feat: Diagnostics

docs/modules/ROOT/pages/design-notes.adoc

@@ -42,9 +42,9 @@ does not vary based on the platform.
 
 == Exceptions
 
-In functions which cannot return an error, such as work submitted to a thread
-pool or in a constructor, the implementation usually throws `Error`. These
-are caught and reported, and the process exits gracefully. If any exception
-is thrown which is not derived from `Error`, then it should not be caught.
-The uncaught exception handler should print a stack trace and exit the process
-immediately.
+Errors thrown by the program should always have type `Exception`. Objects
+of this type are capable of transporting an `Error` object. This is important
+for the scripting to work; exceptions are used to propagate errors from
+library code to scripts and back to the invoking code. For exceptional cases,
+these thrown exceptions should be uncaught. The tool installs an uncaught exception
+handler that prints a stack trace and exits the process immediately.

source/AST/ASTVisitor.cpp

@@ -48,8 +48,8 @@ ASTVisitor(
     clang::CompilerInstance& compiler) noexcept
     : ex_(ex)
     , config_(config)
-    , IsFileInRootDir_(true)
     , compiler_(compiler)
+    , IsFileInRootDir_(true)
 {
 }
 

source/AST/ASTVisitor.hpp

@@ -13,6 +13,7 @@
 #ifndef MRDOX_TOOL_AST_ASTVISITOR_HPP
 #define MRDOX_TOOL_AST_ASTVISITOR_HPP
 
+#include "Diagnostics.hpp"
 #include "Tool/ConfigImpl.hpp"
 #include <mrdox/MetadataFwd.hpp>
 #include <clang/Sema/SemaConsumer.h>
@@ -47,6 +48,12 @@ class ASTVisitor
 
     tooling::ExecutionContext& ex_;
     ConfigImpl const& config_;
+    clang::CompilerInstance& compiler_;
+    Diagnostics diags_;
+
+    ASTContext* astContext_ = nullptr;
+    SourceManager* sourceManager_ = nullptr;
+    Sema* sema_ = nullptr;
 
     llvm::SmallString<512> File_;
     bool IsFileInRootDir_;
@@ -57,12 +64,6 @@ class ASTVisitor
         clang::SourceLocation::UIntTy,
         FileFilter> fileFilter_;
 
-    clang::CompilerInstance& compiler_;
-
-    ASTContext* astContext_ = nullptr;
-    SourceManager* sourceManager_ = nullptr;
-    Sema* sema_ = nullptr;
-
 public:
     ASTVisitor(
         tooling::ExecutionContext& ex,

source/AST/Diagnostics.hpp

@@ -0,0 +1,64 @@
+//
+// Licensed under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// Copyright (c) 2023 Vinnie Falco ([email protected])
+//
+// Official repository: https://github.com/cppalliance/mrdox
+//
+
+#ifndef MRDOX_TOOL_AST_DIAGNOSTICS_HPP
+#define MRDOX_TOOL_AST_DIAGNOSTICS_HPP
+
+#include <mrdox/Support/Error.hpp>
+#include <llvm/Support/raw_ostream.h>
+#include <string>
+#include <unordered_set>
+
+namespace clang {
+namespace mrdox {
+
+/** Diagnostic information accumulated during visitation.
+*/
+class Diagnostics
+{
+    std::size_t errorCount_ = 0;
+    std::unordered_set<std::string> messages_;
+
+public:
+    void reportError(std::string s)
+    {
+        auto result =
+            messages_.emplace(std::move(s));
+        if(result.second)
+            ++errorCount_;
+    }
+
+    void reportWarning(std::string s)
+    {
+        auto result =
+            messages_.emplace(std::move(s));
+        if(result.second)
+            ++errorCount_;
+    }
+
+    void
+    merge(
+        Diagnostics&& other,
+        llvm::raw_ostream* os = nullptr)
+    {
+        for(auto&& s : other.messages_)
+        {
+            auto result = messages_.emplace(std::move(s));
+            if(os && result.second)
+                *os << *result.first;
+        }
+        other.messages_.clear();
+    }
+};
+
+} // mrdox
+} // clang
+
+#endif