Adding some shape to toolchain semantic analysis (#1092)

toolchain/semantics/semantics_ir_factory.cpp

@@ -0,0 +1,58 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include "toolchain/semantics/semantics_ir_factory.h"
+
+#include "common/check.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "toolchain/lexer/tokenized_buffer.h"
+#include "toolchain/parser/parse_node_kind.h"
+
+namespace Carbon {
+
+auto SemanticsIRFactory::Build(const ParseTree& parse_tree) -> SemanticsIR {
+  SemanticsIRFactory builder(parse_tree);
+  builder.ProcessRoots();
+  return builder.semantics_;
+}
+
+void SemanticsIRFactory::ProcessRoots() {
+  for (ParseTree::Node node : semantics_.parse_tree_->roots()) {
+    switch (semantics_.parse_tree_->node_kind(node)) {
+      case ParseNodeKind::FunctionDeclaration():
+        ProcessFunctionNode(semantics_.root_block_, node);
+        break;
+      case ParseNodeKind::FileEnd():
+        // No action needed.
+        break;
+      default:
+        FATAL() << "Unhandled node kind: "
+                << semantics_.parse_tree_->node_kind(node).name();
+    }
+  }
+}
+
+void SemanticsIRFactory::ProcessFunctionNode(SemanticsIR::Block& block,
+                                             ParseTree::Node decl_node) {
+  llvm::Optional<Semantics::Function> fn;
+  for (ParseTree::Node node : semantics_.parse_tree_->children(decl_node)) {
+    switch (semantics_.parse_tree_->node_kind(node)) {
+      case ParseNodeKind::DeclaredName():
+        fn = semantics_.AddFunction(block, decl_node, node);
+        break;
+      case ParseNodeKind::ParameterList():
+        // TODO: Maybe something like Semantics::AddVariable passed to
+        // Function::AddParameter.
+        break;
+      case ParseNodeKind::CodeBlock():
+        // TODO: Should accumulate the definition into the code block.
+        break;
+      default:
+        FATAL() << "Unhandled node kind: "
+                << semantics_.parse_tree_->node_kind(node).name();
+    }
+  }
+}
+
+}  // namespace Carbon