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Merge pull request #13059 from MathiasVP/remove-self-edges

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C++: Remove self edges
This commit is contained in:
Mathias Vorreiter Pedersen
2023-05-10 09:04:08 +01:00
committed by GitHub
parent c376eeb133 89bf335900
commit 720586c437
5 changed files with 17 additions and 1943 deletions
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2
cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll
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@@ -1540,7 +1540,7 @@ private module Cached {
cached
predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
// Post update node -> Node flow
Ssa::ssaFlow(nodeFrom.(PostUpdateNode).getPreUpdateNode(), nodeTo)
Ssa::postUpdateFlow(nodeFrom, nodeTo)
or
// Def-use/Use-use flow
Ssa::ssaFlow(nodeFrom, nodeTo)

18
cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaInternals.qll
View File

@@ -677,7 +677,8 @@ private predicate ssaFlowImpl(SsaDefOrUse defOrUse, Node nodeFrom, Node nodeTo,
not nodeFrom = any(PostUpdateNode pun).getPreUpdateNode() and
nodeToDefOrUse(nodeFrom, defOrUse, uncertain) and
adjacentDefRead(defOrUse, use) and
useToNode(use, nodeTo)
useToNode(use, nodeTo) and
nodeFrom != nodeTo
or
// Initial global variable value to a first use
nodeFrom.(InitialGlobalValue).getGlobalDef() = defOrUse and
@@ -712,11 +713,23 @@ private Node getAPriorDefinition(SsaDefOrUse defOrUse) {
/** Holds if there is def-use or use-use flow from `nodeFrom` to `nodeTo`. */
predicate ssaFlow(Node nodeFrom, Node nodeTo) {
exists(Node nFrom, boolean uncertain, SsaDefOrUse defOrUse |
ssaFlowImpl(defOrUse, nFrom, nodeTo, uncertain) and
ssaFlowImpl(defOrUse, nFrom, nodeTo, uncertain) and nodeFrom != nodeTo
|
if uncertain = true then nodeFrom = [nFrom, getAPriorDefinition(defOrUse)] else nodeFrom = nFrom
)
}
predicate postUpdateFlow(PostUpdateNode pun, Node nodeTo) {
exists(Node preUpdate, Node nFrom, boolean uncertain, SsaDefOrUse defOrUse |
preUpdate = pun.getPreUpdateNode() and
ssaFlowImpl(defOrUse, nFrom, nodeTo, uncertain)
|
if uncertain = true
then preUpdate = [nFrom, getAPriorDefinition(defOrUse)]
else preUpdate = nFrom
)
}
/**
* Holds if `use` is a use of `sv` and is a next adjacent use of `phi` in
* index `i1` in basic block `bb1`.
@@ -742,6 +755,7 @@ predicate fromPhiNode(SsaPhiNode nodeFrom, Node nodeTo) {
fromPhiNodeToUse(phi, sv, bb1, i1, use)
or
exists(PhiNode phiTo |
phi != phiTo and
lastRefRedefExt(phi, _, _, phiTo) and
nodeTo.(SsaPhiNode).getPhiNode() = phiTo
)