diff options
| -rw-r--r-- | src/libexpr/print.cc | 8 | ||||
| -rw-r--r-- | src/libutil/escape-string.cc | 57 | ||||
| -rw-r--r-- | src/libutil/escape-string.hh | 60 | ||||
| -rw-r--r-- | tests/unit/libutil/escape-string.cc | 35 | ||||
| -rw-r--r-- | tests/unit/meson.build | 1 |
5 files changed, 132 insertions, 29 deletions
diff --git a/src/libexpr/print.cc b/src/libexpr/print.cc index e5e6b9b21..8d7e2ab34 100644 --- a/src/libexpr/print.cc +++ b/src/libexpr/print.cc @@ -198,12 +198,14 @@ private: void printString(Value & v) { - // NB: Non-printing characters won't be escaped. escapeString( output, v.string.s, - options.maxStringLength, - options.ansiColors + { + .maxLength = options.maxStringLength, + .outputAnsiColors = options.ansiColors, + // NB: Non-printing characters won't be escaped. + } ); } diff --git a/src/libutil/escape-string.cc b/src/libutil/escape-string.cc index 8160403cd..c3cea96d2 100644 --- a/src/libutil/escape-string.cc +++ b/src/libutil/escape-string.cc @@ -11,30 +11,51 @@ namespace nix { std::ostream & -escapeString(std::ostream & str, const std::string_view string, size_t maxLength, bool ansiColors) +escapeString(std::ostream & output, std::string_view string, EscapeStringOptions options) { size_t charsPrinted = 0; - if (ansiColors) - str << ANSI_MAGENTA; - str << "\""; + if (options.outputAnsiColors) { + output << ANSI_MAGENTA; + } + output << "\""; for (auto i = string.begin(); i != string.end(); ++i) { - if (charsPrinted >= maxLength) { - str << "\" "; - printElided(str, string.length() - charsPrinted, "byte", "bytes", ansiColors); - return str; + if (charsPrinted >= options.maxLength) { + output << "\" "; + printElided( + output, string.length() - charsPrinted, "byte", "bytes", options.outputAnsiColors + ); + return output; + } + + if (*i == '\"' || *i == '\\') { + output << "\\" << *i; + } else if (*i == '\n') { + output << "\\n"; + } else if (*i == '\r') { + output << "\\r"; + } else if (*i == '\t') { + output << "\\t"; + } else if (*i == '$' && *(i + 1) == '{') { + output << "\\" << *i; + } else if (options.escapeNonPrinting && !isprint(*i)) { + output << MaybeHexEscapedChar{*i}; + } else { + output << *i; } - if (*i == '\"' || *i == '\\') str << "\\" << *i; - else if (*i == '\n') str << "\\n"; - else if (*i == '\r') str << "\\r"; - else if (*i == '\t') str << "\\t"; - else if (*i == '$' && *(i+1) == '{') str << "\\" << *i; - else str << *i; charsPrinted++; } - str << "\""; - if (ansiColors) - str << ANSI_NORMAL; - return str; + output << "\""; + if (options.outputAnsiColors) { + output << ANSI_NORMAL; + } + return output; +} + +std::string escapeString(std::string_view s, EscapeStringOptions options) +{ + std::ostringstream output; + escapeString(output, s, options); + return output.str(); } }; // namespace nix diff --git a/src/libutil/escape-string.hh b/src/libutil/escape-string.hh index 28c6c8d64..7f0a9e701 100644 --- a/src/libutil/escape-string.hh +++ b/src/libutil/escape-string.hh @@ -6,6 +6,41 @@ namespace nix { /** + * Options for escaping strings in `escapeString`. + * + * With default optional parameters, the output string will round-trip through + * the Nix evaluator (i.e. you can copy/paste this function's output into the + * REPL and have it evaluate as the string that got passed in). + * + * With non-default optional parameters, the output string will be + * human-readable. + */ +struct EscapeStringOptions +{ + /** + * If `maxLength` is decreased, some trailing portion of the string may be + * omitted with a message like `«123 bytes elided»`. + */ + size_t maxLength = std::numeric_limits<size_t>::max(); + + /** + * If `outputAnsiColors` is set, the string will be colored the color of literals, using + * ANSI escape codes. + */ + bool outputAnsiColors = false; + + /** + * If `escapeNonPrinting` is set, non-printing ASCII characters (i.e. with + * byte values less than 0x20) will be printed in `\xhh` format, like + * `\x1d` (other than those that Nix supports, like `\n`, `\r`, `\t`). + * Note that this format is not yet supported by the Lix parser/evaluator! + * + * See: https://git.lix.systems/lix-project/lix/issues/149 + */ + bool escapeNonPrinting = false; +}; + +/** * Escape a string for output. * * With default optional parameters, the output string will round-trip through @@ -14,21 +49,30 @@ namespace nix { * * With non-default optional parameters, the output string will be * human-readable. + * + * See `EscapeStringOptions` for more details on customizing the output. */ +std::ostream & +escapeString(std::ostream & output, std::string_view s, EscapeStringOptions options = {}); + +inline std::ostream & escapeString(std::ostream & output, const char * s) +{ + return escapeString(output, std::string_view(s)); +} -std::ostream & escapeString( - std::ostream & output, - const std::string_view string, - size_t maxLength = std::numeric_limits<size_t>::max(), - bool ansiColors = false -); +inline std::ostream & escapeString(std::ostream & output, const std::string & s) +{ + return escapeString(output, std::string_view(s)); +} /** * Escape a string for output, writing the escaped result to a new string. */ -inline std::ostream & escapeString(std::ostream & output, const char * string) +std::string escapeString(std::string_view s, EscapeStringOptions options = {}); + +inline std::string escapeString(const char * s, EscapeStringOptions options = {}) { - return escapeString(output, std::string_view(string)); + return escapeString(std::string_view(s), options); } } // namespace nix diff --git a/tests/unit/libutil/escape-string.cc b/tests/unit/libutil/escape-string.cc new file mode 100644 index 000000000..5ce2b73d8 --- /dev/null +++ b/tests/unit/libutil/escape-string.cc @@ -0,0 +1,35 @@ +#include "escape-string.hh" +#include "ansicolor.hh" +#include <gtest/gtest.h> + +namespace nix { + +TEST(EscapeString, simple) { + auto escaped = escapeString("puppy"); + ASSERT_EQ(escaped, "\"puppy\""); +} + +TEST(EscapeString, escaping) { + auto escaped = escapeString("\n\r\t \" \\ ${ooga booga}"); + ASSERT_EQ(escaped, R"RAW("\n\r\t \" \\ \${ooga booga}")RAW"); +} + +TEST(EscapeString, maxLength) { + auto escaped = escapeString("puppy", {.maxLength = 5}); + ASSERT_EQ(escaped, "\"puppy\""); + + escaped = escapeString("puppy doggy", {.maxLength = 5}); + ASSERT_EQ(escaped, "\"puppy\" «6 bytes elided»"); +} + +TEST(EscapeString, ansiColors) { + auto escaped = escapeString("puppy doggy", {.maxLength = 5, .outputAnsiColors = true}); + ASSERT_EQ(escaped, ANSI_MAGENTA "\"puppy\" " ANSI_FAINT "«6 bytes elided»" ANSI_NORMAL); +} + +TEST(EscapeString, escapeNonPrinting) { + auto escaped = escapeString("puppy\u0005doggy", {.escapeNonPrinting = true}); + ASSERT_EQ(escaped, "\"puppy\\x05doggy\""); +} + +} // namespace nix diff --git a/tests/unit/meson.build b/tests/unit/meson.build index a5523a813..60bb2de89 100644 --- a/tests/unit/meson.build +++ b/tests/unit/meson.build @@ -39,6 +39,7 @@ libutil_tests_sources = files( 'libutil/closure.cc', 'libutil/compression.cc', 'libutil/config.cc', + 'libutil/escape-string.cc', 'libutil/git.cc', 'libutil/hash.cc', 'libutil/hilite.cc', |