perf parse-events: Avoid scanning PMUs before parsing

The event parser needs to handle two special cases:
1) legacy events like L1-dcache-load-miss. These event names don't
   appear in JSON or sysfs, and lookup tables are used for the config
   value.
2) raw events where 'r0xead' is the same as 'read' unless the PMU has
   an event called 'read' in which case the event has priority.

The previous parser to handle these cases would scan all PMUs for
components of event names. These components would then be used to
classify in the lexer whether the token should be part of a legacy
event, a raw event or an event. The grammar would handle legacy event
tokens or recombining the tokens back into a regular event name.  The
code wasn't PMU specific and had issues around events like AMD's
branch-brs that would fail to parse as it expects brs to be a suffix
on a legacy event style name:

$ perf stat -e branch-brs true
event syntax error: 'branch-brs'
                           \___ parser error

This change removes processing all PMUs by using the lexer in the form
of a regular expression matcher. The lexer will return the token for
the longest matched sequence of characters, and in the event of a tie
the first. The legacy events are a fixed number of regular
expressions, and by matching these before a name token its possible to
generate an accurate legacy event token with everything else matching
as a name. Because of the lexer change the handling of hyphens in the
grammar can be removed as hyphens just become a part of the name.

To handle raw events and terms the parser is changed to defer trying
to evaluate whether something is a raw event until the PMU is known in
the grammar. Once the PMU is known, the events of the PMU can be
scanned for the 'read' style problem. A new term type is added for
these raw terms, used to enable deferring the evaluation.

While this change is large, it has stats of:
170 insertions(+), 436 deletions(-)
the bulk of the change is deleting the old approach. It isn't possible
to break apart the code added due to the dependencies on how the parts
of the parsing work.

Signed-off-by: Ian Rogers <[email protected]>
Tested-by: Kan Liang <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ahmad Yasin <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Caleb Biggers <[email protected]>
Cc: Edward Baker <[email protected]>
Cc: Florian Fischer <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Kang Minchul <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Perry Taylor <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Ravi Bangoria <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Samantha Alt <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Sumanth Korikkar <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Tiezhu Yang <[email protected]>
Cc: Weilin Wang <[email protected]>
Cc: Xing Zhengjun <[email protected]>
Cc: Yang Jihong <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions