Declarations5: add RULE-8-9

Author: knewbury01

c/common/test/rules/unnecessaryexposedidentifierdeclarationshared/UnnecessaryExposedIdentifierDeclarationShared.expected

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+| test.c:4:12:4:13 | g2 | The declaration g2 should be moved from the global namespace scope$@ into the $@ too minimize its visibility. | file://:0:0:0:0 | (global namespace) | scope | test.c:59:11:59:25 | { ... } | scope |
+| test.c:7:7:7:7 | j | The declaration j should be moved from $@ into the $@ too minimize its visibility. | test.c:6:11:13:1 | { ... } | scope | test.c:8:13:12:3 | { ... } | scope |
+| test.c:62:7:62:7 | i | The declaration i should be moved from $@ into the $@ too minimize its visibility. | test.c:61:11:71:1 | { ... } | scope | test.c:64:13:70:3 | { ... } | scope |
+| test.c:73:8:73:9 | S1 | The declaration S1 should be moved from the global namespace scope$@ into the $@ too minimize its visibility. | file://:0:0:0:0 | (global namespace) | scope | test.c:77:12:77:28 | { ... } | scope |

c/common/test/rules/unnecessaryexposedidentifierdeclarationshared/UnnecessaryExposedIdentifierDeclarationShared.ql

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+// GENERATED FILE - DO NOT MODIFY
+import codingstandards.cpp.rules.unnecessaryexposedidentifierdeclarationshared.UnnecessaryExposedIdentifierDeclarationShared

c/common/test/rules/unnecessaryexposedidentifierdeclarationshared/test.c

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+#include <stdbool.h>
+extern void f1(int i);
+extern int g1; // COMPLIANT
+extern int g2; // NON_COMPLIANT; single use of a global variable
+bool f2() { return g1 == 1; }
+void f3() {
+  int j = g1; // NON_COMPLIANT
+  if (f2()) {
+    int k; // COMPLIANT
+    f1(j);
+    f1(k);
+  }
+}
+
+void f4() {
+  int j = g1; // COMPLIANT; value of g1 changed between
+              // definition and use
+  g1 = 1;
+  if (f2()) {
+    f1(j);
+  }
+}
+
+void f5() {
+  int j = g1; // COMPLIANT; shouldn't be moved inside loop
+  while (true) {
+    int i = g1++;
+    while (f2()) {
+      i += j;
+    }
+
+    if (i % 2)
+      break;
+  }
+}
+
+void f6() {
+  int j = g1; // COMPLIANT; can't moved into smaller scope
+#ifdef FOO
+  if (g1) {
+    g1 = j + 1;
+  }
+#else
+  if (g1) {
+    g1 = j + 2;
+  }
+#endif
+}
+
+void f7() {
+  int j = g1; // COMPLIANT; potentially stores previous value of
+              // g1 so moving this would be incorrect.
+  f1(1);      // f1 may change the value of g1
+  if (f2()) {
+    f1(j);
+  }
+}
+
+void f8() { int i = g2; }
+
+void f9() {
+  int i; // NON_COMPLIANT
+
+  if (f2()) {
+    if (f2()) {
+      i++;
+    } else {
+      i--;
+    }
+  }
+}
+
+struct S1 { // NON_COMPLIANT
+  int i;
+};
+
+void f10() { struct S1 l1; }
+
+void f11() {
+  struct S2 { // COMPLIANT
+    int i;
+  } l1;
+}
+
+struct S3 {
+  int i;
+};
+
+struct S4 { // NON_COMPLIANT; single use in function f13
+  int i;
+};
+
+void f15() {
+  int i; // COMPLIANT
+
+  if (i == 0) {
+    i++;
+  }
+}
+
+void f17() {
+  int i; // COMPLIANT
+  int *ptr;
+  {
+    // Moving the declaration of i into the reduced scope will result in a
+    // dangling pointer
+    ptr = &i;
+  }
+  *ptr = 1;
+}

c/misra/src/rules/RULE-8-9/UnnecessaryExposedIdentifierDeclarationC.ql

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+/**
+ * @id c/misra/unnecessary-exposed-identifier-declaration-c
+ * @name RULE-8-9: An object should be defined at block scope if its identifier only appears in a single function
+ * @description An identifier declared to be an object or type shall be defined in a block that
+ *              minimizes its visibility to prevent any accidental use of the identifier.
+ * @kind problem
+ * @precision high
+ * @problem.severity warning
+ * @tags external/misra/id/rule-8-9
+ *       correctness
+ *       external/misra/obligation/advisory
+ */
+
+import cpp
+import codingstandards.c.misra
+import codingstandards.cpp.rules.unnecessaryexposedidentifierdeclarationshared.UnnecessaryExposedIdentifierDeclarationShared
+
+class UnnecessaryExposedIdentifierDeclarationCQuery extends UnnecessaryExposedIdentifierDeclarationSharedSharedQuery {
+  UnnecessaryExposedIdentifierDeclarationCQuery() {
+    this = Declarations5Package::unnecessaryExposedIdentifierDeclarationCQuery()
+  }
+}

c/misra/test/rules/RULE-8-9/UnnecessaryExposedIdentifierDeclarationC.testref

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+c/common/test/rules/unnecessaryexposedidentifierdeclarationshared/UnnecessaryExposedIdentifierDeclarationShared.ql