[PATCH v2 0/4] trace: add Rust DTrace/SystemTap SDT support

v2:
- Re-export probe::probe!() from the trace crate to avoid the explicit probe
  crate dependency from hpet, pl011, etc. [Paolo]

This series adds SDT probe support so that SystemTap, GDB, etc can trace QEMU's
Rust code when compiled with `./configure --enable-trace-backends=dtrace`.

The dtrace(1) tool that generates the .o and C header file does not support
Rust. Use the probe crate (https://crates.io/crates/probe), which takes care of
emitting SDT probes, and extend tracetool to emit code for the trace events.

While SDT is cross-platform, the probe crate currently only supports Linux
(SystemTap). On other platforms the crate is a nop - it compiles but does
nothing. Future changes to the probe crate may add support for other operating
systems like FreeBSD, macOS, etc without much needed in the way of QEMU code
changes.

Based-on: <[email protected]>

Stefan Hajnoczi (4):
  hpet: remove unused trace events
  rust/hpet: add trace events
  subprojects: add probe crate
  tracetool: add Rust DTrace/SystemTap SDT support

 hw/timer/trace-events                         |  2 -
 rust/Cargo.lock                               |  6 ++
 rust/hw/timer/hpet/Cargo.toml                 |  1 +
 rust/hw/timer/hpet/meson.build                |  1 +
 rust/hw/timer/hpet/src/device.rs              | 45 ++++++++-----
 rust/meson.build                              |  2 +
 rust/trace/Cargo.toml                         |  1 +
 rust/trace/meson.build                        |  2 +-
 rust/trace/src/lib.rs                         |  4 ++
 scripts/archive-source.sh                     |  1 +
 scripts/make-release                          |  2 +-
 scripts/tracetool/__init__.py                 |  1 +
 scripts/tracetool/backend/dtrace.py           | 31 +++++++++
 scripts/tracetool/format/rs.py                | 27 ++++++--
 subprojects/.gitignore                        |  1 +
 .../packagefiles/probe-0.5-rs/meson.build     | 22 +++++++
 subprojects/probe-0.5-rs.wrap                 |  7 ++
 tests/tracetool/dtrace.rs                     | 65 +++++++++++++++++++
 tests/tracetool/ftrace.rs                     | 21 ++++++
 tests/tracetool/log.rs                        | 21 ++++++
 tests/tracetool/simple.rs                     | 21 ++++++
 tests/tracetool/syslog.rs                     | 21 ++++++
 tests/tracetool/tracetool-test.py             |  2 +-
 23 files changed, 280 insertions(+), 27 deletions(-)
 create mode 100644 subprojects/packagefiles/probe-0.5-rs/meson.build
 create mode 100644 subprojects/probe-0.5-rs.wrap
 create mode 100644 tests/tracetool/dtrace.rs

-- 
2.51.1