C++: Remove the taintflow edges that gives performance problems.

MathiasVP · MathiasVP · commit b1ea00fa8563 · 2021-10-28T12:35:01.000+01:00
diff --git a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/TaintTrackingUtil.qll b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/TaintTrackingUtil.qll
@@ -44,8 +44,6 @@ private predicate instructionToOperandTaintStep(Instruction fromInstr, Operand t
     fromInstr = readInstr.getArgumentDef() and
     toOperand = readInstr.getSideEffectOperand()
   )
-  or
-  toOperand.(LoadOperand).getAnyDef() = fromInstr
 }
 
 /**
@@ -84,8 +82,6 @@ private predicate operandToInstructionTaintStep(Operand opFrom, Instruction inst
     instrTo.(FieldAddressInstruction).getField().getDeclaringType() instanceof Union
   )
   or
-  instrTo.(LoadInstruction).getSourceAddressOperand() = opFrom
-  or
   // Flow from an element to an array or union that contains it.
   instrTo.(ChiInstruction).getPartialOperand() = opFrom and
   not instrTo.isResultConflated() and

Original file line number	Diff line number	Diff line change
`@@ -44,8 +44,6 @@ private predicate instructionToOperandTaintStep(Instruction fromInstr, Operand t`
`44`	`44`	`fromInstr = readInstr.getArgumentDef() and`
`45`	`45`	`toOperand = readInstr.getSideEffectOperand()`
`46`	`46`	`)`
`47`		`- or`
`48`		`- toOperand.(LoadOperand).getAnyDef() = fromInstr`
`49`	`47`	`}`
`50`	`48`
`51`	`49`	`/**`
`@@ -84,8 +82,6 @@ private predicate operandToInstructionTaintStep(Operand opFrom, Instruction inst`
`84`	`82`	`instrTo.(FieldAddressInstruction).getField().getDeclaringType() instanceof Union`
`85`	`83`	`)`
`86`	`84`	`or`
`87`		`- instrTo.(LoadInstruction).getSourceAddressOperand() = opFrom`
`88`		`- or`
`89`	`85`	`// Flow from an element to an array or union that contains it.`
`90`	`86`	`instrTo.(ChiInstruction).getPartialOperand() = opFrom and`
`91`	`87`	`not instrTo.isResultConflated() and`