flang/runtime/misc-intrinsic.cpp

   1 //===-- runtime/misc-intrinsic.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 "flang/Runtime/misc-intrinsic.h"
  10 #include "terminator.h"
  11 #include "tools.h"
  12 #include "flang/Common/optional.h"
  13 #include "flang/Runtime/descriptor.h"
  14 #include <algorithm>
  15 #include <cstdio>
  16 #include <cstring>
  17
  18 namespace Fortran::runtime {
  19
  20 static RT_API_ATTRS void TransferImpl(Descriptor &result,
  21     const Descriptor &source, const Descriptor &mold, const char *sourceFile,
  22     int line, Fortran::common::optional<std::int64_t> resultExtent) {
  23   int rank{resultExtent.has_value() ? 1 : 0};
  24   std::size_t elementBytes{mold.ElementBytes()};
  25   result.Establish(mold.type(), elementBytes, nullptr, rank, nullptr,
  26       CFI_attribute_allocatable, mold.Addendum() != nullptr);
  27   if (resultExtent) {
  28     result.GetDimension(0).SetBounds(1, *resultExtent);
  29   }
  30   if (const DescriptorAddendum * addendum{mold.Addendum()}) {
  31     *result.Addendum() = *addendum;
  32   }
  33   if (int stat{result.Allocate()}) {
  34     Terminator{sourceFile, line}.Crash(
  35         "TRANSFER: could not allocate memory for result; STAT=%d", stat);
  36   }
  37   char *to{result.OffsetElement<char>()};
  38   std::size_t resultBytes{result.Elements() * result.ElementBytes()};
  39   const std::size_t sourceElementBytes{source.ElementBytes()};
  40   std::size_t sourceElements{source.Elements()};
  41   SubscriptValue sourceAt[maxRank];
  42   source.GetLowerBounds(sourceAt);
  43   while (resultBytes > 0 && sourceElements > 0) {
  44     std::size_t toMove{std::min(resultBytes, sourceElementBytes)};
  45     std::memcpy(to, source.Element<char>(sourceAt), toMove);
  46     to += toMove;
  47     resultBytes -= toMove;
  48     --sourceElements;
  49     source.IncrementSubscripts(sourceAt);
  50   }
  51   if (resultBytes > 0) {
  52     std::memset(to, 0, resultBytes);
  53   }
  54 }
  55
  56 extern "C" {
  57 RT_EXT_API_GROUP_BEGIN
  58
  59 void RTDEF(Rename)(const Descriptor &path1, const Descriptor &path2,
  60     const Descriptor *status, const char *sourceFile, int line) {
  61   Terminator terminator{sourceFile, line};
  62 #if !defined(RT_DEVICE_COMPILATION)
  63   char *pathSrc{EnsureNullTerminated(
  64       path1.OffsetElement(), path1.ElementBytes(), terminator)};
  65   char *pathDst{EnsureNullTerminated(
  66       path2.OffsetElement(), path2.ElementBytes(), terminator)};
  67
  68   // We simply call rename(2) from POSIX
  69   int result{rename(pathSrc, pathDst)};
  70   if (status) {
  71     // When an error has happened,
  72     int errorCode{0}; // Assume success
  73     if (result != 0) {
  74       // The rename operation has failed, so return the error code as status.
  75       errorCode = errno;
  76     }
  77     StoreIntToDescriptor(status, errorCode, terminator);
  78   }
  79
  80   // Deallocate memory if EnsureNullTerminated dynamically allocated memory
  81   if (pathSrc != path1.OffsetElement()) {
  82     FreeMemory(pathSrc);
  83   }
  84   if (pathDst != path2.OffsetElement()) {
  85     FreeMemory(pathDst);
  86   }
  87 #else // !defined(RT_DEVICE_COMPILATION)
  88   terminator.Crash("RENAME intrinsic is only supported on host devices");
  89 #endif // !defined(RT_DEVICE_COMPILATION)
  90 }
  91
  92 void RTDEF(Transfer)(Descriptor &result, const Descriptor &source,
  93     const Descriptor &mold, const char *sourceFile, int line) {
  94   Fortran::common::optional<std::int64_t> elements;
  95   if (mold.rank() > 0) {
  96     if (std::size_t sourceElementBytes{
  97             source.Elements() * source.ElementBytes()}) {
  98       if (std::size_t moldElementBytes{mold.ElementBytes()}) {
  99         elements = static_cast<std::int64_t>(
 100             (sourceElementBytes + moldElementBytes - 1) / moldElementBytes);
 101       } else {
 102         Terminator{sourceFile, line}.Crash("TRANSFER: zero-sized type of MOLD= "
 103                                            "when SOURCE= is not zero-sized");
 104       }
 105     } else {
 106       elements = std::int64_t{0};
 107     }
 108   }
 109   return TransferImpl(
 110       result, source, mold, sourceFile, line, std::move(elements));
 111 }
 112
 113 void RTDEF(TransferSize)(Descriptor &result, const Descriptor &source,
 114     const Descriptor &mold, const char *sourceFile, int line,
 115     std::int64_t size) {
 116   return TransferImpl(result, source, mold, sourceFile, line, size);
 117 }
 118
 119 RT_EXT_API_GROUP_END
 120 } // extern "C"
 121 } // namespace Fortran::runtime