//===-- runtime/format.h ----------------------------------------*- 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
//
//===----------------------------------------------------------------------===//
// FORMAT string processing
#ifndef FORTRAN_RUNTIME_FORMAT_H_
#define FORTRAN_RUNTIME_FORMAT_H_
#include "environment.h"
#include "io-error.h"
#include "flang/Common/Fortran.h"
#include "flang/Common/optional.h"
#include "flang/Decimal/decimal.h"
#include "flang/Runtime/freestanding-tools.h"
#include <cinttypes>
namespace Fortran::runtime {
class Descriptor;
} // namespace Fortran::runtime
namespace Fortran::runtime::io {
class IoStatementState;
enum EditingFlags {
blankZero = 1, // BLANK=ZERO or BZ edit
decimalComma = 2, // DECIMAL=COMMA or DC edit
signPlus = 4, // SIGN=PLUS or SP edit
};
struct MutableModes {
std::uint8_t editingFlags{0}; // BN, DP, SS
enum decimal::FortranRounding round{
executionEnvironment
.defaultOutputRoundingMode}; // RP/ROUND='PROCESSOR_DEFAULT'
bool pad{true}; // PAD= mode on READ
char delim{'\0'}; // DELIM=
short scale{0}; // kP
bool inNamelist{false}; // skip ! comments
bool nonAdvancing{false}; // ADVANCE='NO', or $ or \ in FORMAT
};
// A single edit descriptor extracted from a FORMAT
struct DataEdit {
char descriptor; // capitalized: one of A, I, B, O, Z, F, E(N/S/X), D, G
// Special internal data edit descriptors for list-directed & NAMELIST I/O
RT_OFFLOAD_VAR_GROUP_BEGIN
static constexpr char ListDirected{'g'}; // non-COMPLEX list-directed
static constexpr char ListDirectedRealPart{'r'}; // emit "(r," or "(r;"
static constexpr char ListDirectedImaginaryPart{'z'}; // emit "z)"
static constexpr char ListDirectedNullValue{'n'}; // see 13.10.3.2
static constexpr char DefinedDerivedType{'d'}; // DT defined I/O
RT_OFFLOAD_VAR_GROUP_END
constexpr RT_API_ATTRS bool IsListDirected() const {
return descriptor == ListDirected || descriptor == ListDirectedRealPart ||
descriptor == ListDirectedImaginaryPart;
}
constexpr RT_API_ATTRS bool IsNamelist() const {
return IsListDirected() && modes.inNamelist;
}
char variation{'\0'}; // N, S, or X for EN, ES, EX; G/l for original G/list
Fortran::common::optional<int> width; // the 'w' field; optional for A
Fortran::common::optional<int> digits; // the 'm' or 'd' field
Fortran::common::optional<int> expoDigits; // 'Ee' field
MutableModes modes;
int repeat{1};
// "iotype" &/or "v_list" values for a DT'iotype'(v_list)
// defined I/O data edit descriptor
RT_OFFLOAD_VAR_GROUP_BEGIN
static constexpr std::size_t maxIoTypeChars{32};
static constexpr std::size_t maxVListEntries{4};
RT_OFFLOAD_VAR_GROUP_END
std::uint8_t ioTypeChars{0};
std::uint8_t vListEntries{0};
char ioType[maxIoTypeChars];
int vList[maxVListEntries];
};
// Generates a sequence of DataEdits from a FORMAT statement or
// default-CHARACTER string. Driven by I/O item list processing.
// Errors are fatal. See subclause 13.4 in Fortran 2018 for background.
template <typename CONTEXT> class FormatControl {
public:
using Context = CONTEXT;
using CharType = char; // formats are always default kind CHARACTER
RT_API_ATTRS FormatControl() {}
RT_API_ATTRS FormatControl(const Terminator &, const CharType *format,
std::size_t formatLength, const Descriptor *formatDescriptor = nullptr,
int maxHeight = maxMaxHeight);
// For attempting to allocate in a user-supplied stack area
static RT_API_ATTRS std::size_t GetNeededSize(int maxHeight) {
return sizeof(FormatControl) -
sizeof(Iteration) * (maxMaxHeight - maxHeight);
}
// Extracts the next data edit descriptor, handling control edit descriptors
// along the way. If maxRepeat==0, this is a peek at the next data edit
// descriptor.
RT_API_ATTRS Fortran::common::optional<DataEdit> GetNextDataEdit(
Context &, int maxRepeat = 1);
// Emit any remaining character literals after the last data item (on output)
// and perform remaining record positioning actions.
RT_API_ATTRS void Finish(Context &);
private:
RT_OFFLOAD_VAR_GROUP_BEGIN
static constexpr std::uint8_t maxMaxHeight{100};
struct Iteration {
static constexpr int unlimited{-1};
int start{0}; // offset in format_ of '(' or a repeated edit descriptor
int remaining{0}; // while >0, decrement and iterate
};
RT_OFFLOAD_VAR_GROUP_END
RT_API_ATTRS void SkipBlanks() {
while (offset_ < formatLength_ &&
(format_[offset_] == ' ' || format_[offset_] == '\t' ||
format_[offset_] == '\v')) {
++offset_;
}
}
RT_API_ATTRS CharType PeekNext() {
SkipBlanks();
return offset_ < formatLength_ ? format_[offset_] : '\0';
}
RT_API_ATTRS CharType GetNextChar(IoErrorHandler &handler) {
SkipBlanks();
if (offset_ >= formatLength_) {
if (formatLength_ == 0) {
handler.SignalError(
IostatErrorInFormat, "Empty or badly assigned FORMAT");
} else {
handler.SignalError(
IostatErrorInFormat, "FORMAT missing at least one ')'");
}
return '\n';
}
return format_[offset_++];
}
RT_API_ATTRS int GetIntField(
IoErrorHandler &, CharType firstCh = '\0', bool *hadError = nullptr);
// Advances through the FORMAT until the next data edit
// descriptor has been found; handles control edit descriptors
// along the way. Returns the repeat count that appeared
// before the descriptor (defaulting to 1) and leaves offset_
// pointing to the data edit.
RT_API_ATTRS int CueUpNextDataEdit(Context &, bool stop = false);
static constexpr RT_API_ATTRS CharType Capitalize(CharType ch) {
return ch >= 'a' && ch <= 'z' ? ch + 'A' - 'a' : ch;
}
RT_API_ATTRS void ReportBadFormat(
Context &context, const char *msg, int offset) const {
if constexpr (std::is_same_v<CharType, char>) {
// Echo the bad format in the error message, but trim any leading or
// trailing spaces.
int firstNonBlank{0};
while (firstNonBlank < formatLength_ && format_[firstNonBlank] == ' ') {
++firstNonBlank;
}
int lastNonBlank{formatLength_ - 1};
while (lastNonBlank > firstNonBlank && format_[lastNonBlank] == ' ') {
--lastNonBlank;
}
if (firstNonBlank <= lastNonBlank) {
context.SignalError(IostatErrorInFormat,
"%s; at offset %d in format '%.*s'", msg, offset,
lastNonBlank - firstNonBlank + 1, format_ + firstNonBlank);
return;
}
}
context.SignalError(IostatErrorInFormat, "%s; at offset %d", msg, offset);
}
// Data members are arranged and typed so as to reduce size.
// This structure may be allocated in stack space loaned by the
// user program for internal I/O.
const std::uint8_t maxHeight_{maxMaxHeight};
std::uint8_t height_{0};
bool freeFormat_{false};
bool hitEnd_{false};
const CharType *format_{nullptr};
int formatLength_{0}; // in units of characters
int offset_{0}; // next item is at format_[offset_]
// must be last, may be incomplete
Iteration stack_[maxMaxHeight];
};
} // namespace Fortran::runtime::io
#endif // FORTRAN_RUNTIME_FORMAT_H_
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