build/clang-plugin/OverrideBaseCallChecker.cpp

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "OverrideBaseCallChecker.h"
   6 #include "CustomMatchers.h"
   7
   8 void OverrideBaseCallChecker::registerMatchers(MatchFinder *AstMatcher) {
   9   AstMatcher->addMatcher(cxxRecordDecl(hasBaseClasses()).bind("class"), this);
  10 }
  11
  12 bool OverrideBaseCallChecker::isRequiredBaseMethod(
  13     const CXXMethodDecl *Method) {
  14   return hasCustomAttribute<moz_required_base_method>(Method);
  15 }
  16
  17 void OverrideBaseCallChecker::evaluateExpression(
  18     const Stmt *StmtExpr, std::list<const CXXMethodDecl *> &MethodList) {
  19   // Continue while we have methods in our list
  20   if (!MethodList.size()) {
  21     return;
  22   }
  23
  24   if (auto MemberFuncCall = dyn_cast<CXXMemberCallExpr>(StmtExpr)) {
  25     if (auto Method =
  26             dyn_cast<CXXMethodDecl>(MemberFuncCall->getDirectCallee())) {
  27       findBaseMethodCall(Method, MethodList);
  28     }
  29   }
  30
  31   for (auto S : StmtExpr->children()) {
  32     if (S) {
  33       evaluateExpression(S, MethodList);
  34     }
  35   }
  36 }
  37
  38 void OverrideBaseCallChecker::getRequiredBaseMethod(
  39     const CXXMethodDecl *Method,
  40     std::list<const CXXMethodDecl *> &MethodsList) {
  41
  42   if (isRequiredBaseMethod(Method)) {
  43     MethodsList.push_back(Method);
  44   } else {
  45     // Loop through all it's base methods.
  46     for (auto BaseMethod = Method->begin_overridden_methods();
  47          BaseMethod != Method->end_overridden_methods(); BaseMethod++) {
  48       getRequiredBaseMethod(*BaseMethod, MethodsList);
  49     }
  50   }
  51 }
  52
  53 void OverrideBaseCallChecker::findBaseMethodCall(
  54     const CXXMethodDecl *Method,
  55     std::list<const CXXMethodDecl *> &MethodsList) {
  56
  57   MethodsList.remove(Method);
  58   // Loop also through all it's base methods;
  59   for (auto BaseMethod = Method->begin_overridden_methods();
  60        BaseMethod != Method->end_overridden_methods(); BaseMethod++) {
  61     findBaseMethodCall(*BaseMethod, MethodsList);
  62   }
  63 }
  64
  65 void OverrideBaseCallChecker::check(const MatchFinder::MatchResult &Result) {
  66   const char *Error =
  67       "Method %0 must be called in all overrides, but is not called in "
  68       "this override defined for class %1";
  69   const CXXRecordDecl *Decl = Result.Nodes.getNodeAs<CXXRecordDecl>("class");
  70
  71   // Loop through the methods and look for the ones that are overridden.
  72   for (auto Method : Decl->methods()) {
  73     // If this method doesn't override other methods or it doesn't have a body,
  74     // continue to the next declaration.
  75     if (!Method->size_overridden_methods() || !Method->hasBody()) {
  76       continue;
  77     }
  78
  79     // Preferred the usage of list instead of vector in order to avoid
  80     // calling erase-remove when deleting items
  81     std::list<const CXXMethodDecl *> MethodsList;
  82     // For each overridden method push it to a list if it meets our
  83     // criteria
  84     for (auto BaseMethod = Method->begin_overridden_methods();
  85          BaseMethod != Method->end_overridden_methods(); BaseMethod++) {
  86       getRequiredBaseMethod(*BaseMethod, MethodsList);
  87     }
  88
  89     // If no method has been found then no annotation was used
  90     // so checking is not needed
  91     if (!MethodsList.size()) {
  92       continue;
  93     }
  94
  95     // Loop through the body of our method and search for calls to
  96     // base methods
  97     evaluateExpression(Method->getBody(), MethodsList);
  98
  99     // If list is not empty pop up errors
 100     for (auto BaseMethod : MethodsList) {
 101       std::string QualName;
 102       raw_string_ostream OS(QualName);
 103       BaseMethod->printQualifiedName(OS);
 104
 105       diag(Method->getLocation(), Error, DiagnosticIDs::Error)
 106           << OS.str() << Decl->getName();
 107     }
 108   }
 109 }