Merge pull request github#3385 from jbj/dataflow-remove-from-post

C++: Remove an unneeded local-flow case

Author: MathiasVP

cpp/ql/src/semmle/code/cpp/dataflow/internal/DataFlowUtil.qll

@@ -496,8 +496,6 @@ predicate simpleLocalFlowStep(Node nodeFrom, Node nodeTo) {
   // Expr -> Expr
   exprToExprStep_nocfg(nodeFrom.asExpr(), nodeTo.asExpr())
   or
-  exprToExprStep_nocfg(nodeFrom.(PostUpdateNode).getPreUpdateNode().asExpr(), nodeTo.asExpr())
-  or
   // Node -> FlowVar -> VariableAccess
   exists(FlowVar var |
     (

cpp/ql/test/library-tests/dataflow/dataflow-tests/localFlow.expected

@@ -44,7 +44,6 @@
 | test.cpp:383:12:383:13 | 0 | test.cpp:384:33:384:35 | tmp |
 | test.cpp:383:12:383:13 | 0 | test.cpp:385:8:385:10 | tmp |
 | test.cpp:384:10:384:13 | & ... | test.cpp:384:3:384:8 | call to memcpy |
-| test.cpp:384:10:384:13 | ref arg & ... | test.cpp:384:3:384:8 | call to memcpy |
 | test.cpp:384:10:384:13 | ref arg & ... | test.cpp:384:33:384:35 | tmp |
 | test.cpp:384:10:384:13 | ref arg & ... | test.cpp:385:8:385:10 | tmp |
 | test.cpp:384:11:384:13 | tmp | test.cpp:384:10:384:13 | & ... |
@@ -59,7 +58,6 @@
 | test.cpp:389:12:389:13 | 0 | test.cpp:394:10:394:12 | tmp |
 | test.cpp:390:19:390:21 | tmp | test.cpp:390:18:390:21 | & ... |
 | test.cpp:391:10:391:13 | & ... | test.cpp:391:3:391:8 | call to memcpy |
-| test.cpp:391:10:391:13 | ref arg & ... | test.cpp:391:3:391:8 | call to memcpy |
 | test.cpp:391:10:391:13 | ref arg & ... | test.cpp:391:33:391:35 | tmp |
 | test.cpp:391:10:391:13 | ref arg & ... | test.cpp:392:8:392:10 | tmp |
 | test.cpp:391:10:391:13 | ref arg & ... | test.cpp:394:10:394:12 | tmp |

cpp/ql/test/library-tests/dataflow/taint-tests/localTaint.expected

@@ -299,7 +299,6 @@
 | taint.cpp:165:24:165:24 | 0 | taint.cpp:165:22:165:25 | {...} | TAINT |
 | taint.cpp:168:8:168:14 | ref arg tainted | taint.cpp:172:18:172:24 | tainted |  |
 | taint.cpp:170:10:170:15 | buffer | taint.cpp:170:3:170:8 | call to strcpy |  |
-| taint.cpp:170:10:170:15 | ref arg buffer | taint.cpp:170:3:170:8 | call to strcpy |  |
 | taint.cpp:170:10:170:15 | ref arg buffer | taint.cpp:171:8:171:13 | buffer |  |
 | taint.cpp:170:10:170:15 | ref arg buffer | taint.cpp:172:10:172:15 | buffer |  |
 | taint.cpp:170:10:170:15 | ref arg buffer | taint.cpp:173:8:173:13 | buffer |  |
@@ -309,7 +308,6 @@
 | taint.cpp:171:8:171:13 | ref arg buffer | taint.cpp:173:8:173:13 | buffer |  |
 | taint.cpp:172:10:172:15 | buffer | taint.cpp:172:3:172:8 | call to strcat |  |
 | taint.cpp:172:10:172:15 | buffer | taint.cpp:172:10:172:15 | ref arg buffer | TAINT |
-| taint.cpp:172:10:172:15 | ref arg buffer | taint.cpp:172:3:172:8 | call to strcat |  |
 | taint.cpp:172:10:172:15 | ref arg buffer | taint.cpp:173:8:173:13 | buffer |  |
 | taint.cpp:172:18:172:24 | tainted | taint.cpp:172:10:172:15 | ref arg buffer | TAINT |
 | taint.cpp:180:19:180:19 | p | taint.cpp:181:9:181:9 | p |  |
@@ -320,7 +318,6 @@
 | taint.cpp:193:6:193:6 | x | taint.cpp:194:10:194:10 | x |  |
 | taint.cpp:193:6:193:6 | x | taint.cpp:195:7:195:7 | x |  |
 | taint.cpp:194:9:194:10 | & ... | taint.cpp:194:2:194:7 | call to memcpy |  |
-| taint.cpp:194:9:194:10 | ref arg & ... | taint.cpp:194:2:194:7 | call to memcpy |  |
 | taint.cpp:194:9:194:10 | ref arg & ... | taint.cpp:195:7:195:7 | x |  |
 | taint.cpp:194:10:194:10 | x | taint.cpp:194:9:194:10 | & ... |  |
 | taint.cpp:194:13:194:18 | source | taint.cpp:194:2:194:7 | call to memcpy | TAINT |