tvl-depot/absl/strings/internal/str_format/bind.cc
Abseil Team 02451914b9 Export of internal Abseil changes.
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74c1330e29f1501f2738258faf9ec4564395c90a by Gennadiy Civil <misterg@google.com>:

Merging https://github.com/abseil/abseil-cpp/pull/166

PiperOrigin-RevId: 212487256

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4ac236574ff8fb3cc1125505292b0bd8c8192da9 by Abseil Team <absl-team@google.com>:

Allow c_move to take rvalue containers.

PiperOrigin-RevId: 212458618

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ce94e23984870db666d4c91623ae45b3c60b5b61 by Matt Armstrong <marmstrong@google.com>:

Internal change.

PiperOrigin-RevId: 212153041

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7d88d286821c5839934756dd63a704ed162c49cb by Chris Kennelly <ckennelly@google.com>:

Internal change

PiperOrigin-RevId: 211982309

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ddae814b3f609948c20551ea3d80bf51b973f480 by Abseil Team <absl-team@google.com>:

Remove unused argument from InlinedVector's AllocatorAndTag

This is not part of InlinedVector's public interface.

PiperOrigin-RevId: 211973017

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051fbfd81648a8da66c62c6603af63038d709c15 by Abseil Team <absl-team@google.com>:

Minor performance fix

PiperOrigin-RevId: 211820453

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c205cb2add7400bc8caf2131cb700eea560b7dbf by Laramie Leavitt <lar@google.com>:

Make absl::Span a tiny bit more consistent.

Add constexper to equivalent absl::Span members as described by
http://open-std.org/JTC1/SC22/WG21/docs/papers/2018/p0122r7.pdf

* Span constructor use consistently delegate to Span(ptr, length)
* Mark more member methods as constexpr.
* Use data() and size() consistently in member methods.

PiperOrigin-RevId: 211707244

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55500c9e941f2f58f4a95c121f32772408866eee by Derek Mauro <dmauro@google.com>:

Stop catching polymorphic exception types by value.
GCC 8 emits a warning for this.

PiperOrigin-RevId: 211684466
GitOrigin-RevId: 74c1330e29f1501f2738258faf9ec4564395c90a
Change-Id: Iceab4a5b30ee35d82ef494830262ad29c028cb0a
2018-09-11 14:28:55 -04:00

229 lines
6.5 KiB
C++

#include "absl/strings/internal/str_format/bind.h"
#include <cerrno>
#include <limits>
#include <sstream>
#include <string>
namespace absl {
namespace str_format_internal {
namespace {
inline bool BindFromPosition(int position, int* value,
absl::Span<const FormatArgImpl> pack) {
assert(position > 0);
if (static_cast<size_t>(position) > pack.size()) {
return false;
}
// -1 because positions are 1-based
return FormatArgImplFriend::ToInt(pack[position - 1], value);
}
class ArgContext {
public:
explicit ArgContext(absl::Span<const FormatArgImpl> pack) : pack_(pack) {}
// Fill 'bound' with the results of applying the context's argument pack
// to the specified 'props'. We synthesize a BoundConversion by
// lining up a UnboundConversion with a user argument. We also
// resolve any '*' specifiers for width and precision, so after
// this call, 'bound' has all the information it needs to be formatted.
// Returns false on failure.
bool Bind(const UnboundConversion *props, BoundConversion *bound);
private:
absl::Span<const FormatArgImpl> pack_;
};
inline bool ArgContext::Bind(const UnboundConversion* unbound,
BoundConversion* bound) {
const FormatArgImpl* arg = nullptr;
int arg_position = unbound->arg_position;
if (static_cast<size_t>(arg_position - 1) >= pack_.size()) return false;
arg = &pack_[arg_position - 1]; // 1-based
if (!unbound->flags.basic) {
int width = unbound->width.value();
bool force_left = false;
if (unbound->width.is_from_arg()) {
if (!BindFromPosition(unbound->width.get_from_arg(), &width, pack_))
return false;
if (width < 0) {
// "A negative field width is taken as a '-' flag followed by a
// positive field width."
force_left = true;
width = -width;
}
}
int precision = unbound->precision.value();
if (unbound->precision.is_from_arg()) {
if (!BindFromPosition(unbound->precision.get_from_arg(), &precision,
pack_))
return false;
}
bound->set_width(width);
bound->set_precision(precision);
bound->set_flags(unbound->flags);
if (force_left)
bound->set_left(true);
} else {
bound->set_flags(unbound->flags);
bound->set_width(-1);
bound->set_precision(-1);
}
bound->set_length_mod(unbound->length_mod);
bound->set_conv(unbound->conv);
bound->set_arg(arg);
return true;
}
template <typename Converter>
class ConverterConsumer {
public:
ConverterConsumer(Converter converter, absl::Span<const FormatArgImpl> pack)
: converter_(converter), arg_context_(pack) {}
bool Append(string_view s) {
converter_.Append(s);
return true;
}
bool ConvertOne(const UnboundConversion& conv, string_view conv_string) {
BoundConversion bound;
if (!arg_context_.Bind(&conv, &bound)) return false;
return converter_.ConvertOne(bound, conv_string);
}
private:
Converter converter_;
ArgContext arg_context_;
};
template <typename Converter>
bool ConvertAll(const UntypedFormatSpecImpl format,
absl::Span<const FormatArgImpl> args, Converter converter) {
if (format.has_parsed_conversion()) {
return format.parsed_conversion()->ProcessFormat(
ConverterConsumer<Converter>(converter, args));
} else {
return ParseFormatString(format.str(),
ConverterConsumer<Converter>(converter, args));
}
}
class DefaultConverter {
public:
explicit DefaultConverter(FormatSinkImpl* sink) : sink_(sink) {}
void Append(string_view s) const { sink_->Append(s); }
bool ConvertOne(const BoundConversion& bound, string_view /*conv*/) const {
return FormatArgImplFriend::Convert(*bound.arg(), bound, sink_);
}
private:
FormatSinkImpl* sink_;
};
class SummarizingConverter {
public:
explicit SummarizingConverter(FormatSinkImpl* sink) : sink_(sink) {}
void Append(string_view s) const { sink_->Append(s); }
bool ConvertOne(const BoundConversion& bound, string_view /*conv*/) const {
UntypedFormatSpecImpl spec("%d");
std::ostringstream ss;
ss << "{" << Streamable(spec, {*bound.arg()}) << ":" << bound.flags();
if (bound.width() >= 0) ss << bound.width();
if (bound.precision() >= 0) ss << "." << bound.precision();
ss << bound.length_mod() << bound.conv() << "}";
Append(ss.str());
return true;
}
private:
FormatSinkImpl* sink_;
};
} // namespace
bool BindWithPack(const UnboundConversion* props,
absl::Span<const FormatArgImpl> pack,
BoundConversion* bound) {
return ArgContext(pack).Bind(props, bound);
}
std::string Summarize(const UntypedFormatSpecImpl format,
absl::Span<const FormatArgImpl> args) {
typedef SummarizingConverter Converter;
std::string out;
{
// inner block to destroy sink before returning out. It ensures a last
// flush.
FormatSinkImpl sink(&out);
if (!ConvertAll(format, args, Converter(&sink))) {
return "";
}
}
return out;
}
bool FormatUntyped(FormatRawSinkImpl raw_sink,
const UntypedFormatSpecImpl format,
absl::Span<const FormatArgImpl> args) {
FormatSinkImpl sink(raw_sink);
using Converter = DefaultConverter;
return ConvertAll(format, args, Converter(&sink));
}
std::ostream& Streamable::Print(std::ostream& os) const {
if (!FormatUntyped(&os, format_, args_)) os.setstate(std::ios::failbit);
return os;
}
std::string& AppendPack(std::string* out, const UntypedFormatSpecImpl format,
absl::Span<const FormatArgImpl> args) {
size_t orig = out->size();
if (ABSL_PREDICT_FALSE(!FormatUntyped(out, format, args))) {
out->erase(orig);
}
return *out;
}
int FprintF(std::FILE* output, const UntypedFormatSpecImpl format,
absl::Span<const FormatArgImpl> args) {
FILERawSink sink(output);
if (!FormatUntyped(&sink, format, args)) {
errno = EINVAL;
return -1;
}
if (sink.error()) {
errno = sink.error();
return -1;
}
if (sink.count() > std::numeric_limits<int>::max()) {
errno = EFBIG;
return -1;
}
return static_cast<int>(sink.count());
}
int SnprintF(char* output, size_t size, const UntypedFormatSpecImpl format,
absl::Span<const FormatArgImpl> args) {
BufferRawSink sink(output, size ? size - 1 : 0);
if (!FormatUntyped(&sink, format, args)) {
errno = EINVAL;
return -1;
}
size_t total = sink.total_written();
if (size) output[std::min(total, size - 1)] = 0;
return static_cast<int>(total);
}
} // namespace str_format_internal
} // namespace absl