[MC] Implement RV64GC assembly emission

1 files changed, 95 insertions, 0 deletions

diff --git a/backend/lib/MC/MCContext.cpp b/backend/lib/MC/MCContext.cpp
new file mode 100644
index 0000000..2aa4c0e
--- /dev/null
+++ b/backend/lib/MC/MCContext.cpp
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "rcc/MC/MCContext.h"
+
+#include <cstdint>
+#include <limits>
+#include <memory>
+#include <string>
+#include <string_view>
+#include <utility>
+
+namespace rcc::mc {
+namespace {
+
+[[nodiscard]] bool isValidName(std::string_view Name) noexcept {
+  if (Name.empty())
+    return false;
+  for (const char RawCharacter : Name) {
+    const auto Character = static_cast<unsigned char>(RawCharacter);
+    if (Character == 0 || Character == '\n' || Character == '\r' || Character == 0x7fU)
+      return false;
+  }
+  return true;
+}
+
+} // namespace
+
+Expected<MCSymbolRef> MCContext::getOrCreateSymbol(std::string Name, MCSymbolKind Kind) {
+  if (!isValidName(Name))
+    return makeUnexpected(ErrorCode::InvalidArgument, "MC symbol has an invalid name");
+
+  const auto Position = Symbols.find(Name);
+  if (Position != Symbols.end()) {
+    const MCSymbolKind ExistingKind = Position->second->kind();
+    if (Kind != MCSymbolKind::Generic && ExistingKind != MCSymbolKind::Generic &&
+        ExistingKind != Kind) {
+      return makeUnexpected(ErrorCode::InvalidArgument,
+                            "MC symbol name is already used by a different symbol kind");
+    }
+    return Position->second;
+  }
+
+  MCSymbolRef Result(new MCSymbol(std::move(Name), Kind));
+  Symbols.emplace(std::string(Result->name()), Result);
+  return Result;
+}
+
+Expected<MCSymbolRef> MCContext::createTemporarySymbol(std::string_view Prefix) {
+  if (!isValidName(Prefix))
+    return makeUnexpected(ErrorCode::InvalidArgument, "temporary MC symbol prefix is invalid");
+  if (NextTemporarySymbol == std::numeric_limits<std::uint64_t>::max()) {
+    return makeUnexpected(ErrorCode::InternalError, "temporary MC symbol sequence is exhausted");
+  }
+
+  while (true) {
+    std::string Name(Prefix);
+    Name += std::to_string(NextTemporarySymbol++);
+    if (Symbols.contains(Name))
+      continue;
+    return getOrCreateSymbol(std::move(Name), MCSymbolKind::Temporary);
+  }
+}
+
+MCSymbolRef MCContext::symbol(std::string_view Name) const noexcept {
+  const auto Position = Symbols.find(Name);
+  return Position == Symbols.end() ? MCSymbolRef{} : Position->second;
+}
+
+Expected<MCSectionRef> MCContext::getOrCreateSection(MCSectionDesc Description) {
+  auto Verification = Description.verify();
+  if (!Verification)
+    return std::unexpected(Verification.error());
+
+  const auto Position = Sections.find(Description.Name);
+  if (Position != Sections.end()) {
+    MCSectionDesc ExistingDescription = Position->second->description();
+    ExistingDescription.Alignment = Description.Alignment;
+    if (ExistingDescription != Description) {
+      return makeUnexpected(ErrorCode::InvalidArgument,
+                            "MC section name is already used by a different description");
+    }
+    return Position->second;
+  }
+
+  MCSectionRef Result(new MCSection(std::move(Description)));
+  Sections.emplace(std::string(Result->name()), Result);
+  return Result;
+}
+
+MCSectionRef MCContext::section(std::string_view Name) const noexcept {
+  const auto Position = Sections.find(Name);
+  return Position == Sections.end() ? MCSectionRef{} : Position->second;
+}
+
+} // namespace rcc::mc