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JS: naming and doc cleanups

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This commit is contained in:
Esben Sparre Andreasen
2018-11-06 08:22:56 +01:00
parent e82f5157c6
commit 1389009388
2 changed files with 12 additions and 12 deletions
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2
javascript/ql/src/Declarations/DeadStore.qhelp
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@@ -4,7 +4,7 @@
<qhelp>
<overview>
<p>
A value is assigned to a location, but either that location is never read
A value is assigned to a variable or property, but either that location is never read
later on, or its value is always overwritten before being read. This means
that the original assignment has no effect, and could indicate a logic error or
incomplete code.

22
javascript/ql/src/Declarations/DeadStoreOfProperty.ql
View File

@@ -1,6 +1,6 @@
/**
* @name Useless assignment to property
* @description An assignment to a property whose value is always overwritten, has no effect.
* @description An assignment to a property whose value is always overwritten has no effect.
* @kind problem
* @problem.severity warning
* @id js/useless-assignment-to-property
@@ -15,7 +15,7 @@ import DeadStore
/**
* Holds if `assign` definitely assigns property `name` of `base`.
*/
predicate unambigiousPropWrite(DataFlow::SourceNode base, string name, Assignment assign) {
predicate unambiguousPropWrite(DataFlow::SourceNode base, string name, Assignment assign) {
exists(DataFlow::PropWrite lhs |
assign.getLhs().flow() = lhs and
base.getAPropertyWrite(name) = lhs and
@@ -33,8 +33,8 @@ predicate postDominatedPropWrite(string name, Assignment assign1, Assignment ass
exists (DataFlow::SourceNode base, ReachableBasicBlock block1, ReachableBasicBlock block2 |
block1 = assign1.getBasicBlock() and
block2 = assign2.getBasicBlock() and
unambigiousPropWrite(base, name, assign1) and
unambigiousPropWrite(base, name, assign2) and
unambiguousPropWrite(base, name, assign1) and
unambiguousPropWrite(base, name, assign2) and
block2.postDominates(block1) and
(block1 = block2 implies
exists (int i1, int i2 |
@@ -61,13 +61,13 @@ predicate maybeAccessesProperty(Expr e, string name) {
*/
predicate isDeadAssignment(string name, Assignment assign1, Assignment assign2) {
postDominatedPropWrite(name, assign1, assign2) and
maybeHasPropAccessBetween(name, assign1, assign2) and
noPropAccessBetween(name, assign1, assign2) and
not isDOMProperty(name)
}
/**
* Holds if `assign` assigns a property `name` that may be accessed somewhere else in the same block,
* `after` indicates if the if the access happens before or after the node for `assign`.
* `after` indicates if the access happens before or after the node for `assign`.
*/
bindingset[name]
predicate maybeAccessesAssignedPropInBlock(string name, Assignment assign, boolean after) {
@@ -86,12 +86,12 @@ predicate maybeAccessesAssignedPropInBlock(string name, Assignment assign, boole
* Holds if `assign1` and `assign2` both assign property `name`, and the assigned property may be accessed between the two assignments.
*/
bindingset[name]
predicate maybeHasPropAccessBetween(string name, Assignment assign1, Assignment assign2) {
predicate noPropAccessBetween(string name, Assignment assign1, Assignment assign2) {
exists (ReachableBasicBlock block1, ReachableBasicBlock block2 |
assign1.getBasicBlock() = block1 and
assign2.getBasicBlock() = block2 and
if block1 = block2 then
// same block: check for read between
// same block: check for access between
not exists (int i1, int iMid, Expr mid, int i2 |
assign1 = block1.getNode(i1) and
assign2 = block2.getNode(i2) and
@@ -102,15 +102,15 @@ predicate maybeHasPropAccessBetween(string name, Assignment assign1, Assignment
else
// other block:
not (
// check for read after in start block
// check for an access after the first write node
maybeAccessesAssignedPropInBlock(name, assign1, true) or
// check for read after in other block
// check for an access between the two write blocks
exists (ReachableBasicBlock mid |
block1.getASuccessor+() = mid and
mid.getASuccessor+() = block2 |
maybeAccessesProperty(mid.getANode(), name)
) or
// check for read before in end block
// check for an access before the second write node
maybeAccessesAssignedPropInBlock(name, assign2, false)
)
)