Files
carbon-lang/toolchain/lexer/string_literal_test.cpp
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312 lines
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// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "toolchain/lexer/string_literal.h"
#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include "common/check.h"
#include "common/ostream.h"
#include "toolchain/diagnostics/diagnostic_emitter.h"
#include "toolchain/lexer/test_helpers.h"
namespace Carbon::Testing {
namespace {
class StringLiteralTest : public ::testing::Test {
protected:
StringLiteralTest() : error_tracker(ConsoleDiagnosticConsumer()) {}
auto Lex(llvm::StringRef text) -> LexedStringLiteral {
llvm::Optional<LexedStringLiteral> result = LexedStringLiteral::Lex(text);
CHECK(result);
EXPECT_EQ(result->text(), text);
return *result;
}
auto Parse(llvm::StringRef text) -> std::string {
LexedStringLiteral token = Lex(text);
Testing::SingleTokenDiagnosticTranslator translator(text);
DiagnosticEmitter<const char*> emitter(translator, error_tracker);
return token.ComputeValue(emitter);
}
ErrorTrackingDiagnosticConsumer error_tracker;
};
TEST_F(StringLiteralTest, StringLiteralBounds) {
llvm::StringLiteral valid[] = {
R"("")",
R"("""
""")",
R"("""
"foo"
""")",
// Escaped terminators don't end the string.
R"("\"")",
R"("\\")",
R"("\\\"")",
R"("""
\"""
""")",
R"("""
"\""
""")",
R"("""
""\"
""")",
R"("""
""\
""")",
R"(#"""
"""\#n
"""#)",
// Only a matching number of '#'s terminates the string.
R"(#""#)",
R"(#"xyz"foo"#)",
R"(##"xyz"#foo"##)",
R"(#"\""#)",
// Escape sequences likewise require a matching number of '#'s.
R"(#"\#"#"#)",
R"(#"\"#)",
R"(#"""
\#"""#
"""#)",
// #"""# does not start a multiline string literal.
R"(#"""#)",
R"(##"""##)",
};
for (llvm::StringLiteral test : valid) {
SCOPED_TRACE(test);
llvm::Optional<LexedStringLiteral> result = LexedStringLiteral::Lex(test);
EXPECT_TRUE(result.hasValue());
if (result) {
EXPECT_EQ(result->text(), test);
}
}
llvm::StringLiteral invalid[] = {
// clang-format off
R"(")",
R"("""
"")",
R"("\)",
R"("\")",
R"("\\)",
R"("\\\")",
R"("""
)",
R"(#"""
""")",
R"(" \
")",
// clang-format on
};
for (llvm::StringLiteral test : invalid) {
SCOPED_TRACE(test);
llvm::Optional<LexedStringLiteral> result = LexedStringLiteral::Lex(test);
EXPECT_TRUE(result.hasValue());
if (result) {
EXPECT_FALSE(result->is_terminated());
}
}
}
TEST_F(StringLiteralTest, StringLiteralContents) {
std::pair<llvm::StringLiteral, llvm::StringLiteral> testcases[] = {
// Empty strings.
{R"("")", ""},
{R"(
"""
"""
)",
""},
// Nearly-empty strings.
{R"(
"""
"""
)",
"\n"},
// Lines containing only whitespace are treated as empty even if they
// contain tabs.
{"\"\"\"\n\t \t\n\"\"\"", "\n"},
// Indent removal.
{R"(
"""file type indicator
indented contents \
"""
)",
" indented contents "},
// Removal of tabs in indent and suffix.
{"\"\"\"\n \t hello \t \n \t \"\"\"", " hello\n"},
{R"(
"""
hello
world
end of test
"""
)",
" hello\nworld\n\n end of test\n"},
// Escape sequences.
{R"(
"\x14,\u{1234},\u{00000010},\n,\r,\t,\0,\",\',\\"
)",
llvm::StringLiteral::withInnerNUL(
"\x14,\xE1\x88\xB4,\x10,\x0A,\x0D,\x09,\x00,\x22,\x27,\x5C")},
{R"(
"\0A\x1234"
)",
llvm::StringLiteral::withInnerNUL("\0A\x12"
"34")},
{R"(
"\u{D7FF},\u{E000},\u{10FFFF}"
)",
"\xED\x9F\xBF,\xEE\x80\x80,\xF4\x8F\xBF\xBF"},
// Escape sequences in 'raw' strings.
{R"(
#"\#x00,\#xFF,\#u{56789},\#u{ABCD},\#u{00000000000000000EF}"#
)",
llvm::StringLiteral::withInnerNUL(
"\x00,\xFF,\xF1\x96\x9E\x89,\xEA\xAF\x8D,\xC3\xAF")},
{R"(
##"\n,\#n,\##n,\##\##n,\##\###n"##
)",
"\\n,\\#n,\n,\\##n,\\###n"},
// Trailing whitespace handling.
{"\"\"\"\n Hello \\\n World \t \n Bye! \\\n \"\"\"",
"Hello World\nBye! "},
};
for (auto [test, contents] : testcases) {
error_tracker.Reset();
auto value = Parse(test.trim());
EXPECT_FALSE(error_tracker.seen_error()) << "`" << test << "`";
EXPECT_EQ(value, contents);
}
}
TEST_F(StringLiteralTest, StringLiteralBadIndent) {
std::pair<llvm::StringLiteral, llvm::StringLiteral> testcases[] = {
// Indent doesn't match the last line.
{"\"\"\"\n \tx\n \"\"\"", "x\n"},
{"\"\"\"\n x\n \"\"\"", "x\n"},
{"\"\"\"\n x\n\t\"\"\"", "x\n"},
{"\"\"\"\n ok\n bad\n \"\"\"", "ok\nbad\n"},
{"\"\"\"\n bad\n ok\n \"\"\"", "bad\nok\n"},
{"\"\"\"\n escaped,\\\n bad\n \"\"\"", "escaped,bad\n"},
// Indent on last line is followed by text.
{"\"\"\"\n x\n x\"\"\"", "x\nx"},
{"\"\"\"\n x\n x\"\"\"", " x\nx"},
{"\"\"\"\n x\n x\"\"\"", "x\nx"},
};
for (auto [test, contents] : testcases) {
error_tracker.Reset();
auto value = Parse(test);
EXPECT_TRUE(error_tracker.seen_error()) << "`" << test << "`";
EXPECT_EQ(value, contents);
}
}
TEST_F(StringLiteralTest, StringLiteralBadEscapeSequence) {
llvm::StringLiteral testcases[] = {
R"("\a")",
R"("\b")",
R"("\e")",
R"("\f")",
R"("\v")",
R"("\?")",
R"("\1")",
R"("\9")",
// \0 can't be followed by a decimal digit.
R"("\01")",
R"("\09")",
// \x requires two (uppercase) hexadecimal digits.
R"("\x")",
R"("\x0")",
R"("\x0G")",
R"("\xab")",
R"("\x\n")",
R"("\x\"")",
// \u requires a braced list of one or more hexadecimal digits.
R"("\u")",
R"("\u?")",
R"("\u\"")",
R"("\u{")",
R"("\u{}")",
R"("\u{A")",
R"("\u{G}")",
R"("\u{0000012323127z}")",
R"("\u{-3}")",
// \u must specify a non-surrogate code point.
R"("\u{110000}")",
R"("\u{000000000000000000000000000000000110000}")",
R"("\u{D800}")",
R"("\u{DFFF}")",
};
for (llvm::StringLiteral test : testcases) {
error_tracker.Reset();
auto value = Parse(test);
EXPECT_TRUE(error_tracker.seen_error()) << "`" << test << "`";
// TODO: Test value produced by error recovery.
}
}
TEST_F(StringLiteralTest, TabInString) {
auto value = Parse("\"x\ty\"");
EXPECT_TRUE(error_tracker.seen_error());
EXPECT_EQ(value, "x\ty");
}
TEST_F(StringLiteralTest, TabAtEndOfString) {
auto value = Parse("\"\t\t\t\"");
EXPECT_TRUE(error_tracker.seen_error());
EXPECT_EQ(value, "\t\t\t");
}
TEST_F(StringLiteralTest, TabInBlockString) {
auto value = Parse("\"\"\"\nx\ty\n\"\"\"");
EXPECT_TRUE(error_tracker.seen_error());
EXPECT_EQ(value, "x\ty\n");
}
TEST_F(StringLiteralTest, UnicodeTooManyDigits) {
std::string text = "u{";
text.append(10000, '9');
text.append("}");
auto value = Parse("\"\\" + text + "\"");
EXPECT_TRUE(error_tracker.seen_error());
EXPECT_EQ(value, text);
}
} // namespace
} // namespace Carbon::Testing