (expr->IsBinary()) {
     return EmitBinary(expr->AsBinary());
   }
+  if (expr->IsCall()) {
+    return EmitCall(expr->AsCall());
+  }
   if (expr->IsConstructor()) {
     return EmitConstructor(expr->AsConstructor());
   }
@@ -525,6 +597,40 @@ bool GeneratorImpl::EmitElse(ast::ElseStatement* stmt) {
   return EmitBlock(stmt->body());
 }
 
+bool GeneratorImpl::has_referenced_in_var_needing_struct(ast::Function* func) {
+  for (auto data : func->referenced_location_variables()) {
+    auto* var = data.first;
+    if (var->storage_class() == ast::StorageClass::kInput) {
+      return true;
+    }
+  }
+
+  for (auto data : func->referenced_builtin_variables()) {
+    auto* var = data.first;
+    if (var->storage_class() == ast::StorageClass::kInput) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool GeneratorImpl::has_referenced_out_var_needing_struct(ast::Function* func) {
+  for (auto data : func->referenced_location_variables()) {
+    auto* var = data.first;
+    if (var->storage_class() == ast::StorageClass::kOutput) {
+      return true;
+    }
+  }
+
+  for (auto data : func->referenced_builtin_variables()) {
+    auto* var = data.first;
+    if (var->storage_class() == ast::StorageClass::kOutput) {
+      return true;
+    }
+  }
+  return false;
+}
+
 bool GeneratorImpl::has_referenced_var_needing_struct(ast::Function* func) {
   for (auto data : func->referenced_location_variables()) {
     auto* var = data.first;
@@ -585,7 +691,16 @@ bool GeneratorImpl::EmitFunctionInternal(ast::Function* func,
     return false;
   }
 
-  out_ << " " << namer_.NameFor(name) << "(";
+  out_ << " ";
+
+  if (emit_duplicate_functions) {
+    name = generate_name(name + "_" + ep_name);
+    ep_func_name_remapped_[ep_name + "_" + func->name()] = name;
+  } else {
+    name = namer_.NameFor(name);
+  }
+
+  out_ << name << "(";
 
   bool first = true;
 
@@ -994,6 +1109,14 @@ bool GeneratorImpl::EmitStatement(ast::Statement* stmt) {
   if (stmt->IsBreak()) {
     return EmitBreak(stmt->AsBreak());
   }
+  if (stmt->IsCall()) {
+    make_indent();
+    if (!EmitCall(stmt->AsCall()->expr())) {
+      return false;
+    }
+    out_ << ";" << std::endl;
+    return true;
+  }
   if (stmt->IsContinue()) {
     return EmitContinue(stmt->AsContinue());
   }

src/writer/hlsl/generator_impl.h

@@ -74,6 +74,10 @@ class GeneratorImpl : public TextGenerator {
   /// @param stmt the statement to emit
   /// @returns true if the statement was emitted successfully
   bool EmitBreak(ast::BreakStatement* stmt);
+  /// Handles generating a call expression
+  /// @param expr the call expression
+  /// @returns true if the call expression is emitted
+  bool EmitCall(ast::CallExpression* expr);
   /// Handles a case statement
   /// @param stmt the statement
   /// @returns true if the statment was emitted successfully
@@ -189,6 +193,14 @@ class GeneratorImpl : public TextGenerator {
   /// @param builtin the builtin to convert
   /// @returns the string name of the builtin or blank on error
   std::string builtin_to_attribute(ast::Builtin builtin) const;
+  /// Determines if the function needs the input struct passed to it.
+  /// @param func the function to check
+  /// @returns true if there are input struct variables used in the function
+  bool has_referenced_in_var_needing_struct(ast::Function* func);
+  /// Determines if the function needs the output struct passed to it.
+  /// @param func the function to check
+  /// @returns true if there are output struct variables used in the function
+  bool has_referenced_out_var_needing_struct(ast::Function* func);
   /// Determines if any used module variable requires an input or output struct.
   /// @param func the function to check
   /// @returns true if an input or output struct is required.
@@ -215,6 +227,11 @@ class GeneratorImpl : public TextGenerator {
   ScopeStack<ast::Variable*> global_variables_;
   std::unordered_map<std::string, EntryPointData> ep_name_to_in_data_;
   std::unordered_map<std::string, EntryPointData> ep_name_to_out_data_;
+
+  // This maps an input of "<entry_point_name>_<function_name>" to a remapped
+  // function name. If there is no entry for a given key then function did
+  // not need to be remapped for the entry point and can be emitted directly.
+  std::unordered_map<std::string, std::string> ep_func_name_remapped_;
 };
 
 }  // namespace hlsl

src/writer/hlsl/generator_impl_call_test.cc

@@ -0,0 +1,95 @@
+// Copyright 2020 The Tint Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <memory>
+
+#include "gtest/gtest.h"
+#include "src/ast/call_expression.h"
+#include "src/ast/call_statement.h"
+#include "src/ast/function.h"
+#include "src/ast/identifier_expression.h"
+#include "src/ast/module.h"
+#include "src/ast/type/void_type.h"
+#include "src/writer/hlsl/generator_impl.h"
+
+namespace tint {
+namespace writer {
+namespace hlsl {
+namespace {
+
+using HlslGeneratorImplTest = testing::Test;
+
+TEST_F(HlslGeneratorImplTest, EmitExpression_Call_WithoutParams) {
+  ast::type::VoidType void_type;
+
+  auto id = std::make_unique<ast::IdentifierExpression>("my_func");
+  ast::CallExpression call(std::move(id), {});
+
+  auto func = std::make_unique<ast::Function>("my_func", ast::VariableList{},
+                                              &void_type);
+
+  ast::Module m;
+  m.AddFunction(std::move(func));
+
+  GeneratorImpl g(&m);
+  ASSERT_TRUE(g.EmitExpression(&call)) << g.error();
+  EXPECT_EQ(g.result(), "my_func()");
+}
+
+TEST_F(HlslGeneratorImplTest, EmitExpression_Call_WithParams) {
+  ast::type::VoidType void_type;
+
+  auto id = std::make_unique<ast::IdentifierExpression>("my_func");
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::IdentifierExpression>("param1"));
+  params.push_back(std::make_unique<ast::IdentifierExpression>("param2"));
+  ast::CallExpression call(std::move(id), std::move(params));
+
+  auto func = std::make_unique<ast::Function>("my_func", ast::VariableList{},
+                                              &void_type);
+
+  ast::Module m;
+  m.AddFunction(std::move(func));
+
+  GeneratorImpl g(&m);
+  ASSERT_TRUE(g.EmitExpression(&call)) << g.error();
+  EXPECT_EQ(g.result(), "my_func(param1, param2)");
+}
+
+TEST_F(HlslGeneratorImplTest, EmitStatement_Call) {
+  ast::type::VoidType void_type;
+
+  auto id = std::make_unique<ast::IdentifierExpression>("my_func");
+  ast::ExpressionList params;
+  params.push_back(std::make_unique<ast::IdentifierExpression>("param1"));
+  params.push_back(std::make_unique<ast::IdentifierExpression>("param2"));
+  ast::CallStatement call(
+      std::make_unique<ast::CallExpression>(std::move(id), std::move(params)));
+
+  auto func = std::make_unique<ast::Function>("my_func", ast::VariableList{},
+                                              &void_type);
+
+  ast::Module m;
+  m.AddFunction(std::move(func));
+
+  GeneratorImpl g(&m);
+  g.increment_indent();
+  ASSERT_TRUE(g.EmitStatement(&call)) << g.error();
+  EXPECT_EQ(g.result(), "  my_func(param1, param2);\n");
+}
+
+}  // namespace
+}  // namespace hlsl
+}  // namespace writer
+}  // namespace tint

src/writer/hlsl/generator_impl_function_test.cc

@@ -379,10 +379,8 @@ TEST_F(HlslGeneratorImplTest,
   EXPECT_EQ(g.result(), R"( ... )");
 }
 
-// TODO(dsinclair): Requires CallExpression
-TEST_F(
-    HlslGeneratorImplTest,
-    DISABLED_Emit_Function_Called_By_EntryPoints_WithLocationGlobals_And_Params) {
+TEST_F(HlslGeneratorImplTest,
+       Emit_Function_Called_By_EntryPoints_WithLocationGlobals_And_Params) {
   ast::type::VoidType void_type;
   ast::type::F32Type f32;
 
@@ -483,9 +481,8 @@ ep_1_out ep_1(ep_1_in tint_in) {
 )");
 }
 
-// TODO(dsinclair): Requires CallExpression
 TEST_F(HlslGeneratorImplTest,
-       DISABLED_Emit_Function_Called_By_EntryPoints_NoUsedGlobals) {
+       Emit_Function_Called_By_EntryPoints_NoUsedGlobals) {
   ast::type::VoidType void_type;
   ast::type::F32Type f32;
   ast::type::VectorType vec4(&f32, 4);
@@ -553,7 +550,7 @@ float sub_func(float param) {
   return param;
 }
 
-fragment ep_1_out ep_1() {
+ep_1_out ep_1() {
   ep_1_out tint_out;
   tint_out.depth = sub_func(1.00000000f);
   return tint_out;
@@ -562,10 +559,8 @@ fragment ep_1_out ep_1() {
 )");
 }
 
-// TODO(dsinclair): Requires CallExpression
-TEST_F(
-    HlslGeneratorImplTest,
-    DISABLED_Emit_Function_Called_By_EntryPoints_WithBuiltinGlobals_And_Params) {
+TEST_F(HlslGeneratorImplTest,
+       Emit_Function_Called_By_EntryPoints_WithBuiltinGlobals_And_Params) {
   ast::type::VoidType void_type;
   ast::type::F32Type f32;
   ast::type::VectorType vec4(&f32, 4);
@@ -640,7 +635,7 @@ TEST_F(
   GeneratorImpl g(&mod);
   ASSERT_TRUE(g.Generate()) << g.error();
   EXPECT_EQ(g.result(), R"(struct ep_1_in {
-  float4 coord : SV_Position;
+  vector<float, 4> coord : SV_Position;
 };
 
 struct ep_1_out {
@@ -972,9 +967,8 @@ ep_1_out ep_1() {
 )");
 }
 
-// TODO(dsinclair): Requires CallExpression support
 TEST_F(HlslGeneratorImplTest,
-       DISABLED_Emit_Function_Called_Two_EntryPoints_WithoutGlobals) {
+       Emit_Function_Called_Two_EntryPoints_WithoutGlobals) {
   ast::type::VoidType void_type;
   ast::type::F32Type f32;
 
@@ -1025,12 +1019,12 @@ TEST_F(HlslGeneratorImplTest,
   return 1.00000000f;
 }
 
-fragment void ep_1() {
+void ep_1() {
   float foo = sub_func();
   return;
 }
 
-fragment void ep_2() {
+void ep_2() {
   float foo = sub_func();
   return;
 }