[PING^2] Re: [PATCH] analyzer: deal with -fshort-enums

[Torbjorn SVENSSON <torbjorn.svensson@foss.st.com>]

Ping!

Kind regards,
Torbjörn

On 2024-02-22 09:51, Torbjorn SVENSSON wrote:
> Ping!
> 
> Kind regards,
> Torbjörn
> 
> On 2024-02-07 17:21, Torbjorn SVENSSON wrote:
>> Hi,
>>
>> Is it okay to backport 3cbab07b08d2f3a3ed34b6ec12e67727c59d285c to 
>> releases/gcc-13?
>>
>> Without this backport, I see these failures on arm-none-eabi:
>>
>> FAIL: gcc.dg/analyzer/switch-enum-1.c  (test for bogus messages, line 26)
>> FAIL: gcc.dg/analyzer/switch-enum-1.c  (test for bogus messages, line 44)
>> FAIL: gcc.dg/analyzer/switch-enum-2.c  (test for bogus messages, line 34)
>> FAIL: gcc.dg/analyzer/switch-enum-2.c  (test for bogus messages, line 52)
>> FAIL: gcc.dg/analyzer/torture/switch-enum-pr105273-doom-p_floor.c   
>> -O0   (test for bogus messages, line 82)
>> FAIL: gcc.dg/analyzer/torture/switch-enum-pr105273-doom-p_maputl.c   
>> -O0    (test for bogus messages, line 83)
>>
>> Kind regards,
>> Torbjörn
>>
>>
>> On 2023-12-06 23:22, David Malcolm wrote:
>>> On Wed, 2023-12-06 at 02:31 -0300, Alexandre Oliva wrote:
>>>> On Nov 22, 2023, Alexandre Oliva <oliva@adacore.com> wrote:
>>>>
>>>>> Ah, nice, that's a great idea, I wish I'd thought of that!  Will
>>>>> do.
>>>>
>>>> Sorry it took me so long, here it is.  I added two tests, so that,
>>>> regardless of the defaults, we get both circumstances tested, without
>>>> repetition.
>>>>
>>>> Regstrapped on x86_64-linux-gnu.  Also tested on arm-eabi.  Ok to
>>>> install?
>>>
>>> Thanks for the updated patch.
>>>
>>> Looks good to me.
>>>
>>> Dave
>>>
>>>>
>>>>
>>>> analyzer: deal with -fshort-enums
>>>>
>>>> On platforms that enable -fshort-enums by default, various switch-
>>>> enum
>>>> analyzer tests fail, because apply_constraints_for_gswitch doesn't
>>>> expect the integral promotion type cast.  I've arranged for the code
>>>> to cope with those casts.
>>>>
>>>>
>>>> for  gcc/analyzer/ChangeLog
>>>>
>>>>          * region-model.cc (has_nondefault_case_for_value_p): Take
>>>>          enumerate type as a parameter.
>>>>          (region_model::apply_constraints_for_gswitch): Cope with
>>>>          integral promotion type casts.
>>>>
>>>> for  gcc/testsuite/ChangeLog
>>>>
>>>>          * gcc.dg/analyzer/switch-short-enum-1.c: New.
>>>>          * gcc.dg/analyzer/switch-no-short-enum-1.c: New.
>>>> ---
>>>>   gcc/analyzer/region-model.cc                       |   27 +++-
>>>>   .../gcc.dg/analyzer/switch-no-short-enum-1.c       |  141
>>>> ++++++++++++++++++++
>>>>   .../gcc.dg/analyzer/switch-short-enum-1.c          |  140
>>>> ++++++++++++++++++++
>>>>   3 files changed, 304 insertions(+), 4 deletions(-)
>>>>   create mode 100644 gcc/testsuite/gcc.dg/analyzer/switch-no-short-
>>>> enum-1.c
>>>>   create mode 100644 gcc/testsuite/gcc.dg/analyzer/switch-short-enum-
>>>> 1.c
>>>>
>>>> diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-
>>>> model.cc
>>>> index 2157ad2578b85..6a7a8bc9f4884 100644
>>>> --- a/gcc/analyzer/region-model.cc
>>>> +++ b/gcc/analyzer/region-model.cc
>>>> @@ -5387,10 +5387,10 @@ has_nondefault_case_for_value_p (const
>>>> gswitch *switch_stmt, tree int_cst)
>>>>      has nondefault cases handling all values in the enum.  */
>>>>   static bool
>>>> -has_nondefault_cases_for_all_enum_values_p (const gswitch
>>>> *switch_stmt)
>>>> +has_nondefault_cases_for_all_enum_values_p (const gswitch
>>>> *switch_stmt,
>>>> +                                           tree type)
>>>>   {
>>>>     gcc_assert (switch_stmt);
>>>> -  tree type = TREE_TYPE (gimple_switch_index (switch_stmt));
>>>>     gcc_assert (TREE_CODE (type) == ENUMERAL_TYPE);
>>>>     for (tree enum_val_iter = TYPE_VALUES (type);
>>>> @@ -5426,6 +5426,23 @@ apply_constraints_for_gswitch (const
>>>> switch_cfg_superedge &edge,
>>>>   {
>>>>     tree index  = gimple_switch_index (switch_stmt);
>>>>     const svalue *index_sval = get_rvalue (index, ctxt);
>>>> +  bool check_index_type = true;
>>>> +
>>>> +  /* With -fshort-enum, there may be a type cast.  */
>>>> +  if (ctxt && index_sval->get_kind () == SK_UNARYOP
>>>> +      && TREE_CODE (index_sval->get_type ()) == INTEGER_TYPE)
>>>> +    {
>>>> +      const unaryop_svalue *unaryop = as_a <const unaryop_svalue *>
>>>> (index_sval);
>>>> +      if (unaryop->get_op () == NOP_EXPR
>>>> +         && is_a <const initial_svalue *> (unaryop->get_arg ()))
>>>> +       if (const initial_svalue *initvalop = (as_a <const
>>>> initial_svalue *>
>>>> +                                              (unaryop->get_arg
>>>> ())))
>>>> +         if (TREE_CODE (initvalop->get_type ()) == ENUMERAL_TYPE)
>>>> +           {
>>>> +             index_sval = initvalop;
>>>> +             check_index_type = false;
>>>> +           }
>>>> +    }
>>>>     /* If we're switching based on an enum type, assume that the user
>>>> is only
>>>>        working with values from the enum.  Hence if this is an
>>>> @@ -5437,12 +5454,14 @@ apply_constraints_for_gswitch (const
>>>> switch_cfg_superedge &edge,
>>>>         ctxt
>>>>         /* Must be an enum value.  */
>>>>         && index_sval->get_type ()
>>>> -      && TREE_CODE (TREE_TYPE (index)) == ENUMERAL_TYPE
>>>> +      && (!check_index_type
>>>> +         || TREE_CODE (TREE_TYPE (index)) == ENUMERAL_TYPE)
>>>>         && TREE_CODE (index_sval->get_type ()) == ENUMERAL_TYPE
>>>>         /* If we have a constant, then we can check it directly.  */
>>>>         && index_sval->get_kind () != SK_CONSTANT
>>>>         && edge.implicitly_created_default_p ()
>>>> -      && has_nondefault_cases_for_all_enum_values_p (switch_stmt)
>>>> +      && has_nondefault_cases_for_all_enum_values_p (switch_stmt,
>>>> +                                                    index_sval-
>>>>> get_type ())
>>>>         /* Don't do this if there's a chance that the index is
>>>>           attacker-controlled.  */
>>>>         && !ctxt->possibly_tainted_p (index_sval))
>>>> diff --git a/gcc/testsuite/gcc.dg/analyzer/switch-no-short-enum-1.c
>>>> b/gcc/testsuite/gcc.dg/analyzer/switch-no-short-enum-1.c
>>>> new file mode 100644
>>>> index 0000000000000..98f6d91f97481
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/analyzer/switch-no-short-enum-1.c
>>>> @@ -0,0 +1,141 @@
>>>> +/* { dg-do compile } */
>>>> +/* { dg-additional-options "-fno-short-enums" } */
>>>> +/* { dg-skip-if "default" { ! short_enums } } */
>>>> +
>>>> +#include "analyzer-decls.h"
>>>> +
>>>> +/* Verify the handling of "switch (enum_value)".  */
>>>> +
>>>> +enum e
>>>> +{
>>>> + E_VAL0,
>>>> + E_VAL1,
>>>> + E_VAL2
>>>> +};
>>>> +
>>>> +/* Verify that we assume that "switch (enum)" doesn't follow
>>>> implicit
>>>> +   "default" if all enum values have cases  */
>>>> +
>>>> +int test_all_values_covered_implicit_default_1 (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    case E_VAL2:
>>>> +      return 1945;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-bogus "path" } */
>>>> +}
>>>> +
>>>> +int test_all_values_covered_implicit_default_2 (enum e x)
>>>> +{
>>>> +  int result;
>>>> +  switch (x)
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      result = 1066;
>>>> +      break;
>>>> +    case E_VAL1:
>>>> +      result = 1776;
>>>> +      break;
>>>> +    case E_VAL2:
>>>> +      result = 1945;
>>>> +      break;
>>>> +    }
>>>> +  return result; /* { dg-bogus "uninitialized" } */
>>>> +}
>>>> +
>>>> +/* Verify that we consider paths that use the implicit default when
>>>> not
>>>> +   all enum values are covered by cases.  */
>>>> +
>>>> +int test_missing_values_implicit_default_1 (enum e x)
>>>> +{
>>>> +  switch (x) /* { dg-message "following 'default:' branch" } */
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-message "path" } */
>>>> +  return 0;
>>>> +}
>>>> +
>>>> +int test_missing_values_implicit_default_2 (enum e x)
>>>> +{
>>>> +  int result;
>>>> +  switch (x) /* { dg-message "following 'default:' branch" } */
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      result = 1066;
>>>> +      break;
>>>> +    case E_VAL1:
>>>> +      result = 1776;
>>>> +      break;
>>>> +    }
>>>> +  return result; /* { dg-warning "uninitialized" } */
>>>> +}
>>>> +
>>>> +/* Verify that explicit "default" isn't rejected.  */
>>>> +
>>>> +int test_all_values_covered_explicit_default_1 (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    case E_VAL2:
>>>> +      return 1945;
>>>> +    default:
>>>> +      __analyzer_dump_path (); /* { dg-message "path" } */
>>>> +      return 0;
>>>> +    }
>>>> +}
>>>> +
>>>> +int test_missing_values_explicit_default_1 (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    default:
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-bogus "path" } */
>>>> +  return 0;
>>>> +}
>>>> +
>>>> +int test_missing_values_explicit_default_2 (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    default:
>>>> +      __analyzer_dump_path (); /* { dg-message "path" } */
>>>> +      return 1945;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-bogus "path" } */
>>>> +  return 0;
>>>> +}
>>>> +
>>>> +int test_just_default (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    default:
>>>> +      __analyzer_dump_path (); /* { dg-message "path" } */
>>>> +      return 42;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-bogus "path" } */
>>>> +  return 0;
>>>> +}
>>>> +
>>>> diff --git a/gcc/testsuite/gcc.dg/analyzer/switch-short-enum-1.c
>>>> b/gcc/testsuite/gcc.dg/analyzer/switch-short-enum-1.c
>>>> new file mode 100644
>>>> index 0000000000000..384113fde5cbf
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/gcc.dg/analyzer/switch-short-enum-1.c
>>>> @@ -0,0 +1,140 @@
>>>> +/* { dg-do compile } */
>>>> +/* { dg-additional-options "-fshort-enums" } */
>>>> +/* { dg-skip-if "default" { short_enums } } */
>>>> +
>>>> +#include "analyzer-decls.h"
>>>> +
>>>> +/* Verify the handling of "switch (enum_value)".  */
>>>> +
>>>> +enum e
>>>> +{
>>>> + E_VAL0,
>>>> + E_VAL1,
>>>> + E_VAL2
>>>> +};
>>>> +
>>>> +/* Verify that we assume that "switch (enum)" doesn't follow
>>>> implicit
>>>> +   "default" if all enum values have cases  */
>>>> +
>>>> +int test_all_values_covered_implicit_default_1 (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    case E_VAL2:
>>>> +      return 1945;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-bogus "path" } */
>>>> +}
>>>> +
>>>> +int test_all_values_covered_implicit_default_2 (enum e x)
>>>> +{
>>>> +  int result;
>>>> +  switch (x)
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      result = 1066;
>>>> +      break;
>>>> +    case E_VAL1:
>>>> +      result = 1776;
>>>> +      break;
>>>> +    case E_VAL2:
>>>> +      result = 1945;
>>>> +      break;
>>>> +    }
>>>> +  return result; /* { dg-bogus "uninitialized" } */
>>>> +}
>>>> +
>>>> +/* Verify that we consider paths that use the implicit default when
>>>> not
>>>> +   all enum values are covered by cases.  */
>>>> +
>>>> +int test_missing_values_implicit_default_1 (enum e x)
>>>> +{
>>>> +  switch (x) /* { dg-message "following 'default:' branch" } */
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-message "path" } */
>>>> +  return 0;
>>>> +}
>>>> +
>>>> +int test_missing_values_implicit_default_2 (enum e x)
>>>> +{
>>>> +  int result;
>>>> +  switch (x) /* { dg-message "following 'default:' branch" } */
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      result = 1066;
>>>> +      break;
>>>> +    case E_VAL1:
>>>> +      result = 1776;
>>>> +      break;
>>>> +    }
>>>> +  return result; /* { dg-warning "uninitialized" } */
>>>> +}
>>>> +
>>>> +/* Verify that explicit "default" isn't rejected.  */
>>>> +
>>>> +int test_all_values_covered_explicit_default_1 (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    case E_VAL2:
>>>> +      return 1945;
>>>> +    default:
>>>> +      __analyzer_dump_path (); /* { dg-message "path" } */
>>>> +      return 0;
>>>> +    }
>>>> +}
>>>> +
>>>> +int test_missing_values_explicit_default_1 (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    default:
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-bogus "path" } */
>>>> +  return 0;
>>>> +}
>>>> +
>>>> +int test_missing_values_explicit_default_2 (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    case E_VAL0:
>>>> +      return 1066;
>>>> +    case E_VAL1:
>>>> +      return 1776;
>>>> +    default:
>>>> +      __analyzer_dump_path (); /* { dg-message "path" } */
>>>> +      return 1945;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-bogus "path" } */
>>>> +  return 0;
>>>> +}
>>>> +
>>>> +int test_just_default (enum e x)
>>>> +{
>>>> +  switch (x)
>>>> +    {
>>>> +    default:
>>>> +      __analyzer_dump_path (); /* { dg-message "path" } */
>>>> +      return 42;
>>>> +    }
>>>> +  __analyzer_dump_path (); /* { dg-bogus "path" } */
>>>> +  return 0;
>>>> +}
>>>>
>>>>
>>>