[llvm] annotate interfaces in llvm/MC and llvm/MCA for DLL export (#142655)

## Purpose

This patch is one in a series of code-mods that annotate LLVM’s public
interface for export. This patch annotates the `llvm/MC` and `llvm/MCA`
libraries. These annotations currently have no meaningful impact on the
LLVM build; however, they are a prerequisite to support an LLVM Windows
DLL (shared library) build.

## Background

This effort is tracked in #109483. Additional context is provided in
[this
discourse](https://discourse.llvm.org/t/psa-annotating-llvm-public-interface/85307),
and documentation for `LLVM_ABI` and related annotations is found in the
LLVM repo
[here](https://github.com/llvm/llvm-project/blob/main/llvm/docs/InterfaceExportAnnotations.rst).

The bulk of these changes were generated automatically using the
[Interface Definition Scanner (IDS)](https://github.com/compnerd/ids)
tool, followed formatting with `git clang-format`.

The following manual adjustments were also applied after running IDS on
Linux:
- Add `#include "llvm/Support/Compiler.h"` to files where it was not
auto-added by IDS due to no pre-existing block of include statements.
- Explicitly make classes non-copyable where needed to due IDS adding
LLVM_ABI at the class level

## Validation

Local builds and tests to validate cross-platform compatibility. This
included llvm, clang, and lldb on the following configurations:

- Windows with MSVC
- Windows with Clang
- Linux with GCC
- Linux with Clang
- Darwin with Clang

Author: andrurogerz

llvm/include/llvm/MC/MCAsmBackend.h

@@ -12,6 +12,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/MC/MCDirectives.h"
 #include "llvm/MC/MCFixup.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Endian.h"
 #include <cstdint>
 
@@ -39,7 +40,7 @@ class StringRef;
 class raw_ostream;
 
 /// Generic interface to target specific assembler backends.
-class MCAsmBackend {
+class LLVM_ABI MCAsmBackend {
 protected: // Can only create subclasses.
   MCAsmBackend(llvm::endianness Endian) : Endian(Endian) {}
 

llvm/include/llvm/MC/MCAsmInfo.h

@@ -20,6 +20,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/MC/MCDirectives.h"
 #include "llvm/MC/MCTargetOptions.h"
+#include "llvm/Support/Compiler.h"
 #include <vector>
 
 namespace llvm {
@@ -55,7 +56,7 @@ enum LCOMMType { NoAlignment, ByteAlignment, Log2Alignment };
 
 /// This class is intended to be used as a base class for asm
 /// properties and features specific to the target.
-class MCAsmInfo {
+class LLVM_ABI MCAsmInfo {
 public:
   /// Assembly character literal syntax types.
   enum AsmCharLiteralSyntax {
@@ -427,6 +428,10 @@ class MCAsmInfo {
   explicit MCAsmInfo();
   virtual ~MCAsmInfo();
 
+  // Explicitly non-copyable.
+  MCAsmInfo(MCAsmInfo const &) = delete;
+  MCAsmInfo &operator=(MCAsmInfo const &) = delete;
+
   /// Get the code pointer size in bytes.
   unsigned getCodePointerSize() const { return CodePointerSize; }
 

llvm/include/llvm/MC/MCAsmMacro.h

@@ -11,6 +11,7 @@
 
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/SMLoc.h"
 #include <vector>
@@ -74,9 +75,9 @@ class AsmToken {
   bool is(TokenKind K) const { return Kind == K; }
   bool isNot(TokenKind K) const { return Kind != K; }
 
-  SMLoc getLoc() const;
-  SMLoc getEndLoc() const;
-  SMRange getLocRange() const;
+  LLVM_ABI SMLoc getLoc() const;
+  LLVM_ABI SMLoc getEndLoc() const;
+  LLVM_ABI SMRange getLocRange() const;
 
   /// Get the contents of a string token (without quotes).
   StringRef getStringContents() const {
@@ -115,7 +116,7 @@ class AsmToken {
     return IntVal;
   }
 
-  void dump(raw_ostream &OS) const;
+  LLVM_ABI void dump(raw_ostream &OS) const;
 };
 
 struct MCAsmMacroParameter {

llvm/include/llvm/MC/MCAssembler.h

@@ -17,6 +17,7 @@
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/SMLoc.h"
 #include <algorithm>
 #include <cassert>
@@ -135,46 +136,48 @@ class MCAssembler {
   // concrete and require clients to pass in a target like object. The other
   // option is to make this abstract, and have targets provide concrete
   // implementations as we do with AsmParser.
-  MCAssembler(MCContext &Context, std::unique_ptr<MCAsmBackend> Backend,
-              std::unique_ptr<MCCodeEmitter> Emitter,
-              std::unique_ptr<MCObjectWriter> Writer);
+  LLVM_ABI MCAssembler(MCContext &Context,
+                       std::unique_ptr<MCAsmBackend> Backend,
+                       std::unique_ptr<MCCodeEmitter> Emitter,
+                       std::unique_ptr<MCObjectWriter> Writer);
   MCAssembler(const MCAssembler &) = delete;
   MCAssembler &operator=(const MCAssembler &) = delete;
 
   /// Compute the effective fragment size.
-  uint64_t computeFragmentSize(const MCFragment &F) const;
+  LLVM_ABI uint64_t computeFragmentSize(const MCFragment &F) const;
 
-  void layoutBundle(MCFragment *Prev, MCFragment *F) const;
+  LLVM_ABI void layoutBundle(MCFragment *Prev, MCFragment *F) const;
 
   // Get the offset of the given fragment inside its containing section.
   uint64_t getFragmentOffset(const MCFragment &F) const { return F.Offset; }
 
-  uint64_t getSectionAddressSize(const MCSection &Sec) const;
-  uint64_t getSectionFileSize(const MCSection &Sec) const;
+  LLVM_ABI uint64_t getSectionAddressSize(const MCSection &Sec) const;
+  LLVM_ABI uint64_t getSectionFileSize(const MCSection &Sec) const;
 
   // Get the offset of the given symbol, as computed in the current
   // layout.
   // \return True on success.
-  bool getSymbolOffset(const MCSymbol &S, uint64_t &Val) const;
+  LLVM_ABI bool getSymbolOffset(const MCSymbol &S, uint64_t &Val) const;
 
   // Variant that reports a fatal error if the offset is not computable.
-  uint64_t getSymbolOffset(const MCSymbol &S) const;
+  LLVM_ABI uint64_t getSymbolOffset(const MCSymbol &S) const;
 
   // If this symbol is equivalent to A + Constant, return A.
-  const MCSymbol *getBaseSymbol(const MCSymbol &Symbol) const;
+  LLVM_ABI const MCSymbol *getBaseSymbol(const MCSymbol &Symbol) const;
 
   /// Emit the section contents to \p OS.
-  void writeSectionData(raw_ostream &OS, const MCSection *Section) const;
+  LLVM_ABI void writeSectionData(raw_ostream &OS,
+                                 const MCSection *Section) const;
 
   /// Check whether a given symbol has been flagged with .thumb_func.
-  bool isThumbFunc(const MCSymbol *Func) const;
+  LLVM_ABI bool isThumbFunc(const MCSymbol *Func) const;
 
   /// Flag a function symbol as the target of a .thumb_func directive.
   void setIsThumbFunc(const MCSymbol *Func) { ThumbFuncs.insert(Func); }
 
   /// Reuse an assembler instance
   ///
-  void reset();
+  LLVM_ABI void reset();
 
   MCContext &getContext() const { return Context; }
 
@@ -193,10 +196,10 @@ class MCAssembler {
   /// Finish - Do final processing and write the object to the output stream.
   /// \p Writer is used for custom object writer (as the MCJIT does),
   /// if not specified it is automatically created from backend.
-  void Finish();
+  LLVM_ABI void Finish();
 
   // Layout all section and prepare them for emission.
-  void layout();
+  LLVM_ABI void layout();
 
   bool hasLayout() const { return HasLayout; }
   bool hasFinalLayout() const { return HasFinalLayout; }
@@ -223,21 +226,22 @@ class MCAssembler {
     return make_pointee_range(Symbols);
   }
 
-  bool registerSection(MCSection &Section);
-  bool registerSymbol(const MCSymbol &Symbol);
+  LLVM_ABI bool registerSection(MCSection &Section);
+  LLVM_ABI bool registerSymbol(const MCSymbol &Symbol);
 
   /// Write the necessary bundle padding to \p OS.
   /// Expects a fragment \p F containing instructions and its size \p FSize.
-  void writeFragmentPadding(raw_ostream &OS, const MCEncodedFragment &F,
-                            uint64_t FSize) const;
+  LLVM_ABI void writeFragmentPadding(raw_ostream &OS,
+                                     const MCEncodedFragment &F,
+                                     uint64_t FSize) const;
 
-  void reportError(SMLoc L, const Twine &Msg) const;
+  LLVM_ABI void reportError(SMLoc L, const Twine &Msg) const;
   // Record pending errors during layout iteration, as they may go away once the
   // layout is finalized.
-  void recordError(SMLoc L, const Twine &Msg) const;
-  void flushPendingErrors() const;
+  LLVM_ABI void recordError(SMLoc L, const Twine &Msg) const;
+  LLVM_ABI void flushPendingErrors() const;
 
-  void dump() const;
+  LLVM_ABI void dump() const;
 };
 
 } // end namespace llvm

llvm/include/llvm/MC/MCCodeEmitter.h

@@ -9,6 +9,8 @@
 #ifndef LLVM_MC_MCCODEEMITTER_H
 #define LLVM_MC_MCCODEEMITTER_H
 
+#include "llvm/Support/Compiler.h"
+
 namespace llvm {
 
 class MCFixup;
@@ -18,7 +20,7 @@ class raw_ostream;
 template<typename T> class SmallVectorImpl;
 
 /// MCCodeEmitter - Generic instruction encoding interface.
-class MCCodeEmitter {
+class LLVM_ABI MCCodeEmitter {
 protected: // Can only create subclasses.
   MCCodeEmitter();