[clang] [NFC] Parameterize Initialization of `clang::CodeGenerator` on a `TargetInfo` instance which may differ from the one in the `ASTContext` (PR #88977)

[Michael Spencer via cfe-commits]

================
@@ -26,123 +26,132 @@ namespace clang {
   class VarDecl;
   class FunctionDecl;
   class ImportDecl;
-
-/// ASTConsumer - This is an abstract interface that should be implemented by
-/// clients that read ASTs.  This abstraction layer allows the client to be
-/// independent of the AST producer (e.g. parser vs AST dump file reader, etc).
-class ASTConsumer {
-  /// Whether this AST consumer also requires information about
-  /// semantic analysis.
-  bool SemaConsumer = false;
-
-  friend class SemaConsumer;
-
-public:
-  ASTConsumer() = default;
-
-  virtual ~ASTConsumer() {}
-
-  /// Initialize - This is called to initialize the consumer, providing the
-  /// ASTContext.
-  virtual void Initialize(ASTContext &Context) {}
-
-  /// HandleTopLevelDecl - Handle the specified top-level declaration.  This is
-  /// called by the parser to process every top-level Decl*.
-  ///
-  /// \returns true to continue parsing, or false to abort parsing.
-  virtual bool HandleTopLevelDecl(DeclGroupRef D);
-
-  /// This callback is invoked each time an inline (method or friend)
-  /// function definition in a class is completed.
-  virtual void HandleInlineFunctionDefinition(FunctionDecl *D) {}
-
-  /// HandleInterestingDecl - Handle the specified interesting declaration. This
-  /// is called by the AST reader when deserializing things that might interest
-  /// the consumer. The default implementation forwards to HandleTopLevelDecl.
-  virtual void HandleInterestingDecl(DeclGroupRef D);
-
-  /// HandleTranslationUnit - This method is called when the ASTs for entire
-  /// translation unit have been parsed.
-  virtual void HandleTranslationUnit(ASTContext &Ctx) {}
-
-  /// HandleTagDeclDefinition - This callback is invoked each time a TagDecl
-  /// (e.g. struct, union, enum, class) is completed.  This allows the client to
-  /// hack on the type, which can occur at any point in the file (because these
-  /// can be defined in declspecs).
-  virtual void HandleTagDeclDefinition(TagDecl *D) {}
-
-  /// This callback is invoked the first time each TagDecl is required to
-  /// be complete.
-  virtual void HandleTagDeclRequiredDefinition(const TagDecl *D) {}
-
-  /// Invoked when a function is implicitly instantiated.
-  /// Note that at this point it does not have a body, its body is
-  /// instantiated at the end of the translation unit and passed to
-  /// HandleTopLevelDecl.
-  virtual void HandleCXXImplicitFunctionInstantiation(FunctionDecl *D) {}
-
-  /// Handle the specified top-level declaration that occurred inside
-  /// and ObjC container.
-  /// The default implementation ignored them.
-  virtual void HandleTopLevelDeclInObjCContainer(DeclGroupRef D);
-
-  /// Handle an ImportDecl that was implicitly created due to an
-  /// inclusion directive.
-  /// The default implementation passes it to HandleTopLevelDecl.
-  virtual void HandleImplicitImportDecl(ImportDecl *D);
-
-  /// CompleteTentativeDefinition - Callback invoked at the end of a translation
-  /// unit to notify the consumer that the given tentative definition should be
-  /// completed.
-  ///
-  /// The variable declaration itself will be a tentative
-  /// definition. If it had an incomplete array type, its type will
-  /// have already been changed to an array of size 1. However, the
-  /// declaration remains a tentative definition and has not been
-  /// modified by the introduction of an implicit zero initializer.
-  virtual void CompleteTentativeDefinition(VarDecl *D) {}
-
-  /// CompleteExternalDeclaration - Callback invoked at the end of a translation
-  /// unit to notify the consumer that the given external declaration should be
-  /// completed.
-  virtual void CompleteExternalDeclaration(VarDecl *D) {}
-
-  /// Callback invoked when an MSInheritanceAttr has been attached to a
-  /// CXXRecordDecl.
-  virtual void AssignInheritanceModel(CXXRecordDecl *RD) {}
-
-  /// HandleCXXStaticMemberVarInstantiation - Tell the consumer that this
-  // variable has been instantiated.
-  virtual void HandleCXXStaticMemberVarInstantiation(VarDecl *D) {}
-
-  /// Callback involved at the end of a translation unit to
-  /// notify the consumer that a vtable for the given C++ class is
-  /// required.
-  ///
-  /// \param RD The class whose vtable was used.
-  virtual void HandleVTable(CXXRecordDecl *RD) {}
-
-  /// If the consumer is interested in entities getting modified after
-  /// their initial creation, it should return a pointer to
-  /// an ASTMutationListener here.
-  virtual ASTMutationListener *GetASTMutationListener() { return nullptr; }
-
-  /// If the consumer is interested in entities being deserialized from
-  /// AST files, it should return a pointer to a ASTDeserializationListener here
-  virtual ASTDeserializationListener *GetASTDeserializationListener() {
-    return nullptr;
-  }
-
-  /// PrintStats - If desired, print any statistics.
-  virtual void PrintStats() {}
-
-  /// This callback is called for each function if the Parser was
-  /// initialized with \c SkipFunctionBodies set to \c true.
-  ///
-  /// \return \c true if the function's body should be skipped. The function
-  /// body may be parsed anyway if it is needed (for instance, if it contains
-  /// the code completion point or is constexpr).
-  virtual bool shouldSkipFunctionBody(Decl *D) { return true; }
+  class TargetInfo;
+
+  /// ASTConsumer - This is an abstract interface that should be implemented by
+  /// clients that read ASTs.  This abstraction layer allows the client to be
+  /// independent of the AST producer (e.g. parser vs AST dump file reader,
+  /// etc).
+  class ASTConsumer {
+    /// Whether this AST consumer also requires information about
+    /// semantic analysis.
+    bool SemaConsumer = false;
+
+    friend class SemaConsumer;
+
+  public:
+    ASTConsumer() = default;
+
+    virtual ~ASTConsumer() {}
+
+    /// Initialize - This is called to initialize the consumer, providing the
+    /// ASTContext.
+    virtual void Initialize(ASTContext &Context) {}
+
+    /// Initialize - This is called to initialize the consumer, providing the
+    /// ASTContext.
----------------
Bigcheese wrote:

This should also say what `CodeGenTargetInfo` is used for, and that you need to make sure it's compatible with `Context`'s target info.

https://github.com/llvm/llvm-project/pull/88977