| Message ID | 20161202013354.GA42106@troutmask.apl.washington.edu |
|---|---|
| State | New |
| Headers | show |
Hi Steve, 2016-12-02 2:33 GMT+01:00 Steve Kargl <sgk@troutmask.apl.washington.edu>: > The attached patch fixes an ICE, a nearby whitespace issue, and > removed the ATTRIBUTE_UNUSED tag. THe change has passed regression > testing on x86_64-*-freebsd. Ok to commit? huh, I don't really understand why the argument of RANK is detected to be an EXPR_FUNCTION for the test case at hand. Shouldn't it rather be an EXPR_CONSTANT? Some debugging in gfc_check_rank shows that a->symtree->n.sym indeed is the symbol "c" (as expected), but that clearly is not a function, so it seems to me that the actual bug here is that a->expr_type is set incorrectly ...? Cheers, Janus > 2016-12-01 Steven G. Kargl <kargl@gcc.gnu.org> > > PR fortran/78618 > * check.c (gfc_check_rank): Remove ATTRIBUTE_UNUSED. Fix whitespace. > Fix ICE where a NULL pointer is dereferenced. > * simplify.c (gfc_convert_char_constant): Do not buffer error. > > 2016-12-01 Steven G. Kargl <kargl@gcc.gnu.org> > > PR fortran/78618 > * gfortran.dg/char_conversion.f90: New test. > > -- > Steve
On Fri, Dec 02, 2016 at 04:47:19PM +0100, Janus Weil wrote: > Hi Steve, > > 2016-12-02 2:33 GMT+01:00 Steve Kargl <sgk@troutmask.apl.washington.edu>: > > The attached patch fixes an ICE, a nearby whitespace issue, and > > removed the ATTRIBUTE_UNUSED tag. THe change has passed regression > > testing on x86_64-*-freebsd. Ok to commit? > > huh, I don't really understand why the argument of RANK is detected to > be an EXPR_FUNCTION for the test case at hand. Shouldn't it rather be > an EXPR_CONSTANT? > > Some debugging in gfc_check_rank shows that a->symtree->n.sym indeed > is the symbol "c" (as expected), but that clearly is not a function, > so it seems to me that the actual bug here is that a->expr_type is set > incorrectly ...? > I found that it is the function __convert_s4_s1. Namely, we have character, parameter :: c = char(256,4) print *, rank(c) c is kind=1 and char(256,4) is kind 4. so, we end up with print *, rank(__convert_s4_s1(...)) As __convert_s4_s1() has neither isym nor esym set, you get a problem.
On Dez 01 2016, Steve Kargl <sgk@troutmask.apl.washington.edu> wrote: > PR fortran/78618 > * gfortran.dg/char_conversion.f90: New test. That test still crashes the compiler on m68k: /daten/aranym/gcc/gcc-20161203/gcc/testsuite/gfortran.dg/char_conversion.f90:8:30: Error: Character '\u0100' in string at (1) cannot be converted into character kind 1 f951: internal compiler error: Segmentation fault 0xb40a7f crash_signal ../../gcc/toplev.c:333 0x58dd52 gfc_is_constant_expr(gfc_expr*) ../../gcc/fortran/expr.c:899 0x5feb90 resolve_fl_procedure ../../gcc/fortran/resolve.c:12013 0x5feb90 resolve_symbol ../../gcc/fortran/resolve.c:14721 0x616e73 do_traverse_symtree ../../gcc/fortran/symbol.c:3994 0x6007d4 resolve_types ../../gcc/fortran/resolve.c:15948 0x5fc3e4 gfc_resolve ../../gcc/fortran/resolve.c:16061 0x5e70b2 resolve_all_program_units ../../gcc/fortran/parse.c:5977 0x5e70b2 gfc_parse_file() ../../gcc/fortran/parse.c:6224 0x629da2 gfc_be_parse_file ../../gcc/fortran/f95-lang.c:202 Andreas.
On Sat, Dec 03, 2016 at 05:58:02PM +0100, Andreas Schwab wrote: > On Dez 01 2016, Steve Kargl <sgk@troutmask.apl.washington.edu> wrote: > > > PR fortran/78618 > > * gfortran.dg/char_conversion.f90: New test. > > That test still crashes the compiler on m68k: > > 0xb40a7f crash_signal > ../../gcc/toplev.c:333 > 0x58dd52 gfc_is_constant_expr(gfc_expr*) > ../../gcc/fortran/expr.c:899 > 0x5feb90 resolve_fl_procedure > ../../gcc/fortran/resolve.c:12013 Yes, we know. I've reopen the PR; see audit trail. It seems to be a used-after-freed issue, but I've been unable to track down the issue.
Index: gcc/fortran/check.c =================================================================== --- gcc/fortran/check.c (revision 243142) +++ gcc/fortran/check.c (working copy) @@ -3667,7 +3667,7 @@ gfc_check_range (gfc_expr *x) bool -gfc_check_rank (gfc_expr *a ATTRIBUTE_UNUSED) +gfc_check_rank (gfc_expr *a) { /* Any data object is allowed; a "data object" is a "constant (4.1.3), variable (6), or subobject of a constant (2.4.3.2.3)" (F2008, 1.3.45). */ @@ -3676,9 +3676,16 @@ gfc_check_rank (gfc_expr *a ATTRIBUTE_UN /* Functions returning pointers are regarded as variable, cf. F2008, R602. */ if (a->expr_type == EXPR_FUNCTION) - is_variable = a->value.function.esym - ? a->value.function.esym->result->attr.pointer - : a->symtree->n.sym->result->attr.pointer; + { + if (a->value.function.esym) + is_variable = a->value.function.esym->result->attr.pointer; + else if (a->symtree->n.sym->result) + is_variable = a->symtree->n.sym->result->attr.pointer; + else if (a->symtree->n.sym->value) + is_variable = true; + else + gfc_internal_error ("gfc_check_rank(): invalid function result"); + } if (a->expr_type == EXPR_OP || a->expr_type == EXPR_NULL || a->expr_type == EXPR_COMPCALL|| a->expr_type == EXPR_PPC Index: gcc/fortran/simplify.c =================================================================== --- gcc/fortran/simplify.c (revision 243142) +++ gcc/fortran/simplify.c (working copy) @@ -7148,7 +7148,7 @@ gfc_convert_char_constant (gfc_expr *e, if (!gfc_check_character_range (result->value.character.string[i], kind)) { - gfc_error ("Character %qs in string at %L cannot be converted " + gfc_error_now ("Character %qs in string at %L cannot be converted " "into character kind %d", gfc_print_wide_char (result->value.character.string[i]), &e->where, kind); Index: gcc/testsuite/gfortran.dg/char_conversion.f90 =================================================================== --- gcc/testsuite/gfortran.dg/char_conversion.f90 (nonexistent) +++ gcc/testsuite/gfortran.dg/char_conversion.f90 (working copy) @@ -0,0 +1,6 @@ +! { dg-do compile } +! PR fortran/78618 +program p + character, parameter :: c = char(256,4) ! { dg-error "cannot be converted" } + if (rank(c) /= 0) call abort +end