[AMDGPU] Add disassembler diagnostics for invalid kernel descriptors (#87400)

These mostly are checking for various reserved bits being set. The diagnostics
for gpu-dependent reserved bits have a bit more context since they seem like the
most likely ones to be observed in practice.

This commit also improves the error handling mechanism for
MCDisassembler::onSymbolStart(). Previously it had a comment stream parameter
that was just being ignored by llvm-objdump, now it returns errors using
Expected<T>.

1 files changed, 12 insertions, 12 deletions

diff --git a/llvm/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp b/llvm/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp
index 861f9f8..3585b5f 100644
--- a/llvm/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp
+++ b/llvm/lib/Target/WebAssembly/Disassembler/WebAssemblyDisassembler.cpp
@@ -47,9 +47,10 @@ class WebAssemblyDisassembler final : public MCDisassembler {
   DecodeStatus getInstruction(MCInst &Instr, uint64_t &Size,
                               ArrayRef<uint8_t> Bytes, uint64_t Address,
                               raw_ostream &CStream) const override;
-  std::optional<DecodeStatus>
-  onSymbolStart(SymbolInfoTy &Symbol, uint64_t &Size, ArrayRef<uint8_t> Bytes,
-                uint64_t Address, raw_ostream &CStream) const override;
+
+  Expected<bool> onSymbolStart(SymbolInfoTy &Symbol, uint64_t &Size,
+                               ArrayRef<uint8_t> Bytes,
+                               uint64_t Address) const override;
 
 public:
   WebAssemblyDisassembler(const MCSubtargetInfo &STI, MCContext &Ctx,
@@ -122,31 +123,30 @@ bool parseImmediate(MCInst &MI, uint64_t &Size, ArrayRef<uint8_t> Bytes) {
   return true;
 }
 
-std::optional<MCDisassembler::DecodeStatus>
-WebAssemblyDisassembler::onSymbolStart(SymbolInfoTy &Symbol, uint64_t &Size,
-                                       ArrayRef<uint8_t> Bytes,
-                                       uint64_t Address,
-                                       raw_ostream &CStream) const {
+Expected<bool> WebAssemblyDisassembler::onSymbolStart(SymbolInfoTy &Symbol,
+                                                      uint64_t &Size,
+                                                      ArrayRef<uint8_t> Bytes,
+                                                      uint64_t Address) const {
   Size = 0;
   if (Symbol.Type == wasm::WASM_SYMBOL_TYPE_SECTION) {
     // Start of a code section: we're parsing only the function count.
     int64_t FunctionCount;
     if (!nextLEB(FunctionCount, Bytes, Size, false))
-      return std::nullopt;
+      return false;
     outs() << "        # " << FunctionCount << " functions in section.";
   } else {
     // Parse the start of a single function.
     int64_t BodySize, LocalEntryCount;
     if (!nextLEB(BodySize, Bytes, Size, false) ||
         !nextLEB(LocalEntryCount, Bytes, Size, false))
-      return std::nullopt;
+      return false;
     if (LocalEntryCount) {
       outs() << "        .local ";
       for (int64_t I = 0; I < LocalEntryCount; I++) {
         int64_t Count, Type;
         if (!nextLEB(Count, Bytes, Size, false) ||
             !nextLEB(Type, Bytes, Size, false))
-          return std::nullopt;
+          return false;
         for (int64_t J = 0; J < Count; J++) {
           if (I || J)
             outs() << ", ";
@@ -156,7 +156,7 @@ WebAssemblyDisassembler::onSymbolStart(SymbolInfoTy &Symbol, uint64_t &Size,
     }
   }
   outs() << "\n";
-  return MCDisassembler::Success;
+  return true;
 }
 
 MCDisassembler::DecodeStatus WebAssemblyDisassembler::getInstruction(