[flang-commits] [PATCH] D112347: [flang] Fix NAMELIST input bug with multiple subscript triplets

[Peter Klausler via Phabricator via flang-commits]

klausler created this revision.
klausler added a reviewer: vdonaldson.
klausler added a project: Flang.
Herald added a subscriber: jdoerfert.
klausler requested review of this revision.

NAMELIST input can contain array subscripts with triplet notation.
The calculation of the default effective stride for the constructed
array descriptor was simply incorrect after the first dimension.


https://reviews.llvm.org/D112347

Files:
  flang/runtime/namelist.cpp


Index: flang/runtime/namelist.cpp
===================================================================
--- flang/runtime/namelist.cpp
+++ flang/runtime/namelist.cpp
@@ -10,6 +10,7 @@
 #include "descriptor-io.h"
 #include "io-stmt.h"
 #include "flang/Runtime/io-api.h"
+#include <algorithm>
 #include <cstring>
 #include <limits>
 
@@ -133,7 +134,7 @@
   // ambiguous within the parentheses.
   SubscriptValue lower[maxRank], upper[maxRank], stride[maxRank];
   int j{0};
-  std::size_t elemLen{source.ElementBytes()};
+  std::size_t contiguousStride{source.ElementBytes()};
   bool ok{true};
   std::optional<char32_t> ch{io.GetNextNonBlank()};
   for (; ch && *ch != ')'; ++j) {
@@ -142,7 +143,9 @@
       const Dimension &dim{source.GetDimension(j)};
       dimLower = dim.LowerBound();
       dimUpper = dim.UpperBound();
-      dimStride = elemLen ? dim.ByteStride() / elemLen : 1;
+      dimStride =
+          dim.ByteStride() / std::max<SubscriptValue>(contiguousStride, 1);
+      contiguousStride *= dim.Extent();
     } else if (ok) {
       handler.SignalError(
           "Too many subscripts for rank-%d NAMELIST group item '%s'",


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