diff --git a/src/libexpr/nixexpr.cc b/src/libexpr/nixexpr.cc index fd380935a..72a8764e6 100644 --- a/src/libexpr/nixexpr.cc +++ b/src/libexpr/nixexpr.cc @@ -4,6 +4,7 @@ #include "symbol-table.hh" #include "util.hh" #include "print.hh" +#include "escape-string.hh" #include @@ -36,7 +37,7 @@ void ExprFloat::show(const SymbolTable & symbols, std::ostream & str) const void ExprString::show(const SymbolTable & symbols, std::ostream & str) const { - printLiteralString(str, s); + escapeString(str, s); } void ExprPath::show(const SymbolTable & symbols, std::ostream & str) const diff --git a/src/libexpr/print-ambiguous.cc b/src/libexpr/print-ambiguous.cc index 3f3c2c45a..ec30f5073 100644 --- a/src/libexpr/print-ambiguous.cc +++ b/src/libexpr/print-ambiguous.cc @@ -2,6 +2,7 @@ #include "print.hh" #include "eval.hh" #include "signals.hh" +#include "escape-string.hh" namespace nix { @@ -27,7 +28,7 @@ void printAmbiguous( printLiteralBool(str, v.boolean); break; case nString: - printLiteralString(str, v.string.s); + escapeString(str, v.string.s); break; case nPath: str << v.path().to_string(); // !!! escaping? diff --git a/src/libexpr/print.cc b/src/libexpr/print.cc index 43e366d08..e5e6b9b21 100644 --- a/src/libexpr/print.cc +++ b/src/libexpr/print.cc @@ -2,6 +2,7 @@ #include #include +#include "escape-string.hh" #include "print.hh" #include "ansicolor.hh" #include "store-api.hh" @@ -11,57 +12,6 @@ namespace nix { -void printElided( - std::ostream & output, - unsigned int value, - const std::string_view single, - const std::string_view plural, - bool ansiColors) -{ - if (ansiColors) - output << ANSI_FAINT; - output << "«"; - pluralize(output, value, single, plural); - output << " elided»"; - if (ansiColors) - output << ANSI_NORMAL; -} - - -std::ostream & -printLiteralString(std::ostream & str, const std::string_view string, size_t maxLength, bool ansiColors) -{ - size_t charsPrinted = 0; - if (ansiColors) - str << ANSI_MAGENTA; - str << "\""; - for (auto i = string.begin(); i != string.end(); ++i) { - if (charsPrinted >= maxLength) { - str << "\" "; - printElided(str, string.length() - charsPrinted, "byte", "bytes", ansiColors); - return str; - } - - 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; -} - -std::ostream & -printLiteralString(std::ostream & str, const std::string_view string) -{ - return printLiteralString(str, string, std::numeric_limits::max(), false); -} - std::ostream & printLiteralBool(std::ostream & str, bool boolean) { @@ -93,7 +43,7 @@ printIdentifier(std::ostream & str, std::string_view s) { else { char c = s[0]; if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_')) { - printLiteralString(str, s); + escapeString(str, s); return str; } for (auto c : s) @@ -101,7 +51,7 @@ printIdentifier(std::ostream & str, std::string_view s) { (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '_' || c == '\'' || c == '-')) { - printLiteralString(str, s); + escapeString(str, s); return str; } str << s; @@ -129,7 +79,7 @@ printAttributeName(std::ostream & str, std::string_view name) { if (isVarName(name)) str << name; else - printLiteralString(str, name); + escapeString(str, name); return str; } @@ -248,7 +198,13 @@ private: void printString(Value & v) { - printLiteralString(output, v.string.s, options.maxStringLength, options.ansiColors); + // NB: Non-printing characters won't be escaped. + escapeString( + output, + v.string.s, + options.maxStringLength, + options.ansiColors + ); } void printPath(Value & v) diff --git a/src/libexpr/print.hh b/src/libexpr/print.hh index 94cb11ca7..42826d94d 100644 --- a/src/libexpr/print.hh +++ b/src/libexpr/print.hh @@ -11,28 +11,13 @@ #include "fmt.hh" #include "print-options.hh" +#include "print-elided.hh" namespace nix { class EvalState; struct Value; -/** - * Print a string as a Nix string literal. - * - * Quotes and fairly minimal escaping are added. - * - * @param o The output stream to print to - * @param s The logical string - */ -std::ostream & printLiteralString(std::ostream & o, std::string_view s); -inline std::ostream & printLiteralString(std::ostream & o, const char * s) { - return printLiteralString(o, std::string_view(s)); -} -inline std::ostream & printLiteralString(std::ostream & o, const std::string & s) { - return printLiteralString(o, std::string_view(s)); -} - /** Print `true` or `false`. */ std::ostream & printLiteralBool(std::ostream & o, bool b); diff --git a/src/libutil/escape-string.cc b/src/libutil/escape-string.cc new file mode 100644 index 000000000..8160403cd --- /dev/null +++ b/src/libutil/escape-string.cc @@ -0,0 +1,40 @@ +#include +#include +#include + +#include "ansicolor.hh" +#include "escape-char.hh" +#include "english.hh" +#include "escape-string.hh" +#include "print-elided.hh" + +namespace nix { + +std::ostream & +escapeString(std::ostream & str, const std::string_view string, size_t maxLength, bool ansiColors) +{ + size_t charsPrinted = 0; + if (ansiColors) + str << ANSI_MAGENTA; + str << "\""; + for (auto i = string.begin(); i != string.end(); ++i) { + if (charsPrinted >= maxLength) { + str << "\" "; + printElided(str, string.length() - charsPrinted, "byte", "bytes", ansiColors); + return str; + } + 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; +} + +}; // namespace nix diff --git a/src/libutil/escape-string.hh b/src/libutil/escape-string.hh new file mode 100644 index 000000000..28c6c8d64 --- /dev/null +++ b/src/libutil/escape-string.hh @@ -0,0 +1,34 @@ +#pragma once + +#include +#include + +namespace nix { + +/** + * Escape a string for output. + * + * 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. + */ + +std::ostream & escapeString( + std::ostream & output, + const std::string_view string, + size_t maxLength = std::numeric_limits::max(), + bool ansiColors = false +); + +/** + * Escape a string for output, writing the escaped result to a new string. + */ +inline std::ostream & escapeString(std::ostream & output, const char * string) +{ + return escapeString(output, std::string_view(string)); +} + +} // namespace nix diff --git a/src/libutil/meson.build b/src/libutil/meson.build index ade925bcf..11bf97ee7 100644 --- a/src/libutil/meson.build +++ b/src/libutil/meson.build @@ -9,6 +9,7 @@ libutil_sources = files( 'english.cc', 'error.cc', 'escape-char.cc', + 'escape-string.cc', 'exit.cc', 'experimental-features.cc', 'filesystem.cc', @@ -19,6 +20,7 @@ libutil_sources = files( 'logging.cc', 'namespaces.cc', 'position.cc', + 'print-elided.cc', 'references.cc', 'serialise.cc', 'shlex.cc', @@ -52,6 +54,7 @@ libutil_headers = files( 'english.hh', 'error.hh', 'escape-char.hh', + 'escape-string.hh', 'exit.hh', 'experimental-features.hh', 'experimental-features-json.hh', @@ -70,6 +73,7 @@ libutil_headers = files( 'namespaces.hh', 'pool.hh', 'position.hh', + 'print-elided.hh', 'ref.hh', 'references.hh', 'regex-combinators.hh', diff --git a/src/libutil/print-elided.cc b/src/libutil/print-elided.cc new file mode 100644 index 000000000..75357e5bc --- /dev/null +++ b/src/libutil/print-elided.cc @@ -0,0 +1,23 @@ +#include "print-elided.hh" +#include "ansicolor.hh" +#include "english.hh" + +namespace nix { + +void printElided( + std::ostream & output, + unsigned int value, + const std::string_view single, + const std::string_view plural, + bool ansiColors) +{ + if (ansiColors) + output << ANSI_FAINT; + output << "«"; + pluralize(output, value, single, plural); + output << " elided»"; + if (ansiColors) + output << ANSI_NORMAL; +} + +} diff --git a/src/libutil/print-elided.hh b/src/libutil/print-elided.hh new file mode 100644 index 000000000..a99b15ca1 --- /dev/null +++ b/src/libutil/print-elided.hh @@ -0,0 +1,23 @@ +#pragma once + +#include + + +namespace nix { + +/** + * Print an `«... elided»` placeholder. + * + * Arguments are forwarded to `pluralize`. + * + * If `ansiColors` is set, the output will be wrapped in `ANSI_FAINT`. + */ +void printElided( + std::ostream & output, + unsigned int value, + const std::string_view single, + const std::string_view plural, + bool ansiColors +); + +} diff --git a/tests/unit/libutil-support/tests/cli-literate-parser.cc b/tests/unit/libutil-support/tests/cli-literate-parser.cc index 08ebddebc..4edf434be 100644 --- a/tests/unit/libutil-support/tests/cli-literate-parser.cc +++ b/tests/unit/libutil-support/tests/cli-literate-parser.cc @@ -1,4 +1,5 @@ #include "cli-literate-parser.hh" +#include "escape-string.hh" #include "libexpr/print.hh" #include "escape-char.hh" #include "types.hh" @@ -41,7 +42,7 @@ auto CLILiterateParser::Node::print() const -> std::string s << "Output "; break; } - printLiteralString(s, this->text); + escapeString(s, this->text); return s.str(); }