Merge pull request github#15410 from MathiasVP/less-dataflow-duplication

C++: Remove more `asExpr` duplication

Author: MathiasVP

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

@@ -1394,11 +1394,21 @@ abstract private class ExprNodeBase extends Node {
   final Expr getExpr(int n) { result = this.getConvertedExpr(n).getUnconverted() }
 }
 
+/**
+ * Holds if there exists a dataflow node whose `asExpr(n)` should evaluate
+ * to `e`.
+ */
+private predicate exprNodeShouldBe(Expr e, int n) {
+  exprNodeShouldBeInstruction(_, e, n) or
+  exprNodeShouldBeOperand(_, e, n) or
+  exprNodeShouldBeIndirectOutNode(_, e, n)
+}
+
 private class InstructionExprNode extends ExprNodeBase, InstructionNode {
   InstructionExprNode() {
     exists(Expr e, int n |
       exprNodeShouldBeInstruction(this, e, n) and
-      not exprNodeShouldBeInstruction(_, e, n + 1)
+      not exprNodeShouldBe(e, n + 1)
     )
   }
 
@@ -1409,7 +1419,7 @@ private class OperandExprNode extends ExprNodeBase, OperandNode {
   OperandExprNode() {
     exists(Expr e, int n |
       exprNodeShouldBeOperand(this, e, n) and
-      not exprNodeShouldBeOperand(_, e, n + 1)
+      not exprNodeShouldBe(e, n + 1)
     )
   }
 

cpp/ql/test/library-tests/dataflow/fields/ir-path-flow.expected

@@ -12,8 +12,6 @@ edges
 | A.cpp:31:20:31:20 | c | A.cpp:31:14:31:21 | call to B [c] |
 | A.cpp:41:5:41:6 | insert output argument | A.cpp:43:10:43:12 | *& ... |
 | A.cpp:41:15:41:21 | new | A.cpp:41:5:41:6 | insert output argument |
-| A.cpp:41:15:41:21 | new | A.cpp:41:5:41:6 | insert output argument |
-| A.cpp:41:15:41:21 | new | A.cpp:41:15:41:21 | new |
 | A.cpp:47:12:47:18 | new | A.cpp:48:20:48:20 | c |
 | A.cpp:48:12:48:18 | *call to make [c] | A.cpp:49:10:49:10 | *b [c] |
 | A.cpp:48:20:48:20 | c | A.cpp:29:23:29:23 | c |
@@ -22,7 +20,6 @@ edges
 | A.cpp:55:5:55:5 | set output argument [c] | A.cpp:56:10:56:10 | *b [c] |
 | A.cpp:55:12:55:19 | new | A.cpp:27:17:27:17 | c |
 | A.cpp:55:12:55:19 | new | A.cpp:55:5:55:5 | set output argument [c] |
-| A.cpp:55:12:55:19 | new | A.cpp:55:12:55:19 | new |
 | A.cpp:56:10:56:10 | *b [c] | A.cpp:28:8:28:10 | *this [c] |
 | A.cpp:56:10:56:10 | *b [c] | A.cpp:56:10:56:17 | call to get |
 | A.cpp:57:11:57:24 | *new [c] | A.cpp:28:8:28:10 | *this [c] |
@@ -33,12 +30,10 @@ edges
 | A.cpp:57:17:57:23 | new | A.cpp:57:17:57:23 | new |
 | A.cpp:64:10:64:15 | *call to setOnB [c] | A.cpp:66:10:66:11 | *b2 [c] |
 | A.cpp:64:21:64:28 | new | A.cpp:64:10:64:15 | *call to setOnB [c] |
-| A.cpp:64:21:64:28 | new | A.cpp:64:21:64:28 | new |
 | A.cpp:64:21:64:28 | new | A.cpp:85:26:85:26 | c |
 | A.cpp:66:10:66:11 | *b2 [c] | A.cpp:66:10:66:14 | c |
 | A.cpp:73:10:73:19 | *call to setOnBWrap [c] | A.cpp:75:10:75:11 | *b2 [c] |
 | A.cpp:73:25:73:32 | new | A.cpp:73:10:73:19 | *call to setOnBWrap [c] |
-| A.cpp:73:25:73:32 | new | A.cpp:73:25:73:32 | new |
 | A.cpp:73:25:73:32 | new | A.cpp:78:27:78:27 | c |
 | A.cpp:75:10:75:11 | *b2 [c] | A.cpp:75:10:75:14 | c |
 | A.cpp:78:27:78:27 | c | A.cpp:81:21:81:21 | c |
@@ -770,7 +765,6 @@ nodes
 | A.cpp:31:20:31:20 | c | semmle.label | c |
 | A.cpp:41:5:41:6 | insert output argument | semmle.label | insert output argument |
 | A.cpp:41:15:41:21 | new | semmle.label | new |
-| A.cpp:41:15:41:21 | new | semmle.label | new |
 | A.cpp:43:10:43:12 | *& ... | semmle.label | *& ... |
 | A.cpp:47:12:47:18 | new | semmle.label | new |
 | A.cpp:48:12:48:18 | *call to make [c] | semmle.label | *call to make [c] |
@@ -779,7 +773,6 @@ nodes
 | A.cpp:49:10:49:13 | c | semmle.label | c |
 | A.cpp:55:5:55:5 | set output argument [c] | semmle.label | set output argument [c] |
 | A.cpp:55:12:55:19 | new | semmle.label | new |
-| A.cpp:55:12:55:19 | new | semmle.label | new |
 | A.cpp:56:10:56:10 | *b [c] | semmle.label | *b [c] |
 | A.cpp:56:10:56:17 | call to get | semmle.label | call to get |
 | A.cpp:57:10:57:32 | call to get | semmle.label | call to get |
@@ -789,12 +782,10 @@ nodes
 | A.cpp:57:17:57:23 | new | semmle.label | new |
 | A.cpp:64:10:64:15 | *call to setOnB [c] | semmle.label | *call to setOnB [c] |
 | A.cpp:64:21:64:28 | new | semmle.label | new |
-| A.cpp:64:21:64:28 | new | semmle.label | new |
 | A.cpp:66:10:66:11 | *b2 [c] | semmle.label | *b2 [c] |
 | A.cpp:66:10:66:14 | c | semmle.label | c |
 | A.cpp:73:10:73:19 | *call to setOnBWrap [c] | semmle.label | *call to setOnBWrap [c] |
 | A.cpp:73:25:73:32 | new | semmle.label | new |
-| A.cpp:73:25:73:32 | new | semmle.label | new |
 | A.cpp:75:10:75:11 | *b2 [c] | semmle.label | *b2 [c] |
 | A.cpp:75:10:75:14 | c | semmle.label | c |
 | A.cpp:78:6:78:15 | **setOnBWrap [c] | semmle.label | **setOnBWrap [c] |
@@ -1608,14 +1599,10 @@ subpaths
 | simple.cpp:84:14:84:20 | *this [f2, f1] | simple.cpp:78:9:78:15 | *this [f2, f1] | simple.cpp:78:9:78:15 | *getf2f1 | simple.cpp:84:14:84:20 | call to getf2f1 |
 #select
 | A.cpp:43:10:43:12 | *& ... | A.cpp:41:15:41:21 | new | A.cpp:43:10:43:12 | *& ... | *& ... flows from $@ | A.cpp:41:15:41:21 | new | new |
-| A.cpp:43:10:43:12 | *& ... | A.cpp:41:15:41:21 | new | A.cpp:43:10:43:12 | *& ... | *& ... flows from $@ | A.cpp:41:15:41:21 | new | new |
 | A.cpp:49:10:49:13 | c | A.cpp:47:12:47:18 | new | A.cpp:49:10:49:13 | c | c flows from $@ | A.cpp:47:12:47:18 | new | new |
 | A.cpp:56:10:56:17 | call to get | A.cpp:55:12:55:19 | new | A.cpp:56:10:56:17 | call to get | call to get flows from $@ | A.cpp:55:12:55:19 | new | new |
-| A.cpp:56:10:56:17 | call to get | A.cpp:55:12:55:19 | new | A.cpp:56:10:56:17 | call to get | call to get flows from $@ | A.cpp:55:12:55:19 | new | new |
 | A.cpp:57:10:57:32 | call to get | A.cpp:57:17:57:23 | new | A.cpp:57:10:57:32 | call to get | call to get flows from $@ | A.cpp:57:17:57:23 | new | new |
 | A.cpp:66:10:66:14 | c | A.cpp:64:21:64:28 | new | A.cpp:66:10:66:14 | c | c flows from $@ | A.cpp:64:21:64:28 | new | new |
-| A.cpp:66:10:66:14 | c | A.cpp:64:21:64:28 | new | A.cpp:66:10:66:14 | c | c flows from $@ | A.cpp:64:21:64:28 | new | new |
-| A.cpp:75:10:75:14 | c | A.cpp:73:25:73:32 | new | A.cpp:75:10:75:14 | c | c flows from $@ | A.cpp:73:25:73:32 | new | new |
 | A.cpp:75:10:75:14 | c | A.cpp:73:25:73:32 | new | A.cpp:75:10:75:14 | c | c flows from $@ | A.cpp:73:25:73:32 | new | new |
 | A.cpp:107:12:107:16 | a | A.cpp:98:12:98:18 | new | A.cpp:107:12:107:16 | a | a flows from $@ | A.cpp:98:12:98:18 | new | new |
 | A.cpp:120:12:120:16 | a | A.cpp:98:12:98:18 | new | A.cpp:120:12:120:16 | a | a flows from $@ | A.cpp:98:12:98:18 | new | new |

cpp/ql/test/library-tests/string_concat/strconcat.expected

@@ -1,11 +1,8 @@
 | concat.cpp:23:27:23:27 | call to operator+ | concat.cpp:23:22:23:25 | str1 | concat.cpp:23:22:23:31 | call to operator+ |
-| concat.cpp:23:27:23:27 | call to operator+ | concat.cpp:23:22:23:25 | str1 | concat.cpp:23:22:23:31 | call to operator+ |
 | concat.cpp:23:27:23:27 | call to operator+ | concat.cpp:23:22:23:25 | str1 | concat.cpp:23:27:23:27 | call to operator+ |
 | concat.cpp:23:27:23:27 | call to operator+ | concat.cpp:23:29:23:31 |   | concat.cpp:23:22:23:31 | call to operator+ |
-| concat.cpp:23:27:23:27 | call to operator+ | concat.cpp:23:29:23:31 |   | concat.cpp:23:22:23:31 | call to operator+ |
 | concat.cpp:23:27:23:27 | call to operator+ | concat.cpp:23:29:23:31 |   | concat.cpp:23:27:23:27 | call to operator+ |
 | concat.cpp:23:33:23:33 | call to operator+ | concat.cpp:23:35:23:38 | str2 | concat.cpp:23:22:23:38 | call to operator+ |
-| concat.cpp:23:33:23:33 | call to operator+ | concat.cpp:23:35:23:38 | str2 | concat.cpp:23:22:23:38 | call to operator+ |
 | concat.cpp:23:33:23:33 | call to operator+ | concat.cpp:23:35:23:38 | str2 | concat.cpp:23:33:23:33 | call to operator+ |
 | concat.cpp:23:40:23:40 | call to operator+ | concat.cpp:23:42:23:45 | str3 | concat.cpp:23:40:23:40 | call to operator+ |
 | concat.cpp:47:8:47:8 | call to operator<< | concat.cpp:47:11:47:14 | str1 | concat.cpp:47:8:47:17 | call to operator<< |