xref: /llvm-project/flang/runtime/ISO_Fortran_util.h (revision 6df4e7c25ffb15ed8cba8ccb9cf9fa18b082013d)
1 //===-- runtime/ISO_Fortran_util.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_RUNTIME_ISO_FORTRAN_UTIL_H_
10 #define FORTRAN_RUNTIME_ISO_FORTRAN_UTIL_H_
11 
12 // Internal utils for establishing CFI_cdesc_t descriptors.
13 
14 #include "terminator.h"
15 #include "flang/ISO_Fortran_binding_wrapper.h"
16 #include "flang/Runtime/descriptor.h"
17 #include "flang/Runtime/type-code.h"
18 #include <cstdlib>
19 
20 namespace Fortran::ISO {
21 static inline constexpr RT_API_ATTRS bool IsCharacterType(CFI_type_t ty) {
22   return ty == CFI_type_char || ty == CFI_type_char16_t ||
23       ty == CFI_type_char32_t;
24 }
25 static inline constexpr RT_API_ATTRS bool IsAssumedSize(const CFI_cdesc_t *dv) {
26   return dv->rank > 0 && dv->dim[dv->rank - 1].extent == -1;
27 }
28 
29 static inline RT_API_ATTRS std::size_t MinElemLen(CFI_type_t type) {
30   auto typeParams{Fortran::runtime::TypeCode{type}.GetCategoryAndKind()};
31   if (!typeParams) {
32     Fortran::runtime::Terminator terminator{__FILE__, __LINE__};
33     terminator.Crash(
34         "not yet implemented: CFI_type_t=%d", static_cast<int>(type));
35   }
36 
37   return Fortran::runtime::Descriptor::BytesFor(
38       typeParams->first, typeParams->second);
39 }
40 
41 static inline RT_API_ATTRS int VerifyEstablishParameters(
42     CFI_cdesc_t *descriptor, void *base_addr, CFI_attribute_t attribute,
43     CFI_type_t type, std::size_t elem_len, CFI_rank_t rank,
44     const CFI_index_t extents[], bool external) {
45   if (attribute != CFI_attribute_other && attribute != CFI_attribute_pointer &&
46       attribute != CFI_attribute_allocatable) {
47     return CFI_INVALID_ATTRIBUTE;
48   }
49   if (rank > CFI_MAX_RANK) {
50     return CFI_INVALID_RANK;
51   }
52   if (base_addr && attribute == CFI_attribute_allocatable) {
53     return CFI_ERROR_BASE_ADDR_NOT_NULL;
54   }
55   if (rank > 0 && base_addr && !extents) {
56     return CFI_INVALID_EXTENT;
57   }
58   if (type < CFI_type_signed_char || type > CFI_TYPE_LAST) {
59     return CFI_INVALID_TYPE;
60   }
61   if (!descriptor) {
62     return CFI_INVALID_DESCRIPTOR;
63   }
64   if (external) {
65     if (type == CFI_type_struct || type == CFI_type_other ||
66         IsCharacterType(type)) {
67       if (elem_len <= 0) {
68         return CFI_INVALID_ELEM_LEN;
69       }
70     }
71   } else {
72     // We do not expect CFI_type_other for internal invocations.
73     if (type == CFI_type_other) {
74       return CFI_INVALID_TYPE;
75     }
76   }
77   return CFI_SUCCESS;
78 }
79 
80 static inline RT_API_ATTRS void EstablishDescriptor(CFI_cdesc_t *descriptor,
81     void *base_addr, CFI_attribute_t attribute, CFI_type_t type,
82     std::size_t elem_len, CFI_rank_t rank, const CFI_index_t extents[]) {
83   descriptor->base_addr = base_addr;
84   descriptor->elem_len = elem_len;
85   descriptor->version = CFI_VERSION;
86   descriptor->rank = rank;
87   descriptor->type = type;
88   descriptor->attribute = attribute;
89   descriptor->extra = 0;
90   std::size_t byteSize{elem_len};
91   constexpr std::size_t lower_bound{0};
92   if (base_addr) {
93     for (std::size_t j{0}; j < rank; ++j) {
94       descriptor->dim[j].lower_bound = lower_bound;
95       descriptor->dim[j].extent = extents[j];
96       descriptor->dim[j].sm = byteSize;
97       byteSize *= extents[j];
98     }
99   }
100 }
101 } // namespace Fortran::ISO
102 #endif // FORTRAN_RUNTIME_ISO_FORTRAN_UTIL_H_
103