Forbid casting of struct types #1873
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
viktormalik
force-pushed
the
forbid-struct-casts
branch
from
6f14aeb to
11d9380
Compare
fbs
reviewed
Jun 9, 2021
tests/semantic_analyser.cpp
Outdated
| { | ||
| // Casting struct by value is forbidden | ||
| test("struct type { int field; }" | ||
| "kprobe:f { $s = (struct type)cpu; $u = (uint32)$s; }", |
There was a problem hiding this comment.
this seems to test the wrong thing
stdin:1:59-74: ERROR: Cannot convert unsigned int64 to struct
struct type { int field; } struct b { int a }; k:f { $s = (struct type )cpu; }
~~~~~~~~~~~~~~~
fbs
reviewed
Jun 9, 2021
fbs
reviewed
Jun 9, 2021
src/ast/semantic_analyser.cpp
Outdated
| if (cast.expr->type.IsRecordTy()) | ||
| { | ||
| LOG(ERROR, cast.loc, err_) | ||
| << "Cannot cast struct type \"" << cast.expr->type << "\""; |
There was a problem hiding this comment.
would be nice to include the target type as well, but that means shuffling a bit
There was a problem hiding this comment.
right, that'll also break some existing tests but we should do that nevertheless
C does not allow casting of struct types by value, so we can follow this behaviour in BPFtrace. Some existing semantic analyser tests used casting to struct types, so they were changed to use pointer casts instead.
viktormalik
force-pushed
the
forbid-struct-casts
branch
from
11d9380 to
867f68f
Compare
|
Updated to block both casts from and to struct types. |
danobi
approved these changes
Jun 13, 2021
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Outdated suggestions cannot be applied.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.
C does not allow casting struct types by value, so we should do the same in BPFtrace.
Resolves #1869.
Checklist
docs/reference_guide.mdCHANGELOG.md