src/reader/wgsl/parser_impl_error_resync_test.cc

// 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 "src/reader/wgsl/parser_impl_test_helper.h"

namespace tint {
namespace reader {
namespace wgsl {
namespace {

const diag::Formatter::Style formatter_style{
    /* print_file: */ true, /* print_severity: */ true,
    /* print_line: */ true, /* print_newline_at_end: */ false};

class ParserImplErrorResyncTest : public ParserImplTest {};

#define EXPECT(SOURCE, EXPECTED)                                               \
  do {                                                                         \
    std::string source = SOURCE;                                               \
    std::string expected = EXPECTED;                                           \
    auto p = parser(source);                                                   \
    EXPECT_EQ(false, p->Parse());                                              \
    auto diagnostics = p->builder().Diagnostics();                             \
    EXPECT_EQ(true, diagnostics.contains_errors());                            \
    EXPECT_EQ(expected, diag::Formatter(formatter_style).format(diagnostics)); \
  } while (false)

TEST_F(ParserImplErrorResyncTest, BadFunctionDecls) {
  EXPECT(R"(
fn .() -> . {}
fn x(.) {}
@_ fn -> {}
fn good() {}
)",
         R"(test.wgsl:2:4 error: expected identifier for function declaration
fn .() -> . {}
   ^

test.wgsl:2:11 error: unable to determine function return type
fn .() -> . {}
          ^

test.wgsl:3:6 error: expected ')' for function declaration
fn x(.) {}
     ^

test.wgsl:4:2 error: expected decoration
@_ fn -> {}
 ^

test.wgsl:4:7 error: expected identifier for function declaration
@_ fn -> {}
      ^^
)");
}

TEST_F(ParserImplErrorResyncTest, AssignmentStatement) {
  EXPECT(R"(
fn f() {
  blah blah blah blah;
  good = 1;
  blah blah blah blah;
  x = .;
  good = 1;
}
)",
         R"(test.wgsl:3:8 error: expected '=' for assignment
  blah blah blah blah;
       ^^^^

test.wgsl:5:8 error: expected '=' for assignment
  blah blah blah blah;
       ^^^^

test.wgsl:6:7 error: unable to parse right side of assignment
  x = .;
      ^
)");
}

TEST_F(ParserImplErrorResyncTest, DiscardStatement) {
  EXPECT(R"(
fn f() {
  discard blah blah blah;
  a = 1;
  discard blah blah blah;
}
)",
         R"(test.wgsl:3:11 error: expected ';' for discard statement
  discard blah blah blah;
          ^^^^

test.wgsl:5:11 error: expected ';' for discard statement
  discard blah blah blah;
          ^^^^
)");
}

TEST_F(ParserImplErrorResyncTest, StructMembers) {
  EXPECT(R"(
struct S {
    blah blah blah;
    a : i32;
    blah blah blah;
    b : i32;
    @- x : i32;
    c : i32;
}
)",
         R"(test.wgsl:3:10 error: expected ':' for struct member
    blah blah blah;
         ^^^^

test.wgsl:5:10 error: expected ':' for struct member
    blah blah blah;
         ^^^^

test.wgsl:7:6 error: expected decoration
    @- x : i32;
     ^
)");
}

// Check that the forward scan in resynchronize() stop at nested sync points.
// In this test the inner resynchronize() is looking for a terminating ';', and
// the outer resynchronize() is looking for a terminating '}' for the function
// scope.
TEST_F(ParserImplErrorResyncTest, NestedSyncPoints) {
  EXPECT(R"(
fn f() {
  x = 1;
  discard
}
struct S { blah };
)",
         R"(test.wgsl:5:1 error: expected ';' for discard statement
}
^

test.wgsl:6:17 error: expected ':' for struct member
struct S { blah };
                ^
)");
}

TEST_F(ParserImplErrorResyncTest, BracketCounting) {
  EXPECT(
      R"(
fn f(x(((())))) {
  meow = {{{}}}
}
struct S { blah };
)",
      R"(test.wgsl:2:7 error: expected ':' for parameter
fn f(x(((())))) {
      ^

test.wgsl:3:10 error: unable to parse right side of assignment
  meow = {{{}}}
         ^

test.wgsl:5:17 error: expected ':' for struct member
struct S { blah };
                ^
)");
}

}  // namespace
}  // namespace wgsl
}  // namespace reader
}  // namespace tint