hohn/codeql
1
0
Fork 0
mirror of https://github.com/github/codeql.git synced 2025-12-16 16:53:25 +01:00
Code Issues Packages Projects Releases Wiki Activity

SSA: Remove empty predicates and dead code.

Browse Source
This commit is contained in:
Anders Schack-Mulligen
2025-03-27 16:03:00 +01:00
parent 308d15401f
commit 5a986f5327
7 changed files with 3 additions and 114 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaInternals.qll
View File

@@ -956,8 +956,6 @@ class GlobalDef extends Definition {
private module SsaImpl = SsaImplCommon::Make<Location, SsaInput>;
private module DataFlowIntegrationInput implements SsaImpl::DataFlowIntegrationInputSig {
private import codeql.util.Void
class Expr extends Instruction {
Expr() {
exists(IRBlock bb, int i |
@@ -979,14 +977,6 @@ private module DataFlowIntegrationInput implements SsaImpl::DataFlowIntegrationI
predicate ssaDefHasSource(SsaImpl::WriteDefinition def) { none() }
predicate ssaDefAssigns(SsaImpl::WriteDefinition def, Expr value) { none() }
class Parameter extends Void {
Location getLocation() { none() }
}
predicate ssaDefInitializesParam(SsaImpl::WriteDefinition def, Parameter p) { none() }
predicate allowFlowIntoUncertainDef(SsaImpl::UncertainWriteDefinition def) { any() }
private EdgeKind getConditionalEdge(boolean branch) {

10
csharp/ql/lib/semmle/code/csharp/dataflow/internal/SsaImpl.qll
View File

@@ -1029,16 +1029,6 @@ private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInpu
def instanceof Ssa::ImplicitParameterDefinition
}
predicate ssaDefAssigns(WriteDefinition def, Expr value) {
// exclude flow directly from RHS to SSA definition, as we instead want to
// go from RHS to matching assingnable definition, and from there to SSA definition
none()
}
class Parameter = Ssa::ImplicitParameterDefinition;
predicate ssaDefInitializesParam(WriteDefinition def, Parameter p) { none() }
/**
* Allows for flow into uncertain defintions that are not call definitions,
* as we, conservatively, consider such definitions to be certain.

6
java/ql/lib/semmle/code/java/dataflow/internal/SsaImpl.qll
View File

@@ -647,16 +647,10 @@ private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInpu
Expr getARead(Definition def) { result = getAUse(def) }
class Parameter = J::Parameter;
predicate ssaDefHasSource(WriteDefinition def) {
def instanceof SsaExplicitUpdate or def.(SsaImplicitInit).isParameterDefinition(_)
}
predicate ssaDefAssigns(Impl::WriteDefinition def, Expr value) { none() }
predicate ssaDefInitializesParam(Impl::WriteDefinition def, Parameter p) { none() }
predicate allowFlowIntoUncertainDef(UncertainWriteDefinition def) {
def instanceof SsaUncertainImplicitUpdate
}

12
javascript/ql/lib/semmle/javascript/dataflow/internal/sharedlib/Ssa.qll
View File

@@ -61,18 +61,6 @@ module SsaDataflowInput implements DataFlowIntegrationInputSig {
none()
}
predicate ssaDefAssigns(WriteDefinition def, Expr value) {
// This library only handles use-use flow after a post-update, there are no definitions, only uses.
none()
}
class Parameter = js::Parameter;
predicate ssaDefInitializesParam(WriteDefinition def, Parameter p) {
// This library only handles use-use flow after a post-update, there are no definitions, only uses.
none()
}
cached
Expr getARead(Definition def) {
// Copied from implementation so we can cache it here

6
ruby/ql/lib/codeql/ruby/dataflow/internal/SsaImpl.qll
View File

@@ -473,18 +473,12 @@ class ParameterExt extends TParameterExt {
private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInputSig {
private import codeql.ruby.controlflow.internal.Guards as Guards
class Parameter = ParameterExt;
class Expr extends Cfg::CfgNodes::ExprCfgNode {
predicate hasCfgNode(SsaInput::BasicBlock bb, int i) { this = bb.getNode(i) }
}
Expr getARead(Definition def) { result = Cached::getARead(def) }
predicate ssaDefAssigns(WriteDefinition def, Expr value) { none() }
predicate ssaDefInitializesParam(WriteDefinition def, Parameter p) { none() }
class Guard extends Cfg::CfgNodes::AstCfgNode {
/**
* Holds if the control flow branching from `bb1` is dependent on this guard,

12
rust/ql/lib/codeql/rust/dataflow/internal/SsaImpl.qll
View File

@@ -342,11 +342,6 @@ private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInpu
predicate ssaDefHasSource(WriteDefinition def) { none() } // handled in `DataFlowImpl.qll` instead
/** Holds if SSA definition `def` assigns `value` to the underlying variable. */
predicate ssaDefAssigns(WriteDefinition def, Expr value) {
none() // handled in `DataFlowImpl.qll` instead
}
private predicate isArg(CfgNodes::CallExprBaseCfgNode call, CfgNodes::ExprCfgNode e) {
call.getArgument(_) = e
or
@@ -366,13 +361,6 @@ private module DataFlowIntegrationInput implements Impl::DataFlowIntegrationInpu
)
}
class Parameter = CfgNodes::ParamBaseCfgNode;
/** Holds if SSA definition `def` initializes parameter `p` at function entry. */
predicate ssaDefInitializesParam(WriteDefinition def, Parameter p) {
none() // handled in `DataFlowImpl.qll` instead
}
class Guard extends CfgNodes::AstCfgNode {
/**
* Holds if the control flow branching from `bb1` is dependent on this guard,

61
shared/ssa/codeql/ssa/Ssa.qll
View File

@@ -1468,21 +1468,6 @@ module Make<LocationSig Location, InputSig<Location> Input> {
*/
default predicate ssaDefHasSource(WriteDefinition def) { any() }
/** Holds if SSA definition `def` assigns `value` to the underlying variable. */
predicate ssaDefAssigns(WriteDefinition def, Expr value);
/** A parameter. */
class Parameter {
/** Gets a textual representation of this parameter. */
string toString();
/** Gets the location of this parameter. */
Location getLocation();
}
/** Holds if SSA definition `def` initializes parameter `p` at function entry. */
predicate ssaDefInitializesParam(WriteDefinition def, Parameter p);
/**
* Holds if flow should be allowed into uncertain SSA definition `def` from
* previous definitions or reads.
@@ -1675,17 +1660,7 @@ module Make<LocationSig Location, InputSig<Location> Input> {
cached
private newtype TNode =
TWriteDefSource(WriteDefinition def) { DfInput::ssaDefHasSource(def) } or
TParamNode(DfInput::Parameter p) {
exists(WriteDefinition def | DfInput::ssaDefInitializesParam(def, p))
} or
TExprNode(DfInput::Expr e, Boolean isPost) {
e = DfInput::getARead(_)
or
exists(DefinitionExt def |
DfInput::ssaDefAssigns(def, e) and
isPost = false
)
} or
TExprNode(DfInput::Expr e, Boolean isPost) { e = DfInput::getARead(_) } or
TSsaDefinitionNode(DefinitionExt def) { not phiHasUniqNextNode(def) } or
TSsaInputNode(SsaPhiExt phi, BasicBlock input) { relevantPhiInputNode(phi, input) }
@@ -1722,22 +1697,6 @@ module Make<LocationSig Location, InputSig<Location> Input> {
final class WriteDefSourceNode = WriteDefSourceNodeImpl;
/** A parameter node. */
private class ParameterNodeImpl extends NodeImpl, TParamNode {
private DfInput::Parameter p;
ParameterNodeImpl() { this = TParamNode(p) }
/** Gets the underlying parameter. */
DfInput::Parameter getParameter() { result = p }
override string toString() { result = p.toString() }
override Location getLocation() { result = p.getLocation() }
}
final class ParameterNode = ParameterNodeImpl;
/** A (post-update) expression node. */
abstract private class ExprNodePreOrPostImpl extends NodeImpl, TExprNode {
DfInput::Expr e;
@@ -2003,14 +1962,7 @@ module Make<LocationSig Location, InputSig<Location> Input> {
predicate localFlowStep(SourceVariable v, Node nodeFrom, Node nodeTo, boolean isUseStep) {
exists(Definition def |
// Flow from write definition source into SSA definition
nodeFrom = TWriteDefSource(def)
or
// Flow from assignment into SSA definition
DfInput::ssaDefAssigns(def, nodeFrom.(ExprNode).getExpr())
or
// Flow from parameter into entry definition
DfInput::ssaDefInitializesParam(def, nodeFrom.(ParameterNode).getParameter())
|
nodeFrom = TWriteDefSource(def) and
isUseStep = false and
if DfInput::includeWriteDefsInFlowStep()
then
@@ -2042,14 +1994,7 @@ module Make<LocationSig Location, InputSig<Location> Input> {
predicate localMustFlowStep(SourceVariable v, Node nodeFrom, Node nodeTo) {
exists(Definition def |
// Flow from write definition source into SSA definition
nodeFrom = TWriteDefSource(def)
or
// Flow from assignment into SSA definition
DfInput::ssaDefAssigns(def, nodeFrom.(ExprNode).getExpr())
or
// Flow from parameter into entry definition
DfInput::ssaDefInitializesParam(def, nodeFrom.(ParameterNode).getParameter())
|
nodeFrom = TWriteDefSource(def) and
v = def.getSourceVariable() and
if DfInput::includeWriteDefsInFlowStep()
then nodeTo.(SsaDefinitionNode).getDefinition() = def