C++: value number string constants

Author: Robert Marsh

cpp/ql/src/semmle/code/cpp/ir/implementation/aliased_ssa/gvn/ValueNumbering.qll

@@ -31,6 +31,9 @@ newtype TValueNumber =
   TConstantValueNumber(IRFunction irFunc, Type type, string value) {
     constantValueNumber(_, irFunc, type, value)
   } or
+  TStringConstantValueNumber(IRFunction irFunc, Type type, string value) {
+    stringConstantValueNumber(_, irFunc, type, value)
+  } or
   TFieldAddressValueNumber(IRFunction irFunc, Field field, ValueNumber objectAddress) {
     fieldAddressValueNumber(_, irFunc, field, objectAddress)
   } or
@@ -127,6 +130,7 @@ private predicate numberableInstruction(Instruction instr) {
   instr instanceof InitializeParameterInstruction or
   instr instanceof InitializeThisInstruction or
   instr instanceof ConstantInstruction or
+  instr instanceof StringConstantInstruction or
   instr instanceof FieldAddressInstruction or
   instr instanceof BinaryInstruction or
   instr instanceof UnaryInstruction or
@@ -157,6 +161,13 @@ private predicate constantValueNumber(ConstantInstruction instr, IRFunction irFu
   instr.getValue() = value
 }
 
+private predicate stringConstantValueNumber(StringConstantInstruction instr, IRFunction irFunc, Type type,
+    string value) {
+  instr.getEnclosingIRFunction() = irFunc and
+  instr.getResultType() = type and
+  instr.getValue().getValue() = value
+}
+
 private predicate fieldAddressValueNumber(FieldAddressInstruction instr, IRFunction irFunc,
     Field field, ValueNumber objectAddress) {
   instr.getEnclosingIRFunction() = irFunc and
@@ -255,6 +266,10 @@ private ValueNumber nonUniqueValueNumber(Instruction instr) {
         constantValueNumber(instr, irFunc, type, value) and
         result = TConstantValueNumber(irFunc, type, value)
       ) or
+      exists(Type type, string value |
+        stringConstantValueNumber(instr, irFunc, type, value) and
+        result = TStringConstantValueNumber(irFunc, type, value)
+      ) or
       exists(Field field, ValueNumber objectAddress |
         fieldAddressValueNumber(instr, irFunc, field, objectAddress) and
         result = TFieldAddressValueNumber(irFunc, field, objectAddress)

cpp/ql/src/semmle/code/cpp/ir/implementation/raw/gvn/ValueNumbering.qll

@@ -31,6 +31,9 @@ newtype TValueNumber =
   TConstantValueNumber(IRFunction irFunc, Type type, string value) {
     constantValueNumber(_, irFunc, type, value)
   } or
+  TStringConstantValueNumber(IRFunction irFunc, Type type, string value) {
+    stringConstantValueNumber(_, irFunc, type, value)
+  } or
   TFieldAddressValueNumber(IRFunction irFunc, Field field, ValueNumber objectAddress) {
     fieldAddressValueNumber(_, irFunc, field, objectAddress)
   } or
@@ -127,6 +130,7 @@ private predicate numberableInstruction(Instruction instr) {
   instr instanceof InitializeParameterInstruction or
   instr instanceof InitializeThisInstruction or
   instr instanceof ConstantInstruction or
+  instr instanceof StringConstantInstruction or
   instr instanceof FieldAddressInstruction or
   instr instanceof BinaryInstruction or
   instr instanceof UnaryInstruction or
@@ -157,6 +161,13 @@ private predicate constantValueNumber(ConstantInstruction instr, IRFunction irFu
   instr.getValue() = value
 }
 
+private predicate stringConstantValueNumber(StringConstantInstruction instr, IRFunction irFunc, Type type,
+    string value) {
+  instr.getEnclosingIRFunction() = irFunc and
+  instr.getResultType() = type and
+  instr.getValue().getValue() = value
+}
+
 private predicate fieldAddressValueNumber(FieldAddressInstruction instr, IRFunction irFunc,
     Field field, ValueNumber objectAddress) {
   instr.getEnclosingIRFunction() = irFunc and
@@ -255,6 +266,10 @@ private ValueNumber nonUniqueValueNumber(Instruction instr) {
         constantValueNumber(instr, irFunc, type, value) and
         result = TConstantValueNumber(irFunc, type, value)
       ) or
+      exists(Type type, string value |
+        stringConstantValueNumber(instr, irFunc, type, value) and
+        result = TStringConstantValueNumber(irFunc, type, value)
+      ) or
       exists(Field field, ValueNumber objectAddress |
         fieldAddressValueNumber(instr, irFunc, field, objectAddress) and
         result = TFieldAddressValueNumber(irFunc, field, objectAddress)

cpp/ql/src/semmle/code/cpp/ir/implementation/unaliased_ssa/gvn/ValueNumbering.qll

@@ -31,6 +31,9 @@ newtype TValueNumber =
   TConstantValueNumber(IRFunction irFunc, Type type, string value) {
     constantValueNumber(_, irFunc, type, value)
   } or
+  TStringConstantValueNumber(IRFunction irFunc, Type type, string value) {
+    stringConstantValueNumber(_, irFunc, type, value)
+  } or
   TFieldAddressValueNumber(IRFunction irFunc, Field field, ValueNumber objectAddress) {
     fieldAddressValueNumber(_, irFunc, field, objectAddress)
   } or
@@ -127,6 +130,7 @@ private predicate numberableInstruction(Instruction instr) {
   instr instanceof InitializeParameterInstruction or
   instr instanceof InitializeThisInstruction or
   instr instanceof ConstantInstruction or
+  instr instanceof StringConstantInstruction or
   instr instanceof FieldAddressInstruction or
   instr instanceof BinaryInstruction or
   instr instanceof UnaryInstruction or
@@ -157,6 +161,13 @@ private predicate constantValueNumber(ConstantInstruction instr, IRFunction irFu
   instr.getValue() = value
 }
 
+private predicate stringConstantValueNumber(StringConstantInstruction instr, IRFunction irFunc, Type type,
+    string value) {
+  instr.getEnclosingIRFunction() = irFunc and
+  instr.getResultType() = type and
+  instr.getValue().getValue() = value
+}
+
 private predicate fieldAddressValueNumber(FieldAddressInstruction instr, IRFunction irFunc,
     Field field, ValueNumber objectAddress) {
   instr.getEnclosingIRFunction() = irFunc and
@@ -255,6 +266,10 @@ private ValueNumber nonUniqueValueNumber(Instruction instr) {
         constantValueNumber(instr, irFunc, type, value) and
         result = TConstantValueNumber(irFunc, type, value)
       ) or
+      exists(Type type, string value |
+        stringConstantValueNumber(instr, irFunc, type, value) and
+        result = TStringConstantValueNumber(irFunc, type, value)
+      ) or
       exists(Field field, ValueNumber objectAddress |
         fieldAddressValueNumber(instr, irFunc, field, objectAddress) and
         result = TFieldAddressValueNumber(irFunc, field, objectAddress)