C++: fix handling of aligned allocators

Author: rdmarsh2

cpp/ql/src/semmle/code/cpp/valuenumbering/HashCons.qll

@@ -92,11 +92,11 @@ private cached newtype HCBase =
     mk_MemberFunctionCall(trg, qual, args, _)
   }
   or
-  HC_NewExpr(Type t, HC_Alloc alloc, HC_Init init) {
-    mk_NewExpr(t, alloc, init, _, _)
+  HC_NewExpr(Type t, HC_Alloc alloc, HC_Init init, HC_Align align) {
+    mk_NewExpr(t, alloc, init, align, _, _)
   }  or
-  HC_NewArrayExpr(Type t, HC_Alloc alloc, HC_Init init) {
-    mk_NewArrayExpr(t, alloc, init, _, _)
+  HC_NewArrayExpr(Type t, HC_Alloc alloc, HC_Init init, HC_Align align) {
+    mk_NewArrayExpr(t, alloc, init, align, _, _)
   }
   or
   HC_SizeofType(Type t) {mk_SizeofType(t, _)}
@@ -123,11 +123,18 @@ private newtype HC_Alloc =
   }
   or
   HC_NoAlloc()
+
+/** Used to implement optional init on `new` expressions */
 private newtype HC_Init =
   HC_NoInit()
   or
   HC_HasInit(HashCons hc) {mk_HasInit(hc, _)}
 
+private newtype HC_Align = 
+  HC_NoAlign()
+  or
+  HC_HasAlign(HashCons hc) {mk_HasAlign(hc, _)}
+
 /** Used to implement hash-consing of argument lists  */
 private newtype HC_Args =
   HC_EmptyArgs(Function fcn) {
@@ -525,6 +532,10 @@ private predicate mk_HasInit(HashCons hc, NewOrNewArrayExpr new) {
   hc = hashCons(new.(NewArrayExpr).getInitializer())
 }
 
+private predicate mk_HasAlign(HashCons hc, NewOrNewArrayExpr new) {
+  hc = hashCons(new.getAlignmentArgument())
+}
+
 private predicate analyzableNewExpr(NewExpr new) {
   strictcount(new.getAllocatedType()) = 1 and
   (
@@ -538,14 +549,16 @@ private predicate analyzableNewExpr(NewExpr new) {
   )
 }
 
-private predicate mk_NewExpr(Type t, HC_Alloc alloc, HC_Init init, boolean aligned, NewExpr new) {
+private predicate mk_NewExpr(Type t, HC_Alloc alloc, HC_Init init, HC_Align align, boolean aligned,
+  NewExpr new) {
   analyzableNewExpr(new) and
   t = new.getAllocatedType() and
   (
-    new.hasAlignedAllocation() and
+    align = HC_HasAlign(hashCons(new.getAlignmentArgument())) and
     aligned = true
     or
     not new.hasAlignedAllocation() and
+    align = HC_NoAlign() and
     aligned = false
   )
   and
@@ -594,15 +607,16 @@ private predicate analyzableNewArrayExpr(NewArrayExpr new) {
   )
 }
 
-private predicate mk_NewArrayExpr(Type t, HC_Alloc alloc, HC_Init init, boolean aligned,
-  NewArrayExpr new) {
+private predicate mk_NewArrayExpr(Type t, HC_Alloc alloc, HC_Init init, HC_Align align,
+  boolean aligned, NewArrayExpr new) {
   analyzableNewArrayExpr(new) and
   t = new.getAllocatedType() and
   (
-    new.hasAlignedAllocation() and
+    align = HC_HasAlign(hashCons(new.getAlignmentArgument())) and
     aligned = true
     or
     not new.hasAlignedAllocation() and
+    align = HC_NoAlign() and
     aligned = false
   )
   and
@@ -744,14 +758,14 @@ cached HashCons hashCons(Expr e) {
     result = HC_MemberFunctionCall(fcn, qual, args)
   )
   or
-  exists(Type t, HC_Alloc alloc, HC_Init init, boolean aligned
-  | mk_NewExpr(t, alloc, init, aligned, e) and
-    result = HC_NewExpr(t, alloc, init)
+  exists(Type t, HC_Alloc alloc, HC_Init init, HC_Align align, boolean aligned
+  | mk_NewExpr(t, alloc, init, align, aligned, e) and
+    result = HC_NewExpr(t, alloc, init, align)
   )
   or
-  exists(Type t, HC_Alloc alloc, HC_Init init, boolean aligned
-  | mk_NewArrayExpr(t, alloc, init, aligned, e) and
-    result = HC_NewArrayExpr(t, alloc, init)
+  exists(Type t, HC_Alloc alloc, HC_Init init, HC_Align align, boolean aligned
+  | mk_NewArrayExpr(t, alloc, init, align, aligned, e) and
+    result = HC_NewArrayExpr(t, alloc, init, align)
   )
   or
   exists(Type t

cpp/ql/test/library-tests/valuenumbering/HashCons/HashCons.expected

@@ -38,9 +38,9 @@
 | test.cpp:92:11:92:11 | x | 92:c11-c11 93:c10-c10 |
 | test.cpp:97:3:97:3 | x | 97:c3-c3 98:c3-c3 |
 | test.cpp:97:3:97:5 | ... ++ | 97:c3-c5 98:c3-c5 |
-| test.cpp:103:10:103:11 | 1 | 103:c10-c11 104:c7-c7 107:c7-c7 108:c7-c7 10:c16-c16 179:c21-c21 247:c11-c11 248:c11-c11 270:c19-c19 271:c19-c19 |
+| test.cpp:103:10:103:11 | 1 | 103:c10-c11 104:c7-c7 107:c7-c7 108:c7-c7 10:c16-c16 179:c21-c21 247:c11-c11 248:c11-c11 271:c19-c19 272:c19-c19 |
 | test.cpp:104:3:104:3 | x | 104:c3-c3 105:c3-c3 106:c3-c3 107:c3-c3 108:c3-c3 |
-| test.cpp:105:7:105:7 | 2 | 105:c7-c7 106:c7-c7 107:c11-c11 108:c11-c11 21:c16-c16 249:c11-c11 270:c15-c15 270:c22-c22 271:c15-c15 271:c22-c22 272:c15-c15 |
+| test.cpp:105:7:105:7 | 2 | 105:c7-c7 106:c7-c7 107:c11-c11 108:c11-c11 21:c16-c16 249:c11-c11 271:c15-c15 271:c22-c22 272:c15-c15 272:c22-c22 273:c15-c15 |
 | test.cpp:107:7:107:11 | ... + ... | 107:c7-c11 108:c7-c11 |
 | test.cpp:110:15:110:17 | 1 | 110:c15-c17 111:c9-c11 |
 | test.cpp:110:15:110:17 | (char *)... | 110:c15-c17 111:c9-c11 |
@@ -86,14 +86,14 @@
 | test.cpp:247:3:247:12 | new | 247:c3-c12 248:c3-c12 |
 | test.cpp:253:16:253:36 | new[] | 253:c16-c36 254:c16-c36 |
 | test.cpp:256:3:256:21 | new | 256:c3-c21 257:c3-c21 |
-| test.cpp:256:7:256:10 | (void *)... | 256:c7-c10 257:c7-c10 260:c11-c14 261:c11-c14 |
-| test.cpp:256:7:256:10 | ptr1 | 256:c7-c10 257:c7-c10 260:c11-c14 261:c11-c14 |
+| test.cpp:256:7:256:10 | (void *)... | 256:c7-c10 257:c7-c10 260:c11-c14 261:c11-c14 263:c11-c14 |
+| test.cpp:256:7:256:10 | ptr1 | 256:c7-c10 257:c7-c10 260:c11-c14 261:c11-c14 263:c11-c14 |
 | test.cpp:258:7:258:10 | (void *)... | 258:c7-c10 262:c11-c14 |
 | test.cpp:258:7:258:10 | ptr2 | 258:c7-c10 262:c11-c14 |
 | test.cpp:260:3:260:25 | new | 260:c3-c25 261:c3-c25 |
-| test.cpp:260:7:260:8 | 32 | 260:c7-c8 261:c7-c8 262:c7-c8 264:c7-c8 265:c7-c8 267:c7-c8 268:c7-c8 270:c7-c8 271:c7-c8 272:c7-c8 |
-| test.cpp:260:7:260:8 | (size_t)... | 260:c7-c8 261:c7-c8 262:c7-c8 264:c7-c8 265:c7-c8 267:c7-c8 268:c7-c8 270:c7-c8 271:c7-c8 272:c7-c8 |
-| test.cpp:264:3:264:19 | new | 264:c3-c19 265:c3-c19 |
-| test.cpp:267:3:267:23 | new[] | 267:c3-c23 268:c3-c23 |
-| test.cpp:267:21:267:22 | 10 | 267:c21-c22 268:c21-c22 92:c15-c16 |
-| test.cpp:272:19:272:19 | 3 | 272:c19-c19 35:c16-c16 |
+| test.cpp:260:7:260:8 | 32 | 260:c7-c8 261:c7-c8 262:c7-c8 265:c7-c8 266:c7-c8 268:c7-c8 269:c7-c8 271:c7-c8 272:c7-c8 273:c7-c8 |
+| test.cpp:260:7:260:8 | (size_t)... | 260:c7-c8 261:c7-c8 262:c7-c8 265:c7-c8 266:c7-c8 268:c7-c8 269:c7-c8 271:c7-c8 272:c7-c8 273:c7-c8 |
+| test.cpp:265:3:265:19 | new | 265:c3-c19 266:c3-c19 |
+| test.cpp:268:3:268:23 | new[] | 268:c3-c23 269:c3-c23 |
+| test.cpp:268:21:268:22 | 10 | 268:c21-c22 269:c21-c22 92:c15-c16 |
+| test.cpp:273:19:273:19 | 3 | 273:c19-c19 35:c16-c16 |

cpp/ql/test/library-tests/valuenumbering/HashCons/test.cpp

@@ -260,6 +260,7 @@ void test16() {
   new(32, ptr1) IntHolder;
   new(32, ptr1) IntHolder;
   new(32, ptr2) IntHolder;
+  new(16, ptr1) IntHolder;
 
   new(32) IntHolder;
   new(32) IntHolder;