commit 946bb09a5adc7d591498b4504aa5d9354457953e
author David Srbecky <dsrbecky@google.com> Fri Mar 09 17:23:01 2018 +0000
committer David Srbecky <dsrbecky@google.com> Thu Mar 15 14:59:21 2018 +0000
tree 3f1931a9117856c806b8371987700b5646a7d195
parent 68f0680e83179cfe0127fda54a8e02a8552bf619

Support unwinding though the switch interpreter.

Wrap the switch interpreter in small assembly method which defines
DEX PC in CFI and thus it allows libunwind to backtrace through it.

Bug: 22414682
Test: testrunner.py --host -t 137
Test: testrunner.py --target -t 137
Change-Id: I31dad9f0fb446151baaa99234b64f25c8ca2fa87

runtime/arch/arm64/quick_entrypoints_arm64.S

diff --git a/runtime/arch/arm64/quick_entrypoints_arm64.S b/runtime/arch/arm64/quick_entrypoints_arm64.S
index 375b050..fb449ed 100644
--- a/runtime/arch/arm64/quick_entrypoints_arm64.S
+++ b/runtime/arch/arm64/quick_entrypoints_arm64.S
@@ -15,6 +15,7 @@
  */
 
 #include "asm_support_arm64.S"
+#include "interpreter/cfi_asm_support.h"
 
 #include "arch/quick_alloc_entrypoints.S"
 
@@ -2928,3 +2929,16 @@
     .text
 
 END  art_quick_invoke_polymorphic
+
+// Wrap ExecuteSwitchImpl in assembly method which specifies DEX PC for unwinding.
+//  Argument 0: x0: The context pointer for ExecuteSwitchImpl.
+//  Argument 1: x1: Pointer to the templated ExecuteSwitchImpl to call.
+//  Argument 2: x2: The value of DEX PC (memory address of the methods bytecode).
+ENTRY ExecuteSwitchImplAsm
+    SAVE_TWO_REGS_INCREASE_FRAME x19, xLR, 16
+    mov x19, x2                                   // x19 = DEX PC
+    CFI_DEFINE_DEX_PC_WITH_OFFSET(0 /* x0 */, 19 /* x19 */, 0)
+    blr x1                                        // Call the wrapped method.
+    RESTORE_TWO_REGS_DECREASE_FRAME x19, xLR, 16
+    ret
+END ExecuteSwitchImplAsm