Incorporate notes into the pattern-matching manifesto. A few more random

observations that weren't brought up during the meeting.



Swift SVN r567

lib/IRGen/IRGenModule.cpp

@@ -16,13 +16,124 @@
 
 #include "swift/AST/Decl.h"
 #include "swift/AST/Expr.h"
-
+#include "swift/AST/Stmt.h"
+#include "swift/AST/Type.h"
 #include "swift/IRGen/IRGen.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/GlobalValue.h"
+#include "llvm/Module.h"
+#include "llvm/ADT/PointerUnion.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "IRGenModule.h"
 
 using namespace swift;
 using namespace irgen;
 
-void IRGenModule::emitTranslationUnit(TranslationUnitDecl *TU) {
-  // TODO
+namespace {
+  struct LinkInfo {
+    std::string Name;
+    llvm::GlobalValue::LinkageTypes Linkage;
+    llvm::GlobalValue::VisibilityTypes Visibility;
+  };
+}
+
+static LinkInfo computeLinkInfo(NamedDecl *D) {
+  LinkInfo Link;
+
+  // TODO, obviously.
+
+  Link.Name = D->Name.str();
+  Link.Linkage = llvm::GlobalValue::ExternalLinkage;
+  Link.Visibility = llvm::GlobalValue::DefaultVisibility;
+
+  return Link;
+}
+
+/// Emit a top-level context.
+void IRGenModule::emitTopLevel(BraceStmt *Body) {
+  for (unsigned I = 0, E = Body->NumElements; I != E; ++I) {
+    BraceStmt::ExprStmtOrDecl Elt = Body->Elements[I];
+    if (Decl *D = Elt.dyn_cast<Decl*>())
+      emitGlobalDecl(D);
+    // TODO: handle top-level statements and expressions.
+  }
+}
+
+/// Emit all the top-level code in the translation unit.
+void IRGenModule::emitTranslationUnit(TranslationUnitDecl *TU) {
+  // The semantics of the top-level BraceStmt are a bit different from
+  // the normal semantics.
+  emitTopLevel(TU->Body);
+}
+
+/// Emit a global declaration.
+void IRGenModule::emitGlobalDecl(Decl *D) {
+  switch (D->Kind) {
+  case DeclKind::TranslationUnit:
+  case DeclKind::OneOfElement:
+  case DeclKind::Arg:
+  case DeclKind::ElementRef:
+    llvm_unreachable("cannot encounter this decl here");
+    break;
+  
+  // These declarations don't require IR-gen support.
+  case DeclKind::Import:
+  case DeclKind::TypeAlias:
+    break;
+
+  case DeclKind::Var:
+    emitGlobalVariable(cast<VarDecl>(D));
+    break;
+
+  case DeclKind::Func:
+    emitGlobalFunction(cast<FuncDecl>(D));
+    break;
+  }
+}
+
+llvm::GlobalVariable *IRGenModule::getAddrOfGlobalVariable(VarDecl *VD) {
+  // Check whether we've cached this.
+  llvm::Constant *&Entry = Globals[VD];
+  if (Entry) return cast<llvm::GlobalVariable>(Entry);
+
+  llvm::Type *Type = convertType(VD->Ty);
+  LinkInfo Link = computeLinkInfo(VD);
+  llvm::GlobalVariable *Addr
+    = new llvm::GlobalVariable(Module, Type, /*constant*/ false,
+                               Link.Linkage, /*initializer*/ nullptr,
+                               Link.Name);
+  Addr->setVisibility(Link.Visibility);
+
+  Entry = Addr;
+  return Addr;
+}
+
+void IRGenModule::emitGlobalVariable(VarDecl *VD) {
+  llvm::GlobalVariable *Addr = getAddrOfGlobalVariable(VD);
+  // FIXME: initializer
+  (void) Addr;
+}
+
+llvm::Function *IRGenModule::getAddrOfGlobalFunction(FuncDecl *FD) {
+  // Check whether we've cached this.
+  llvm::Constant *&Entry = Globals[FD];
+  if (Entry) return cast<llvm::Function>(Entry);
+
+  llvm::FunctionType *Type = cast<llvm::FunctionType>(convertType(FD->Ty));
+
+  LinkInfo Link = computeLinkInfo(FD);
+  llvm::Function *Addr
+    = cast<llvm::Function>(Module.getOrInsertFunction(Link.Name, Type));
+  Addr->setLinkage(Link.Linkage);
+  Addr->setVisibility(Link.Visibility);
+
+  Entry = Addr;
+  return Addr;
+}
+
+void IRGenModule::emitGlobalFunction(FuncDecl *FD) {
+  llvm::Function *Addr = getAddrOfGlobalFunction(FD);
+  // FIXME: body
+  (void) Addr;
 }