Implement RULE-2-8, project should not contain unused object definitions.

Also add a new AlertReporting shared query library for deduplicating results
across macro definitions/invocations/etc.

Split __attribute__((unused)) variables (and similar) to a Strict pair of queries.

Author: MichaelRFairhurst

c/misra/src/rules/RULE-2-8/UnusedObjectDefinition.ql

@@ -0,0 +1,24 @@
+/**
+ * @id c/misra/unused-object-definition
+ * @name RULE-2-8: A project should not contain unused object definitions
+ * @description Object definitions which are unused should be removed.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity recommendation
+ * @tags external/misra/id/rule-2-8
+ *       maintainability
+ *       performance
+ *       external/misra/c/2012/amendment4
+ *       external/misra/obligation/advisory
+ */
+
+import cpp
+import codingstandards.c.misra
+import codingstandards.cpp.deadcode.UnusedObjects
+
+from ReportDeadObjectAtDefinition report
+where
+  not isExcluded(report.getPrimaryElement(), DeadCode2Package::unusedObjectDefinitionQuery()) and
+  not report.hasAttrUnused()
+select report.getPrimaryElement(), report.getMessage(), report.getOptionalPlaceholderLocation(),
+  report.getOptionalPlaceholderMessage()

c/misra/src/rules/RULE-2-8/UnusedObjectDefinitionInMacro.ql

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+/**
+ * @id c/misra/unused-object-definition-in-macro
+ * @name RULE-2-8: Project macros should not include unused object definitions
+ * @description Macros should not have unused object definitions.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity recommendation
+ * @tags external/misra/id/rule-2-8
+ *       maintainability
+ *       performance
+ *       external/misra/c/2012/amendment4
+ *       external/misra/obligation/advisory
+ */
+
+import cpp
+import codingstandards.c.misra
+import codingstandards.cpp.deadcode.UnusedObjects
+
+from ReportDeadObjectInMacro report
+where
+  not isExcluded(report.getPrimaryElement(), DeadCode2Package::unusedObjectDefinitionInMacroQuery()) and
+  not report.hasAttrUnused()
+select report.getPrimaryElement(), report.getMessage(), report.getOptionalPlaceholderLocation(),
+  report.getOptionalPlaceholderMessage()

c/misra/src/rules/RULE-2-8/UnusedObjectDefinitionInMacroStrict.ql

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+/**
+ * @id c/misra/unused-object-definition-in-macro-strict
+ * @name RULE-2-8: Project macros should not include '__attribute__((unused))' object definitions
+ * @description A strict query which reports all unused object definitions in macros with
+ *              '__attribute__((unused))'.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity recommendation
+ * @tags external/misra/id/rule-2-8
+ *       maintainability
+ *       performance
+ *       external/misra/c/2012/amendment4
+ *       external/misra/c/strict
+ *       external/misra/obligation/advisory
+ */
+
+import cpp
+import codingstandards.c.misra
+import codingstandards.cpp.deadcode.UnusedObjects
+
+from ReportDeadObjectInMacro report
+where
+  not isExcluded(report.getPrimaryElement(),
+    DeadCode2Package::unusedObjectDefinitionInMacroStrictQuery()) and
+  report.hasAttrUnused()
+select report.getPrimaryElement(), report.getMessage(), report.getOptionalPlaceholderLocation(),
+  report.getOptionalPlaceholderMessage()

c/misra/src/rules/RULE-2-8/UnusedObjectDefinitionStrict.ql

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+/**
+ * @id c/misra/unused-object-definition-strict
+ * @name RULE-2-8: A project should not contain '__attribute__((unused))' object definitions
+ * @description A strict query which reports all unused object definitions with
+ *              '__attribute__((unused))'.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity recommendation
+ * @tags external/misra/id/rule-2-8
+ *       maintainability
+ *       performance
+ *       external/misra/c/2012/amendment4
+ *       external/misra/c/strict
+ *       external/misra/obligation/advisory
+ */
+
+import cpp
+import codingstandards.c.misra
+import codingstandards.cpp.deadcode.UnusedObjects
+
+from ReportDeadObjectAtDefinition report
+where
+  not isExcluded(report.getPrimaryElement(), DeadCode2Package::unusedObjectDefinitionStrictQuery()) and
+  report.hasAttrUnused()
+select report.getPrimaryElement(), report.getMessage(), report.getOptionalPlaceholderLocation(),
+  report.getOptionalPlaceholderMessage()

c/misra/test/rules/RULE-2-8/UnusedObjectDefinition.expected

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+| test.c:6:5:6:6 | definition of g2 | Unused object definition 'g2'. | test.c:6:5:6:6 | test.c:6:5:6:6 |  |
+| test.c:9:5:9:6 | definition of g3 | Unused object definition 'g3'. | test.c:9:5:9:6 | test.c:9:5:9:6 |  |
+| test.c:20:7:20:8 | definition of l2 | Unused object definition 'l2'. | test.c:20:7:20:8 | test.c:20:7:20:8 |  |
+| test.c:27:7:27:8 | definition of l5 | Unused object definition 'l5'. | test.c:27:7:27:8 | test.c:27:7:27:8 |  |
+| test.c:37:10:37:11 | definition of g5 | Unused object definition 'g5'. | test.c:37:10:37:11 | test.c:37:10:37:11 |  |
+| test.c:45:9:45:10 | definition of g6 | Unused object definition 'g6'. | test.c:45:9:45:10 | test.c:45:9:45:10 |  |
+| test.c:51:5:51:6 | definition of g7 | Unused object definition 'g7'. | test.c:51:5:51:6 | test.c:51:5:51:6 |  |
+| test.c:64:3:64:18 | ONLY_DEF_VAR(x) | Unused object definition 'l2' from macro '$@'. | test.c:60:1:60:34 | test.c:60:1:60:34 | ONLY_DEF_VAR |

c/misra/test/rules/RULE-2-8/UnusedObjectDefinition.qlref

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+rules/RULE-2-8/UnusedObjectDefinition.ql

c/misra/test/rules/RULE-2-8/UnusedObjectDefinitionInMacro.expected

@@ -0,0 +1,2 @@
+| test.c:68:1:71:5 | #define ALSO_DEF_VAR(x) int x = 0; while (1) ; | Macro 'ALSO_DEF_VAR' defines unused object of varied names, for example, '$@'. | test.c:73:16:73:17 | test.c:73:16:73:17 | l1 |
+| test.c:77:1:82:3 | #define DEF_UNUSED_INNER_VAR() { int _v = 0; while (1) ; } | Macro 'DEF_UNUSED_INNER_VAR' defines unused object '_v'. | test.c:77:1:82:3 | test.c:77:1:82:3 | (ignored) |

c/misra/test/rules/RULE-2-8/UnusedObjectDefinitionInMacro.qlref

@@ -0,0 +1 @@
+rules/RULE-2-8/UnusedObjectDefinitionInMacro.ql

c/misra/test/rules/RULE-2-8/UnusedObjectDefinitionInMacroStrict.expected

@@ -0,0 +1,2 @@
+| test.c:94:1:97:5 | #define ALSO_DEF_ATTR_UNUSED_VAR(x) __attribute__((unused)) int x = 0; while (1) ; | Macro 'ALSO_DEF_ATTR_UNUSED_VAR' defines unused object of varied names, for example, '$@'. | test.c:99:28:99:29 | test.c:99:28:99:29 | l1 |
+| test.c:104:1:109:3 | #define DEF_ATTR_UNUSED_INNER_VAR() { __attribute__((unused)) int _v = 0; while (1) ; } | Macro 'DEF_ATTR_UNUSED_INNER_VAR' defines unused object '_v'. | test.c:104:1:109:3 | test.c:104:1:109:3 | (ignored) |

c/misra/test/rules/RULE-2-8/UnusedObjectDefinitionInMacroStrict.qlref

@@ -0,0 +1 @@
+rules/RULE-2-8/UnusedObjectDefinitionInMacroStrict.ql