misra.py: Add R18.7 check (#1934)

* misra.py: Add 18.7 check

* Simplify R18.7 check

* use token.link

* Remove isStruct method

addons/misra.py

@@ -1628,6 +1628,24 @@ class MisraChecker:
                 self.reportError(var.nameToken, 18, 5)
 
 
+    def misra_18_7(self, data):
+        for scope in data.scopes:
+            if scope.type != 'Struct':
+                continue
+
+            token = scope.bodyStart.next
+            while token != scope.bodyEnd and token is not None:
+                # Handle nested structures to not duplicate an error.
+                if token.str == '{':
+                    token = token.link
+
+                if cppcheckdata.simpleMatch(token, "[ ]"):
+                    self.reportError(token, 18, 7)
+                    break
+                token = token.next
+
+
+
     def misra_18_8(self, data):
         for var in data.variables:
             if not var.isArray or not var.isLocal:
@@ -2287,6 +2305,7 @@ class MisraChecker:
             self.misra_17_7(cfg)
             self.misra_17_8(cfg)
             self.misra_18_5(cfg)
+            self.misra_18_7(cfg)
             self.misra_18_8(cfg)
             self.misra_19_2(cfg)
             self.misra_20_1(cfg)

addons/test/misra-test.c

@@ -507,6 +507,25 @@ void misra_18_5() {
   int *** p;  // 18.5
 }
 
+struct {
+  uint16_t len;
+  struct {
+    uint8_t data_1[]; // 18.7
+  } nested_1;
+  struct named {
+    struct {
+      uint8_t len_1;
+      uint32_t data_2[]; // 18.7
+    } nested_2;
+    uint8_t data_3[]; // 18.7
+  } nested_3;
+} _18_7_struct;
+struct {
+  uint16_t len;
+  uint8_t data_1[ 19 ];
+  uint8_t data_2[   ]; // 18.7
+} _18_7_struct;
+
 void misra_18_8(int x) {
   int buf1[10];
   int buf2[sizeof(int)];