//===- FormatProviders.h - Formatters for common LLVM types -----*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements format providers for many common LLVM types, for example
// allowing precision and width specifiers for scalar and string types.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_FORMATPROVIDERS_H
#define LLVM_SUPPORT_FORMATPROVIDERS_H
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/FormatVariadicDetails.h"
#include "llvm/Support/NativeFormatting.h"
#include <array>
#include <optional>
#include <type_traits>
namespace llvm {
namespace detail {
template <typename T>
struct use_integral_formatter
: public std::integral_constant<
bool, is_one_of<T, uint8_t, int16_t, uint16_t, int32_t, uint32_t,
int64_t, uint64_t, int, unsigned, long, unsigned long,
long long, unsigned long long>::value> {};
template <typename T>
struct use_char_formatter
: public std::integral_constant<bool, std::is_same<T, char>::value> {};
template <typename T>
struct is_cstring
: public std::integral_constant<bool,
is_one_of<T, char *, const char *>::value> {
};
template <typename T>
struct use_string_formatter
: public std::integral_constant<bool,
std::is_convertible<T, llvm::StringRef>::value> {};
template <typename T>
struct use_pointer_formatter
: public std::integral_constant<bool, std::is_pointer<T>::value &&
!is_cstring<T>::value> {};
template <typename T>
struct use_double_formatter
: public std::integral_constant<bool, std::is_floating_point<T>::value> {};
class HelperFunctions {
protected:
static std::optional<size_t> parseNumericPrecision(StringRef Str) {
size_t Prec;
std::optional<size_t> Result;
if (Str.empty())
Result = std::nullopt;
else if (Str.getAsInteger(10, Prec)) {
assert(false && "Invalid precision specifier");
Result = std::nullopt;
} else {
assert(Prec < 100 && "Precision out of range");
Result = std::min<size_t>(99u, Prec);
}
return Result;
}
static bool consumeHexStyle(StringRef &Str, HexPrintStyle &Style) {
if (!Str.startswith_insensitive("x"))
return false;
if (Str.consume_front("x-"))
Style = HexPrintStyle::Lower;
else if (Str.consume_front("X-"))
Style = HexPrintStyle::Upper;
else if (Str.consume_front("x+") || Str.consume_front("x"))
Style = HexPrintStyle::PrefixLower;
else if (Str.consume_front("X+") || Str.consume_front("X"))
Style = HexPrintStyle::PrefixUpper;
return true;
}
static size_t consumeNumHexDigits(StringRef &Str, HexPrintStyle Style,
size_t Default) {
Str.consumeInteger(10, Default);
if (isPrefixedHexStyle(Style))
Default += 2;
return Default;
}
};
}
/// Implementation of format_provider<T> for integral arithmetic types.
///
/// The options string of an integral type has the grammar:
///
/// integer_options :: [style][digits]
/// style :: <see table below>
/// digits :: <non-negative integer> 0-99
///
/// ==========================================================================
/// | style | Meaning | Example | Digits Meaning |
/// --------------------------------------------------------------------------
/// | | | Input | Output | |
/// ==========================================================================
/// | x- | Hex no prefix, lower | 42 | 2a | Minimum # digits |
/// | X- | Hex no prefix, upper | 42 | 2A | Minimum # digits |
/// | x+ / x | Hex + prefix, lower | 42 | 0x2a | Minimum # digits |
/// | X+ / X | Hex + prefix, upper | 42 | 0x2A | Minimum # digits |
/// | N / n | Digit grouped number | 123456 | 123,456 | Ignored |
/// | D / d | Integer | 100000 | 100000 | Ignored |
/// | (empty) | Same as D / d | | | |
/// ==========================================================================
///
template <typename T>
struct format_provider<
T, std::enable_if_t<detail::use_integral_formatter<T>::value>>
: public detail::HelperFunctions {
private:
public:
static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) {
HexPrintStyle HS;
size_t Digits = 0;
if (consumeHexStyle(Style, HS)) {
Digits = consumeNumHexDigits(Style, HS, 0);
write_hex(Stream, V, HS, Digits);
return;
}
IntegerStyle IS = IntegerStyle::Integer;
if (Style.consume_front("N") || Style.consume_front("n"))
IS = IntegerStyle::Number;
else if (Style.consume_front("D") || Style.consume_front("d"))
IS = IntegerStyle::Integer;
Style.consumeInteger(10, Digits);
assert(Style.empty() && "Invalid integral format style!");
write_integer(Stream, V, Digits, IS);
}
};
/// Implementation of format_provider<T> for integral pointer types.
///
/// The options string of a pointer type has the grammar:
///
/// pointer_options :: [style][precision]
/// style :: <see table below>
/// digits :: <non-negative integer> 0-sizeof(void*)
///
/// ==========================================================================
/// | S | Meaning | Example |
/// --------------------------------------------------------------------------
/// | | | Input | Output |
/// ==========================================================================
/// | x- | Hex no prefix, lower | 0xDEADBEEF | deadbeef |
/// | X- | Hex no prefix, upper | 0xDEADBEEF | DEADBEEF |
/// | x+ / x | Hex + prefix, lower | 0xDEADBEEF | 0xdeadbeef |
/// | X+ / X | Hex + prefix, upper | 0xDEADBEEF | 0xDEADBEEF |
/// | (empty) | Same as X+ / X | | |
/// ==========================================================================
///
/// The default precision is the number of nibbles in a machine word, and in all
/// cases indicates the minimum number of nibbles to print.
template <typename T>
struct format_provider<
T, std::enable_if_t<detail::use_pointer_formatter<T>::value>>
: public detail::HelperFunctions {
private:
public:
static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) {
HexPrintStyle HS = HexPrintStyle::PrefixUpper;
consumeHexStyle(Style, HS);
size_t Digits = consumeNumHexDigits(Style, HS, sizeof(void *) * 2);
write_hex(Stream, reinterpret_cast<std::uintptr_t>(V), HS, Digits);
}
};
/// Implementation of format_provider<T> for c-style strings and string
/// objects such as std::string and llvm::StringRef.
///
/// The options string of a string type has the grammar:
///
/// string_options :: [length]
///
/// where `length` is an optional integer specifying the maximum number of
/// characters in the string to print. If `length` is omitted, the string is
/// printed up to the null terminator.
template <typename T>
struct format_provider<
T, std::enable_if_t<detail::use_string_formatter<T>::value>> {
static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) {
size_t N = StringRef::npos;
if (!Style.empty() && Style.getAsInteger(10, N)) {
assert(false && "Style is not a valid integer");
}
llvm::StringRef S = V;
Stream << S.substr(0, N);
}
};
/// Implementation of format_provider<T> for llvm::Twine.
///
/// This follows the same rules as the string formatter.
template <> struct format_provider<Twine> {
static void format(const Twine &V, llvm::raw_ostream &Stream,
StringRef Style) {
format_provider<std::string>::format(V.str(), Stream, Style);
}
};
/// Implementation of format_provider<T> for characters.
///
/// The options string of a character type has the grammar:
///
/// char_options :: (empty) | [integer_options]
///
/// If `char_options` is empty, the character is displayed as an ASCII
/// character. Otherwise, it is treated as an integer options string.
///
template <typename T>
struct format_provider<T,
std::enable_if_t<detail::use_char_formatter<T>::value>> {
static void format(const char &V, llvm::raw_ostream &Stream,
StringRef Style) {
if (Style.empty())
Stream << V;
else {
int X = static_cast<int>(V);
format_provider<int>::format(X, Stream, Style);
}
}
};
/// Implementation of format_provider<T> for type `bool`
///
/// The options string of a boolean type has the grammar:
///
/// bool_options :: "" | "Y" | "y" | "D" | "d" | "T" | "t"
///
/// ==================================
/// | C | Meaning |
/// ==================================
/// | Y | YES / NO |
/// | y | yes / no |
/// | D / d | Integer 0 or 1 |
/// | T | TRUE / FALSE |
/// | t | true / false |
/// | (empty) | Equivalent to 't' |
/// ==================================
template <> struct format_provider<bool> {
static void format(const bool &B, llvm::raw_ostream &Stream,
StringRef Style) {
Stream << StringSwitch<const char *>(Style)
.Case("Y", B ? "YES" : "NO")
.Case("y", B ? "yes" : "no")
.CaseLower("D", B ? "1" : "0")
.Case("T", B ? "TRUE" : "FALSE")
.Cases("t", "", B ? "true" : "false")
.Default(B ? "1" : "0");
}
};
/// Implementation of format_provider<T> for floating point types.
///
/// The options string of a floating point type has the format:
///
/// float_options :: [style][precision]
/// style :: <see table below>
/// precision :: <non-negative integer> 0-99
///
/// =====================================================
/// | style | Meaning | Example |
/// -----------------------------------------------------
/// | | | Input | Output |
/// =====================================================
/// | P / p | Percentage | 0.05 | 5.00% |
/// | F / f | Fixed point | 1.0 | 1.00 |
/// | E | Exponential with E | 100000 | 1.0E+05 |
/// | e | Exponential with e | 100000 | 1.0e+05 |
/// | (empty) | Same as F / f | | |
/// =====================================================
///
/// The default precision is 6 for exponential (E / e) and 2 for everything
/// else.
template <typename T>
struct format_provider<T,
std::enable_if_t<detail::use_double_formatter<T>::value>>
: public detail::HelperFunctions {
static void format(const T &V, llvm::raw_ostream &Stream, StringRef Style) {
FloatStyle S;
if (Style.consume_front("P") || Style.consume_front("p"))
S = FloatStyle::Percent;
else if (Style.consume_front("F") || Style.consume_front("f"))
S = FloatStyle::Fixed;
else if (Style.consume_front("E"))
S = FloatStyle::ExponentUpper;
else if (Style.consume_front("e"))
S = FloatStyle::Exponent;
else
S = FloatStyle::Fixed;
std::optional<size_t> Precision = parseNumericPrecision(Style);
if (!Precision)
Precision = getDefaultPrecision(S);
write_double(Stream, static_cast<double>(V), S, Precision);
}
};
namespace detail {
template <typename IterT>
using IterValue = typename std::iterator_traits<IterT>::value_type;
template <typename IterT>
struct range_item_has_provider
: public std::integral_constant<
bool, !uses_missing_provider<IterValue<IterT>>::value> {};
}
/// Implementation of format_provider<T> for ranges.
///
/// This will print an arbitrary range as a delimited sequence of items.
///
/// The options string of a range type has the grammar:
///
/// range_style ::= [separator] [element_style]
/// separator ::= "$" delimeted_expr
/// element_style ::= "@" delimeted_expr
/// delimeted_expr ::= "[" expr "]" | "(" expr ")" | "<" expr ">"
/// expr ::= <any string not containing delimeter>
///
/// where the separator expression is the string to insert between consecutive
/// items in the range and the argument expression is the Style specification to
/// be used when formatting the underlying type. The default separator if
/// unspecified is ' ' (space). The syntax of the argument expression follows
/// whatever grammar is dictated by the format provider or format adapter used
/// to format the value type.
///
/// Note that attempting to format an `iterator_range<T>` where no format
/// provider can be found for T will result in a compile error.
///
template <typename IterT> class format_provider<llvm::iterator_range<IterT>> {
using value = typename std::iterator_traits<IterT>::value_type;
static StringRef consumeOneOption(StringRef &Style, char Indicator,
StringRef Default) {
if (Style.empty())
return Default;
if (Style.front() != Indicator)
return Default;
Style = Style.drop_front();
if (Style.empty()) {
assert(false && "Invalid range style");
return Default;
}
for (const char *D : std::array<const char *, 3>{"[]", "<>", "()"}) {
if (Style.front() != D[0])
continue;
size_t End = Style.find_first_of(D[1]);
if (End == StringRef::npos) {
assert(false && "Missing range option end delimeter!");
return Default;
}
StringRef Result = Style.slice(1, End);
Style = Style.drop_front(End + 1);
return Result;
}
assert(false && "Invalid range style!");
return Default;
}
static std::pair<StringRef, StringRef> parseOptions(StringRef Style) {
StringRef Sep = consumeOneOption(Style, '$', ", ");
StringRef Args = consumeOneOption(Style, '@', "");
assert(Style.empty() && "Unexpected text in range option string!");
return std::make_pair(Sep, Args);
}
public:
static_assert(detail::range_item_has_provider<IterT>::value,
"Range value_type does not have a format provider!");
static void format(const llvm::iterator_range<IterT> &V,
llvm::raw_ostream &Stream, StringRef Style) {
StringRef Sep;
StringRef ArgStyle;
std::tie(Sep, ArgStyle) = parseOptions(Style);
auto Begin = V.begin();
auto End = V.end();
if (Begin != End) {
auto Adapter = detail::build_format_adapter(*Begin);
Adapter.format(Stream, ArgStyle);
++Begin;
}
while (Begin != End) {
Stream << Sep;
auto Adapter = detail::build_format_adapter(*Begin);
Adapter.format(Stream, ArgStyle);
++Begin;
}
}
};
}
#endif