From b1c9c20eb270e54de95000d8923813c6a44fe467 Mon Sep 17 00:00:00 2001
From: Christopher Ferris <cferris@google.com>
Date: Fri, 25 Jan 2019 14:28:13 -0800
Subject: [PATCH] Add GetPrintableBuildID().

The GetBuildID() function returns the raw build id data, so add a function
to get the printable hex version of the data.

Bug: 120606663

Test: New unit tests pass.
Change-Id: Ia5aefc97457efb08bbd30ea96cbb2d47ae59f954
---
 libunwindstack/MapInfo.cpp                     | 14 ++++++++++++++
 libunwindstack/include/unwindstack/MapInfo.h   |  4 ++++
 libunwindstack/tests/MapInfoGetBuildIDTest.cpp |  3 +++
 3 files changed, 21 insertions(+)

diff --git a/libunwindstack/MapInfo.cpp b/libunwindstack/MapInfo.cpp
index f3199711b..9e6bcd4e3 100644
--- a/libunwindstack/MapInfo.cpp
+++ b/libunwindstack/MapInfo.cpp
@@ -22,6 +22,8 @@
 #include <mutex>
 #include <string>
 
+#include <android-base/stringprintf.h>
+
 #include <unwindstack/Elf.h>
 #include <unwindstack/MapInfo.h>
 #include <unwindstack/Maps.h>
@@ -311,4 +313,16 @@ std::string MapInfo::GetBuildID() {
   return *reinterpret_cast<std::string*>(id);
 }
 
+std::string MapInfo::GetPrintableBuildID() {
+  std::string raw_build_id = GetBuildID();
+  if (raw_build_id.empty()) {
+    return "";
+  }
+  std::string printable_build_id;
+  for (const char& c : raw_build_id) {
+    printable_build_id += android::base::StringPrintf("%02x", c);
+  }
+  return printable_build_id;
+}
+
 }  // namespace unwindstack
diff --git a/libunwindstack/include/unwindstack/MapInfo.h b/libunwindstack/include/unwindstack/MapInfo.h
index 5143ff1f5..e938986d8 100644
--- a/libunwindstack/include/unwindstack/MapInfo.h
+++ b/libunwindstack/include/unwindstack/MapInfo.h
@@ -84,8 +84,12 @@ struct MapInfo {
 
   bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset);
 
+  // Returns the raw build id read from the elf data.
   std::string GetBuildID();
 
+  // Returns the printable version of the build id (hex dump of raw data).
+  std::string GetPrintableBuildID();
+
  private:
   MapInfo(const MapInfo&) = delete;
   void operator=(const MapInfo&) = delete;
diff --git a/libunwindstack/tests/MapInfoGetBuildIDTest.cpp b/libunwindstack/tests/MapInfoGetBuildIDTest.cpp
index 3b89c5961..ea9befcda 100644
--- a/libunwindstack/tests/MapInfoGetBuildIDTest.cpp
+++ b/libunwindstack/tests/MapInfoGetBuildIDTest.cpp
@@ -67,6 +67,7 @@ TEST_F(MapInfoGetBuildIDTest, no_elf_and_no_valid_elf_in_memory) {
   MapInfo info(nullptr, 0x1000, 0x2000, 0, PROT_READ, "");
 
   EXPECT_EQ("", info.GetBuildID());
+  EXPECT_EQ("", info.GetPrintableBuildID());
 }
 
 TEST_F(MapInfoGetBuildIDTest, from_elf) {
@@ -74,6 +75,7 @@ TEST_F(MapInfoGetBuildIDTest, from_elf) {
   elf_interface_->FakeSetBuildID("FAKE_BUILD_ID");
 
   EXPECT_EQ("FAKE_BUILD_ID", map_info_->GetBuildID());
+  EXPECT_EQ("46414b455f4255494c445f4944", map_info_->GetPrintableBuildID());
 }
 
 void MapInfoGetBuildIDTest::MultipleThreadTest(std::string expected_build_id) {
@@ -172,6 +174,7 @@ TEST_F(MapInfoGetBuildIDTest, from_memory) {
   InitElfData(tf_->fd);
 
   EXPECT_EQ("ELF_BUILDID", map_info_->GetBuildID());
+  EXPECT_EQ("454c465f4255494c444944", map_info_->GetPrintableBuildID());
 }
 
 TEST_F(MapInfoGetBuildIDTest, multiple_thread_elf_exists_in_memory) {