[Intel-gfx] [PATCH v3 01/19] test-dyndbg: fixup CLASSMAP usage error

Jim Cromie
2023-01-25T20:38:06Z

more careful reading of test output reveals:

lib/test_dynamic_debug.c:103 [test_dynamic_debug]do_cats =pmf "doing categories\n"
lib/test_dynamic_debug.c:105 [test_dynamic_debug]do_cats =p "LOW msg\n" class:MID
lib/test_dynamic_debug.c:106 [test_dynamic_debug]do_cats =p "MID msg\n" class:HI
lib/test_dynamic_debug.c:107 [test_dynamic_debug]do_cats =_ "HI msg\n" class unknown, _id:13

That last line is wrong, the HI class is declared.

But the enum's 1st val (explicitly initialized) was wrong; it must be
_base, not _base+1 (a DECLARE_DYNDBG_CLASSMAP param). So the last
enumeration exceeded the range of mapped class-id's, which triggered
the "class unknown" report. Basically, I coded in an error, and
forgot to verify it and remove it.

RFC:

This patch fixes a bad usage of DECLARE_DYNDBG_CLASSMAP([1]), showing that
it is too error-prone. As noted in test-dynamic-debug.c comments:

* Using the CLASSMAP api:
* - classmaps must have corresponding enum
* - enum symbols must match/correlate with class-name strings in the map.
* - base must equal enum's 1st value
* - multiple maps must set their base to share the 0-62 class_id space !!
* (build-bug-on tips welcome)

Those shortcomings could largely be fixed with a __stringify_list
(which doesn't exist) used in DEFINE_DYNAMIC_DEBUG_CLASSMAP(), on
__VA_ARGS__ a 2nd time. Then, DRM would pass DRM_UT_* ; all the
categories, in order, and not their stringifications, which created
all the usage complications above.

[1] name changed later to DYNDBG_CLASSMAP_DEFINE

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
lib/test_dynamic_debug.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 8dd250ad022b..a01f0193a419 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -75,7 +75,7 @@ DD_SYS_WRAP(disjoint_bits, p);
DD_SYS_WRAP(disjoint_bits, T);

/* symbolic input, independent bits */
-enum cat_disjoint_names { LOW = 11, MID, HI };
+enum cat_disjoint_names { LOW = 10, MID, HI };
DECLARE_DYNDBG_CLASSMAP(map_disjoint_names, DD_CLASS_TYPE_DISJOINT_NAMES, 10,
"LOW", "MID", "HI");
DD_SYS_WRAP(disjoint_names, p);
--
2.39.1