Exclude non integer literals in RULE-7-3

c/common/src/codingstandards/c/Literals.qll

@@ -0,0 +1,4 @@
+// Reuse the `IntegerLiteral` class
+import codingstandards.cpp.Cpp14Literal
+
+class IntegerLiteral = Cpp14Literal::IntegerLiteral;

c/misra/src/rules/RULE-7-3/LowercaseCharacterLUsedInLiteralSuffix.ql

@@ -14,10 +14,10 @@
 
 import cpp
 import codingstandards.c.misra
+import codingstandards.c.Literals
 
-from Literal l
+from IntegerLiteral l
 where
   not isExcluded(l, SyntaxPackage::lowercaseCharacterLUsedInLiteralSuffixQuery()) and
-  not l instanceof StringLiteral and
   exists(l.getValueText().indexOf("l"))
 select l, "Lowercase 'l' used as a literal suffix."

c/misra/test/rules/RULE-7-3/cpp/LowercaseCharacterLUsedInLiteralSuffix.qlref

@@ -0,0 +1 @@
+rules/RULE-7-3/LowercaseCharacterLUsedInLiteralSuffix.ql

c/misra/test/rules/RULE-7-3/cpp/README.md

@@ -0,0 +1 @@
+This test case was added to validate FP report [#319](https://github.com/github/codeql-coding-standards/issues/319) that occurs when this rule is run on a translation unit with language mode c++.

c/misra/test/rules/RULE-7-3/cpp/options

@@ -0,0 +1 @@
+semmle-extractor-options:--clang -std=c++14 --edg --diag_error=implicit_func_decl -nostdinc -I../../../../../cpp/common/test/includes/standard-library

c/misra/test/rules/RULE-7-3/cpp/test.cpp

@@ -0,0 +1 @@
+int x = false; // COMPLIANT - reported as FP in #319

c/misra/test/rules/RULE-7-3/test.c

@@ -41,4 +41,4 @@ long d9 = 001LU; // COMPLIANT
 
 char *e1 = "";
 char *e2 = "ul";
-char *e3 = "UL";
+char *e3 = "UL";

change_notes/2024-01-18-fix-reported-fp-for-rule-7-3.md

@@ -0,0 +1,2 @@
+`RULE-7-3`: `c/misra/lowercase-character-l-used-in-literal-suffix`
+    - Exclude non integer literals. This removes a false positive triggered when analyzing C++ code containing the `false` literal.

cpp/common/src/codingstandards/cpp/Cpp14Literal.qll

@@ -24,7 +24,7 @@ module Cpp14Literal {
    * Octal literals must always start with the digit `0`.
    */
   class OctalLiteral extends IntegerLiteral {
-    OctalLiteral() { getValueText().regexpMatch("\\s*0[0-7']+[uUlL]*\\s*") }
+    OctalLiteral() { getValueText().regexpMatch("\\s*0[0-7']*[uUlL]*\\s*") }
 
     override string getAPrimaryQlClass() { result = "OctalLiteral" }
   }