commit e62f4c4d4c016322bda7f17f7111d3f7d4d35dc8
author David Srbecky <dsrbecky@google.com> Fri Mar 16 18:44:04 2018 +0000
committer David Srbecky <dsrbecky@google.com> Mon Mar 19 11:20:00 2018 +0000
tree f005c26e51f808bc59b042311321ecf2cc09f825
parent 6fe59afe53b2cd791935e27338dd994f9fd9a319

Don't include map name if the consumer doesn't want names.

Simpleperf doesn't need the name, so avoid the string copies.

This seems to speed up simpleperf by around 20%.

Test: backtrace_test libunwindstack_test
Change-Id: Iba064c7078f7e5ecfc9d8539ba09c14495a52158

libunwindstack/Unwinder.cpp

diff --git a/libunwindstack/Unwinder.cpp b/libunwindstack/Unwinder.cpp
index 94edb1c..27262bd 100644
--- a/libunwindstack/Unwinder.cpp
+++ b/libunwindstack/Unwinder.cpp
@@ -61,7 +61,9 @@
     frame->map_offset = info->offset;
     frame->map_load_bias = info->load_bias;
     frame->map_flags = info->flags;
-    frame->map_name = info->name;
+    if (resolve_names_) {
+      frame->map_name = info->name;
+    }
     frame->rel_pc = dex_pc - info->start;
   } else {
     frame->rel_pc = dex_pc;
@@ -96,7 +98,9 @@
     return;
   }
 
-  frame->map_name = map_info->name;
+  if (resolve_names_) {
+    frame->map_name = map_info->name;
+  }
   frame->map_offset = map_info->offset;
   frame->map_start = map_info->start;
   frame->map_end = map_info->end;

libunwindstack/tests/UnwinderTest.cpp

diff --git a/libunwindstack/tests/UnwinderTest.cpp b/libunwindstack/tests/UnwinderTest.cpp
index e44b225..551f46c 100644
--- a/libunwindstack/tests/UnwinderTest.cpp
+++ b/libunwindstack/tests/UnwinderTest.cpp
@@ -221,7 +221,7 @@
   EXPECT_EQ(0x10000U, frame->sp);
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
-  EXPECT_EQ("/system/fake/libc.so", frame->map_name);
+  EXPECT_EQ("", frame->map_name);
   EXPECT_EQ(0U, frame->map_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
@@ -235,7 +235,7 @@
   EXPECT_EQ(0x10010U, frame->sp);
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
-  EXPECT_EQ("/system/fake/libc.so", frame->map_name);
+  EXPECT_EQ("", frame->map_name);
   EXPECT_EQ(0U, frame->map_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);
@@ -249,7 +249,7 @@
   EXPECT_EQ(0x10020U, frame->sp);
   EXPECT_EQ("", frame->function_name);
   EXPECT_EQ(0U, frame->function_offset);
-  EXPECT_EQ("/system/fake/libc.so", frame->map_name);
+  EXPECT_EQ("", frame->map_name);
   EXPECT_EQ(0U, frame->map_offset);
   EXPECT_EQ(0x1000U, frame->map_start);
   EXPECT_EQ(0x8000U, frame->map_end);