SSA: Add locations to ease debugging

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

@@ -59,6 +59,9 @@ private module SourceVariables {
       then result = base.getType()
       else result = getTypeImpl(base.getType(), ind - 1)
     }
+
+    /** Gets the location of this variable. */
+    Location getLocation() { result = this.getBaseVariable().getLocation() }
   }
 }
 
@@ -869,7 +872,7 @@ private predicate sourceVariableIsGlobal(
   )
 }
 
-private module SsaInput implements SsaImplCommon::InputSig {
+private module SsaInput implements SsaImplCommon::InputSig<Location> {
   import InputSigCommon
   import SourceVariables
 
@@ -1092,7 +1095,7 @@ class Def extends DefOrUse {
   predicate isCertain() { defOrUse.isCertain() }
 }
 
-private module SsaImpl = SsaImplCommon::Make<SsaInput>;
+private module SsaImpl = SsaImplCommon::Make<Location, SsaInput>;
 
 class PhiNode extends SsaImpl::DefinitionExt {
   PhiNode() {

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaInternalsCommon.qll

@@ -377,6 +377,9 @@ abstract private class AbstractBaseSourceVariable extends TBaseSourceVariable {
   /** Gets a textual representation of this element. */
   abstract string toString();
 
+  /** Gets the location of this variable. */
+  abstract Location getLocation();
+
   /** Gets the type of this base source variable. */
   final DataFlowType getType() { this.getLanguageType().hasUnspecifiedType(result, _) }
 
@@ -395,6 +398,8 @@ class BaseIRVariable extends AbstractBaseSourceVariable, TBaseIRVariable {
 
   override string toString() { result = var.toString() }
 
+  override Location getLocation() { result = var.getLocation() }
+
   override CppType getLanguageType() { result = var.getLanguageType() }
 }
 
@@ -407,6 +412,8 @@ class BaseCallVariable extends AbstractBaseSourceVariable, TBaseCallVariable {
 
   override string toString() { result = call.toString() }
 
+  override Location getLocation() { result = call.getLocation() }
+
   override CppType getLanguageType() { result = getResultLanguageType(call) }
 }
 

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/ssa0/SsaInternals.qll

@@ -229,7 +229,7 @@ private class FinalParameterUse extends UseImpl, TFinalParameterUse {
   override predicate isCertain() { any() }
 }
 
-private module SsaInput implements SsaImplCommon::InputSig {
+private module SsaInput implements SsaImplCommon::InputSig<Location> {
   import InputSigCommon
   import SourceVariables
 
@@ -335,7 +335,7 @@ class Def extends DefOrUse {
   predicate isIteratorDef() { defOrUse instanceof IteratorDef }
 }
 
-private module SsaImpl = SsaImplCommon::Make<SsaInput>;
+private module SsaImpl = SsaImplCommon::Make<Location, SsaInput>;
 
 class PhiNode extends SsaImpl::DefinitionExt {
   PhiNode() {