AAPT2: allow regexes for extensions to not compress

Change-Id: I09d2ad1d1466643ca7628c6480224e16b9002ee5
Fixes: 67575899
Test: added + manual
diff --git a/tools/aapt2/cmd/Link.cpp b/tools/aapt2/cmd/Link.cpp
index 8463046..0befb6f 100644
--- a/tools/aapt2/cmd/Link.cpp
+++ b/tools/aapt2/cmd/Link.cpp
@@ -268,6 +268,7 @@
   bool update_proguard_spec = false;
   OutputFormat output_format = OutputFormat::kApk;
   std::unordered_set<std::string> extensions_to_not_compress;
+  Maybe<std::regex> regex_to_not_compress;
 };
 
 // A sampling of public framework resource IDs.
@@ -377,11 +378,18 @@
   }
 }
 
+// TODO(rtmitchell): turn this function into a variable that points to a method that retrieves the
+// compression flag
 uint32_t ResourceFileFlattener::GetCompressionFlags(const StringPiece& str) {
   if (options_.do_not_compress_anything) {
     return 0;
   }
 
+  if (options_.regex_to_not_compress
+      && std::regex_search(str.to_string(), options_.regex_to_not_compress.value())) {
+    return 0;
+  }
+
   for (const std::string& extension : options_.extensions_to_not_compress) {
     if (util::EndsWith(str, extension)) {
       return 0;
@@ -1530,7 +1538,11 @@
     for (auto& entry : merged_assets) {
       uint32_t compression_flags = ArchiveEntry::kCompress;
       std::string extension = file::GetExtension(entry.first).to_string();
-      if (options_.extensions_to_not_compress.count(extension) > 0) {
+
+      if (options_.do_not_compress_anything
+          || options_.extensions_to_not_compress.count(extension) > 0
+          || (options_.regex_to_not_compress
+              && std::regex_search(extension, options_.regex_to_not_compress.value()))) {
         compression_flags = 0u;
       }
 
@@ -1558,6 +1570,7 @@
     file_flattener_options.keep_raw_values = keep_raw_values;
     file_flattener_options.do_not_compress_anything = options_.do_not_compress_anything;
     file_flattener_options.extensions_to_not_compress = options_.extensions_to_not_compress;
+    file_flattener_options.regex_to_not_compress = options_.regex_to_not_compress;
     file_flattener_options.no_auto_version = options_.no_auto_version;
     file_flattener_options.no_version_vectors = options_.no_version_vectors;
     file_flattener_options.no_version_transitions = options_.no_version_transitions;
@@ -2165,6 +2178,20 @@
     }
   }
 
+  if (no_compress_regex) {
+    std::string regex = no_compress_regex.value();
+    if (util::StartsWith(regex, "@")) {
+      const std::string path = regex.substr(1, regex.size() -1);
+      std::string error;
+      if (!file::AppendSetArgsFromFile(path, &options_.extensions_to_not_compress, &error)) {
+        context.GetDiagnostics()->Error(DiagMessage(path) << error);
+        return 1;
+      }
+    } else {
+      options_.regex_to_not_compress = GetRegularExpression(no_compress_regex.value());
+    }
+  }
+
   // Populate some default no-compress extensions that are already compressed.
   options_.extensions_to_not_compress.insert(
       {".jpg",   ".jpeg", ".png",  ".gif", ".wav",  ".mp2",  ".mp3",  ".ogg",
diff --git a/tools/aapt2/cmd/Link.h b/tools/aapt2/cmd/Link.h
index 590a6bb..1fc149a 100644
--- a/tools/aapt2/cmd/Link.h
+++ b/tools/aapt2/cmd/Link.h
@@ -17,6 +17,8 @@
 #ifndef AAPT2_LINK_H
 #define AAPT2_LINK_H
 
+#include <regex>
+
 #include "Command.h"
 #include "Diagnostics.h"
 #include "Resource.h"
@@ -63,6 +65,7 @@
   bool no_xml_namespaces = false;
   bool do_not_compress_anything = false;
   std::unordered_set<std::string> extensions_to_not_compress;
+  Maybe<std::regex> regex_to_not_compress;
 
   // Static lib options.
   bool no_static_lib_packages = false;
@@ -250,6 +253,11 @@
         &options_.do_not_compress_anything);
     AddOptionalSwitch("--keep-raw-values", "Preserve raw attribute values in xml files.",
         &options_.keep_raw_values);
+    AddOptionalFlag("--no-compress-regex",
+        "Do not compress extensions matching the regular expression. Remember to\n"
+            " use the '$' symbol for end of line. Uses a non case-sensitive\n"
+            " ECMAScript regular expression grammar.",
+        &no_compress_regex);
     AddOptionalSwitch("--warn-manifest-validation",
         "Treat manifest validation errors as warnings.",
         &options_.manifest_fixer_options.warn_validation);
@@ -283,6 +291,7 @@
   std::vector<std::string> configs_;
   Maybe<std::string> preferred_density_;
   Maybe<std::string> product_list_;
+  Maybe<std::string> no_compress_regex;
   bool legacy_x_flag_ = false;
   bool require_localization_ = false;
   bool verbose_ = false;
diff --git a/tools/aapt2/cmd/Util.cpp b/tools/aapt2/cmd/Util.cpp
index 792120e..e2c65ba7 100644
--- a/tools/aapt2/cmd/Util.cpp
+++ b/tools/aapt2/cmd/Util.cpp
@@ -435,4 +435,11 @@
   }
 }
 
+std::regex GetRegularExpression(const std::string &input) {
+  // Standard ECMAScript grammar plus case insensitive.
+  std::regex case_insensitive(
+      input, std::regex_constants::icase | std::regex_constants::ECMAScript);
+  return case_insensitive;
+}
+
 }  // namespace aapt
diff --git a/tools/aapt2/cmd/Util.h b/tools/aapt2/cmd/Util.h
index cf1443e..2a7c62e 100644
--- a/tools/aapt2/cmd/Util.h
+++ b/tools/aapt2/cmd/Util.h
@@ -17,6 +17,8 @@
 #ifndef AAPT_SPLIT_UTIL_H
 #define AAPT_SPLIT_UTIL_H
 
+#include <regex>
+
 #include "androidfw/StringPiece.h"
 
 #include "AppInfo.h"
@@ -72,6 +74,9 @@
 // versionCodeMajor if the version code requires more than 32 bits.
 void SetLongVersionCode(xml::Element* manifest, uint64_t version_code);
 
+// Returns a case insensitive regular expression based on the input.
+std::regex GetRegularExpression(const std::string &input);
+
 }  // namespace aapt
 
 #endif /* AAPT_SPLIT_UTIL_H */
diff --git a/tools/aapt2/cmd/Util_test.cpp b/tools/aapt2/cmd/Util_test.cpp
index f92f1e3..7e49261 100644
--- a/tools/aapt2/cmd/Util_test.cpp
+++ b/tools/aapt2/cmd/Util_test.cpp
@@ -383,4 +383,12 @@
   EXPECT_NE(*adjusted_contraints[1].configs.begin(), ConfigDescription::DefaultConfig());
 }
 
+TEST(UtilTest, RegularExperssions) {
+  std::string valid(".bc$");
+  std::regex expression = GetRegularExpression(valid);
+  EXPECT_TRUE(std::regex_search("file.abc", expression));
+  EXPECT_TRUE(std::regex_search("file.123bc", expression));
+  EXPECT_FALSE(std::regex_search("abc.zip", expression));
+}
+
 }  // namespace aapt
diff --git a/tools/aapt2/util/Files.cpp b/tools/aapt2/util/Files.cpp
index 7b268bb..604b257 100644
--- a/tools/aapt2/util/Files.cpp
+++ b/tools/aapt2/util/Files.cpp
@@ -251,6 +251,25 @@
   return true;
 }
 
+bool AppendSetArgsFromFile(const StringPiece& path, std::unordered_set<std::string>* out_argset,
+                           std::string* out_error) {
+  std::string contents;
+  if(!ReadFileToString(path.to_string(), &contents, true /*follow_symlinks*/)) {
+    if (out_error) {
+      *out_error = "failed to read argument-list file";
+    }
+    return false;
+  }
+
+  for (StringPiece line : util::Tokenize(contents, ' ')) {
+    line = util::TrimWhitespace(line);
+    if (!line.empty()) {
+      out_argset->insert(line.to_string());
+    }
+  }
+  return true;
+}
+
 bool FileFilter::SetPattern(const StringPiece& pattern) {
   pattern_tokens_ = util::SplitAndLowercase(pattern, ':');
   return true;
diff --git a/tools/aapt2/util/Files.h b/tools/aapt2/util/Files.h
index 5839552..481a4cd 100644
--- a/tools/aapt2/util/Files.h
+++ b/tools/aapt2/util/Files.h
@@ -19,6 +19,7 @@
 
 #include <memory>
 #include <string>
+#include <unordered_set>
 #include <vector>
 
 #include "android-base/macros.h"
@@ -86,6 +87,10 @@
 bool AppendArgsFromFile(const android::StringPiece& path, std::vector<std::string>* out_arglist,
                         std::string* out_error);
 
+// Reads the file at path and appends each line to the outargset set.
+bool AppendSetArgsFromFile(const android::StringPiece& path,
+                        std::unordered_set<std::string>* out_argset, std::string* out_error);
+
 // Filter that determines which resource files/directories are
 // processed by AAPT. Takes a pattern string supplied by the user.
 // Pattern format is specified in the FileFilter::SetPattern() method.