C++: Add more tests.

Author: MathiasVP

cpp/ql/test/library-tests/controlflow/guards/GuardsInline.expected

@@ -0,0 +1,21 @@
+| test.cpp:370:5:370:7 | Call: call to chk | 'call to testNotNull1:true' |
+| test.cpp:370:5:370:7 | Call: call to chk | 'p:not null' |
+| test.cpp:372:5:372:7 | Call: call to chk | 'call to testNotNull1:false' |
+| test.cpp:372:5:372:7 | Call: call to chk | p:null |
+| test.cpp:376:5:376:7 | Call: call to chk | 'call to testNotNull2:true' |
+| test.cpp:378:5:378:7 | Call: call to chk | 'call to testNotNull2:false' |
+| test.cpp:382:5:382:7 | Call: call to chk | '0 == call to getNumOrDefault:true' |
+| test.cpp:382:5:382:7 | Call: call to chk | 'call to getNumOrDefault:0' |
+| test.cpp:384:5:384:7 | Call: call to chk | '0 == call to getNumOrDefault:false' |
+| test.cpp:384:5:384:7 | Call: call to chk | 'call to getNumOrDefault:not 0' |
+| test.cpp:384:5:384:7 | Call: call to chk | 'i:not null' |
+| test.cpp:388:5:388:7 | Call: call to chk | '0 == call to returnAIfNoneAreNull:true' |
+| test.cpp:388:5:388:7 | Call: call to chk | 'call to returnAIfNoneAreNull:0' |
+| test.cpp:390:5:390:7 | Call: call to chk | '0 == call to returnAIfNoneAreNull:false' |
+| test.cpp:390:5:390:7 | Call: call to chk | 'call to returnAIfNoneAreNull:not 0' |
+| test.cpp:395:7:395:9 | Call: call to chk | 'call to testEnumWrapper:1' |
+| test.cpp:395:7:395:9 | Call: call to chk | 'call to testEnumWrapper=SUCCESS:true' |
+| test.cpp:395:7:395:9 | Call: call to chk | b:true |
+| test.cpp:398:7:398:9 | Call: call to chk | 'call to testEnumWrapper:2' |
+| test.cpp:398:7:398:9 | Call: call to chk | 'call to testEnumWrapper=FAILURE:true' |
+| test.cpp:398:7:398:9 | Call: call to chk | b:false |

cpp/ql/test/library-tests/controlflow/guards/GuardsInline.ql

@@ -0,0 +1,44 @@
+import cpp
+import semmle.code.cpp.controlflow.Guards
+import codeql.util.Boolean
+
+bindingset[s]
+string escape(string s) { if s.matches("% %") then result = "'" + s + "'" else result = s }
+
+Expr getUnconverted(Element e) {
+  not e instanceof Expr and
+  result = e
+  or
+  result = e.(Expr).getUnconverted()
+}
+
+string ppGuard(IRGuardCondition g, GuardValue val) {
+  exists(BinaryOperation bin |
+    bin = getUnconverted(g.getAst()) and
+    result =
+      bin.getLeftOperand() + " " + bin.getOperator() + " " + bin.getRightOperand() + ":" + val
+  )
+  or
+  exists(SwitchCase cc, Expr s, string value |
+    cc = g.getAst() and
+    cc.getExpr() = s and
+    result = cc.getSwitchStmt().getExpr() + "=" + value + ":" + val
+  |
+    value = cc.getExpr().toString()
+    or
+    cc.isDefault() and value = "default"
+  )
+}
+
+query predicate guarded(CallInstruction c, string guard) {
+  c.getStaticCallTarget().hasName("chk") and
+  exists(IRGuardCondition g, IRBlock bb, GuardValue val |
+    g.valueControls(bb, val) and
+    c.getBlock() = bb
+  |
+    guard = escape(ppGuard(g, val))
+    or
+    not exists(ppGuard(g, val)) and
+    guard = escape(getUnconverted(g.getAst()).toString() + ":" + val)
+  )
+}

cpp/ql/test/library-tests/controlflow/guards/GuardsInline.qlref

@@ -0,0 +1,2 @@
+query: GuardsInline.ql
+postprocess: utils/test/InlineExpectationsTestQuery.ql

cpp/ql/test/library-tests/controlflow/guards/test.cpp

@@ -337,4 +337,75 @@ void test_constant_value_and_case_range(bool b)
     // should not be guarded by `foo() = 40..50`
     use(x);
   }
-}
+}
+
+void chk();
+
+bool testNotNull1(void* input) {
+  return input != nullptr;
+}
+
+bool testNotNull2(void* input) {
+  if (input == nullptr) return false;
+  return true;
+}
+
+int getNumOrDefault(int* number) {
+  return number == nullptr ? 0 : *number;
+}
+
+char returnAIfNoneAreNull(char* s1, char* s2) {
+  if (!s1 || !s2) return '\0';
+  return 'a';
+}
+
+enum class Status { SUCCESS = 1, FAILURE = 2 };
+
+Status testEnumWrapper(bool flag) {
+  return flag ? Status::SUCCESS : Status::FAILURE;
+}
+
+void testWrappers(void* p, int* i, char* s, bool b) {
+  if (testNotNull1(p)) {
+    chk(); // $ guarded='p:not null' guarded='call to testNotNull1:true'
+  } else {
+    chk(); // $ guarded=p:null guarded='call to testNotNull1:false'
+  }
+
+  if (testNotNull2(p)) {
+    chk(); // $ guarded='call to testNotNull2:true' MISSING: guarded='p:not null'
+  } else {
+    chk(); // $ guarded='call to testNotNull2:false'
+  }
+
+  if (0 == getNumOrDefault(i)) {
+    chk(); // $ guarded='0 == call to getNumOrDefault:true' guarded='call to getNumOrDefault:0'
+  } else {
+    chk(); // $ guarded='0 == call to getNumOrDefault:false' guarded='call to getNumOrDefault:not 0' guarded='i:not null'
+  }
+
+  if ('\0' == returnAIfNoneAreNull(s, "suffix")) {
+    chk(); // $ guarded='0 == call to returnAIfNoneAreNull:true' guarded='call to returnAIfNoneAreNull:0'
+  } else {
+    chk(); // $ guarded='0 == call to returnAIfNoneAreNull:false' guarded='call to returnAIfNoneAreNull:not 0' MISSING: guarded='s:not null'
+  }
+
+  switch (testEnumWrapper(b)) {
+    case Status::SUCCESS:
+      chk(); // $ guarded='call to testEnumWrapper=SUCCESS:true' guarded='call to testEnumWrapper:1' guarded=b:true 
+      break;
+    case Status::FAILURE:
+      chk(); // $ guarded='call to testEnumWrapper=FAILURE:true' guarded='call to testEnumWrapper:2' guarded=b:false
+      break;
+  }
+}
+
+void ensureNotNull(void* o) {
+  if (!o) throw 42;
+}
+
+void testExceptionWrapper(void* s) {
+  chk(); // nothing guards here
+  ensureNotNull(s);
+  chk(); // $ MISSING: guarded='call to ensureNotNull:no exception' guarded='s:not null'
+}