1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "xml/XmlActionExecutor.h"
18 
19 using ::android::StringPiece;
20 
21 namespace aapt {
22 namespace xml {
23 
wrapper_one(XmlNodeAction::ActionFunc & f,Element * el,SourcePathDiagnostics *)24 static bool wrapper_one(XmlNodeAction::ActionFunc& f, Element* el, SourcePathDiagnostics*) {
25   return f(el);
26 }
27 
wrapper_two(XmlNodeAction::ActionFuncWithDiag & f,Element * el,SourcePathDiagnostics * diag)28 static bool wrapper_two(XmlNodeAction::ActionFuncWithDiag& f, Element* el,
29                         SourcePathDiagnostics* diag) {
30   return f(el, diag);
31 }
32 
Action(XmlNodeAction::ActionFunc f)33 void XmlNodeAction::Action(XmlNodeAction::ActionFunc f) {
34   actions_.emplace_back(std::bind(
35       wrapper_one, std::move(f), std::placeholders::_1, std::placeholders::_2));
36 }
37 
Action(XmlNodeAction::ActionFuncWithDiag f)38 void XmlNodeAction::Action(XmlNodeAction::ActionFuncWithDiag f) {
39   actions_.emplace_back(std::bind(
40       wrapper_two, std::move(f), std::placeholders::_1, std::placeholders::_2));
41 }
42 
PrintElementToDiagMessage(const Element * el,DiagMessage * msg)43 static void PrintElementToDiagMessage(const Element* el, DiagMessage* msg) {
44   *msg << "<";
45   if (!el->namespace_uri.empty()) {
46     *msg << el->namespace_uri << ":";
47   }
48   *msg << el->name << ">";
49 }
50 
Execute(XmlActionExecutorPolicy policy,std::vector<StringPiece> * bread_crumb,SourcePathDiagnostics * diag,Element * el) const51 bool XmlNodeAction::Execute(XmlActionExecutorPolicy policy, std::vector<StringPiece>* bread_crumb,
52                             SourcePathDiagnostics* diag, Element* el) const {
53   bool error = false;
54   for (const ActionFuncWithDiag& action : actions_) {
55     error |= !action(el, diag);
56   }
57 
58   for (Element* child_el : el->GetChildElements()) {
59     if (child_el->namespace_uri.empty()) {
60       std::map<std::string, XmlNodeAction>::const_iterator iter = map_.find(child_el->name);
61       if (iter != map_.end()) {
62         // Use the iterator's copy of the element name, because the element may be modified.
63         bread_crumb->push_back(iter->first);
64         error |= !iter->second.Execute(policy, bread_crumb, diag, child_el);
65         bread_crumb->pop_back();
66         continue;
67       }
68 
69       if (policy != XmlActionExecutorPolicy::kNone) {
70         DiagMessage error_msg(child_el->line_number);
71         error_msg << "unexpected element ";
72         PrintElementToDiagMessage(child_el, &error_msg);
73         error_msg << " found in ";
74         for (const StringPiece& element : *bread_crumb) {
75           error_msg << "<" << element << ">";
76         }
77         if (policy == XmlActionExecutorPolicy::kWhitelistWarning) {
78           // Treat the error only as a warning.
79           diag->Warn(error_msg);
80         } else {
81           // Policy is XmlActionExecutorPolicy::kWhitelist, we should fail.
82           diag->Error(error_msg);
83           error = true;
84         }
85       }
86     }
87   }
88   return !error;
89 }
90 
Execute(XmlActionExecutorPolicy policy,IDiagnostics * diag,XmlResource * doc) const91 bool XmlActionExecutor::Execute(XmlActionExecutorPolicy policy, IDiagnostics* diag,
92                                 XmlResource* doc) const {
93   SourcePathDiagnostics source_diag(doc->file.source, diag);
94 
95   Element* el = doc->root.get();
96   if (!el) {
97     if (policy == XmlActionExecutorPolicy::kWhitelist) {
98       source_diag.Error(DiagMessage() << "no root XML tag found");
99       return false;
100     }
101     return true;
102   }
103 
104   if (el->namespace_uri.empty()) {
105     std::map<std::string, XmlNodeAction>::const_iterator iter = map_.find(el->name);
106     if (iter != map_.end()) {
107       std::vector<StringPiece> bread_crumb;
108       bread_crumb.push_back(iter->first);
109       return iter->second.Execute(policy, &bread_crumb, &source_diag, el);
110     }
111 
112     if (policy == XmlActionExecutorPolicy::kWhitelist) {
113       DiagMessage error_msg(el->line_number);
114       error_msg << "unexpected root element ";
115       PrintElementToDiagMessage(el, &error_msg);
116       source_diag.Error(error_msg);
117       return false;
118     }
119   }
120   return true;
121 }
122 
123 }  // namespace xml
124 }  // namespace aapt
125