Add ErrorConsole UI for Extension Install Warnings

extensions/browser/manifest_highlighter.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stack>
+
+#include "extensions/browser/manifest_highlighter.h"
+
+namespace extensions {
+
+namespace {
+
+size_t FindNextQuote(const std::string& string, size_t index) {
+  bool found = false;
+  while (!found && index < string.size()) {
+    if (string[index] == '\\')
+      index += 2;  // if we find an escaped character, skip it.
+    else if (string[index] == '"')
+      found = true;
+    else
+      ++index;
+  }
+  return index < string.size() ? index : std::string::npos;

[Yoyo Zhou, 2013/08/19 21:48:51]

Should this test use found?

[Devlin, 2013/08/20 20:38:22]

Done.

+}
+
+}  // namespace
+
+ManifestHighlighter::ManifestHighlighter(const std::string& manifest,
+                                         const std::string& key,
+                                         const std::string& specific)
+    : manifest_(manifest),
+      start_(manifest_.find('{') + 1),
+      end_(manifest_.rfind('}')) {
+  Parse(key, specific);
+}
+
+ManifestHighlighter::~ManifestHighlighter() {
+}
+
+std::string ManifestHighlighter::GetBeforeFeature() const {
+  return manifest_.substr(0, start_);
+}
+
+std::string ManifestHighlighter::GetFeature() const {
+  return manifest_.substr(start_, end_ - start_);
+}
+
+std::string ManifestHighlighter::GetAfterFeature() const {
+  return manifest_.substr(end_);
+}
+
+void ManifestHighlighter::Parse(const std::string& key,
+                                const std::string& specific) {
+  // First, try to find the bounds of the full key.
+  if (FindBounds(key, true) /* enforce at top level */ ) {
+    // If we succeed, and we have a specific location, find the bounds of the
+    // specific.
+    if (!specific.empty())
+      FindBounds(specific, false /* don't enforce at top level */ );
+
+    // We may have found trailing whitespace. Don't use base::TrimWhitespace,
+    // because we want to keep any whitespace we find - just not highlight it.
+    size_t trim = manifest_.find_last_not_of(" \t\n\r", end_ - 1);
+    if (trim < end_ && trim > start_)
+      end_ = trim + 1;
+  } else {
+    // If we fail, then we set start to end so that the highlighted portion is
+    // empty.
+    start_ = end_;
+  }
+}
+
+bool ManifestHighlighter::FindBounds(const std::string& feature,
+                                     bool enforce_at_top_level) {
+  char c = '\0';
+  while (start_ < end_) {
+    c = manifest_[start_];
+    if (c == '"') {
+      // The feature may be quoted.
+      size_t quote_end = FindNextQuote(manifest_, start_ + 1);
+      if (manifest_.substr(start_ + 1, quote_end - 1 - start_) == feature) {
+        FindBoundsEnd(feature, quote_end + 1);
+        return true;
+      } else {
+        // If it's not the feature, then we can skip the quoted section.
+        start_ = quote_end + 1;
+      }
+    } else if (manifest_.substr(start_, feature.size()) == feature) {
+        FindBoundsEnd(feature, start_ + feature.size() + 1);
+        return true;
+    } else if (enforce_at_top_level && (c == '{' || c == '[')) {
+      // If we don't have to be at the top level, then we can skip any chunks
+      // we find.
+      ChunkIncrement(&start_);
+    } else {
+      CommentSafeIncrement(&start_);
+    }
+  }
+  return false;
+}
+
+void ManifestHighlighter::FindBoundsEnd(const std::string& feature,
+                                        size_t local_start) {
+  char c = '\0';
+  while (local_start < end_) {
+    c = manifest_[local_start];
+    // We're done when we find a terminating character (i.e., either a comma or
+    // an ending bracket.
+    if (c == ',' || c == '}' || c == ']') {
+      end_ = local_start;
+      return;
+    }
+    // We can skip any chunks we find, since we are looking for the end of the
+    // current feature, and don't want to go any deeper.
+    if (c == '"' || c == '{' || c == '[')
+      ChunkIncrement(&local_start);
+    else
+      CommentSafeIncrement(&local_start);
+  }
+}
+
+void ManifestHighlighter::ChunkIncrement(size_t* index) {
+  char c = manifest_[*index];
+  std::stack<char> stack;
+  do {
+    if (c == '"')
+      *index = FindNextQuote(manifest_, *index + 1);
+    else if (c == '[')
+      stack.push(']');
+    else if (c == '{')
+      stack.push('}');
+    else if (!stack.empty() && c == stack.top())
+      stack.pop();
+    CommentSafeIncrement(index);
+    c = manifest_[*index];
+  } while (!stack.empty() && *index < end_);
+}
+
+void ManifestHighlighter::CommentSafeIncrement(size_t* index) {

[Yoyo Zhou, 2013/08/19 21:48:51]

nit: seems like this and FindNextQuote are in the same family, so they should
both be in the anon namespace and have the same interface.

[Devlin, 2013/08/20 20:38:22]

Done.

+  size_t i = *index;
+  if (manifest_[i] == '/' && i + 1 < manifest_.size()) {
+    // Eat a single-line comment.
+    if (manifest_[i + 1] == '/') {
+      i += 2;  // Eat the '//'.
+      while (i < manifest_.size() &&
+             manifest_[i] != '\n' && manifest_[i] != '\r') {
+        ++i;
+      }
+    } else if (manifest_[i + 1] == '*') {  // Eat a multi-line comment.
+      i += 3;  // Advance to the first possible comment end.
+      while (i < manifest_.size() &&
+             !(manifest_[i - 1] == '*' && manifest_[i] == '/')) {
+        ++i;
+      }
+    }
+  }
+  *index = i + 1;
+}
+
+}  // namespace extensions