Merge pull request #779 from jbj/commented-out-code-braces

geoffw0 · web-flow · commit 821a7bfadd32 · 2019-01-21T09:37:30.000Z
C++: Relax commented-out code heuristic for `}`
diff --git a/cpp/ql/src/Documentation/CommentedOutCode.qll b/cpp/ql/src/Documentation/CommentedOutCode.qll
@@ -20,6 +20,18 @@ private predicate looksLikeCode(string line) {
     exists(string trimmed |
            trimmed = line.regexpReplaceAll("(?i)(^\\s+|&#?[a-z0-9]{1,31};|\\s+$)", "") |
            trimmed.regexpMatch(".*[{};]")
+           and (
+              // If this line looks like code because it ends with a closing
+              // brace that's preceded by something other than whitespace ...
+              trimmed.regexpMatch(".*.\\}")
+              implies
+              // ... then there has to be ") {" (with some variation of
+              // whitespace) on the line, suggesting it's a statement like `if`
+              // or a function declaration. Otherwise it's likely to be a
+              // benign use of braces such as a JSON example or explanatory
+              // pseudocode.
+              trimmed.regexpMatch(".*\\)\\s*\\{.*")
+           )
            and not trimmed.regexpMatch("(>.*|.*[\\\\@][{}].*|(optional|repeated) .*;|.*(\\{\\{\\{|\\}\\}\\}).*|\\{[-0-9a-zA-Z]+\\})"))
 }
 
diff --git a/cpp/ql/test/query-tests/Documentation/CommentedOutCode/CommentedOutCode.expected b/cpp/ql/test/query-tests/Documentation/CommentedOutCode/CommentedOutCode.expected
@@ -1,3 +1,4 @@
+| test2.cpp:37:1:37:39 | // int myFunction() { return myValue; } | This comment appears to contain commented-out code |
 | test.c:2:1:2:22 | // commented out code; | This comment appears to contain commented-out code |
 | test.c:4:1:7:8 | // some; | This comment appears to contain commented-out code |
 | test.c:9:1:13:8 | // also; | This comment appears to contain commented-out code |
diff --git a/cpp/ql/test/query-tests/Documentation/CommentedOutCode/test2.cpp b/cpp/ql/test/query-tests/Documentation/CommentedOutCode/test2.cpp
@@ -0,0 +1,37 @@
+/*
+ * This sentence contains a semicolon;
+ * however, this doesn't make it code.
+ */
+
+// This sentence contains a semicolon;
+// however, this doesn't make it code.
+
+/* Mention a ';' */
+
+/* Mention a '{' */
+
+/* JSON example: {"foo":"bar"} */
+
+/* JSON example in backticks: `{"foo":"bar"}` */
+
+/* JSON example in quotes: '{"foo":"bar"}' */
+
+/*
+ * Code example: `return 0;`.
+ */
+
+// Code example:
+//
+//     return 0;
+
+// Code example:
+//
+// ```
+// return 0;
+// ```
+
+// { 1, 2, 3, 4 }
+
+// Example: { 1, 2, 3, 4 }
+
+// int myFunction() { return myValue; }

Original file line number	Diff line number	Diff line change
`@@ -1,3 +1,4 @@`
	`1`	`+\| test2.cpp:37:1:37:39 \| // int myFunction() { return myValue; } \| This comment appears to contain commented-out code \|`
`1`	`2`	`\| test.c:2:1:2:22 \| // commented out code; \| This comment appears to contain commented-out code \|`
`2`	`3`	`\| test.c:4:1:7:8 \| // some; \| This comment appears to contain commented-out code \|`
`3`	`4`	`\| test.c:9:1:13:8 \| // also; \| This comment appears to contain commented-out code \|`