[support] Add packed_endian_specific_integral::value()

[labath]

They are already implicitly convertible to the underlying type, but that doesn't work in some contexts, and it can be useful to get the underlying value without needing the remember/guess the right type.

I converted a couple of call sites to demonstrate usefulness, but there's likely more of them. I know at least of at least a few in LLDB, but I don't want to make this a cross-project patch.

[llvmbot]

@llvm/pr-subscribers-llvm-support

Author: Pavel Labath (labath)

Changes

They are already implicitly convertible to the underlying type, but that doesn't work in some contexts, and it can be useful to get the underlying value without needing the remember/guess the right type.

I converted a couple of call sites to demonstrate usefulness, but there's likely more of them. I know at least of at least a few in LLDB, but I don't want to make this a cross-project patch.

---

Full diff: https://github.com/llvm/llvm-project/pull/147974.diff

2 Files Affected:

• (modified) llvm/include/llvm/Support/Endian.h (+2-1)
• (modified) llvm/lib/ExecutionEngine/JITLink/aarch32.cpp (+3-4)

diff --git a/llvm/include/llvm/Support/Endian.h b/llvm/include/llvm/Support/Endian.h
index 574f9508420a0..02a3194e09784 100644
--- a/llvm/include/llvm/Support/Endian.h
+++ b/llvm/include/llvm/Support/Endian.h
@@ -223,10 +223,11 @@ struct packed_endian_specific_integral {
 
   explicit packed_endian_specific_integral(value_type val) { *this = val; }
 
-  operator value_type() const {
+  value_type value() const {
     return endian::read<value_type, endian, alignment>(
       (const void*)Value.buffer);
   }
+  operator value_type() const { return value(); }
 
   void operator=(value_type newValue) {
     endian::write<value_type, endian, alignment>(
diff --git a/llvm/lib/ExecutionEngine/JITLink/aarch32.cpp b/llvm/lib/ExecutionEngine/JITLink/aarch32.cpp
index 1e325d76bd515..12d31f809f882 100644
--- a/llvm/lib/ExecutionEngine/JITLink/aarch32.cpp
+++ b/llvm/lib/ExecutionEngine/JITLink/aarch32.cpp
@@ -239,15 +239,14 @@ Error makeUnexpectedOpcodeError(const LinkGraph &G, const ThumbRelocation &R,
                                 Edge::Kind Kind) {
   return make_error<JITLinkError>(
       formatv("Invalid opcode [ {0:x4}, {1:x4} ] for relocation: {2}",
-              static_cast<uint16_t>(R.Hi), static_cast<uint16_t>(R.Lo),
-              G.getEdgeKindName(Kind)));
+              R.Hi.value(), R.Lo.value(), G.getEdgeKindName(Kind)));
 }
 
 Error makeUnexpectedOpcodeError(const LinkGraph &G, const ArmRelocation &R,
                                 Edge::Kind Kind) {
   return make_error<JITLinkError>(
-      formatv("Invalid opcode {0:x8} for relocation: {1}",
-              static_cast<uint32_t>(R.Wd), G.getEdgeKindName(Kind)));
+      formatv("Invalid opcode {0:x8} for relocation: {1}", R.Wd.value(),
+              G.getEdgeKindName(Kind)));
 }
 
 template <EdgeKind_aarch32 K> constexpr bool isArm() {

[dwblaikie]

I guess there's already unit test coverage for Endian - could extend it to cover the new function?

[labath]

There isn't much in the obvious place, but sure, I can add something there.