[willow]: Diagnostics and plumbing (#2)

7 files changed, 149 insertions, 0 deletions

diff --git a/BUILD b/BUILD.bazel
index 6cbf83c..6cbf83c 100644
--- a/BUILD
+++ b/BUILD.bazel
diff --git a/willow/include/willow/IR/Context.h b/willow/include/willow/IR/Context.h
new file mode 100644
index 0000000..3468e8f
--- /dev/null
+++ b/willow/include/willow/IR/Context.h
@@ -0,0 +1,18 @@
+#ifndef WILLOW_INCLUDE_CONTEXT_H
+#define WILLOW_INCLUDE_CONTEXT_H
+
+#include <willow/IR/Module.h>
+#include <willow/IR/TypeContext.h>
+
+namespace willow {
+
+/// The global context. Contains all shared state.
+class WillowContext {
+  TypeContext ctx;
+
+  std::vector<std::unique_ptr<Module>> modules;
+};
+
+} // namespace willow
+
+#endif // WILLOW_INCLUDE_CONTEXT_H
diff --git a/willow/include/willow/IR/Diagnostic.h b/willow/include/willow/IR/Diagnostic.h
new file mode 100644
index 0000000..2a74898
--- /dev/null
+++ b/willow/include/willow/IR/Diagnostic.h
@@ -0,0 +1,30 @@
+#ifndef WILLOW_INCLUDE_IR_DIAGNOSTIC_H
+#define WILLOW_INCLUDE_IR_DIAGNOSTIC_H
+
+#include <willow/IR/Module.h>
+
+#include <cstdint>
+#include <string>
+
+namespace willow {
+
+enum class Severity { Debug, Remark, Warning, Error };
+
+struct Location {
+  std::string filename;
+  int line;
+  int col;
+};
+
+struct Diagnostic {
+  Severity severity;
+  std::string message;
+  std::optional<Location> location;
+  /// Extra lines that will be printed after the diagnostic. Call sites, extra
+  /// info, etc
+  std::vector<std::string> notes;
+};
+
+} // namespace willow
+
+#endif // WILLOW_INCLUDE_SUPPORT_DIAGNOSTICS_H
diff --git a/willow/include/willow/IR/DiagnosticEngine.h b/willow/include/willow/IR/DiagnosticEngine.h
new file mode 100644
index 0000000..2293734
--- /dev/null
+++ b/willow/include/willow/IR/DiagnosticEngine.h
@@ -0,0 +1,83 @@
+#ifndef WILLOW_INCLUDE_IR_DIAGNOSTIC_ENGINE_H
+#define WILLOW_INCLUDE_IR_DIAGNOSTIC_ENGINE_H
+
+/// \file DiagnosticEngine.h Portable diagnostic handling
+
+#include <willow/IR/Diagnostic.h>
+#include <willow/Util/LogicalResult.h>
+
+#include <sstream>
+
+namespace willow {
+
+class DiagnosticEngine {
+public:
+  using Handler = std::function<void(const Diagnostic &)>;
+
+  DiagnosticEngine() = default;
+  explicit DiagnosticEngine(Handler h) : handler(std::move(h)) {}
+
+  void setHandler(Handler h) { handler = std::move(h); }
+
+  void report(Diagnostic d) { // NOLINT(performance-unnecessary-value-param)
+    if (handler)
+      handler(d);
+  }
+
+private:
+  Handler handler;
+};
+
+/// Helper class for building, propagating and reporting a Diagnostic.
+class DiagnosticBuilder {
+  DiagnosticEngine *engine = nullptr;
+  Diagnostic diag;
+  std::ostringstream os;
+
+public:
+  DiagnosticBuilder(const DiagnosticBuilder &) = delete;
+  DiagnosticBuilder &operator=(const DiagnosticBuilder &) = delete;
+
+  DiagnosticBuilder(DiagnosticEngine &eng, Severity severity,
+                    std::optional<Location> loc)
+      : engine(&eng) {
+    diag.severity = severity;
+    diag.location = std::move(loc);
+  }
+
+  DiagnosticBuilder(DiagnosticBuilder &&other) noexcept
+      : engine(std::exchange(other.engine, nullptr)),
+        diag(std::move(other.diag)), os(std::move(other.os)) {}
+
+  ~DiagnosticBuilder() {
+    if (!engine) // was moved from
+      return;
+
+    diag.message += os.str();
+    engine->report(std::move(diag));
+  }
+
+  template <typename T>
+  DiagnosticBuilder &operator<<(T &&x) {
+    os << std::forward<T>(x);
+  }
+
+  /// Add a note to the diagnostic. Will be printed on its own line, following
+  /// the diagnostic itself.
+  DiagnosticBuilder &note(std::string n) {
+    diag.notes.push_back(std::move(n));
+    return *this;
+  }
+
+  operator LogicalResult() const { return LogicalResult::Failure; }
+};
+
+/// DiagnosticBuilder factory.
+inline DiagnosticBuilder emit(DiagnosticEngine &eng, Severity severity,
+                              std::optional<Location> loc = std::nullopt) {
+  return DiagnosticBuilder(eng, severity, std::move(loc));
+}
+
+} // namespace willow
+
+#endif // WILLOW_INCLUDE_IR_DIAGNOSTIC_ENGINE_H
diff --git a/willow/include/willow/IR/Instruction.h b/willow/include/willow/IR/Instruction.h
index a4dfbbb..f1bd0e6 100644
--- a/willow/include/willow/IR/Instruction.h
+++ b/willow/include/willow/IR/Instruction.h
@@ -80,6 +80,8 @@ public:
       operand->delUse(this);
   }
 
+  virtual bool verify(std::ostream &os) = 0;
+
   bool hasParent() const { return parent != nullptr; }
   BasicBlock *getParent() { return parent; }
   const BasicBlock *getParent() const { return parent; }
@@ -107,6 +109,7 @@ public:
   }
 };
 
+/// The base class for unary arithemetic instructions
 class UnaryInst : public Instruction {
 public:
   UnaryInst(std::string name, Type type, Op op, Value *value)
diff --git a/willow/include/willow/Util/LogicalResult.h b/willow/include/willow/Util/LogicalResult.h
new file mode 100644
index 0000000..3a345eb
--- /dev/null
+++ b/willow/include/willow/Util/LogicalResult.h
@@ -0,0 +1,14 @@
+#ifndef WILLOW_INCLUDE_LOGICAL_RESULT_H
+#define WILLOW_INCLUDE_LOGICAL_RESULT_H
+
+#include <cstdint>
+
+namespace willow {
+
+enum class LogicalResult : uint8_t { Success, Failure };
+inline bool succeeded(LogicalResult r) { return r == LogicalResult::Success; }
+inline bool failed(LogicalResult r) { return r == LogicalResult::Failure; }
+
+} // namespace willow
+
+#endif // WILLOW_INCLUDE_LOGICAL_RESULT_H
diff --git a/willow/lib/IR/Instruction.cpp b/willow/lib/IR/Instruction.cpp
new file mode 100644
index 0000000..21a4cae
--- /dev/null
+++ b/willow/lib/IR/Instruction.cpp
@@ -0,0 +1 @@
+#include <willow/IR/Instruction.h>