hohn/codeql
1
0
Fork 0
mirror of https://github.com/github/codeql.git synced 2026-04-30 19:26:02 +02:00
Code Issues Packages Projects Releases Wiki Activity

mention purity check in docstring for maybeAssignsAccessedPropInBlock

Browse Source
This commit is contained in:
Erik Krogh Kristensen
2020-08-11 14:27:12 +02:00
parent 374b1b7b97
commit 9e768375ce
1 changed files with 5 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
javascript/ql/src/Declarations/DeadStoreOfProperty.ql
View File

@@ -107,6 +107,9 @@ predicate isDeadAssignment(string name, DataFlow::PropWrite assign1, DataFlow::P
/**
* Holds if `assign` assigns a property that may be accessed somewhere else in the same block,
* `after` indicates if the access happens before or after the node for `assign`.
*
* The access can either be a direct property access of the same name,
* or an impure expression where we assume that the expression can access the property.
*/
predicate maybeAssignsAccessedPropInBlock(DataFlow::PropWrite assign, boolean after) {
(
@@ -116,6 +119,7 @@ predicate maybeAssignsAccessedPropInBlock(DataFlow::PropWrite assign, boolean af
after = false and postDominatedPropWrite(_, _, assign, false)
) and
(
// direct property write before/after assign
exists(ReachableBasicBlock block, int i, int j, Expr e, string name |
i = getRank(block, assign.getWriteNode(), name) and
j = getRank(block, e, name) and
@@ -126,6 +130,7 @@ predicate maybeAssignsAccessedPropInBlock(DataFlow::PropWrite assign, boolean af
after = false and j < i
)
or
// impure expression that might access the property before/after assign
exists(ReachableBasicBlock block | assign.getWriteNode().getBasicBlock() = block |
after = true and isBeforeImpure(assign, block)
or