1 //===-- include/flang/Parser/format-specification.h -------------*- C++ -*-===//
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 #ifndef FORTRAN_PARSER_FORMAT_SPECIFICATION_H_
10 #define FORTRAN_PARSER_FORMAT_SPECIFICATION_H_
11 
12 // Represent parses of Fortran format specifications from FORMAT statements
13 // and character literals in formatted I/O statements at compilation time
14 // as well as from character variables and expressions at run time.
15 // From requirement productions R1302-R1321 of the Fortran 2018 draft
16 // standard (q.v.), extended with Hollerith.  These structures have been
17 // isolated so that they may be used in the run-time without introducing
18 // dependences on other parts of the compiler's source code.
19 // TODO: support Q formatting extension?
20 
21 #include <cinttypes>
22 #include <list>
23 #include <optional>
24 #include <string>
25 #include <variant>
26 
27 namespace Fortran::format {
28 
29 // R1307 data-edit-desc (part 1 of 2) ->
30 //         I w [. m] | B w [. m] | O w [. m] | Z w [. m] | F w . d |
31 //         E w . d [E e] | EN w . d [E e] | ES w . d [E e] | EX w . d [E e] |
32 //         G w [. d [E e]] | L w | A [w] | D w . d
33 // R1308 w -> digit-string
34 // R1309 m -> digit-string
35 // R1310 d -> digit-string
36 // R1311 e -> digit-string
37 struct IntrinsicTypeDataEditDesc {
38   enum class Kind { I, B, O, Z, F, E, EN, ES, EX, G, L, A, D };
39   IntrinsicTypeDataEditDesc() = delete;
40   IntrinsicTypeDataEditDesc(IntrinsicTypeDataEditDesc &&) = default;
41   IntrinsicTypeDataEditDesc &operator=(IntrinsicTypeDataEditDesc &&) = default;
IntrinsicTypeDataEditDescIntrinsicTypeDataEditDesc42   IntrinsicTypeDataEditDesc(Kind &&k, std::optional<int> &&w,
43       std::optional<int> &&d, std::optional<int> &&e)
44       : kind{k}, width{std::move(w)}, digits{std::move(d)}, exponentWidth{
45                                                                 std::move(e)} {}
46   Kind kind;
47   std::optional<int> width; // w
48   std::optional<int> digits; // m or d
49   std::optional<int> exponentWidth; // e
50 };
51 
52 // R1307 data-edit-desc (part 2 of 2) ->
53 //         DT [char-literal-constant] [( v-list )]
54 // R1312 v -> [sign] digit-string
55 struct DerivedTypeDataEditDesc {
56   DerivedTypeDataEditDesc() = delete;
57   DerivedTypeDataEditDesc(DerivedTypeDataEditDesc &&) = default;
58   DerivedTypeDataEditDesc &operator=(DerivedTypeDataEditDesc &&) = default;
DerivedTypeDataEditDescDerivedTypeDataEditDesc59   DerivedTypeDataEditDesc(std::string &&t, std::list<std::int64_t> &&p)
60       : type{std::move(t)}, parameters{std::move(p)} {}
61   std::string type;
62   std::list<std::int64_t> parameters;
63 };
64 
65 // R1313 control-edit-desc ->
66 //         position-edit-desc | [r] / | : | sign-edit-desc | k P |
67 //         blank-interp-edit-desc | round-edit-desc | decimal-edit-desc |
68 //         @ \ | $
69 // R1315 position-edit-desc -> T n | TL n | TR n | n X
70 // R1316 n -> digit-string
71 // R1317 sign-edit-desc -> SS | SP | S
72 // R1318 blank-interp-edit-desc -> BN | BZ
73 // R1319 round-edit-desc -> RU | RD | RZ | RN | RC | RP
74 // R1320 decimal-edit-desc -> DC | DP
75 struct ControlEditDesc {
76   enum class Kind {
77     T,
78     TL,
79     TR,
80     X,
81     Slash,
82     Colon,
83     SS,
84     SP,
85     S,
86     P,
87     BN,
88     BZ,
89     RU,
90     RD,
91     RZ,
92     RN,
93     RC,
94     RP,
95     DC,
96     DP,
97     Dollar, // extension: inhibit newline on output
98     Backslash, // ditto, but only on terminals
99   };
100   ControlEditDesc() = delete;
101   ControlEditDesc(ControlEditDesc &&) = default;
102   ControlEditDesc &operator=(ControlEditDesc &&) = default;
ControlEditDescControlEditDesc103   explicit ControlEditDesc(Kind k) : kind{k} {}
ControlEditDescControlEditDesc104   ControlEditDesc(Kind k, std::int64_t ct) : kind{k}, count{ct} {}
ControlEditDescControlEditDesc105   ControlEditDesc(std::int64_t ct, Kind k) : kind{k}, count{ct} {}
106   Kind kind;
107   std::int64_t count{1}; // r, k, or n
108 };
109 
110 // R1304 format-item ->
111 //         [r] data-edit-desc | control-edit-desc | char-string-edit-desc |
112 //         [r] ( format-items )
113 // R1306 r -> digit-string
114 // R1321 char-string-edit-desc
115 struct FormatItem {
116   FormatItem() = delete;
117   FormatItem(FormatItem &&) = default;
118   FormatItem &operator=(FormatItem &&) = default;
119   template <typename A, typename = common::NoLvalue<A>>
FormatItemFormatItem120   FormatItem(std::optional<std::uint64_t> &&r, A &&x)
121       : repeatCount{std::move(r)}, u{std::move(x)} {}
122   template <typename A, typename = common::NoLvalue<A>>
FormatItemFormatItem123   explicit FormatItem(A &&x) : u{std::move(x)} {}
124   std::optional<std::uint64_t> repeatCount;
125   std::variant<IntrinsicTypeDataEditDesc, DerivedTypeDataEditDesc,
126       ControlEditDesc, std::string, std::list<FormatItem>>
127       u;
128 };
129 
130 // R1302 format-specification ->
131 //         ( [format-items] ) | ( [format-items ,] unlimited-format-item )
132 // R1303 format-items -> format-item [[,] format-item]...
133 // R1305 unlimited-format-item -> * ( format-items )
134 struct FormatSpecification {
135   FormatSpecification() = delete;
136   FormatSpecification(FormatSpecification &&) = default;
137   FormatSpecification &operator=(FormatSpecification &&) = default;
FormatSpecificationFormatSpecification138   explicit FormatSpecification(std::list<FormatItem> &&is)
139       : items(std::move(is)) {}
FormatSpecificationFormatSpecification140   FormatSpecification(std::list<FormatItem> &&is, std::list<FormatItem> &&us)
141       : items(std::move(is)), unlimitedItems(std::move(us)) {}
142   std::list<FormatItem> items, unlimitedItems;
143 };
144 } // namespace Fortran::format
145 #endif // FORTRAN_PARSER_FORMAT_SPECIFICATION_H_
146