Declarations6: add RULE-17-3

and refactor Identifiers to include new predicate

Author: knewbury01

.vscode/tasks.json

@@ -206,6 +206,7 @@
                 "Declarations",
                 "Declarations1",
                 "Declarations2",
+                "Declarations6",
                 "Exceptions1",
                 "Exceptions2",
                 "Expressions",

c/misra/src/rules/RULE-17-3/FunctionDeclaredImplicitly.ql

@@ -0,0 +1,29 @@
+/**
+ * @id c/misra/function-declared-implicitly
+ * @name RULE-17-3: A function shall not be declared implicitly
+ * @description Omission of type specifiers may not be supported by some compilers. Additionally
+ *              implicit typing can lead to undefined behaviour.
+ * @kind problem
+ * @precision very-high
+ * @problem.severity error
+ * @tags external/misra/id/rule-17-3
+ *       correctness
+ *       readability
+ *       external/misra/obligation/mandatory
+ */
+
+import cpp
+import codingstandards.c.misra
+import codingstandards.cpp.Identifiers
+
+from FunctionDeclarationEntry fde
+where
+  not isExcluded(fde, Declarations6Package::functionDeclaredImplicitlyQuery()) and
+  (
+    //use before declaration
+    fde.isImplicit()
+    or
+    //declared but type not explicit
+    isDeclaredImplicit(fde.getDeclaration())
+  )
+select fde, "Function declaration is implicit."

c/misra/test/rules/RULE-17-3/FunctionDeclaredImplicitly.expected

@@ -0,0 +1,2 @@
+| test.c:3:1:3:2 | declaration of f2 | Function declaration is implicit. |
+| test.c:11:17:11:17 | declaration of f3 | Function declaration is implicit. |

c/misra/test/rules/RULE-17-3/FunctionDeclaredImplicitly.qlref

@@ -0,0 +1 @@
+rules/RULE-17-3/FunctionDeclaredImplicitly.ql

c/misra/test/rules/RULE-17-3/test.c

@@ -0,0 +1,13 @@
+// semmle-extractor-options:--clang -std=c11 -nostdinc
+// -I../../../../common/test/includes/standard-library
+double f1(double x); // COMPLIANT
+f2(double x);        // NON_COMPLIANT
+
+void f() {
+  double l = 1;
+  double l1 = f1(l);
+
+  double l2 = f2(l);
+
+  double l3 = f3(l); // NON_COMPLIANT
+}

cpp/common/src/codingstandards/cpp/Identifiers.qll

@@ -0,0 +1,46 @@
+import cpp
+import codingstandards.cpp.Linkage
+
+class ExternalIdentifiers extends InterestingIdentifiers {
+  ExternalIdentifiers() {
+    hasExternalLinkage(this) and
+    getNamespace() instanceof GlobalNamespace
+  }
+
+  string getSignificantName() {
+    //C99 states the first 31 characters of external identifiers are significant
+    //C90 states the first 6 characters of external identifiers are significant and case is not required to be significant
+    //C90 is not currently considered by this rule
+    result = this.getName().prefix(31)
+  }
+}
+
+//Identifiers that are candidates for checking uniqueness
+class InterestingIdentifiers extends Declaration {
+  InterestingIdentifiers() {
+    not this.isFromTemplateInstantiation(_) and
+    not this.isFromUninstantiatedTemplate(_) and
+    not this instanceof TemplateParameter and
+    not this.hasDeclaringType() and
+    not this instanceof Operator and
+    not this.hasName("main") and
+    exists(this.getADeclarationLocation())
+  }
+
+  //this definition of significant relies on the number of significant characters for a macro name (C99)
+  //this is used on macro name comparisons only
+  //not necessarily against other types of identifiers
+  string getSignificantNameComparedToMacro() { result = this.getName().prefix(63) }
+}
+
+//Declarations that omit type - C90 compiler assumes int
+predicate isDeclaredImplicit(Declaration d) {
+  d.hasSpecifier("implicit_int") and
+  exists(Type t |
+    (d.(Variable).getType() = t or d.(Function).getType() = t) and
+    // Exclude "short" or "long", as opposed to "short int" or "long int".
+    t instanceof IntType and
+    // Exclude "signed" or "unsigned", as opposed to "signed int" or "unsigned int".
+    not exists(IntegralType it | it = t | it.isExplicitlySigned() or it.isExplicitlyUnsigned())
+  )
+}

cpp/common/src/codingstandards/cpp/exclusions/c/Declarations6.qll

@@ -0,0 +1,26 @@
+//** THIS FILE IS AUTOGENERATED, DO NOT MODIFY DIRECTLY.  **/
+import cpp
+import RuleMetadata
+import codingstandards.cpp.exclusions.RuleMetadata
+
+newtype Declarations6Query = TFunctionDeclaredImplicitlyQuery()
+
+predicate isDeclarations6QueryMetadata(Query query, string queryId, string ruleId, string category) {
+  query =
+    // `Query` instance for the `functionDeclaredImplicitly` query
+    Declarations6Package::functionDeclaredImplicitlyQuery() and
+  queryId =
+    // `@id` for the `functionDeclaredImplicitly` query
+    "c/misra/function-declared-implicitly" and
+  ruleId = "RULE-17-3" and
+  category = "mandatory"
+}
+
+module Declarations6Package {
+  Query functionDeclaredImplicitlyQuery() {
+    //autogenerate `Query` type
+    result =
+      // `Query` type for `functionDeclaredImplicitly` query
+      TQueryC(TDeclarations6PackageQuery(TFunctionDeclaredImplicitlyQuery()))
+  }
+}

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

@@ -15,6 +15,7 @@ import Contracts4
 import Declarations1
 import Declarations2
 import Declarations3
+import Declarations6
 import Expressions
 import IO1
 import IO2
@@ -53,6 +54,7 @@ newtype TCQuery =
   TDeclarations1PackageQuery(Declarations1Query q) or
   TDeclarations2PackageQuery(Declarations2Query q) or
   TDeclarations3PackageQuery(Declarations3Query q) or
+  TDeclarations6PackageQuery(Declarations6Query q) or
   TExpressionsPackageQuery(ExpressionsQuery q) or
   TIO1PackageQuery(IO1Query q) or
   TIO2PackageQuery(IO2Query q) or
@@ -91,6 +93,7 @@ predicate isQueryMetadata(Query query, string queryId, string ruleId, string cat
   isDeclarations1QueryMetadata(query, queryId, ruleId, category) or
   isDeclarations2QueryMetadata(query, queryId, ruleId, category) or
   isDeclarations3QueryMetadata(query, queryId, ruleId, category) or
+  isDeclarations6QueryMetadata(query, queryId, ruleId, category) or
   isExpressionsQueryMetadata(query, queryId, ruleId, category) or
   isIO1QueryMetadata(query, queryId, ruleId, category) or
   isIO2QueryMetadata(query, queryId, ruleId, category) or

cpp/common/src/codingstandards/cpp/rules/typeomitted/TypeOmitted.qll

@@ -5,20 +5,14 @@
 import cpp
 import codingstandards.cpp.Customizations
 import codingstandards.cpp.Exclusions
+import codingstandards.cpp.Identifiers
 
 abstract class TypeOmittedSharedQuery extends Query { }
 
 Query getQuery() { result instanceof TypeOmittedSharedQuery }
 
 query predicate problems(Declaration d, string message) {
   not isExcluded(d, getQuery()) and
-  d.hasSpecifier("implicit_int") and
-  exists(Type t |
-    (d.(Variable).getType() = t or d.(Function).getType() = t) and
-    // Exclude "short" or "long", as opposed to "short int" or "long int".
-    t instanceof IntType and
-    // Exclude "signed" or "unsigned", as opposed to "signed int" or "unsigned int".
-    not exists(IntegralType it | it = t | it.isExplicitlySigned() or it.isExplicitlyUnsigned())
-  ) and
+  isDeclaredImplicit(d) and
   message = "Declaration " + d.getName() + " is missing a type specifier."
 }

rule_packages/c/Declarations6.json

@@ -0,0 +1,24 @@
+{
+  "MISRA-C-2012": {
+    "RULE-17-3": {
+      "properties": {
+        "obligation": "mandatory"
+      },
+      "queries": [
+        {
+          "description": "Omission of type specifiers may not be supported by some compilers. Additionally implicit typing can lead to undefined behaviour.",
+          "kind": "problem",
+          "name": "A function shall not be declared implicitly",
+          "precision": "very-high",
+          "severity": "error",
+          "short_name": "FunctionDeclaredImplicitly",
+          "tags": [
+            "correctness",
+            "readability"
+          ]
+        }
+      ],
+      "title": "A function shall not be declared implicitly"
+    }
+  }
+}

rules.csv

@@ -713,7 +713,7 @@ c,MISRA-C-2012,RULE-16-6,Yes,Required,,,Every switch statement shall have at lea
 c,MISRA-C-2012,RULE-16-7,Yes,Required,,,A switch-expression shall not have essentially Boolean type,M6-4-7,Statements,Medium,
 c,MISRA-C-2012,RULE-17-1,Yes,Required,,,The features of <stdarg.h> shall not be used,,Banned,Easy,
 c,MISRA-C-2012,RULE-17-2,Yes,Required,,,"Functions shall not call themselves, either directly or indirectly",A7-5-2,Statements,Import,
-c,MISRA-C-2012,RULE-17-3,Yes,Mandatory,,,A function shall not be declared implicitly,,Declarations,Medium,
+c,MISRA-C-2012,RULE-17-3,Yes,Mandatory,,,A function shall not be declared implicitly,,Declarations6,Medium,
 c,MISRA-C-2012,RULE-17-4,Yes,Mandatory,,,All exit paths from a function with non-void return type shall have an explicit return statement with an expression,MSC52-CPP,Statements,Medium,
 c,MISRA-C-2012,RULE-17-5,Yes,Advisory,,,The function argument corresponding to a parameter declared to have an array type shall have an appropriate number of elements,,Contracts,Hard,
 c,MISRA-C-2012,RULE-17-6,No,Mandatory,,,The declaration of an array parameter shall not contain the static keyword between the [ ],,,,