diff options
Diffstat (limited to 'gcc/fortran/trans-array.cc')
| -rw-r--r-- | gcc/fortran/trans-array.cc | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/gcc/fortran/trans-array.cc b/gcc/fortran/trans-array.cc index 44b091a..ec627dd 100644 --- a/gcc/fortran/trans-array.cc +++ b/gcc/fortran/trans-array.cc @@ -8925,6 +8925,7 @@ gfc_conv_array_parameter (gfc_se *se, gfc_expr *expr, bool g77, bool good_allocatable; bool ultimate_ptr_comp; bool ultimate_alloc_comp; + bool readonly; gfc_symbol *sym; stmtblock_t block; gfc_ref *ref; @@ -9381,8 +9382,13 @@ gfc_conv_array_parameter (gfc_se *se, gfc_expr *expr, bool g77, gfc_start_block (&block); - /* Copy the data back. */ - if (fsym == NULL || fsym->attr.intent != INTENT_IN) + /* Copy the data back. If input expr is read-only, e.g. a PARAMETER + array, copying back modified values is undefined behavior. */ + readonly = (expr->expr_type == EXPR_VARIABLE + && expr->symtree + && expr->symtree->n.sym->attr.flavor == FL_PARAMETER); + + if ((fsym == NULL || fsym->attr.intent != INTENT_IN) && !readonly) { if (ctree) { |