diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/fortran/gfortran.h | 20 | ||||
| -rw-r--r-- | gcc/fortran/parse.cc | 3 |
2 files changed, 20 insertions, 3 deletions
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h index f4a1c10..6caf776 100644 --- a/gcc/fortran/gfortran.h +++ b/gcc/fortran/gfortran.h @@ -1944,7 +1944,27 @@ typedef struct gfc_symbol according to the Fortran standard. */ unsigned pass_as_value:1; + /* Reference counter, used for memory management. + + Some symbols may be present in more than one namespace, for example + function and subroutine symbols are present both in the outer namespace and + the procedure body namespace. Freeing symbols with the namespaces they are + in would result in double free for those symbols. This field counts + references and is used to delay the memory release until the last reference + to the symbol is removed. + + Not every symbol pointer is accounted for reference counting. Fields + gfc_symtree::n::sym are, and gfc_finalizer::proc_sym as well. But most of + them (dummy arguments, generic list elements, etc) are "weak" pointers; + the reference count isn't updated when they are assigned, and they are + ignored when the surrounding structure memory is released. This is not a + problem because there is always a namespace as surrounding context and + symbols have a name they can be referred with in that context, so the + namespace keeps the symbol from being freed, keeping the pointer valid. + When the namespace ceases to exist, and the symbols with it, the other + structures referencing symbols cease to exist as well. */ int refs; + struct gfc_namespace *ns; /* namespace containing this symbol */ tree backend_decl; diff --git a/gcc/fortran/parse.cc b/gcc/fortran/parse.cc index 8f09ddf..5838680 100644 --- a/gcc/fortran/parse.cc +++ b/gcc/fortran/parse.cc @@ -4064,9 +4064,6 @@ loop: accept_statement (st); prog_unit = gfc_new_block; prog_unit->formal_ns = gfc_current_ns; - if (prog_unit == prog_unit->formal_ns->proc_name - && prog_unit->ns != prog_unit->formal_ns) - prog_unit->refs++; decl: /* Read data declaration statements. */ |