Java: Improve concatenation in loops #16859
Conversation
- create test - check for statements being executed often
- add test for recursive function - update test expectations
- Use a deep callgraph traversal to identify loops. This should be checked for performance issues and possibly be restriceted/optimised. - Add inline expectation test. Currently dupicating the query code. It should be refactored so that the code can be reused.
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| /** | ||
| * An assignment of the form | ||
| * | ||
| * ``` | ||
| * v = ... + ... v ... | ||
| * ``` | ||
| * or | ||
| * | ||
| * ``` | ||
| * v += ... | ||
| * ``` | ||
| * where `v` is a simple variable (and not, for example, | ||
| * an array element). | ||
| */ |
Check warning
Code scanning / CodeQL
Predicate QLDoc style. Warning test
| exists(ControlFlowNode n | a.getControlFlowNode() = n | getADeepSuccessor(n) = n) | ||
| } | ||
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| /** Gets a sucessor of `n`, also following function calls. */ |
Check warning
Code scanning / CodeQL
Misspelling Warning
| exists(ControlFlowNode n | a.getControlFlowNode() = n | getADeepSuccessor(n) = n) | ||
| } | ||
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| /** Gets a sucessor of `n`, also following function calls. */ |
Check warning
Code scanning / CodeQL
Misspelling Warning test
| } | ||
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| predicate queryResult(Assignment a) { | ||
| exists(Variable v | |
Check warning
Code scanning / CodeQL
Omittable 'exists' variable Warning test
| /** | ||
| * Holds if `e` is executed often in loop `loop`. | ||
| */ | ||
| predicate executedOften(Assignment a) { |
Check warning
Code scanning / CodeQL
Missing QLDoc for parameter Warning
| /** | ||
| * Holds if `e` is executed often in loop `loop`. | ||
| */ | ||
| predicate executedOften(Assignment a) { |
Check warning
Code scanning / CodeQL
Missing QLDoc for parameter Warning test
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| module TheQuery { | ||
| import semmle.code.java.Type | ||
| import semmle.code.java.Expr |
Check warning
Code scanning / CodeQL
Redundant import Warning test
| import semmle.code.java.Type | ||
| import semmle.code.java.Expr | ||
| import semmle.code.java.Statement | ||
| import semmle.code.java.JDK |
Check warning
Code scanning / CodeQL
Redundant import Warning test
This is the results so far of a series of mob pairing sessions to improve the query finding concatenation in loops.
One thing I wanted to illustrate is the inline tests, but currently I had to include the query code in the test to make it work. Thus, this PR is not quite ready to merge.