CPP: Add a test examining the LoopEntryConditionEvaluator on this code.

Author: geoffw0

cpp/ql/test/query-tests/Security/CWE/CWE-457/semmle/tests/LoopConditionsConst.expected

@@ -0,0 +1,20 @@
+| test.cpp:35:2:37:2 | for(...;...;...) ... | test.cpp:35:18:35:23 | ... < ... | 1 | i | { ... } | i | ExprStmt |
+| test.cpp:43:2:45:2 | for(...;...;...) ... | test.cpp:43:18:43:26 | ... < ... |  | i | { ... } | i | ExprStmt |
+| test.cpp:74:2:77:2 | while (...) ... | test.cpp:74:9:74:17 | ... > ... | 1 | count | { ... } | count | ExprStmt |
+| test.cpp:84:2:88:2 | while (...) ... | test.cpp:84:9:84:17 | ... > ... |  | count | { ... } | count | if (...) ...  |
+| test.cpp:171:3:173:3 | while (...) ... | test.cpp:171:10:171:43 | ... != ... | 0 |  | { ... } | 0 | return ... |
+| test.cpp:251:2:255:2 | while (...) ... | test.cpp:251:9:251:12 | loop | 1 | loop | { ... } | loop | return ... |
+| test.cpp:263:2:267:2 | while (...) ... | test.cpp:263:9:263:20 | ... && ... | 1 | 1 | { ... } | ... && ... | return ... |
+| test.cpp:275:2:279:2 | while (...) ... | test.cpp:275:9:275:13 | ! ... | 1 | stop | { ... } | stop | return ... |
+| test.cpp:287:2:291:2 | while (...) ... | test.cpp:287:9:287:20 | ... && ... | 1 | loop | { ... } | loop | return ... |
+| test.cpp:299:2:303:2 | while (...) ... | test.cpp:299:9:299:20 | ... && ... | 1 | loop | { ... } | ... && ..., loop | return ... |
+| test.cpp:311:2:315:2 | while (...) ... | test.cpp:311:9:311:21 | ... \|\| ... | 1 | ... \|\| ... | { ... } | 0 | return ... |
+| test.cpp:323:2:328:2 | while (...) ... | test.cpp:323:9:323:17 | ... ? ... : ... |  | b, c | { ... } | c | return ... |
+| test.cpp:336:2:341:2 | while (...) ... | test.cpp:336:9:336:21 | ... \|\| ... | 1 | b, c | { ... } | c | return ... |
+| test.cpp:348:2:351:17 | do (...) ... | test.cpp:351:11:351:15 | 0 |  | { ... } | { ... } | { ... } | return ... |
+| test.cpp:361:2:364:2 | while (...) ... | test.cpp:361:9:361:21 | ... \|\| ... | 1 | ... \|\| ... | { ... } | 0 | while (...) ... |
+| test.cpp:365:2:368:2 | while (...) ... | test.cpp:365:9:365:13 | ! ... | 1 | stop | { ... } | stop | while (...) ... |
+| test.cpp:369:2:373:2 | while (...) ... | test.cpp:369:9:369:21 | ... \|\| ... | 1 | b, c | { ... } | c | do (...) ... |
+| test.cpp:374:2:376:17 | do (...) ... | test.cpp:376:11:376:15 | 0 |  | do (...) ... | { ... } | { ... } | return ... |
+| test.cpp:384:2:386:2 | while (...) ... | test.cpp:384:9:384:12 | 1 | 1 | 1 | { ... } |  | return ... |
+| test.cpp:394:2:396:2 | while (...) ... | test.cpp:394:9:394:21 | ... , ... |  | { ... } | { ... } |  |  |

cpp/ql/test/query-tests/Security/CWE/CWE-457/semmle/tests/LoopConditionsConst.ql

@@ -0,0 +1,30 @@
+import cpp
+import LoopConditionsConst
+
+from Loop l, Expr condition
+where
+	l.getCondition() = condition
+select
+	l, condition,
+	concat(int val | loopEntryConst(condition, val) | val.toString(), ", "),
+	concat(BasicBlock bb | bb.getASuccessor() = l.getStmt() | bb.toString(), ", "),
+	concat(l.getStmt().toString(), ", "),
+	concat(BasicBlock bb | bb.getASuccessor() = l.getFollowingStmt() | bb.toString(), ", "),
+	concat(l.getFollowingStmt().toString(), ", ")
+
+/*
+dump a graph of BasicBlocks
+
+import semmle.code.cpp.controlflow.LocalScopeVariableReachability
+
+from BasicBlock pred
+select
+	pred,
+	concat(BasicBlock succ |
+		pred.getASuccessor() = succ |
+		pred.toString() + " -> " + succ.toString(), ", "),
+	concat(BasicBlock succ, boolean predSkip, boolean succSkip |
+		bbSuccessorEntryReachesLoopInvariant(pred, succ, predSkip, succSkip) |
+		pred.toString() + " (" + predSkip.toString() + ") -> " + succ.toString() + " (" + succSkip.toString() + ")", ", "
+	)
+*/

cpp/ql/test/query-tests/Security/CWE/CWE-457/semmle/tests/LoopConditionsConst.qll

@@ -0,0 +1,10 @@
+import cpp
+import semmle.code.cpp.controlflow.internal.ConstantExprs
+
+predicate loopEntryConst(Expr condition, int val)
+{
+	exists(LoopEntryConditionEvaluator x, ControlFlowNode loop |
+		x.isLoopEntry(condition, loop) and
+		val = x.getValue(condition)
+	)
+}