Re: [PATCH][gcc] libgccjit: handle long literals in playback::context::new_string_literal

[Andrea Corallo <Andrea.Corallo@arm.com>]

> Andrea Corallo writes:
>
>> Andrea Corallo writes:
>>
>>> Andrea Corallo writes:
>>>
>>>> Hi all,
>>>> yesterday I've found an interesting bug in libgccjit.
>>>> Seems we have an hard limitation of 200 characters for literal strings.
>>>> Attempting to create longer strings lead to ICE during pass_expand
>>>> while performing a sanity check in get_constant_size.
>>>>
>>>> Tracking down the issue seems the code we have was inspired from
>>>> c-family/c-common.c:c_common_nodes_and_builtins were array_domain_type
>>>> is actually defined with a size of 200.
>>>> The comment that follows that point sounded premonitory :) :)
>>>>
>>>> /* Make a type for arrays of characters.
>>>>    With luck nothing will ever really depend on the length of this
>>>>    array type.  */
>>>>
>>>> At least in the current implementation the type is set by
>>>> fix_string_type were the actual string length is taken in account.
>>>>
>>>> I attach a patch updating the logic accordingly and a new testcase
>>>>  for that.
>>>>
>>>> make check-jit is passing clean.
>>>>
>>>> Best Regards
>>>>   Andrea
>>>>
>>>> gcc/jit/ChangeLog
>>>> 2019-??-??  Andrea Corallo  <andrea.corallo@arm.com>
>>>>
>>>> 	* jit-playback.h
>>>> 	(gcc::jit::recording::context m_recording_ctxt): Remove
>>>> 	m_char_array_type_node field.
>>>> 	* jit-playback.c
>>>> 	(playback::context::context) Remove m_char_array_type_node from member
>>>> 	initializer list.
>>>> 	(playback::context::new_string_literal) Fix logic to handle string
>>>> 	length > 200.
>>>>
>>>> gcc/testsuite/ChangeLog
>>>> 2019-??-??  Andrea Corallo  <andrea.corallo@arm.com>
>>>>
>>>> 	* jit.dg/all-non-failing-tests.h: Add test-long-string-literal.c.
>>>> 	* jit.dg/test-long-string-literal.c: New testcase.
>>>> diff --git a/gcc/jit/jit-playback.c b/gcc/jit/jit-playback.c
>>>> index 9eeb2a7..a26b8d3 100644
>>>> --- a/gcc/jit/jit-playback.c
>>>> +++ b/gcc/jit/jit-playback.c
>>>> @@ -88,7 +88,6 @@ playback::context::context (recording::context *ctxt)
>>>>    : log_user (ctxt->get_logger ()),
>>>>      m_recording_ctxt (ctxt),
>>>>      m_tempdir (NULL),
>>>> -    m_char_array_type_node (NULL),
>>>>      m_const_char_ptr (NULL)
>>>>  {
>>>>    JIT_LOG_SCOPE (get_logger ());
>>>> @@ -670,9 +669,12 @@ playback::rvalue *
>>>>  playback::context::
>>>>  new_string_literal (const char *value)
>>>>  {
>>>> -  tree t_str = build_string (strlen (value), value);
>>>> -  gcc_assert (m_char_array_type_node);
>>>> -  TREE_TYPE (t_str) = m_char_array_type_node;
>>>> +  /* Compare with c-family/c-common.c: fix_string_type.  */
>>>> +  size_t len = strlen (value);
>>>> +  tree i_type = build_index_type (size_int (len));
>>>> +  tree a_type = build_array_type (char_type_node, i_type);
>>>> +  tree t_str = build_string (len, value);
>>>> +  TREE_TYPE (t_str) = a_type;
>>>>
>>>>    /* Convert to (const char*), loosely based on
>>>>       c/c-typeck.c: array_to_pointer_conversion,
>>>> @@ -2703,10 +2705,6 @@ playback::context::
>>>>  replay ()
>>>>  {
>>>>    JIT_LOG_SCOPE (get_logger ());
>>>> -  /* Adapted from c-common.c:c_common_nodes_and_builtins.  */
>>>> -  tree array_domain_type = build_index_type (size_int (200));
>>>> -  m_char_array_type_node
>>>> -    = build_array_type (char_type_node, array_domain_type);
>>>>
>>>>    m_const_char_ptr
>>>>      = build_pointer_type (build_qualified_type (char_type_node,
>>>> diff --git a/gcc/jit/jit-playback.h b/gcc/jit/jit-playback.h
>>>> index d4b148e..801f610 100644
>>>> --- a/gcc/jit/jit-playback.h
>>>> +++ b/gcc/jit/jit-playback.h
>>>> @@ -322,7 +322,6 @@ private:
>>>>
>>>>    auto_vec<function *> m_functions;
>>>>    auto_vec<tree> m_globals;
>>>> -  tree m_char_array_type_node;
>>>>    tree m_const_char_ptr;
>>>>
>>>>    /* Source location handling.  */
>>>> diff --git a/gcc/testsuite/jit.dg/all-non-failing-tests.h b/gcc/testsuite/jit.dg/all-non-failing-tests.h
>>>> index 0272e6f8..1b3d561 100644
>>>> --- a/gcc/testsuite/jit.dg/all-non-failing-tests.h
>>>> +++ b/gcc/testsuite/jit.dg/all-non-failing-tests.h
>>>> @@ -220,6 +220,13 @@
>>>>  #undef create_code
>>>>  #undef verify_code
>>>>
>>>> +/* test-long-string-literal.c */
>>>> +#define create_code create_code_long_string_literal
>>>> +#define verify_code verify_code_long_string_literal
>>>> +#include "test-long-string-literal.c"
>>>> +#undef create_code
>>>> +#undef verify_code
>>>> +
>>>>  /* test-sum-of-squares.c */
>>>>  #define create_code create_code_sum_of_squares
>>>>  #define verify_code verify_code_sum_of_squares
>>>> diff --git a/gcc/testsuite/jit.dg/test-long-string-literal.c b/gcc/testsuite/jit.dg/test-long-string-literal.c
>>>> new file mode 100644
>>>> index 0000000..882567c
>>>> --- /dev/null
>>>> +++ b/gcc/testsuite/jit.dg/test-long-string-literal.c
>>>> @@ -0,0 +1,48 @@
>>>> +#include <stdlib.h>
>>>> +#include <stdio.h>
>>>> +#include <string.h>
>>>> +
>>>> +#include "libgccjit.h"
>>>> +
>>>> +#include "harness.h"
>>>> +
>>>> +const char very_long_string[] =
>>>> +  "abcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabc"
>>>> +  "abcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabc"
>>>> +  "abcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabcabc"
>>>> +  "abcabcabcabcabcabcabcabcabcabca";
>>>> +
>>>> +void
>>>> +create_code (gcc_jit_context *ctxt, void *user_data)
>>>> +{
>>>> +  /* Build the test_fn.  */
>>>> +  gcc_jit_function *f =
>>>> +    gcc_jit_context_new_function (
>>>> +      ctxt, NULL,
>>>> +      GCC_JIT_FUNCTION_EXPORTED,
>>>> +      gcc_jit_context_get_type(ctxt,
>>>> +			       GCC_JIT_TYPE_CONST_CHAR_PTR),
>>>> +				"test_long_string_literal",
>>>> +				0, NULL, 0);
>>>> +  gcc_jit_block *blk =
>>>> +    gcc_jit_function_new_block (f, "init_block");
>>>> +  gcc_jit_rvalue *res =
>>>> +    gcc_jit_context_new_string_literal (ctxt, very_long_string);
>>>> +
>>>> +  gcc_jit_block_end_with_return (blk, NULL, res);
>>>> +}
>>>> +
>>>> +void
>>>> +verify_code (gcc_jit_context *ctxt, gcc_jit_result *result)
>>>> +{
>>>> +  typedef const char *(*fn_type) (void);
>>>> +  CHECK_NON_NULL (result);
>>>> +  fn_type test_long_string_literal =
>>>> +    (fn_type)gcc_jit_result_get_code (result, "test_long_string_literal");
>>>> +  CHECK_NON_NULL (test_long_string_literal);
>>>> +
>>>> +  /* Call the JIT-generated function.  */
>>>> +  const char *str = test_long_string_literal ();
>>>> +  CHECK_NON_NULL (str);
>>>> +  CHECK_VALUE (strcmp (str, very_long_string), 0);
>>>> +}
>>>
>>> Kindly pinging
>>>
>>> Bests
>>>   Andrea
>>
>> Hi,
>> I'd like to ping this patch.
>>
>> Bests
>>  Andrea
>
> Pinging again.
>
> Bests
>   Andrea
> ----------

Ping