| Message ID | 20140810135549.3b9ca9cd@vepi2.private |
|---|---|
| State | New |
| Headers | show |
Hello, Le 10/08/2014 13:55, Andre Vehreschild a écrit : > Hi, > > I am proposing another patch, this time to resolve PR60289. The issue in the bug > reported is, that a code like: > > class(*), pointer :: P > allocate(character(20)::P) > > is rejected by trunk's gfortran compiler. janus@gcc.gnu.org proposed a first > patch in the PR, which my patch extends. > > Motivation: Previously parsing of the type association to the unlimited > polymorphic variable P was not allowed and reported the error "Error: > Allocating p at (1) with type-spec requires the same character-length parameter > as in the declaration", after the errorneous error report was fixed by > janus' patch, an ICE occured in trans-stmt.c's gfc_trans_allocate()-routine. > The ICE reported in PR60289 is something different and does not occur in trunk > anymore. The ICE reported now boils down to line 5056 in trans-stmt.c: > > tmp= al->expr->ts.u.cl->backend_decl; > > The dereferencing of ts.u's cl member is valid only, when ts.type is of > BT_CHARACTER. With al->expr being an unlimited polymorphic type, the > backend_decl is not available in cl. > > Although there is a backend_decl available in ts.u.derived, I was not able to > get it compatible for the fold_convert in the line following the assignment to > tmp: > > gfc_add_modify (&se.pre, tmp, fold_convert (TREE_TYPE(tmp), > se_sz.expr)); > > My current solution therefore is to execute those two statements only, when > ts.type is of BT_CHARACTER. My knowledge of unlimited polymorphic types is limited, but I think that this is not correct. The new length of the string has to be stored somewhere. If you don't do that, for example the intrinsic len() function won't work. > > Can someone explain what the fold_convert is doing in that specific place? I > assume that it is checking for and ensuring some type compatibility. Is there > some documentation available, explaining this? Is something similar needed for > the unlimited polymorphic variable? Well, I didn't find any documentation for fold_convert - except the code. In general, the fold_foo functions try to do foo, simplifying away useless operations. So fold_convert adds a type conversion, unless that is unnecessary (if the types are already the same for example). Mikael
diff --git a/gcc/fortran/resolve.c b/gcc/fortran/resolve.c index 15d8dab..15d3613 100644 --- a/gcc/fortran/resolve.c +++ b/gcc/fortran/resolve.c @@ -6878,7 +6878,9 @@ resolve_allocate_expr (gfc_expr *e, gfc_code *code) goto failure; } - if (code->ext.alloc.ts.type == BT_CHARACTER && !e->ts.deferred) + /* Check F08:C632. */ + if (code->ext.alloc.ts.type == BT_CHARACTER && !e->ts.deferred + && !UNLIMITED_POLY (e)) { int cmp = gfc_dep_compare_expr (e->ts.u.cl->length, code->ext.alloc.ts.u.cl->length); diff --git a/gcc/fortran/trans-stmt.c b/gcc/fortran/trans-stmt.c index 547e9c1..575342d 100644 --- a/gcc/fortran/trans-stmt.c +++ b/gcc/fortran/trans-stmt.c @@ -5046,7 +5046,7 @@ gfc_trans_allocate (gfc_code * code) if (unlimited_char) tmp = TREE_TYPE (gfc_typenode_for_spec (&code->expr3->ts)); else - tmp = TREE_TYPE (gfc_typenode_for_spec (&al->expr->ts)); + tmp = TREE_TYPE (gfc_typenode_for_spec (&al->expr->ts)); tmp = TYPE_SIZE_UNIT (tmp); memsz = fold_build2_loc (input_location, MULT_EXPR, TREE_TYPE (tmp), tmp, @@ -5061,10 +5061,14 @@ gfc_trans_allocate (gfc_code * code) gfc_add_block_to_block (&se.pre, &se_sz.pre); se_sz.expr = gfc_evaluate_now (se_sz.expr, &se.pre); gfc_add_block_to_block (&se.pre, &se_sz.post); - /* Store the string length. */ - tmp = al->expr->ts.u.cl->backend_decl; - gfc_add_modify (&se.pre, tmp, fold_convert (TREE_TYPE (tmp), - se_sz.expr)); + /* Store the string length only when variable allocated is + a character array. */ + if(al->expr->ts.type== BT_CHARACTER) + { + tmp= al->expr->ts.u.cl->backend_decl; + gfc_add_modify (&se.pre, tmp, fold_convert (TREE_TYPE(tmp), + se_sz.expr)); + } tmp = TREE_TYPE (gfc_typenode_for_spec (&code->ext.alloc.ts)); tmp = TYPE_SIZE_UNIT (tmp); memsz = fold_build2_loc (input_location, MULT_EXPR, diff --git a/gcc/testsuite/gfortran.dg/unlimited_polymorphic_20.f90 b/gcc/testsuite/gfortran.dg/unlimited_polymorphic_20.f90 new file mode 100644 index 0000000..070ba89 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/unlimited_polymorphic_20.f90 @@ -0,0 +1,24 @@ +! { dg-do run } +! Testing fix for +! PR fortran/60289 +! +program test + implicit none + + class(*), pointer :: P + + allocate(character(20)::P) + + select type(P) + type is (character(*)) + P ="some test string" + if (P .ne. "some test string") then + call abort() + end if + class default + call abort() + end select + + deallocate(P) +end program test +