Merge #24

24: add support for all ITM packet types and replace Decoder with Stream parser r=therealprof a=japaric

as this is a breaking change and requires a minor version bump, this commit
also:

- sets MSRV to 1.31.0
- changes the crate edition to 2018
- removes `itmdump` (more info below)

---

The rationale for dropping the existing `Decoder` API is that it doesn't handle
well streams of data that contain errors, like missing bytes (occurs in ~0.2% of
packets according to my unscientific measurements). Namely, `Decoder` can't
backtrack the stream because it has no internal buffer; meaning that once a byte
is lost it will continue to parse packets with an offset of one (i.e. the first
byte of the payload will be treated as the packet header) leading to a cascade
of errors.

The `Stream` API has an internal buffer so when it encounters a packet error due
to a missing byte it can backtrack the stream and retry parsing from the most
likely place. Also, thanks to the internal buffer `Stream` greatly reduces the
number of read syscalls -- the `Decoder` API was doing 1-byte read syscalls in
some places.

(For historic purposes, I have pushed [the branch] where I was adding full
parsing support to the `Decoder` API)

[the branch]: https://github.com/rust-embedded/itm/tree/decoder

With this new API and support for all the different ITM packets I have created a
set of tools ([`itm-tools`]) for analyzing ITM traces. One of the tools,
`port-demux`, is a more general version of `itmdump` and should be preferred
over it. The other reason for removing `itmdump` and not providing tools in this
crate is that it makes version management easier: breaking changes in the
library don't necessarily mean breaking changes in the tool CLI.

[`itm-tools`]: https://github.com/japaric/itm-tools

r? @rust-embedded/tools
cc @rust-embedded/cortex-m

Co-authored-by: Jorge Aparicio <[email protected]>

Author: bors[bot]

.gitignore

@@ -1,3 +1,4 @@
 *.rs.bk
 .#*
+Cargo.lock
 target

.travis.yml

@@ -4,6 +4,8 @@ matrix:
   include:
     - env: TARGET=x86_64-unknown-linux-gnu
       if: (branch = staging OR branch = trying) OR (type = pull_request AND branch = master)
+      # MSRV
+      rust: 1.31.0
 
 before_install:
   - set -e