Refactor the node stack into its own class. (#2505)

Currently, there's a mix of accessing node_stack_ both directly and indirectly, and there are already several Push/Pop methods to help wrap the behavior. However, there's also direct access because of shifting over time, as well as variations in _how_ the stack is used. This migrates to a separate class in order to make a more specific contract for the API. It cleans up existing uses and adds APIs where needed.
2026-09-24 22:02:23 +01:00 · 2023-01-05 15:16:05 -08:00
parent 78ac6cb7d1
commit 2a163ca6cd
8 changed files with 419 additions and 228 deletions
@@ -0,0 +1,140 @@
+// 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_node_stack.h"
+
+#include "common/vlog.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "toolchain/semantics/semantics_node.h"
+
+namespace Carbon {
+
+auto SemanticsNodeStack::PushEntry(Entry entry, bool is_node_id) -> void {
+  CARBON_VLOG() << "Push " << stack_.size() << ": "
+                << parse_tree_->node_kind(entry.parse_node) << " -> ";
+  if (is_node_id) {
+    CARBON_VLOG() << entry.node_id;
+  } else {
+    CARBON_VLOG() << entry.name_id;
+  }
+  CARBON_VLOG() << "\n";
+  CARBON_CHECK(stack_.size() < (1 << 20))
+      << "Excessive stack size: likely infinite loop";
+  stack_.push_back(entry);
+}
+
+auto SemanticsNodeStack::PopEntry() -> Entry {
+  auto back = stack_.pop_back_val();
+  CARBON_VLOG() << "Pop " << stack_.size() << ": any ("
+                << parse_tree_->node_kind(back.parse_node) << ") -> "
+                << back.node_id << "\n";
+  return back;
+}
+
+auto SemanticsNodeStack::PopEntry(ParseNodeKind pop_parse_kind) -> Entry {
+  auto back = stack_.pop_back_val();
+  CARBON_VLOG() << "Pop " << stack_.size() << ": " << pop_parse_kind << " -> "
+                << back.node_id << "\n";
+  RequireParseKind(back, pop_parse_kind);
+  return back;
+}
+
+auto SemanticsNodeStack::RequireParseKind(Entry entry,
+                                          ParseNodeKind require_kind) -> void {
+  auto actual_kind = parse_tree_->node_kind(entry.parse_node);
+  CARBON_CHECK(require_kind == actual_kind)
+      << "Expected " << require_kind << ", found " << actual_kind;
+}
+
+auto SemanticsNodeStack::RequireSoloParseNode(Entry entry) -> void {
+  CARBON_CHECK(!entry.node_id.is_valid())
+      << "Expected invalid node_id on "
+      << parse_tree_->node_kind(entry.parse_node) << ", was " << entry.node_id;
+}
+
+auto SemanticsNodeStack::RequireNodeId(Entry entry) -> void {
+  CARBON_CHECK(entry.node_id.is_valid())
+      << "Expected valid node_id on "
+      << parse_tree_->node_kind(entry.parse_node);
+}
+
+auto SemanticsNodeStack::PopAndDiscardSoloParseNode(
+    ParseNodeKind pop_parse_kind) -> void {
+  auto back = PopEntry(pop_parse_kind);
+  RequireSoloParseNode(back);
+}
+
+auto SemanticsNodeStack::PopForSoloParseNode() -> ParseTree::Node {
+  auto back = PopEntry();
+  RequireSoloParseNode(back);
+  return back.parse_node;
+}
+
+auto SemanticsNodeStack::PopForSoloParseNode(ParseNodeKind pop_parse_kind)
+    -> ParseTree::Node {
+  auto back = PopEntry(pop_parse_kind);
+  RequireSoloParseNode(back);
+  return back.parse_node;
+}
+
+auto SemanticsNodeStack::PopForNodeId() -> SemanticsNodeId {
+  auto back = PopEntry();
+  RequireNodeId(back);
+  return back.node_id;
+}
+
+auto SemanticsNodeStack::PopForNodeId(ParseNodeKind pop_parse_kind)
+    -> SemanticsNodeId {
+  auto back = PopEntry(pop_parse_kind);
+  RequireNodeId(back);
+  return back.node_id;
+}
+
+auto SemanticsNodeStack::PopForParseNodeAndNodeId()
+    -> std::pair<ParseTree::Node, SemanticsNodeId> {
+  auto back = PopEntry();
+  RequireNodeId(back);
+  return {back.parse_node, back.node_id};
+}
+
+auto SemanticsNodeStack::PopForParseNodeAndNodeId(ParseNodeKind pop_parse_kind)
+    -> std::pair<ParseTree::Node, SemanticsNodeId> {
+  auto back = PopEntry(pop_parse_kind);
+  RequireNodeId(back);
+  return {back.parse_node, back.node_id};
+}
+
+auto SemanticsNodeStack::PopForParseNodeAndNameId()
+    -> std::pair<ParseTree::Node, SemanticsStringId> {
+  auto back = PopEntry(ParseNodeKind::PatternBinding);
+  RequireNodeId(back);
+  return {back.parse_node, back.name_id};
+}
+
+auto SemanticsNodeStack::PeekForNameId() -> SemanticsStringId {
+  auto back = stack_.back();
+  RequireParseKind(back, ParseNodeKind::PatternBinding);
+  RequireNodeId(back);
+  return back.name_id;
+}
+
+auto SemanticsNodeStack::PrintForStackDump(llvm::raw_ostream& output) const
+    -> void {
+  output << "node_stack_:\n";
+  for (int i = 0; i < static_cast<int>(stack_.size()); ++i) {
+    const auto& entry = stack_[i];
+    auto parse_node_kind = parse_tree_->node_kind(entry.parse_node);
+    output << "\t" << i << ".\t" << parse_node_kind;
+    if (parse_node_kind == ParseNodeKind::PatternBinding) {
+      output << " -> " << entry.name_id;
+    } else {
+      if (entry.node_id.is_valid()) {
+        output << " -> " << entry.node_id;
+      }
+    }
+    output << "\n";
+  }
+}
+
+}  // namespace Carbon