1 //===-- runtime/internal-unit.cpp -----------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "internal-unit.h"
10 #include "io-error.h"
11 #include "flang/Runtime/descriptor.h"
12 #include <algorithm>
13 #include <type_traits>
14
15 namespace Fortran::runtime::io {
16
17 template <Direction DIR>
InternalDescriptorUnit(Scalar scalar,std::size_t length)18 InternalDescriptorUnit<DIR>::InternalDescriptorUnit(
19 Scalar scalar, std::size_t length) {
20 recordLength = length;
21 endfileRecordNumber = 2;
22 void *pointer{reinterpret_cast<void *>(const_cast<char *>(scalar))};
23 descriptor().Establish(TypeCode{CFI_type_char}, length, pointer, 0, nullptr,
24 CFI_attribute_pointer);
25 }
26
27 template <Direction DIR>
InternalDescriptorUnit(const Descriptor & that,const Terminator & terminator)28 InternalDescriptorUnit<DIR>::InternalDescriptorUnit(
29 const Descriptor &that, const Terminator &terminator) {
30 RUNTIME_CHECK(terminator, that.type().IsCharacter());
31 Descriptor &d{descriptor()};
32 RUNTIME_CHECK(
33 terminator, that.SizeInBytes() <= d.SizeInBytes(maxRank, true, 0));
34 new (&d) Descriptor{that};
35 d.Check();
36 recordLength = d.ElementBytes();
37 endfileRecordNumber = d.Elements() + 1;
38 }
39
EndIoStatement()40 template <Direction DIR> void InternalDescriptorUnit<DIR>::EndIoStatement() {
41 if constexpr (DIR == Direction::Output) {
42 // Clear the remainder of the current record if anything was written
43 // to it, or if it is the only record.
44 auto end{endfileRecordNumber.value_or(0)};
45 if (currentRecordNumber < end &&
46 (end == 2 || furthestPositionInRecord > 0)) {
47 BlankFillOutputRecord();
48 }
49 }
50 }
51
52 template <Direction DIR>
Emit(const char * data,std::size_t bytes,IoErrorHandler & handler)53 bool InternalDescriptorUnit<DIR>::Emit(
54 const char *data, std::size_t bytes, IoErrorHandler &handler) {
55 if constexpr (DIR == Direction::Input) {
56 handler.Crash("InternalDescriptorUnit<Direction::Input>::Emit() called");
57 return false && data[bytes] != 0; // bogus compare silences GCC warning
58 } else {
59 if (bytes <= 0) {
60 return true;
61 }
62 char *record{CurrentRecord()};
63 if (!record) {
64 handler.SignalError(IostatInternalWriteOverrun);
65 return false;
66 }
67 auto furthestAfter{std::max(furthestPositionInRecord,
68 positionInRecord + static_cast<std::int64_t>(bytes))};
69 bool ok{true};
70 if (furthestAfter > static_cast<std::int64_t>(recordLength.value_or(0))) {
71 handler.SignalError(IostatRecordWriteOverrun);
72 furthestAfter = recordLength.value_or(0);
73 bytes = std::max(std::int64_t{0}, furthestAfter - positionInRecord);
74 ok = false;
75 } else if (positionInRecord > furthestPositionInRecord) {
76 std::fill_n(record + furthestPositionInRecord,
77 positionInRecord - furthestPositionInRecord, ' ');
78 }
79 std::memcpy(record + positionInRecord, data, bytes);
80 positionInRecord += bytes;
81 furthestPositionInRecord = furthestAfter;
82 return ok;
83 }
84 }
85
86 template <Direction DIR>
GetNextInputBytes(const char * & p,IoErrorHandler & handler)87 std::size_t InternalDescriptorUnit<DIR>::GetNextInputBytes(
88 const char *&p, IoErrorHandler &handler) {
89 if constexpr (DIR == Direction::Output) {
90 handler.Crash("InternalDescriptorUnit<Direction::Output>::"
91 "GetNextInputBytes() called");
92 return 0;
93 } else {
94 const char *record{CurrentRecord()};
95 if (!record) {
96 handler.SignalEnd();
97 return 0;
98 } else if (positionInRecord >= recordLength.value_or(positionInRecord)) {
99 return 0;
100 } else {
101 p = &record[positionInRecord];
102 return *recordLength - positionInRecord;
103 }
104 }
105 }
106
107 template <Direction DIR>
AdvanceRecord(IoErrorHandler & handler)108 bool InternalDescriptorUnit<DIR>::AdvanceRecord(IoErrorHandler &handler) {
109 if (currentRecordNumber >= endfileRecordNumber.value_or(0)) {
110 handler.SignalEnd();
111 return false;
112 }
113 if constexpr (DIR == Direction::Output) {
114 BlankFillOutputRecord();
115 }
116 ++currentRecordNumber;
117 BeginRecord();
118 return true;
119 }
120
121 template <Direction DIR>
BlankFillOutputRecord()122 void InternalDescriptorUnit<DIR>::BlankFillOutputRecord() {
123 if constexpr (DIR == Direction::Output) {
124 if (furthestPositionInRecord <
125 recordLength.value_or(furthestPositionInRecord)) {
126 char *record{CurrentRecord()};
127 std::fill_n(record + furthestPositionInRecord,
128 *recordLength - furthestPositionInRecord, ' ');
129 }
130 }
131 }
132
133 template <Direction DIR>
BackspaceRecord(IoErrorHandler & handler)134 void InternalDescriptorUnit<DIR>::BackspaceRecord(IoErrorHandler &handler) {
135 RUNTIME_CHECK(handler, currentRecordNumber > 1);
136 --currentRecordNumber;
137 BeginRecord();
138 }
139
140 template class InternalDescriptorUnit<Direction::Output>;
141 template class InternalDescriptorUnit<Direction::Input>;
142 } // namespace Fortran::runtime::io
143