[llvm] [AArch64][Windows] Add llvm-readobj support for ec_context unwind opcode (PR #69515)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-binary-utilities

Author: Billy Laws (bylaws)

<details>
<summary>Changes</summary>

ARM64EC uses the same CONTEXT structure as x86_64 as opposed to the regular ARM64 context, a [new unwind opcode](https://learn.microsoft.com/en-us/cpp/build/arm64-exception-handling?view=msvc-170) (MSFT_OP_EC_CONTEXT) is added to handle this.

---
Full diff: https://github.com/llvm/llvm-project/pull/69515.diff


2 Files Affected:

- (modified) llvm/tools/llvm-readobj/ARMWinEHPrinter.cpp (+8) 
- (modified) llvm/tools/llvm-readobj/ARMWinEHPrinter.h (+2) 


``````````diff
diff --git a/llvm/tools/llvm-readobj/ARMWinEHPrinter.cpp b/llvm/tools/llvm-readobj/ARMWinEHPrinter.cpp
index ef77d4b2fd224bd..cf5c77cf107c36f 100644
--- a/llvm/tools/llvm-readobj/ARMWinEHPrinter.cpp
+++ b/llvm/tools/llvm-readobj/ARMWinEHPrinter.cpp
@@ -171,6 +171,7 @@ const Decoder::RingEntry Decoder::Ring64[] = {
     {0xff, 0xe8, 1, &Decoder::opcode_trap_frame},
     {0xff, 0xe9, 1, &Decoder::opcode_machine_frame},
     {0xff, 0xea, 1, &Decoder::opcode_context},
+    {0xff, 0xeb, 1, &Decoder::opcode_ec_context},
     {0xff, 0xec, 1, &Decoder::opcode_clear_unwound_to_call},
     {0xff, 0xfc, 1, &Decoder::opcode_pac_sign_lr},
 };
@@ -969,6 +970,13 @@ bool Decoder::opcode_context(const uint8_t *OC, unsigned &Offset,
   return false;
 }
 
+bool Decoder::opcode_ec_context(const uint8_t *OC, unsigned &Offset,
+                                unsigned Length, bool Prologue) {
+  SW.startLine() << format("0x%02x                ; EC context\n", OC[Offset]);
+  ++Offset;
+  return false;
+}
+
 bool Decoder::opcode_clear_unwound_to_call(const uint8_t *OC, unsigned &Offset,
                                            unsigned Length, bool Prologue) {
   SW.startLine() << format("0x%02x                ; clear unwound to call\n",
diff --git a/llvm/tools/llvm-readobj/ARMWinEHPrinter.h b/llvm/tools/llvm-readobj/ARMWinEHPrinter.h
index 0ffebe5834c480b..92b3a78e4330098 100644
--- a/llvm/tools/llvm-readobj/ARMWinEHPrinter.h
+++ b/llvm/tools/llvm-readobj/ARMWinEHPrinter.h
@@ -129,6 +129,8 @@ class Decoder {
                             unsigned Length, bool Prologue);
   bool opcode_context(const uint8_t *Opcodes, unsigned &Offset, unsigned Length,
                       bool Prologue);
+  bool opcode_ec_context(const uint8_t *Opcodes, unsigned &Offset, unsigned Length,
+                         bool Prologue);
   bool opcode_clear_unwound_to_call(const uint8_t *Opcodes, unsigned &Offset,
                                     unsigned Length, bool Prologue);
   bool opcode_pac_sign_lr(const uint8_t *Opcodes, unsigned &Offset,

``````````

</details>


https://github.com/llvm/llvm-project/pull/69515