[clang] [CIR] Call code gen; create empty cir.func op (PR #113483)

[Erich Keane via cfe-commits]

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@@ -24,9 +27,140 @@ CIRGenModule::CIRGenModule(mlir::MLIRContext &context,
                            clang::ASTContext &astctx,
                            const clang::CodeGenOptions &cgo,
                            DiagnosticsEngine &diags)
-    : astCtx(astctx), langOpts(astctx.getLangOpts()),
-      theModule{mlir::ModuleOp::create(mlir::UnknownLoc())},
-      target(astCtx.getTargetInfo()) {}
+    : builder(&context), astCtx(astctx), langOpts(astctx.getLangOpts()),
+      theModule{mlir::ModuleOp::create(mlir::UnknownLoc::get(&context))},
+      diags(diags), target(astCtx.getTargetInfo()) {}
+
+mlir::Location CIRGenModule::getLoc(SourceLocation cLoc) {
+  assert(cLoc.isValid() && "expected valid source location");
+  const SourceManager &sm = astCtx.getSourceManager();
+  PresumedLoc pLoc = sm.getPresumedLoc(cLoc);
+  StringRef filename = pLoc.getFilename();
+  return mlir::FileLineColLoc::get(builder.getStringAttr(filename),
+                                   pLoc.getLine(), pLoc.getColumn());
+}
+
+mlir::Location CIRGenModule::getLoc(SourceRange cRange) {
+  assert(cRange.isValid() && "expected a valid source range");
+  mlir::Location begin = getLoc(cRange.getBegin());
+  mlir::Location end = getLoc(cRange.getEnd());
+  SmallVector<mlir::Location, 2> locs = {begin, end};
+  mlir::Attribute metadata;
+  return mlir::FusedLoc::get(locs, metadata, builder.getContext());
+}
+
+void CIRGenModule::buildGlobal(clang::GlobalDecl gd) {
+  const auto *global = cast<ValueDecl>(gd.getDecl());
+
+  if (const auto *fd = dyn_cast<FunctionDecl>(global)) {
+    // Update deferred annotations with the latest declaration if the function
+    // was already used or defined.
+    if (fd->hasAttr<AnnotateAttr>()) {
+      errorNYI(fd->getSourceRange(), "defferedAnnotations");
+    }
+    if (!fd->doesThisDeclarationHaveABody()) {
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erichkeane wrote:

Should we make sure we're looking at the 'latest' declaration before we ask this?  You could otherwise get the 'canonical' declaration (or a first, etc, if the body of the referring declrefexpr was formed before the definition exists) that doesn't have a definition, despite it being defined later.

https://github.com/llvm/llvm-project/pull/113483