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Re: [gimplefe] "Unknown tree: c_maybe_const_expr" error while parsing conditional expression
On 11 August 2016 at 15:58, Richard Biener <richard.guenther@gmail.com> wrote:
> On Thu, Aug 11, 2016 at 7:47 AM, Prasad Ghangal
> <prasad.ghangal@gmail.com> wrote:
>> In this patch I am trying to parse gimple call. But I am getting weird
>> gimple dump for that.
>>
>> for this testcase:
>> int __GIMPLE() bar()
>> {
>> int a;
>> a = a + 1;
>> return a;
>> }
>>
>> void __GIMPLE() foo()
>> {
>> int b;
>> b = bar();
>> }
>>
>> I am getting ssa dump as:
>>
>> /* Function bar (bar, funcdef_no=0, decl_uid=1744, cgraph_uid=0,
>> symbol_order=0)*/
>>
>> int
>> bar ()
>> {
>> struct FRAME.bar FRAME.0;
>> int a;
>> void * D_1754;
>> void * _3;
>>
>> bb_2:
>> _3 = __builtin_dwarf_cfa (0);
>> FRAME.0.FRAME_BASE.PARENT = _3;
>> a_6 = a_5(D) + 1;
>> return a_6;
>>
>> }
>>
>>
>>
>> /* Function foo (foo, funcdef_no=1, decl_uid=1747, cgraph_uid=1,
>> symbol_order=1)*/
>>
>> void
>> foo ()
>> {
>> int b;
>>
>> bb_2:
>> b_3 = bar ();
>> return;
>>
>> }
>>
>
> Somehow foo is treated as nested in bar. Note this even happens
> without calls if you
> have two functions in the testcase. Usually this means after
> finishing parsing of a function
> you fail to reset. Looks like the following fixes it:
>
> diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
> index 95615bc..b35eada 100644
> --- a/gcc/c/c-parser.c
> +++ b/gcc/c/c-parser.c
> @@ -2164,6 +2165,8 @@ c_parser_declaration_or_fndef (c_parser *parser, bool fnde
> f_ok,
> c_parser_parse_gimple_body (parser);
> in_late_binary_op = saved;
> cgraph_node::finalize_function (current_function_decl, false);
> + set_cfun (NULL);
> + current_function_decl = NULL;
> timevar_pop (tv);
> return;
> }
>
> Richard.
>
I have updated the patch and committed along with testcases
Thanks,
Prasad
>>
>> On 9 August 2016 at 14:37, Richard Biener <richard.guenther@gmail.com> wrote:
>>> On Sun, Aug 7, 2016 at 3:19 PM, Prasad Ghangal <prasad.ghangal@gmail.com> wrote:
>>>> On 4 August 2016 at 18:29, Richard Biener <richard.guenther@gmail.com> wrote:
>>>>> On Thu, Aug 4, 2016 at 1:31 PM, Prasad Ghangal <prasad.ghangal@gmail.com> wrote:
>>>>>> On 2 August 2016 at 14:29, Richard Biener <richard.guenther@gmail.com> wrote:
>>>>>>> On Mon, Aug 1, 2016 at 4:52 PM, Prasad Ghangal <prasad.ghangal@gmail.com> wrote:
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> I am trying to replace c_parser_paren_condition (parser) in
>>>>>>>> c_parser_gimple_if_stmt by c_parser_gimple_paren_condition (parser) as
>>>>>>>> described in the patch
>>>>>>>>
>>>>>>>> I am trying test case
>>>>>>>> void __GIMPLE () foo ()
>>>>>>>> {
>>>>>>>> int a;
>>>>>>>> bb_2:
>>>>>>>> if (a == 2)
>>>>>>>> goto bb_3;
>>>>>>>> else
>>>>>>>> goto bb_4;
>>>>>>>> bb_3:
>>>>>>>> a_2 = 4;
>>>>>>>> bb_4:
>>>>>>>> return;
>>>>>>>> }
>>>>>>>>
>>>>>>>> but it fails to parse gimple expression and produces error as
>>>>>>>> /home/prasad/test3.c: In function ‘foo’:
>>>>>>>> /home/prasad/test3.c:1:18: error: invalid operands in gimple comparison
>>>>>>>> void __GIMPLE () foo ()
>>>>>>>> ^~~
>>>>>>>> if (<<< Unknown tree: c_maybe_const_expr
>>>>>>>>
>>>>>>>> a >>> == 2) goto bb_3; else goto bb_4;
>>>>>>>> /home/prasad/test3.c:1:18: internal compiler error: verify_gimple failed
>>>>>>>>
>>>>>>>> I failed to debug where it is setting to C_MAYBE_CONST_EXPR
>>>>>>>
>>>>>>> It's in parsing the binary expression. Btw, you don't need lvalue_to_rvalue
>>>>>>> conversion or truthvalue conversion - source that would require this would
>>>>>>> not be valid GIMPLE. Let me try to debug:
>>>>>>>
>>>>>>>
>>>>>>> (gdb) p debug_tree (cond.value)
>>>>>>> <eq_expr 0x7ffff6997960
>>>>>>> type <integer_type 0x7ffff688b7e0 int public SI
>>>>>>> size <integer_cst 0x7ffff6887ee8 constant 32>
>>>>>>> unit size <integer_cst 0x7ffff6887f00 constant 4>
>>>>>>> align 32 symtab 0 alias set -1 canonical type 0x7ffff688b7e0
>>>>>>> precision 32 min <integer_cst 0x7ffff6887ea0 -2147483648> max
>>>>>>> <integer_cst 0x7ffff6887eb8 2147483647>
>>>>>>> pointer_to_this <pointer_type 0x7ffff68a5930>>
>>>>>>>
>>>>>>> arg 0 <c_maybe_const_expr 0x7ffff6997938 type <integer_type
>>>>>>> 0x7ffff688b7e0 int>
>>>>>>>
>>>>>>> arg 1 <var_decl 0x7ffff7fefcf0 a type <integer_type 0x7ffff688b7e0 int>
>>>>>>> used SI file t.c line 3 col 7 size <integer_cst
>>>>>>> 0x7ffff6887ee8 32> unit size <integer_cst 0x7ffff6887f00 4>
>>>>>>> align 32 context <function_decl 0x7ffff699c500 foo>>>
>>>>>>> arg 1 <integer_cst 0x7ffff68a4318 type <integer_type
>>>>>>> 0x7ffff688b7e0 int> constant 2>
>>>>>>> t.c:5:9 start: t.c:5:7 finish: t.c:5:12>
>>>>>>> $5 = void
>>>>>>> (gdb) b ggc-page.c:1444 if result == 0x7ffff6997938
>>>>>>> Breakpoint 6 at 0x8a0d3e: file
>>>>>>> /space/rguenther/src/gcc_gimple_fe/gcc/ggc-page.c, line 1444.
>>>>>>> (gdb) run
>>>>>>>
>>>>>>> Breakpoint 6, ggc_internal_alloc (size=40, f=0x0, s=0, n=1)
>>>>>>> at /space/rguenther/src/gcc_gimple_fe/gcc/ggc-page.c:1444
>>>>>>> 1444 return result;
>>>>>>> (gdb) fin (a few times)
>>>>>>> Run till exit from #0 0x00000000011821b7 in build2_stat (
>>>>>>> code=C_MAYBE_CONST_EXPR, tt=<integer_type 0x7ffff688b7e0 int>,
>>>>>>> arg0=<tree 0x0>, arg1=<var_decl 0x7ffff7fefcf0 a>)
>>>>>>> at /space/rguenther/src/gcc_gimple_fe/gcc/tree.c:4466
>>>>>>> 0x000000000081d263 in c_wrap_maybe_const (expr=<var_decl 0x7ffff7fefcf0 a>,
>>>>>>> non_const=false)
>>>>>>> at /space/rguenther/src/gcc_gimple_fe/gcc/c-family/c-common.c:4359
>>>>>>> 4359 expr = build2 (C_MAYBE_CONST_EXPR, TREE_TYPE (expr), NULL, expr);
>>>>>>> Value returned is $11 = (tree_node *) 0x7ffff6997938
>>>>>>> (gdb) up
>>>>>>> #1 0x00000000007b8e81 in build_binary_op (location=176833, code=EQ_EXPR,
>>>>>>> orig_op0=<var_decl 0x7ffff7fefcf0 a>,
>>>>>>> orig_op1=<integer_cst 0x7ffff68a4318>, convert_p=1)
>>>>>>> at /space/rguenther/src/gcc_gimple_fe/gcc/c/c-typeck.c:11549
>>>>>>> 11549 op0 = c_wrap_maybe_const (op0, !op0_maybe_const);
>>>>>>>
>>>>>>> and this is guarded by !in_late_binary_op (which also seems to guard folding).
>>>>>>> So I suggest to somewhere at the start of parsing to set in_late_binary_op to
>>>>>>> true for -fgimple. Not sure if it works for everything, but you
>>>>>>> should have accumulated
>>>>>>> quite some tests for -fgimple in the testsuite to make sure it doesn't
>>>>>>> regress anything.
>>>>>>>
>>>>>> I did bootstrap build for the trunk and testing is in progress. How
>>>>>> can I test with -fgimple flag enabled?
>>>>>
>>>>> You can do
>>>>>
>>>>> make check-gcc RUNTESTFLAGS="--target_board=unix/-fgimple"
>>>>>
>>>>> Richard.
>>>>>
>>>> I was comparing result from latest commit and "gcc initial version". I
>>>> found most of the testcases failed due to modified gimple dump.
>>>
>>> Good, that's expected. Can you wrap up as for how is the status on
>>> the project schedule? As said, adding more testcases would be good
>>> for the SSA parsing feature. A big part missing is now is parsing of
>>> function calls?
>>>
>>> Thanks,
>>> Richard.
>>>
>>>>
>>>> Thanks,
>>>> Prasad
>>>>
>>>>>>
>>>>>> Thanks,
>>>>>> Prasad
>>>>>>> The following works for me:
>>>>>>>
>>>>>>> diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
>>>>>>> index 70800a2..c8c087a 100644
>>>>>>> --- a/gcc/c/c-parser.c
>>>>>>> +++ b/gcc/c/c-parser.c
>>>>>>> @@ -2158,7 +2159,10 @@ c_parser_declaration_or_fndef (c_parser
>>>>>>> *parser, bool fndef_ok,
>>>>>>>
>>>>>>> if (gimple_body_p && flag_gimple)
>>>>>>> {
>>>>>>> + bool saved = in_late_binary_op;
>>>>>>> + in_late_binary_op = true;
>>>>>>> c_parser_parse_gimple_body (parser);
>>>>>>> + in_late_binary_op = saved;
>>>>>>> cgraph_node::finalize_function (current_function_decl, false);
>>>>>>> timevar_pop (tv);
>>>>>>> return;
>>>>>>>
>>>>>>>
>>>>>>> Richard.
>>>>>>>
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Prasad