Support lvalue expressions #839
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The bmv2 expression engine can now returns references to bmv2 primitive objects (Data, Header, ...) when the expression being evaluated is an lvalue. This means that we can now handle assignments to complex lvalue expressions which do not statically resolve to a field / header / union. One example would be an assignment to a header stack field accessed through a runtime index. Unit tests were added, although at the moment they do not support all the possible cases (e.g. expressions which evaluate to a header union). The JSON version number was bumped up to 2.23. Even though no additions were made to the format, we now support additional cases and the documentation now includes an example of a "complex" assignment statement. Fixes #838
Codecov Report
@@ Coverage Diff @@
## master #839 +/- ##
==========================================
- Coverage 74.77% 74.56% -0.22%
==========================================
Files 115 115
Lines 10193 10207 +14
==========================================
- Hits 7622 7611 -11
- Misses 2571 2596 +25
Continue to review full report at Codecov.
|
antoninbas
added a commit
that referenced
this pull request
May 10, 2020
When adding support for returning lvalues in the expression evaluation engine (#839), we introduced support for using expressions which do not evaluate to a simple Data value as primitive arguments. In particular, we can use an expression which evaluates to a Header object as a primitive argument. However, the code responsible for parsing the bmv2 input JSON and instantiating Action objects was treating all expressions used as primitive arguments as "Data expressions", thus causing bmv2 to crash when it was actually not the case. Fixes #887
antoninbas
added a commit
that referenced
this pull request
May 10, 2020
When adding support for returning lvalues in the expression evaluation engine (#839), we introduced support for using expressions which do not evaluate to a simple Data value as primitive arguments. In particular, we can use an expression which evaluates to a Header object as a primitive argument. However, the code responsible for parsing the bmv2 input JSON and instantiating Action objects was treating all expressions used as primitive arguments as "Data expressions", thus causing bmv2 to crash when it was actually not the case. Fixes #887
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The bmv2 expression engine can now returns references to bmv2 primitive
objects (Data, Header, ...) when the expression being evaluated is an
lvalue. This means that we can now handle assignments to complex lvalue
expressions which do not statically resolve to a field / header /
union. One example would be an assignment to a header stack field
accessed through a runtime index.
Unit tests were added, although at the moment they do not support all
the possible cases (e.g. expressions which evaluate to a header union).
The JSON version number was bumped up to 2.23. Even though no additions
were made to the format, we now support additional cases and the
documentation now includes an example of a "complex" assignment
statement.
Fixes #838