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-rw-r--r--absl/strings/internal/str_format/parser.cc75
-rw-r--r--absl/strings/internal/str_format/parser_test.cc16
2 files changed, 58 insertions, 33 deletions
diff --git a/absl/strings/internal/str_format/parser.cc b/absl/strings/internal/str_format/parser.cc
index c3e16fce..5e3d0d05 100644
--- a/absl/strings/internal/str_format/parser.cc
+++ b/absl/strings/internal/str_format/parser.cc
@@ -84,16 +84,24 @@ bool ConsumeConversion(string_view *src, UnboundConversion *conv,
const char *pos = src->data();
const char *const end = pos + src->size();
char c;
- // Read the next char into `c` and update `pos`. Reads '\0' if at end.
- const auto get_char = [&] { c = pos == end ? '\0' : *pos++; };
+ // Read the next char into `c` and update `pos`. Returns false if there are
+ // no more chars to read.
+#define ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR() \
+ do { \
+ if (ABSL_PREDICT_FALSE(pos == end)) return false; \
+ c = *pos++; \
+ } while (0)
const auto parse_digits = [&] {
int digits = c - '0';
- // We do not want to overflow `digits` so we consume at most digits10-1
+ // We do not want to overflow `digits` so we consume at most digits10
// digits. If there are more digits the parsing will fail later on when the
// digit doesn't match the expected characters.
- int num_digits = std::numeric_limits<int>::digits10 - 2;
- for (get_char(); num_digits && std::isdigit(c); get_char()) {
+ int num_digits = std::numeric_limits<int>::digits10;
+ for (;;) {
+ if (ABSL_PREDICT_FALSE(pos == end || !num_digits)) break;
+ c = *pos++;
+ if (!std::isdigit(c)) break;
--num_digits;
digits = 10 * digits + c - '0';
}
@@ -101,14 +109,14 @@ bool ConsumeConversion(string_view *src, UnboundConversion *conv,
};
if (is_positional) {
- get_char();
- if (c < '1' || c > '9') return false;
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
+ if (ABSL_PREDICT_FALSE(c < '1' || c > '9')) return false;
conv->arg_position = parse_digits();
assert(conv->arg_position > 0);
- if (c != '$') return false;
+ if (ABSL_PREDICT_FALSE(c != '$')) return false;
}
- get_char();
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
// We should start with the basic flag on.
assert(conv->flags.basic);
@@ -119,32 +127,39 @@ bool ConsumeConversion(string_view *src, UnboundConversion *conv,
if (c < 'A') {
conv->flags.basic = false;
- for (; c <= '0'; get_char()) {
+ for (; c <= '0';) {
+ // FIXME: We might be able to speed this up reusing the kIds lookup table
+ // from above.
+ // It might require changing Flags to be a plain integer where we can |= a
+ // value.
switch (c) {
case '-':
conv->flags.left = true;
- continue;
+ break;
case '+':
conv->flags.show_pos = true;
- continue;
+ break;
case ' ':
conv->flags.sign_col = true;
- continue;
+ break;
case '#':
conv->flags.alt = true;
- continue;
+ break;
case '0':
conv->flags.zero = true;
- continue;
+ break;
+ default:
+ goto flags_done;
}
- break;
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
}
+flags_done:
if (c <= '9') {
if (c >= '0') {
int maybe_width = parse_digits();
if (!is_positional && c == '$') {
- if (*next_arg != 0) return false;
+ if (ABSL_PREDICT_FALSE(*next_arg != 0)) return false;
// Positional conversion.
*next_arg = -1;
conv->flags = Flags();
@@ -153,12 +168,12 @@ bool ConsumeConversion(string_view *src, UnboundConversion *conv,
}
conv->width.set_value(maybe_width);
} else if (c == '*') {
- get_char();
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
if (is_positional) {
- if (c < '1' || c > '9') return false;
+ if (ABSL_PREDICT_FALSE(c < '1' || c > '9')) return false;
conv->width.set_from_arg(parse_digits());
- if (c != '$') return false;
- get_char();
+ if (ABSL_PREDICT_FALSE(c != '$')) return false;
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
} else {
conv->width.set_from_arg(++*next_arg);
}
@@ -166,16 +181,16 @@ bool ConsumeConversion(string_view *src, UnboundConversion *conv,
}
if (c == '.') {
- get_char();
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
if (std::isdigit(c)) {
conv->precision.set_value(parse_digits());
} else if (c == '*') {
- get_char();
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
if (is_positional) {
- if (c < '1' || c > '9') return false;
+ if (ABSL_PREDICT_FALSE(c < '1' || c > '9')) return false;
conv->precision.set_from_arg(parse_digits());
if (c != '$') return false;
- get_char();
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
} else {
conv->precision.set_from_arg(++*next_arg);
}
@@ -188,23 +203,23 @@ bool ConsumeConversion(string_view *src, UnboundConversion *conv,
std::int8_t id = kIds[static_cast<unsigned char>(c)];
if (id < 0) {
- if (id == none) return false;
+ if (ABSL_PREDICT_FALSE(id == none)) return false;
// It is a length modifier.
using str_format_internal::LengthMod;
LengthMod length_mod = LengthMod::FromId(static_cast<LM>(~id));
- get_char();
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
if (c == 'h' && length_mod.id() == LengthMod::h) {
conv->length_mod = LengthMod::FromId(LengthMod::hh);
- get_char();
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
} else if (c == 'l' && length_mod.id() == LengthMod::l) {
conv->length_mod = LengthMod::FromId(LengthMod::ll);
- get_char();
+ ABSL_FORMAT_PARSER_INTERNAL_GET_CHAR();
} else {
conv->length_mod = length_mod;
}
id = kIds[static_cast<unsigned char>(c)];
- if (id < 0) return false;
+ if (ABSL_PREDICT_FALSE(id < 0)) return false;
}
assert(CheckFastPathSetting(*conv));
diff --git a/absl/strings/internal/str_format/parser_test.cc b/absl/strings/internal/str_format/parser_test.cc
index ac6886d0..ae402031 100644
--- a/absl/strings/internal/str_format/parser_test.cc
+++ b/absl/strings/internal/str_format/parser_test.cc
@@ -84,9 +84,9 @@ class ConsumeUnboundConversionTest : public ::testing::Test {
TEST_F(ConsumeUnboundConversionTest, ConsumeSpecification) {
struct Expectation {
int line;
- const char *src;
- const char *out;
- const char *src_post;
+ string_view src;
+ string_view out;
+ string_view src_post;
};
const Expectation kExpect[] = {
{__LINE__, "", "", "" },
@@ -236,6 +236,16 @@ TEST_F(ConsumeUnboundConversionTest, WidthAndPrecision) {
EXPECT_EQ(9, o.precision.get_from_arg());
EXPECT_FALSE(Run(".*0$d")) << "no arg 0";
+
+ // Large values
+ EXPECT_TRUE(Run("999999999.999999999d"));
+ EXPECT_FALSE(o.width.is_from_arg());
+ EXPECT_EQ(999999999, o.width.value());
+ EXPECT_FALSE(o.precision.is_from_arg());
+ EXPECT_EQ(999999999, o.precision.value());
+
+ EXPECT_FALSE(Run("1000000000.999999999d"));
+ EXPECT_FALSE(Run("999999999.1000000000d"));
}
TEST_F(ConsumeUnboundConversionTest, Flags) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 09:22:52 +0000