unwindstack: add Memory::ReadPartially.

Add a way to read while allowing for partial reads.

Test: new tests added to libunwindstack_test, ran 32/64 on hikey960, sailfish
Test: ran unwind on hikey960/sailfish
Change-Id: I8b11d9230fcd3122148ef3f980863ac1404ad70a

1 files changed, 18 insertions, 3 deletions

diff --git a/libunwindstack/tests/MemoryRangeTest.cpp b/libunwindstack/tests/MemoryRangeTest.cpp
index 680fae9c1..4a764f59f 100644
--- a/libunwindstack/tests/MemoryRangeTest.cpp
+++ b/libunwindstack/tests/MemoryRangeTest.cpp
@@ -35,7 +35,7 @@ TEST(MemoryRangeTest, read) {
   std::shared_ptr<Memory> process_memory(memory_fake);
   memory_fake->SetMemory(9001, src);
 
-  MemoryRange range(process_memory, 9001, 9001 + src.size());
+  MemoryRange range(process_memory, 9001, src.size(), 0);
 
   std::vector<uint8_t> dst(1024);
   ASSERT_TRUE(range.Read(0, dst.data(), src.size()));
@@ -51,7 +51,7 @@ TEST(MemoryRangeTest, read_near_limit) {
   std::shared_ptr<Memory> process_memory(memory_fake);
   memory_fake->SetMemory(1000, src);
 
-  MemoryRange range(process_memory, 1000, 2024);
+  MemoryRange range(process_memory, 1000, 1024, 0);
 
   std::vector<uint8_t> dst(1024);
   ASSERT_TRUE(range.Read(1020, dst.data(), 4));
@@ -72,8 +72,23 @@ TEST(MemoryRangeTest, read_overflow) {
   std::vector<uint8_t> buffer(100);
 
   std::shared_ptr<Memory> process_memory(new MemoryFakeAlwaysReadZero);
-  std::unique_ptr<MemoryRange> overflow(new MemoryRange(process_memory, 100, 200));
+  std::unique_ptr<MemoryRange> overflow(new MemoryRange(process_memory, 100, 200, 0));
   ASSERT_FALSE(overflow->Read(UINT64_MAX - 10, buffer.data(), 100));
 }
 
+TEST(MemoryRangeTest, ReadPartially) {
+  std::vector<uint8_t> src(4096);
+  memset(src.data(), 0x4c, 4096);
+  MemoryFake* memory_fake = new MemoryFake;
+  std::shared_ptr<Memory> process_memory(memory_fake);
+  memory_fake->SetMemory(1000, src);
+
+  MemoryRange range(process_memory, 1000, 1024, 0);
+  std::vector<uint8_t> dst(1024);
+  ASSERT_EQ(4U, range.ReadPartially(1020, dst.data(), 1024));
+  for (size_t i = 0; i < 4; i++) {
+    ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
+  }
+}
+
 }  // namespace unwindstack