1 files changed, 32 insertions, 1 deletions

diff --git a/compiler/elf_writer_quick.cc b/compiler/elf_writer_quick.cc
index 36cd2327c4..0d6575cffd 100644
--- a/compiler/elf_writer_quick.cc
+++ b/compiler/elf_writer_quick.cc
@@ -16,6 +16,7 @@
 
 #include "elf_writer_quick.h"
 
+#include <openssl/sha.h>
 #include <unordered_map>
 #include <unordered_set>
 
@@ -126,6 +127,8 @@ class ElfWriterQuick FINAL : public ElfWriter {
   std::unique_ptr<DebugInfoTask> debug_info_task_;
   std::unique_ptr<ThreadPool> debug_info_thread_pool_;
 
+  void ComputeFileBuildId(uint8_t (*build_id)[ElfBuilder<ElfTypes>::kBuildIdLen]);
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(ElfWriterQuick);
 };
 
@@ -167,6 +170,9 @@ ElfWriterQuick<ElfTypes>::~ElfWriterQuick() {}
 template <typename ElfTypes>
 void ElfWriterQuick<ElfTypes>::Start() {
   builder_->Start();
+  if (compiler_options_->GetGenerateBuildId()) {
+    builder_->WriteBuildIdSection();
+  }
 }
 
 template <typename ElfTypes>
@@ -275,11 +281,36 @@ void ElfWriterQuick<ElfTypes>::WritePatchLocations(
 template <typename ElfTypes>
 bool ElfWriterQuick<ElfTypes>::End() {
   builder_->End();
-
+  if (compiler_options_->GetGenerateBuildId()) {
+    uint8_t build_id[ElfBuilder<ElfTypes>::kBuildIdLen];
+    ComputeFileBuildId(&build_id);
+    builder_->WriteBuildId(build_id);
+  }
   return builder_->Good();
 }
 
 template <typename ElfTypes>
+void ElfWriterQuick<ElfTypes>::ComputeFileBuildId(
+    uint8_t (*build_id)[ElfBuilder<ElfTypes>::kBuildIdLen]) {
+  constexpr int kBufSize = 8192;
+  std::vector<char> buffer(kBufSize);
+  int64_t offset = 0;
+  SHA_CTX ctx;
+  SHA1_Init(&ctx);
+  while (true) {
+    int64_t bytes_read = elf_file_->Read(buffer.data(), kBufSize, offset);
+    CHECK_GE(bytes_read, 0);
+    if (bytes_read == 0) {
+      // End of file.
+      break;
+    }
+    SHA1_Update(&ctx, buffer.data(), bytes_read);
+    offset += bytes_read;
+  }
+  SHA1_Final(*build_id, &ctx);
+}
+
+template <typename ElfTypes>
 OutputStream* ElfWriterQuick<ElfTypes>::GetStream() {
   return builder_->GetStream();
 }