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

[Erich Keane via cfe-commits]

================
@@ -24,9 +27,135 @@ 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());
+  mlir::Attribute metadata;
+  return mlir::FusedLoc::get({begin, end}, 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()) {
+      if (!fd->doesDeclarationForceExternallyVisibleDefinition())
+        return;
+
+      errorNYI(fd->getSourceRange(),
+               "function declaration that forces code gen");
+      return;
+    }
+  } else {
+    errorNYI(global->getSourceRange(), "global variable declaration");
+  }
+
+  // TODO(CIR): Defer emitting some global definitions until later
+  buildGlobalDefinition(gd);
+}
+
+void CIRGenModule::buildGlobalFunctionDefinition(clang::GlobalDecl gd,
+                                                 mlir::Operation *op) {
+  auto const *funcDecl = cast<FunctionDecl>(gd.getDecl());
+  auto funcOp = builder.create<mlir::cir::FuncOp>(
+      getLoc(funcDecl->getSourceRange()), funcDecl->getIdentifier()->getName());
----------------
erichkeane wrote:

> (1) the feature is implemented and tested in the ClangIR incubator project, or (2) there is an issue to implement the feature in the ClangIR incubator project.

I believe this is consistent with what I suggested.  We can't really depend on our existing tests, as they are... questionable in some cases, so I'd like to make sure it gets captured on the CIR project. IF it is actually already implemented though, I expect that the PR owner should write any missing test coverage.

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