add support for better error messages
This includes extended error messages which show the original format string. It works for 'char' type with wchar_t returning only the message. The thrown exception class now has a format() method to retrieve the pointer to the original format.
This commit is contained in:
Gregory Czajkowski
parent
225d4f7032
commit
62466cc3d9
447
format.cc
447
format.cc
@ -409,241 +409,248 @@ void fmt::BasicFormatter<Char>::CheckSign(const Char *&s, const Arg &arg) {
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template <typename Char>
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void fmt::BasicFormatter<Char>::DoFormat() {
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const Char *start = format_;
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const Char *start = format_; // capture the format string before it is reset
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const Char *original = format_;
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format_ = 0;
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next_arg_index_ = 0;
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const Char *s = start;
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typedef internal::Array<Char, BasicWriter<Char>::INLINE_BUFFER_SIZE> Buffer;
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BasicWriter<Char> &writer = *writer_;
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while (*s) {
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Char c = *s++;
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if (c != '{' && c != '}') continue;
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if (*s == c) {
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writer.buffer_.append(start, s);
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start = ++s;
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continue;
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}
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if (c == '}')
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throw FormatError("unmatched '}' in format");
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num_open_braces_= 1;
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writer.buffer_.append(start, s - 1);
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const Arg &arg = ParseArgIndex(s);
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FormatSpec spec;
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int precision = -1;
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if (*s == ':') {
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++s;
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// Parse fill and alignment.
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if (Char c = *s) {
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const Char *p = s + 1;
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spec.align_ = ALIGN_DEFAULT;
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do {
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switch (*p) {
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case '<':
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spec.align_ = ALIGN_LEFT;
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break;
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case '>':
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spec.align_ = ALIGN_RIGHT;
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break;
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case '=':
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spec.align_ = ALIGN_NUMERIC;
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break;
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case '^':
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spec.align_ = ALIGN_CENTER;
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break;
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}
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if (spec.align_ != ALIGN_DEFAULT) {
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if (p != s) {
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if (c == '}') break;
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if (c == '{')
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ReportError(s, "invalid fill character '{'");
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s += 2;
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spec.fill_ = c;
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} else ++s;
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if (spec.align_ == ALIGN_NUMERIC && arg.type > LAST_NUMERIC_TYPE)
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ReportError(s, "format specifier '=' requires numeric argument");
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break;
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}
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} while (--p >= s);
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try {
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while (*s) {
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Char c = *s++;
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if (c != '{' && c != '}') continue;
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if (*s == c) {
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writer.buffer_.append(start, s);
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start = ++s;
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continue;
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}
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if (c == '}')
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throw FormatError("unmatched '}' in format");
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num_open_braces_= 1;
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writer.buffer_.append(start, s - 1);
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// Parse sign.
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switch (*s) {
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case '+':
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CheckSign(s, arg);
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spec.flags_ |= SIGN_FLAG | PLUS_FLAG;
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break;
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case '-':
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CheckSign(s, arg);
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break;
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case ' ':
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CheckSign(s, arg);
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spec.flags_ |= SIGN_FLAG;
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break;
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}
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const Arg &arg = ParseArgIndex(s);
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if (*s == '#') {
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if (arg.type > LAST_NUMERIC_TYPE)
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ReportError(s, "format specifier '#' requires numeric argument");
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spec.flags_ |= HASH_FLAG;
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FormatSpec spec;
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int precision = -1;
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if (*s == ':') {
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++s;
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}
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// Parse width and zero flag.
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if ('0' <= *s && *s <= '9') {
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if (*s == '0') {
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if (arg.type > LAST_NUMERIC_TYPE)
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ReportError(s, "format specifier '0' requires numeric argument");
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spec.align_ = ALIGN_NUMERIC;
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spec.fill_ = '0';
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// Parse fill and alignment.
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if (Char c = *s) {
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const Char *p = s + 1;
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spec.align_ = ALIGN_DEFAULT;
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do {
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switch (*p) {
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case '<':
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spec.align_ = ALIGN_LEFT;
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break;
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case '>':
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spec.align_ = ALIGN_RIGHT;
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break;
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case '=':
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spec.align_ = ALIGN_NUMERIC;
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break;
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case '^':
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spec.align_ = ALIGN_CENTER;
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break;
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}
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if (spec.align_ != ALIGN_DEFAULT) {
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if (p != s) {
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if (c == '}') break;
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if (c == '{')
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ReportError(s, "invalid fill character '{'");
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s += 2;
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spec.fill_ = c;
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} else ++s;
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if (spec.align_ == ALIGN_NUMERIC && arg.type > LAST_NUMERIC_TYPE)
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ReportError(s, "format specifier '=' requires numeric argument");
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break;
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}
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} while (--p >= s);
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}
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// Zero may be parsed again as a part of the width, but it is simpler
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// and more efficient than checking if the next char is a digit.
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unsigned value = ParseUInt(s);
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if (value > INT_MAX)
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ReportError(s, "number is too big in format");
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spec.width_ = value;
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}
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// Parse precision.
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if (*s == '.') {
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++s;
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precision = 0;
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// Parse sign.
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switch (*s) {
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case '+':
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CheckSign(s, arg);
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spec.flags_ |= SIGN_FLAG | PLUS_FLAG;
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break;
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case '-':
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CheckSign(s, arg);
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break;
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case ' ':
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CheckSign(s, arg);
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spec.flags_ |= SIGN_FLAG;
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break;
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}
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if (*s == '#') {
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if (arg.type > LAST_NUMERIC_TYPE)
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ReportError(s, "format specifier '#' requires numeric argument");
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spec.flags_ |= HASH_FLAG;
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++s;
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}
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// Parse width and zero flag.
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if ('0' <= *s && *s <= '9') {
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if (*s == '0') {
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if (arg.type > LAST_NUMERIC_TYPE)
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ReportError(s, "format specifier '0' requires numeric argument");
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spec.align_ = ALIGN_NUMERIC;
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spec.fill_ = '0';
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}
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// Zero may be parsed again as a part of the width, but it is simpler
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// and more efficient than checking if the next char is a digit.
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unsigned value = ParseUInt(s);
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if (value > INT_MAX)
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ReportError(s, "number is too big in format");
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precision = value;
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} else if (*s == '{') {
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spec.width_ = value;
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}
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// Parse precision.
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if (*s == '.') {
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++s;
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++num_open_braces_;
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const Arg &precision_arg = ParseArgIndex(s);
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unsigned long long value = 0;
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switch (precision_arg.type) {
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case INT:
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if (precision_arg.int_value < 0)
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ReportError(s, "negative precision in format");
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value = precision_arg.int_value;
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break;
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case UINT:
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value = precision_arg.uint_value;
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break;
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case LONG:
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if (precision_arg.long_value < 0)
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ReportError(s, "negative precision in format");
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value = precision_arg.long_value;
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break;
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case ULONG:
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value = precision_arg.ulong_value;
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break;
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case ULLONG:
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value = precision_arg.ulong_long_value;
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break;
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default:
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ReportError(s, "precision is not integer");
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precision = 0;
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if ('0' <= *s && *s <= '9') {
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unsigned value = ParseUInt(s);
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if (value > INT_MAX)
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ReportError(s, "number is too big in format");
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precision = value;
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} else if (*s == '{') {
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++s;
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++num_open_braces_;
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const Arg &precision_arg = ParseArgIndex(s);
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unsigned long long value = 0;
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switch (precision_arg.type) {
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case INT:
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if (precision_arg.int_value < 0)
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ReportError(s, "negative precision in format");
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value = precision_arg.int_value;
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break;
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case UINT:
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value = precision_arg.uint_value;
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break;
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case LONG:
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if (precision_arg.long_value < 0)
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ReportError(s, "negative precision in format");
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value = precision_arg.long_value;
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break;
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case ULONG:
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value = precision_arg.ulong_value;
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break;
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case ULLONG:
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value = precision_arg.ulong_long_value;
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break;
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default:
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ReportError(s, "precision is not integer");
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}
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if (value > INT_MAX)
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ReportError(s, "number is too big in format");
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precision = static_cast<int>(value);
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if (*s++ != '}')
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throw FormatError("unmatched '{' in format");
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--num_open_braces_;
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} else {
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ReportError(s, "missing precision in format");
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}
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if (arg.type != DOUBLE && arg.type != LONG_DOUBLE) {
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ReportError(s,
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"precision specifier requires floating-point argument");
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}
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}
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// Parse type.
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if (*s != '}' && *s)
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spec.type_ = static_cast<char>(*s++);
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}
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if (*s++ != '}')
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throw FormatError("unmatched '{' in format");
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start = s;
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// Format argument.
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switch (arg.type) {
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case INT:
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writer.FormatInt(arg.int_value, spec);
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break;
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case UINT:
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writer.FormatInt(arg.uint_value, spec);
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break;
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case LONG:
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writer.FormatInt(arg.long_value, spec);
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break;
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case ULONG:
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writer.FormatInt(arg.ulong_value, spec);
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break;
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case ULLONG:
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writer.FormatInt(arg.ulong_long_value, spec);
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break;
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case DOUBLE:
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writer.FormatDouble(arg.double_value, spec, precision);
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break;
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case LONG_DOUBLE:
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writer.FormatDouble(arg.long_double_value, spec, precision);
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break;
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case CHAR: {
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if (spec.type_ && spec.type_ != 'c')
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internal::ReportUnknownType(spec.type_, "char");
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typedef typename BasicWriter<Char>::CharPtr CharPtr;
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CharPtr out = CharPtr();
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if (spec.width_ > 1) {
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Char fill = static_cast<Char>(spec.fill());
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out = writer.GrowBuffer(spec.width_);
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if (spec.align_ == ALIGN_RIGHT) {
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std::fill_n(out, spec.width_ - 1, fill);
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out += spec.width_ - 1;
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} else if (spec.align_ == ALIGN_CENTER) {
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out = writer.FillPadding(out, spec.width_, 1, fill);
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} else {
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std::fill_n(out + 1, spec.width_ - 1, fill);
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}
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if (value > INT_MAX)
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ReportError(s, "number is too big in format");
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precision = static_cast<int>(value);
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if (*s++ != '}')
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throw FormatError("unmatched '{' in format");
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--num_open_braces_;
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} else {
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ReportError(s, "missing precision in format");
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out = writer.GrowBuffer(1);
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}
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if (arg.type != DOUBLE && arg.type != LONG_DOUBLE) {
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ReportError(s,
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"precision specifier requires floating-point argument");
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*out = arg.int_value;
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break;
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}
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case STRING: {
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if (spec.type_ && spec.type_ != 's')
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internal::ReportUnknownType(spec.type_, "string");
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const Char *str = arg.string.value;
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std::size_t size = arg.string.size;
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if (size == 0) {
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if (!str)
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throw FormatError("string pointer is null");
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if (*str)
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size = std::char_traits<Char>::length(str);
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}
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writer.FormatString(str, size, spec);
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break;
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}
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// Parse type.
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if (*s != '}' && *s)
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spec.type_ = static_cast<char>(*s++);
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}
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if (*s++ != '}')
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throw FormatError("unmatched '{' in format");
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start = s;
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// Format argument.
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switch (arg.type) {
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case INT:
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writer.FormatInt(arg.int_value, spec);
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break;
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case UINT:
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writer.FormatInt(arg.uint_value, spec);
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break;
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case LONG:
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writer.FormatInt(arg.long_value, spec);
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break;
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case ULONG:
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writer.FormatInt(arg.ulong_value, spec);
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break;
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case ULLONG:
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writer.FormatInt(arg.ulong_long_value, spec);
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break;
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case DOUBLE:
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writer.FormatDouble(arg.double_value, spec, precision);
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break;
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case LONG_DOUBLE:
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writer.FormatDouble(arg.long_double_value, spec, precision);
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break;
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case CHAR: {
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if (spec.type_ && spec.type_ != 'c')
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internal::ReportUnknownType(spec.type_, "char");
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typedef typename BasicWriter<Char>::CharPtr CharPtr;
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CharPtr out = CharPtr();
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if (spec.width_ > 1) {
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Char fill = static_cast<Char>(spec.fill());
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out = writer.GrowBuffer(spec.width_);
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if (spec.align_ == ALIGN_RIGHT) {
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std::fill_n(out, spec.width_ - 1, fill);
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out += spec.width_ - 1;
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} else if (spec.align_ == ALIGN_CENTER) {
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out = writer.FillPadding(out, spec.width_, 1, fill);
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} else {
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std::fill_n(out + 1, spec.width_ - 1, fill);
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}
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} else {
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out = writer.GrowBuffer(1);
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case POINTER:
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if (spec.type_ && spec.type_ != 'p')
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internal::ReportUnknownType(spec.type_, "pointer");
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spec.flags_= HASH_FLAG;
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spec.type_ = 'x';
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writer.FormatInt(reinterpret_cast<uintptr_t>(arg.pointer_value), spec);
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break;
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case CUSTOM:
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if (spec.type_)
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internal::ReportUnknownType(spec.type_, "object");
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arg.custom.format(writer, arg.custom.value, spec);
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break;
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default:
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assert(false);
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break;
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}
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*out = arg.int_value;
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break;
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}
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case STRING: {
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if (spec.type_ && spec.type_ != 's')
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internal::ReportUnknownType(spec.type_, "string");
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const Char *str = arg.string.value;
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std::size_t size = arg.string.size;
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if (size == 0) {
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if (!str)
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throw FormatError("string pointer is null");
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if (*str)
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size = std::char_traits<Char>::length(str);
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}
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writer.FormatString(str, size, spec);
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break;
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}
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case POINTER:
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if (spec.type_ && spec.type_ != 'p')
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internal::ReportUnknownType(spec.type_, "pointer");
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spec.flags_= HASH_FLAG;
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spec.type_ = 'x';
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writer.FormatInt(reinterpret_cast<uintptr_t>(arg.pointer_value), spec);
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break;
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case CUSTOM:
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if (spec.type_)
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internal::ReportUnknownType(spec.type_, "object");
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arg.custom.format(writer, arg.custom.value, spec);
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break;
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default:
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assert(false);
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break;
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}
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}
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} catch (const FormatError &e) {
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// rethrow FormatError with the format string pointed to by start
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throw BasicFormatError<Char>(e.what(), original);
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}
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writer.buffer_.append(start, s);
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}
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@ -679,6 +686,17 @@ template void fmt::BasicFormatter<char>::CheckSign(
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template void fmt::BasicFormatter<char>::DoFormat();
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const char* FormatErrorMessage(const std::string &message, const char* format) {
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return fmt::c_str(fmt::Format("error: {} while parsing {}") << message << format);
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}
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template<> fmt::BasicFormatError<char>::BasicFormatError(const std::string &message, const char *format)
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: std::runtime_error(FormatErrorMessage(message, format)), format_(format) {}
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template<> fmt::BasicFormatError<char>::~BasicFormatError() {
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std::runtime_error::~runtime_error();
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}
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// Explicit instantiations for wchar_t.
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template void fmt::BasicWriter<wchar_t>::FormatDouble<double>(
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@ -711,3 +729,10 @@ template void fmt::BasicFormatter<wchar_t>::CheckSign(
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const wchar_t *&s, const Arg &arg);
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template void fmt::BasicFormatter<wchar_t>::DoFormat();
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template<> fmt::BasicFormatError<wchar_t>::BasicFormatError(const std::string &message, const wchar_t *format)
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: std::runtime_error(message), format_(format){}
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template<> fmt::BasicFormatError<wchar_t>::~BasicFormatError() {
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std::runtime_error::~runtime_error();
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}
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10
format.h
10
format.h
@ -292,6 +292,16 @@ class FormatError : public std::runtime_error {
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: std::runtime_error(message) {}
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};
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template <typename Char>
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class BasicFormatError : public std::runtime_error {
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private:
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std::basic_string<Char> format_;
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public:
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explicit BasicFormatError(const std::string &message, const Char *format);
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virtual ~BasicFormatError() throw();
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const Char *format() const { return format_.c_str(); }
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};
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enum Alignment {
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ALIGN_DEFAULT, ALIGN_LEFT, ALIGN_RIGHT, ALIGN_CENTER, ALIGN_NUMERIC
|
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};
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