Add trigraph rule for RULE-5-0-1

Author: knewbury01

.vscode/tasks.json

@@ -290,6 +290,7 @@
                 "Strings3",
                 "Syntax",
                 "Templates",
+                "Trigraph",
                 "TypeRanges",
                 "Lambdas",
                 "Pointers",

cpp/common/src/codingstandards/cpp/exclusions/cpp/RuleMetadata.qll

@@ -59,6 +59,7 @@ import Statements
 import Strings
 import Templates
 import Toolchain
+import Trigraph
 import TrustBoundaries
 import TypeRanges
 import Uninitialized
@@ -123,6 +124,7 @@ newtype TCPPQuery =
   TStringsPackageQuery(StringsQuery q) or
   TTemplatesPackageQuery(TemplatesQuery q) or
   TToolchainPackageQuery(ToolchainQuery q) or
+  TTrigraphPackageQuery(TrigraphQuery q) or
   TTrustBoundariesPackageQuery(TrustBoundariesQuery q) or
   TTypeRangesPackageQuery(TypeRangesQuery q) or
   TUninitializedPackageQuery(UninitializedQuery q) or
@@ -187,6 +189,7 @@ predicate isQueryMetadata(Query query, string queryId, string ruleId, string cat
   isStringsQueryMetadata(query, queryId, ruleId, category) or
   isTemplatesQueryMetadata(query, queryId, ruleId, category) or
   isToolchainQueryMetadata(query, queryId, ruleId, category) or
+  isTrigraphQueryMetadata(query, queryId, ruleId, category) or
   isTrustBoundariesQueryMetadata(query, queryId, ruleId, category) or
   isTypeRangesQueryMetadata(query, queryId, ruleId, category) or
   isUninitializedQueryMetadata(query, queryId, ruleId, category) or

cpp/common/src/codingstandards/cpp/exclusions/cpp/Trigraph.qll

@@ -0,0 +1,26 @@
+//** THIS FILE IS AUTOGENERATED, DO NOT MODIFY DIRECTLY.  **/
+import cpp
+import RuleMetadata
+import codingstandards.cpp.exclusions.RuleMetadata
+
+newtype TrigraphQuery = TTrigraphLikeSequencesShouldNotBeUsedQuery()
+
+predicate isTrigraphQueryMetadata(Query query, string queryId, string ruleId, string category) {
+  query =
+    // `Query` instance for the `trigraphLikeSequencesShouldNotBeUsed` query
+    TrigraphPackage::trigraphLikeSequencesShouldNotBeUsedQuery() and
+  queryId =
+    // `@id` for the `trigraphLikeSequencesShouldNotBeUsed` query
+    "cpp/misra/trigraph-like-sequences-should-not-be-used" and
+  ruleId = "RULE-5-0-1" and
+  category = "advisory"
+}
+
+module TrigraphPackage {
+  Query trigraphLikeSequencesShouldNotBeUsedQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `trigraphLikeSequencesShouldNotBeUsed` query
+      TQueryCPP(TTrigraphPackageQuery(TTrigraphLikeSequencesShouldNotBeUsedQuery()))
+  }
+}

cpp/misra/src/rules/RULE-5-0-1/TrigraphLikeSequencesShouldNotBeUsed.ql

@@ -0,0 +1,24 @@
+/**
+ * @id cpp/misra/trigraph-like-sequences-should-not-be-used
+ * @name RULE-5-0-1: Trigraph-like sequences should not be used
+ * @description Using trigraph-like sequences can lead to developer confusion.
+ * @kind problem
+ * @precision medium
+ * @problem.severity warning
+ * @tags external/misra/id/rule-5-0-1
+ *       readability
+ *       scope/single-translation-unit
+ *       external/misra/enforcement/decidable
+ *       external/misra/obligation/advisory
+ */
+
+import cpp
+import codingstandards.cpp.misra
+
+from StringLiteral s, int occurrenceOffset
+where
+  not isExcluded(s, TrigraphPackage::trigraphLikeSequencesShouldNotBeUsedQuery()) and
+  exists(s.getValue().regexpFind("\\?\\?[=/'()!<>-]", _, occurrenceOffset)) and
+  //one escape character is enough to mean this isnt a trigraph-like sequence
+  not exists(s.getASimpleEscapeSequence(_, occurrenceOffset + 1))
+select s, "Trigraph-like sequence used in string literal."

cpp/misra/test/rules/RULE-5-0-1/TrigraphLikeSequencesShouldNotBeUsed.expected

@@ -0,0 +1,9 @@
+| test.cpp:1:18:1:22 | ??= | Trigraph-like sequence used in string literal. |
+| test.cpp:2:19:2:23 | ??/ | Trigraph-like sequence used in string literal. |
+| test.cpp:3:19:3:23 | ??' | Trigraph-like sequence used in string literal. |
+| test.cpp:4:19:4:23 | ??( | Trigraph-like sequence used in string literal. |
+| test.cpp:5:19:5:23 | ??) | Trigraph-like sequence used in string literal. |
+| test.cpp:6:19:6:23 | ??! | Trigraph-like sequence used in string literal. |
+| test.cpp:7:19:7:23 | ??< | Trigraph-like sequence used in string literal. |
+| test.cpp:8:19:8:23 | ??> | Trigraph-like sequence used in string literal. |
+| test.cpp:9:19:9:23 | ??- | Trigraph-like sequence used in string literal. |

cpp/misra/test/rules/RULE-5-0-1/TrigraphLikeSequencesShouldNotBeUsed.qlref

@@ -0,0 +1 @@
+rules/RULE-5-0-1/TrigraphLikeSequencesShouldNotBeUsed.ql

cpp/misra/test/rules/RULE-5-0-1/test.cpp

@@ -0,0 +1,12 @@
+const char * g = "??="; // NON_COMPLIANT
+const char * g1 = "??/"; // NON_COMPLIANT
+const char * g2 = "??'"; // NON_COMPLIANT
+const char * g3 = "??("; // NON_COMPLIANT
+const char * g4 = "??)"; // NON_COMPLIANT
+const char * g5 = "??!"; // NON_COMPLIANT
+const char * g6 = "??<"; // NON_COMPLIANT
+const char * g7 = "??>"; // NON_COMPLIANT
+const char * g8 = "??-"; // NON_COMPLIANT
+
+const char * g9 = "\?\?="; // COMPLIANT[FALSE_POSITIVE]
+const char * g10 = "?="; // COMPLIANT

rule_packages/cpp/Trigraph.json

@@ -0,0 +1,28 @@
+{
+  "MISRA-C++-2023": {
+    "RULE-5-0-1": {
+      "properties": {
+        "enforcement": "decidable",
+        "obligation": "advisory"
+      },
+      "queries": [
+        {
+          "description": "Using trigraph-like sequences can lead to developer confusion.",
+          "kind": "problem",
+          "name": "Trigraph-like sequences should not be used",
+          "precision": "medium",
+          "severity": "warning",
+          "short_name": "TrigraphLikeSequencesShouldNotBeUsed",
+          "tags": [
+            "readability",
+            "scope/single-translation-unit"
+          ],
+          "implementation_scope": {
+            "description": "The rule checks within string literals only for trigraph-like sequences."
+          }
+        }
+      ],
+      "title": "Trigraph-like sequences should not be used"
+    }
+  }
+}