Add error propagation into Unwinder/Elf objects.
The backtrace offline code uses these error codes to diagnose errors.
In addtion, I've had cases where seeing these errors would help diagnose
failures.
This also allows us to add a few features to indicate why an unwind
terminated (such as max frames exceeded).
Bug: 65682279
Test: Updated unit tests pass.
Change-Id: If82b5092698e8a194016d670efff1320f9b44d50
diff --git a/libunwindstack/tests/ElfInterfaceArmTest.cpp b/libunwindstack/tests/ElfInterfaceArmTest.cpp
index e6763ab..31d6a63 100644
--- a/libunwindstack/tests/ElfInterfaceArmTest.cpp
+++ b/libunwindstack/tests/ElfInterfaceArmTest.cpp
@@ -303,6 +303,7 @@
// FindEntry fails.
bool finished;
ASSERT_FALSE(interface.StepExidx(0x7000, 0, nullptr, nullptr, &finished));
+ EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());
// ExtractEntry should fail.
interface.FakeSetStartOffset(0x1000);
@@ -316,14 +317,18 @@
regs.set_sp(regs[ARM_REG_SP]);
regs.set_pc(0x1234);
ASSERT_FALSE(interface.StepExidx(0x7000, 0, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_MEMORY_INVALID, interface.LastErrorCode());
+ EXPECT_EQ(0x1004U, interface.LastErrorAddress());
// Eval should fail.
memory_.SetData32(0x1004, 0x81000000);
ASSERT_FALSE(interface.StepExidx(0x7000, 0, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());
// Everything should pass.
memory_.SetData32(0x1004, 0x80b0b0b0);
ASSERT_TRUE(interface.StepExidx(0x7000, 0, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());
ASSERT_FALSE(finished);
ASSERT_EQ(0x1000U, regs.sp());
ASSERT_EQ(0x1000U, regs[ARM_REG_SP]);
@@ -332,9 +337,11 @@
// Load bias is non-zero.
ASSERT_TRUE(interface.StepExidx(0x8000, 0x1000, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());
// Pc too small.
ASSERT_FALSE(interface.StepExidx(0x8000, 0x9000, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_UNWIND_INFO, interface.LastErrorCode());
}
TEST_F(ElfInterfaceArmTest, StepExidx_pc_set) {
@@ -356,6 +363,7 @@
// Everything should pass.
bool finished;
ASSERT_TRUE(interface.StepExidx(0x7000, 0, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
ASSERT_FALSE(finished);
ASSERT_EQ(0x10004U, regs.sp());
ASSERT_EQ(0x10004U, regs[ARM_REG_SP]);
@@ -379,6 +387,7 @@
bool finished;
ASSERT_TRUE(interface.StepExidx(0x7000, 0, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
ASSERT_TRUE(finished);
ASSERT_EQ(0x10000U, regs.sp());
ASSERT_EQ(0x10000U, regs[ARM_REG_SP]);
@@ -401,6 +410,7 @@
bool finished;
ASSERT_TRUE(interface.StepExidx(0x7000, 0, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
ASSERT_TRUE(finished);
ASSERT_EQ(0x10000U, regs.sp());
ASSERT_EQ(0x10000U, regs[ARM_REG_SP]);
@@ -427,6 +437,7 @@
bool finished;
ASSERT_TRUE(interface.StepExidx(0x7000, 0, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
ASSERT_TRUE(finished);
ASSERT_EQ(0U, regs.pc());
@@ -439,6 +450,7 @@
regs.set_pc(0x1234);
ASSERT_TRUE(interface.StepExidx(0x7000, 0, ®s, &process_memory_, &finished));
+ EXPECT_EQ(ERROR_NONE, interface.LastErrorCode());
ASSERT_TRUE(finished);
ASSERT_EQ(0U, regs.pc());
}