Add diagnostic_logger

include/cppast/diagnostic.hpp

@@ -0,0 +1,80 @@
+// Copyright (C) 2017 Jonathan Müller <jonathanmueller.dev@gmail.com>
+// This file is subject to the license terms in the LICENSE file
+// found in the top-level directory of this distribution.
+
+#ifndef CPPAST_DIAGNOSTIC_HPP_INCLUDED
+#define CPPAST_DIAGNOSTIC_HPP_INCLUDED
+
+#include <string>
+
+#include <type_safe/optional.hpp>
+
+namespace cppast
+{
+    /// Describes a physical source location attached to a [cppast::diagnostic]().
+    /// \notes All information might be unavailable.
+    struct source_location
+    {
+        type_safe::optional<std::string> entity;
+        type_safe::optional<std::string> file;
+        type_safe::optional<unsigned>    line;
+
+        /// \returns A source location where all information is available.
+        static source_location make(std::string entity, std::string file, unsigned line)
+        {
+            return {std::move(entity), std::move(file), line};
+        }
+
+        /// \returns A source location where only file and line information is available.
+        static source_location make(std::string file, unsigned line)
+        {
+            return {type_safe::nullopt, std::move(file), line};
+        }
+
+        /// \returns A source location where only the entity name is available.
+        static source_location make(std::string entity)
+        {
+            return {std::move(entity), type_safe::nullopt, type_safe::nullopt};
+        }
+
+        /// \returns A possible string representation of the source location.
+        /// \notes It will include a separator, but no trailing whitespace.
+        std::string to_string() const
+        {
+            std::string result;
+            if (file)
+            {
+                result += file.value() + ":";
+                if (line)
+                    result += line.value() + ":";
+                if (entity)
+                    result += " (" + entity.value() + "):";
+            }
+            else if (entity)
+                result += entity.value() + ":";
+
+            return result;
+        }
+    };
+
+    /// The severity of a [cppast::diagnostic]().
+    enum class severity
+    {
+        warning,  //< A warning that doesn't impact AST generation.
+        error,    //< A non-critical error that does impact AST generation but not critically.
+        critical, //< A critical error where AST generation isn't possible.
+        /// \notes This will usually result in an exception being thrown after the diagnostic has been displayed.
+    };
+
+    /// A diagnostic.
+    ///
+    /// It represents an error message from a [cppast::parser]().
+    struct diagnostic
+    {
+        std::string      message;
+        source_location  location;
+        cppast::severity severity;
+    };
+} // namespace cppast
+
+#endif // CPPAST_DIAGNOSTIC_HPP_INCLUDED

include/cppast/libclang_parser.hpp

@@ -69,7 +69,7 @@ namespace cppast
     class libclang_parser final : public parser
     {
     public:
-        libclang_parser();
+        explicit libclang_parser(type_safe::object_ref<const diagnostic_logger> logger);
         ~libclang_parser() noexcept override;
 
     private:

include/cppast/parser.hpp

@@ -11,6 +11,39 @@
 namespace cppast
 {
     class cpp_entity_index;
+    class diagnostic;
+
+    /// Base class for a [cppast::diagnostic]() logger.
+    ///
+    /// Its task is controlling how diagnostic are being displayed.
+    class diagnostic_logger
+    {
+    public:
+        diagnostic_logger() noexcept                = default;
+        diagnostic_logger(const diagnostic_logger&) = delete;
+        diagnostic_logger& operator=(const diagnostic_logger&) = delete;
+        virtual ~diagnostic_logger() noexcept                  = default;
+
+        /// \effects Logs the diagnostic by invoking the `do_log()` member function.
+        /// \returns Whether or not the diagnostic was logged.
+        /// \notes `source` points to a string literal that gives additional context to what generates the message.
+        bool log(const char* source, const diagnostic& d) const
+        {
+            return do_log(source, d);
+        }
+
+    private:
+        virtual bool do_log(const char* source, const diagnostic& d) const = 0;
+    };
+
+    /// A [cppast::diagnostic_logger]() that logs to `stderr`.
+    ///
+    /// It prints all diagnostics in an implementation-defined format.
+    class stderr_diagnostic_logger final : public diagnostic_logger
+    {
+    private:
+        bool do_log(const char* source, const diagnostic& d) const override;
+    };
 
     /// Base class for a parser.
     ///
@@ -33,13 +66,24 @@ namespace cppast
         }
 
     protected:
-        parser() = default;
+        /// \effects Creates it giving it a reference to the logger it uses.
+        explicit parser(type_safe::object_ref<const diagnostic_logger> logger) : logger_(logger)
+        {
+        }
+
+        /// \returns A reference to the logger used.
+        const diagnostic_logger& logger() const noexcept
+        {
+            return *logger_;
+        }
 
     private:
         /// \effects Parses the given file.
         /// \returns The [cppast::cpp_file]() object describing it.
         virtual std::unique_ptr<cpp_file> do_parse(const cpp_entity_index& idx, std::string path,
                                                    const compile_config& config) const = 0;
+
+        type_safe::object_ref<const diagnostic_logger> logger_;
     };
 } // namespace cppast
 

src/libclang/libclang_parser.cpp

@@ -95,7 +95,8 @@ struct libclang_parser::impl
     }
 };
 
-libclang_parser::libclang_parser() : pimpl_(new impl)
+libclang_parser::libclang_parser(type_safe::object_ref<const diagnostic_logger> logger)
+: parser(logger), pimpl_(new impl)
 {
 }
 
@@ -164,7 +165,7 @@ std::unique_ptr<cpp_file> libclang_parser::do_parse(const cpp_entity_index& idx,
     auto& config = static_cast<const libclang_compile_config&>(c);
 
     // preprocess + parse
-    auto preprocessed = detail::preprocess(config, path.c_str());
+    auto preprocessed = detail::preprocess(config, path.c_str(), logger());
     auto tu           = get_cxunit(pimpl_->index, config, path.c_str(), preprocessed.source);
 
     // convert entity hierachies

src/libclang/preprocessor.cpp

@@ -7,7 +7,6 @@
 #include <algorithm>
 #include <cstddef>
 #include <cstring>
-#include <cstdio>
 
 // treat the tiny-process-library as header only
 #include <process.hpp>
@@ -23,6 +22,7 @@
 #include <type_safe/reference.hpp>
 
 #include <cppast/cpp_entity_kind.hpp>
+#include <cppast/diagnostic.hpp>
 
 using namespace cppast;
 namespace ts = type_safe;
@@ -54,9 +54,10 @@ namespace
     }
 
     // gets the full preprocessor output
-    std::string get_full_preprocess_output(const libclang_compile_config& c, const char* full_path)
+    std::string get_full_preprocess_output(const libclang_compile_config& c, const char* full_path,
+                                           const diagnostic_logger& logger)
     {
-        std::string preprocessed;
+        std::string preprocessed, diagnostics;
 
         auto    cmd = get_command(c, full_path);
         Process process(cmd, "",
@@ -66,16 +67,20 @@ namespace
                                 if (*str != '\r')
                                     preprocessed.push_back(*str);
                         },
-                        [&](const char* str, std::size_t n) {
+                        [&](const char* str, std::size_t n) { diagnostics.append(str, n); });
-                            std::fprintf(stderr, "%.*s\n", static_cast<int>(n),
-                                         str); // TODO: log error properly
-                        });
 
         auto exit_code = process.get_exit_status();
         if (exit_code != 0)
+        {
+            if (!diagnostics.empty())
+                logger.log("preprocessor",
+                           diagnostic{std::move(diagnostics), {}, severity::critical});
             throw libclang_error("preprocessor: command '" + cmd
                                  + "' exited with non-zero exit code (" + std::to_string(exit_code)
                                  + ")");
+        }
+        else if (!diagnostics.empty())
+            logger.log("preprocessor", diagnostic{std::move(diagnostics), {}, severity::error});
 
         return preprocessed;
     }
@@ -369,11 +374,11 @@ namespace
 }
 
 detail::preprocessor_output detail::preprocess(const libclang_compile_config& config,
-                                               const char*                    path)
+                                               const char* path, const diagnostic_logger& logger)
 {
     detail::preprocessor_output result;
 
-    auto output = get_full_preprocess_output(config, path);
+    auto output = get_full_preprocess_output(config, path, logger);
 
     position    p(ts::ref(result.source), output.c_str());
     std::size_t file_depth = 0u;

src/libclang/preprocessor.hpp

@@ -24,7 +24,8 @@ namespace cppast
             std::vector<pp_entity> entities;
         };
 
-        preprocessor_output preprocess(const libclang_compile_config& config, const char* path);
+        preprocessor_output preprocess(const libclang_compile_config& config, const char* path,
+                                       const diagnostic_logger& logger);
     }
 } // namespace cppast::detail
 

src/parser.cpp

@@ -0,0 +1,18 @@
+// Copyright (C) 2017 Jonathan Müller <jonathanmueller.dev@gmail.com>
+// This file is subject to the license terms in the LICENSE file
+// found in the top-level directory of this distribution.
+
+#include <cppast/parser.hpp>
+
+#include <cstdio>
+#include <mutex>
+
+#include <cppast/diagnostic.hpp>
+
+using namespace cppast;
+
+bool stderr_diagnostic_logger::do_log(const char* source, const diagnostic& d) const
+{
+    std::fprintf(stderr, "[%s] %s %s", source, d.location.to_string().c_str(), d.message.c_str());
+    return true;
+}

test/test_parser.hpp

@@ -29,7 +29,8 @@ std::unique_ptr<cppast::cpp_file> parse(const cppast::cpp_entity_index& idx, con
     libclang_compile_config config;
     config.set_flags(cpp_standard::cpp_latest);
 
-    libclang_parser p;
+    static stderr_diagnostic_logger logger;
+    libclang_parser                 p(type_safe::ref(logger));
     return p.parse(idx, name, config);
 }