Expensive selftests: torture testing for fix-it boundary conditions (PR c/82050)

This patch adds selftest coverage for the fix for PR c/82050 (r255214).

The selftest iterates over various "interesting" column and line-width
values to try to shake out bugs in the fix-it printing routines, a kind
of "torture" selftest.

Unfortunately this selftest is noticably slower than the other selftests;
adding it to diagnostic-show-locus.c led to:
  -fself-test: 40218 pass(es) in 0.172000 seconds
slowing down to:
  -fself-test: 97315 pass(es) in 6.109000 seconds
for an unoptimized build (e.g. when hacking with --disable-bootstrap).

Given that this affects the compile-edit-test cycle of the "gcc"
subdirectory, this felt like an unacceptable amount of overhead to add.

I attempted to optimize the test by reducing the amount of coverage, but
the test seems useful, and there seems to be a valid role for "torture"
selftests.

Hence this patch adds a:
  gcc.dg/plugin/expensive_selftests_plugin.c
with the responsibility for running "expensive" selftests, and adds the
expensive test there.  The patch moves a small amount of code from
selftest::run_tests into a helper class so that the plugin can print
a useful summary line (to reassure us that the tests are actually being
run).

With that, the compile-edit-test cycle of the "gcc" subdir is unaffected;
the plugin takes:
  expensive_selftests_plugin: 26641 pass(es) in 3.127000 seconds
which seems reasonable within the much longer time taken by "make check"
(I optimized some of the overhead away, hence the reduction from 6 seconds
above down to 3 seconds).

Successfully bootstrapped&regrtested on x86_64-pc-linux-gnu.

OK for trunk?

gcc/ChangeLog:
	PR c/82050
	* selftest-run-tests.c (selftest::run_tests): Move start/finish code
	to...
	* selftest.c (selftest::test_runner::test_runner): New ctor.
	(selftest::test_runner::~test_runner): New dtor.
	* selftest.h (class selftest::test_runner): New class.

gcc/testsuite/ChangeLog:
	PR c/82050
	* gcc.dg/plugin/expensive-selftests-1.c: New file.
	* gcc.dg/plugin/expensive_selftests_plugin.c: New file.
	* gcc.dg/plugin/plugin.exp (plugin_test_list): Add the above.
---
 gcc/selftest-run-tests.c                           |  11 +-
 gcc/selftest.c                                     |  22 +++
 gcc/selftest.h                                     |  14 ++
 .../gcc.dg/plugin/expensive-selftests-1.c          |   3 +
 .../gcc.dg/plugin/expensive_selftests_plugin.c     | 175 +++++++++++++++++++++
 gcc/testsuite/gcc.dg/plugin/plugin.exp             |   2 +
 6 files changed, 218 insertions(+), 9 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/plugin/expensive-selftests-1.c
 create mode 100644 gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.c

Ping: https://gcc.gnu.org/ml/gcc-patches/2017-11/msg02459.html

On Tue, 2017-11-28 at 14:31 -0500, David Malcolm wrote:
> This patch adds selftest coverage for the fix for PR c/82050
> (r255214).
> 
> The selftest iterates over various "interesting" column and line-
> width
> values to try to shake out bugs in the fix-it printing routines, a
> kind
> of "torture" selftest.
> 
> Unfortunately this selftest is noticably slower than the other
> selftests;
> adding it to diagnostic-show-locus.c led to:
>   -fself-test: 40218 pass(es) in 0.172000 seconds
> slowing down to:
>   -fself-test: 97315 pass(es) in 6.109000 seconds
> for an unoptimized build (e.g. when hacking with --disable-
> bootstrap).
> 
> Given that this affects the compile-edit-test cycle of the "gcc"
> subdirectory, this felt like an unacceptable amount of overhead to
> add.
> 
> I attempted to optimize the test by reducing the amount of coverage,
> but
> the test seems useful, and there seems to be a valid role for
> "torture"
> selftests.
> 
> Hence this patch adds a:
>   gcc.dg/plugin/expensive_selftests_plugin.c
> with the responsibility for running "expensive" selftests, and adds
> the
> expensive test there.  The patch moves a small amount of code from
> selftest::run_tests into a helper class so that the plugin can print
> a useful summary line (to reassure us that the tests are actually
> being
> run).
> 
> With that, the compile-edit-test cycle of the "gcc" subdir is
> unaffected;
> the plugin takes:
>   expensive_selftests_plugin: 26641 pass(es) in 3.127000 seconds
> which seems reasonable within the much longer time taken by "make
> check"
> (I optimized some of the overhead away, hence the reduction from 6
> seconds
> above down to 3 seconds).
> 
> Successfully bootstrapped&regrtested on x86_64-pc-linux-gnu.
> 
> OK for trunk?
> 
> gcc/ChangeLog:
> 	PR c/82050
> 	* selftest-run-tests.c (selftest::run_tests): Move start/finish
> code
> 	to...
> 	* selftest.c (selftest::test_runner::test_runner): New ctor.
> 	(selftest::test_runner::~test_runner): New dtor.
> 	* selftest.h (class selftest::test_runner): New class.
> 
> gcc/testsuite/ChangeLog:
> 	PR c/82050
> 	* gcc.dg/plugin/expensive-selftests-1.c: New file.
> 	* gcc.dg/plugin/expensive_selftests_plugin.c: New file.
> 	* gcc.dg/plugin/plugin.exp (plugin_test_list): Add the above.
> ---
>  gcc/selftest-run-tests.c                           |  11 +-
>  gcc/selftest.c                                     |  22 +++
>  gcc/selftest.h                                     |  14 ++
>  .../gcc.dg/plugin/expensive-selftests-1.c          |   3 +
>  .../gcc.dg/plugin/expensive_selftests_plugin.c     | 175
> +++++++++++++++++++++
>  gcc/testsuite/gcc.dg/plugin/plugin.exp             |   2 +
>  6 files changed, 218 insertions(+), 9 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.dg/plugin/expensive-selftests-
> 1.c
>  create mode 100644
> gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.c
> 
> diff --git a/gcc/selftest-run-tests.c b/gcc/selftest-run-tests.c
> index 6030d3b..f539c66 100644
> --- a/gcc/selftest-run-tests.c
> +++ b/gcc/selftest-run-tests.c
> @@ -46,7 +46,7 @@ selftest::run_tests ()
>       option-handling.  */
>    path_to_selftest_files = flag_self_test;
>  
> -  long start_time = get_run_time ();
> +  test_runner r ("-fself-test");
>  
>    /* Run all the tests, in hand-coded order of (approximate)
> dependencies:
>       run the tests for lowest-level code first.  */
> @@ -106,14 +106,7 @@ selftest::run_tests ()
>       failed to be finalized can be detected by valgrind.  */
>    forcibly_ggc_collect ();
>  
> -  /* Finished running tests.  */
> -  long finish_time = get_run_time ();
> -  long elapsed_time = finish_time - start_time;
> -
> -  fprintf (stderr,
> -	   "-fself-test: %i pass(es) in %ld.%06ld seconds\n",
> -	   num_passes,
> -	   elapsed_time / 1000000, elapsed_time % 1000000);
> +  /* Finished running tests; the test_runner dtor will print a
> summary.  */
>  }
>  
>  #endif /* #if CHECKING_P */
> diff --git a/gcc/selftest.c b/gcc/selftest.c
> index b41b9f5..ca84bfa 100644
> --- a/gcc/selftest.c
> +++ b/gcc/selftest.c
> @@ -213,6 +213,28 @@ locate_file (const char *name)
>    return concat (path_to_selftest_files, "/", name, NULL);
>  }
>  
> +/* selftest::test_runner's ctor.  */
> +
> +test_runner::test_runner (const char *name)
> +: m_name (name),
> +  m_start_time (get_run_time ())
> +{
> +}
> +
> +/* selftest::test_runner's dtor.  Print a summary line to
> stderr.  */
> +
> +test_runner::~test_runner ()
> +{
> +  /* Finished running tests.  */
> +  long finish_time = get_run_time ();
> +  long elapsed_time = finish_time - m_start_time;
> +
> +  fprintf (stderr,
> +	   "%s: %i pass(es) in %ld.%06ld seconds\n",
> +	   m_name, num_passes,
> +	   elapsed_time / 1000000, elapsed_time % 1000000);
> +}
> +
>  /* Selftests for libiberty.  */
>  
>  /* Verify that xstrndup generates EXPECTED when called on SRC and
> N.  */
> diff --git a/gcc/selftest.h b/gcc/selftest.h
> index cdad939..f282055 100644
> --- a/gcc/selftest.h
> +++ b/gcc/selftest.h
> @@ -168,6 +168,20 @@ extern char *locate_file (const char *path);
>  
>  extern const char *path_to_selftest_files;
>  
> +/* selftest::test_runner is an implementation detail of
> selftest::run_tests,
> +   exposed here to allow plugins to run their own suites of
> tests.  */
> +
> +class test_runner
> +{
> + public:
> +  test_runner (const char *name);
> +  ~test_runner ();
> +
> + private:
> +  const char *m_name;
> +  long m_start_time;
> +};
> +
>  /* Declarations for specific families of tests (by source file), in
>     alphabetical order.  */
>  extern void bitmap_c_tests ();
> diff --git a/gcc/testsuite/gcc.dg/plugin/expensive-selftests-1.c
> b/gcc/testsuite/gcc.dg/plugin/expensive-selftests-1.c
> new file mode 100644
> index 0000000..e464117
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/plugin/expensive-selftests-1.c
> @@ -0,0 +1,3 @@
> +int not_empty;
> +
> +/* { dg-regexp "expensive_selftests_plugin: .* pass\\(es\\) in .*
> seconds" } */
> diff --git a/gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.c
> b/gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.c
> new file mode 100644
> index 0000000..9470764
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.c
> @@ -0,0 +1,175 @@
> +/* Run expensive selftests.  */
> +/* { dg-options "-O" } */
> +
> +#include "gcc-plugin.h"
> +#include "config.h"
> +#include "system.h"
> +#include "coretypes.h"
> +#include "diagnostic.h"
> +#include "edit-context.h"
> +#include "selftest.h"
> +#include "selftest-diagnostic.h"
> +
> +int plugin_is_GPL_compatible;
> +
> +#if CHECKING_P
> +
> +namespace selftest {
> +
> +/* Subroutine of test_fixit_on_very_long_line.
> +   Verify that LOC has the EXPECTED_COLUMN, apart from the various
> +   cases where it can't.  */
> +
> +static void
> +verify_column (location_t loc,
> +	       const line_map_ordinary *ord_map,
> +	       int line_width,
> +	       int expected_column)
> +{
> +  ASSERT_TRUE (/* Normal case.  */
> +	       LOCATION_COLUMN (loc) == expected_column
> +	       /* ord_map can't store columns e.g. due to
> +		  max_column_hint being too high.  */
> +	       || ord_map->m_column_and_range_bits == 0
> +	       /* Running out of location_t values.  */
> +	       || loc > LINE_MAP_MAX_LOCATION_WITH_COLS
> +	       /* column exceeds LINE_MAP_MAX_COLUMN_NUMBER.  */
> +	       || expected_column > (int)LINE_MAP_MAX_COLUMN_NUMBER
> +	       /* column exceeds max_column_hint for ord_map.  */
> +	       || expected_column > line_width);
> +}
> +
> +/* Subroutine of test_fixit_on_very_long_line.
> +   Run various things for RICHLOC, but don't check; we just want
> them
> +   to survive.  */
> +
> +static void
> +test_richloc (rich_location *richloc)
> +{
> +  /* Run the diagnostic and fix-it printing code.  */
> +  test_diagnostic_context dc;
> +  diagnostic_show_locus (&dc, richloc, DK_ERROR);
> +
> +  /* Generate a diff.  */
> +  edit_context ec;
> +  ec.add_fixits (richloc);
> +  char *diff = ec.generate_diff (true);
> +  free (diff);
> +}
> +
> +/* Verify that the fix-it-printing code can cope with very long
> lines
> +   (PR c/82050).  */
> +
> +static void
> +test_fixit_on_very_long_line (const line_table_case &case_)
> +{
> +  /* Various interesting column/line-width values, to try to tickle
> +     out bugs.  */
> +  const int VERY_LONG_LINE = 8192;
> +  const int columns[] = {0,
> +			 1,
> +			 80,
> +			 LINE_MAP_MAX_COLUMN_NUMBER - 2,
> +			 LINE_MAP_MAX_COLUMN_NUMBER - 1,
> +			 LINE_MAP_MAX_COLUMN_NUMBER,
> +			 LINE_MAP_MAX_COLUMN_NUMBER + 1,
> +			 LINE_MAP_MAX_COLUMN_NUMBER + 2,
> +			 VERY_LONG_LINE,
> +			 VERY_LONG_LINE + 5};
> +  for (unsigned int width_idx = 0; width_idx < ARRAY_SIZE (columns);
> +       width_idx++)
> +    {
> +      int line_width = columns[width_idx];
> +
> +      /* Create a source file with a very long line.  */
> +      named_temp_file tmp (".c");
> +      FILE *f = fopen (tmp.get_filename (), "w");
> +      for (int i = 0; i < line_width; i++)
> +	fputc (' ', f);
> +      fputc ('\n', f);
> +      fclose (f);
> +
> +      line_table_test ltt (case_);
> +      const line_map_ordinary *ord_map = linemap_check_ordinary
> +	(linemap_add (line_table, LC_ENTER, false, tmp.get_filename
> (), 0));
> +      linemap_line_start (line_table, 1, line_width);
> +
> +      for (unsigned int start_idx = 0; start_idx < ARRAY_SIZE
> (columns);
> +	   start_idx++)
> +	{
> +	  int start_col = columns[start_idx];
> +	  location_t start_loc
> +	    = linemap_position_for_line_and_column (line_table,
> ord_map, 1,
> +						    start_col);
> +	  verify_column (start_loc, ord_map, line_width, start_col);
> +	  for (unsigned int finish_idx = 0; finish_idx < ARRAY_SIZE
> (columns);
> +	       finish_idx++)
> +	    {
> +	      int finish_col = columns[finish_idx];
> +	      location_t finish_loc
> +		= linemap_position_for_line_and_column (line_table,
> ord_map, 1,
> +							finish_col);
> +	      verify_column (finish_loc, ord_map, line_width,
> finish_col);
> +
> +	      /* Now use start-finish to exercise the fix-it code.
> +		 In each case, run the printing code, but don't
> check;
> +		 we just want it to survive.  */
> +
> +	      /* Insertion.  */
> +	      {
> +		rich_location richloc (line_table, start_loc);
> +		richloc.add_fixit_insert_after (start_loc,
> "insertion");
> +		test_richloc (&richloc);
> +	      }
> +
> +	      /* Replacement.  */
> +	      {
> +		rich_location richloc (line_table, start_loc);
> +		source_range range
> +		  = source_range::from_locations (start_loc,
> finish_loc);
> +		richloc.add_fixit_replace (range, "replacement");
> +		test_richloc (&richloc);
> +	      }
> +
> +	      /* Deletion.  */
> +	      {
> +		rich_location richloc (line_table, start_loc);
> +		source_range range
> +		  = source_range::from_locations (start_loc,
> finish_loc);
> +		richloc.add_fixit_remove (range);
> +		test_richloc (&richloc);
> +	      }
> +	    }
> +	}
> +    }
> +}
> +
> +/* Callback handler for the PLUGIN_FINISH event.
> +   At this point, all GCC subsystems should be initialized and
> +   "warmed up"; this is where we run our unit tests.  */
> +
> +static void
> +expensive_tests (void */*gcc_data*/, void */*user_data*/)
> +{
> +  test_runner r ("expensive_selftests_plugin");
> +
> +  for_each_line_table_case (test_fixit_on_very_long_line);
> +}
> +
> +} // namespace selftest
> +
> +#endif /* #if CHECKING_P */
> +
> +int
> +plugin_init (struct plugin_name_args *plugin_info,
> +	     struct plugin_gcc_version *version)
> +{
> +#if CHECKING_P
> +  const char *plugin_name = plugin_info->base_name;
> +  register_callback (plugin_info->base_name,
> +		     PLUGIN_FINISH,
> +		     selftest::expensive_tests,
> +		     NULL); /* void *user_data */
> +  return 0;
> +#endif /* #if CHECKING_P */
> +}
> diff --git a/gcc/testsuite/gcc.dg/plugin/plugin.exp
> b/gcc/testsuite/gcc.dg/plugin/plugin.exp
> index c7a3b4d..ff3c976 100644
> --- a/gcc/testsuite/gcc.dg/plugin/plugin.exp
> +++ b/gcc/testsuite/gcc.dg/plugin/plugin.exp
> @@ -82,6 +82,8 @@ set plugin_test_list [list \
>      { must_tail_call_plugin.c \
>  	  must-tail-call-1.c \
>  	  must-tail-call-2.c } \
> +    { expensive_selftests_plugin.c \
> +	  expensive-selftests-1.c } \
>  ]
>  
>  foreach plugin_test $plugin_test_list {

On 11/28/2017 12:31 PM, David Malcolm wrote:
> This patch adds selftest coverage for the fix for PR c/82050 (r255214).
> 
> The selftest iterates over various "interesting" column and line-width
> values to try to shake out bugs in the fix-it printing routines, a kind
> of "torture" selftest.
> 
> Unfortunately this selftest is noticably slower than the other selftests;
> adding it to diagnostic-show-locus.c led to:
>   -fself-test: 40218 pass(es) in 0.172000 seconds
> slowing down to:
>   -fself-test: 97315 pass(es) in 6.109000 seconds
> for an unoptimized build (e.g. when hacking with --disable-bootstrap).
> 
> Given that this affects the compile-edit-test cycle of the "gcc"
> subdirectory, this felt like an unacceptable amount of overhead to add.
> 
> I attempted to optimize the test by reducing the amount of coverage, but
> the test seems useful, and there seems to be a valid role for "torture"
> selftests.
> 
> Hence this patch adds a:
>   gcc.dg/plugin/expensive_selftests_plugin.c
> with the responsibility for running "expensive" selftests, and adds the
> expensive test there.  The patch moves a small amount of code from
> selftest::run_tests into a helper class so that the plugin can print
> a useful summary line (to reassure us that the tests are actually being
> run).
> 
> With that, the compile-edit-test cycle of the "gcc" subdir is unaffected;
> the plugin takes:
>   expensive_selftests_plugin: 26641 pass(es) in 3.127000 seconds
> which seems reasonable within the much longer time taken by "make check"
> (I optimized some of the overhead away, hence the reduction from 6 seconds
> above down to 3 seconds).
> 
> Successfully bootstrapped&regrtested on x86_64-pc-linux-gnu.
> 
> OK for trunk?
> 
> gcc/ChangeLog:
> 	PR c/82050
> 	* selftest-run-tests.c (selftest::run_tests): Move start/finish code
> 	to...
> 	* selftest.c (selftest::test_runner::test_runner): New ctor.
> 	(selftest::test_runner::~test_runner): New dtor.
> 	* selftest.h (class selftest::test_runner): New class.
> 
> gcc/testsuite/ChangeLog:
> 	PR c/82050
> 	* gcc.dg/plugin/expensive-selftests-1.c: New file.
> 	* gcc.dg/plugin/expensive_selftests_plugin.c: New file.
> 	* gcc.dg/plugin/plugin.exp (plugin_test_list): Add the above.
OK.
jeff

/daten/gcc/gcc-20180101/gcc/testsuite/gcc.dg/plugin/expensive_selftests_plugin.c:175:1: warning: no return statement in function returning non-void [-Wreturn-type]

Andreas.