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 {
+
+// Increment |index| to the position of the next quote ('"') in |str|, skipping
+// over any escaped quotes. If no next quote is found, |index| is set to
+// std::string::npos. Assumes |index| currently points to a quote.
+void QuoteIncrement(const std::string& str, size_t* index) {
+  size_t i = *index + 1;  // Skip over the first quote.
+  bool found = false;
+  while (!found && i < str.size()) {
+    if (str[i] == '\\')
+      i += 2;  // if we find an escaped character, skip it.
+    else if (str[i] == '"')
+      found = true;
+    else
+      ++i;
+  }
+  *index = found ? i : std::string::npos;
+}
+
+// Increment |index| by one if the next character is not a comment. Increment
+// index until the end of the comment if it is a comment.
+void CommentSafeIncrement(const std::string& str, size_t* index) {
+  size_t i = *index;
+  if (str[i] == '/' && i + 1 < str.size()) {
+    // Eat a single-line comment.
+    if (str[i + 1] == '/') {
+      i += 2;  // Eat the '//'.
+      while (i < str.size() && str[i] != '\n' && str[i] != '\r')
+        ++i;
+    } else if (str[i + 1] == '*') {  // Eat a multi-line comment.
+      i += 3;  // Advance to the first possible comment end.
+      while (i < str.size() && !(str[i - 1] == '*' && str[i] == '/'))
+        ++i;
+    }
+  }
+  *index = i + 1;
+}
+
+// Increment index until the end of the current "chunk"; a "chunk" is a JSON-
+// style list, object, or string literal, without exceeding |end|. Assumes
+// |index| currently points to a chunk's starting character ('{', '[', or '"').
+void ChunkIncrement(const std::string& str, size_t* index, size_t end) {
+  char c = str[*index];
+  std::stack<char> stack;
+  do {
+    if (c == '"')
+      QuoteIncrement(str, index);
+    else if (c == '[')
+      stack.push(']');
+    else if (c == '{')
+      stack.push('}');
+    else if (!stack.empty() && c == stack.top())
+      stack.pop();
+    CommentSafeIncrement(str, index);
+    c = str[*index];
+  } while (!stack.empty() && *index < end);
+}
+
+}  // 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 = start_;
+      QuoteIncrement(manifest_, &quote_end);
+      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(manifest_, &start_, end_);
+    } else {
+      CommentSafeIncrement(manifest_, &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(manifest_, &local_start, end_);
+    else
+      CommentSafeIncrement(manifest_, &local_start);
+  }
+}
+
+}  // namespace extensions