feat: tagfiles generation for cross-referencing in doxygen format

include/mrdocs/Corpus.hpp

@@ -160,6 +160,39 @@ class MRDOCS_VISIBLE
         }
     }
 
+    /** Visit the members of specified Info.
+
+        This function iterates the members of the specified
+        Info `I`. For each member associated with a
+        function with the same name as the member, the
+        function object `f` is invoked with the member
+        as the first argument, followed by `args...`.
+
+        When there are more than one member function
+        with the same name, the function object `f` is
+        invoked with an @ref OverloadSet as the first
+        argument, followed by `args...`.    
+
+        @param I The Info to traverse.
+        @param pred The predicate to use to determine if the member should be visited.
+        @param f The function to invoke with the member as the first argument, followed by `args...`.
+        @param args The arguments to pass to the function.
+    */
+    template <InfoParent T, class Pred, class F, class... Args>
+    void
+    traverseIf(
+        T const& I, Pred&& pred, F&& f, Args&&... args) const
+    {
+        for (auto const& id : I.Members)
+        {
+            if (pred(get(id))) 
+            {
+                visit(get(id), std::forward<F>(f),
+                      std::forward<Args>(args)...);
+            }
+        }
+    }
+
     /** Visit the function members of specified Info.
 
         This function iterates the members of the specified

include/mrdocs/Generator.hpp

@@ -115,13 +115,16 @@ class MRDOCS_VISIBLE
         @param os The stream to write to.
 
         @param corpus The metadata to emit.
+
+        @param fileName The file name to use for the output.
     */
     MRDOCS_DECL
     virtual
     Error
     buildOne(
         std::ostream& os,
-        Corpus const& corpus) const = 0;
+        Corpus const& corpus,
+        std::string_view fileName) const = 0;
 
     /** Build the reference as a single page to a file.
 

src/lib/Gen/adoc/AdocGenerator.cpp

@@ -15,9 +15,13 @@
 #include "MultiPageVisitor.hpp"
 #include "SinglePageVisitor.hpp"
 #include "lib/Support/LegibleNames.hpp"
+#include "lib/Support/RawOstream.hpp"
+#include <llvm/Support/FileSystem.h>
+#include <llvm/Support/Path.h>
 #include <mrdocs/Metadata/DomMetadata.hpp>
 #include <mrdocs/Support/Error.hpp>
 #include <mrdocs/Support/Path.hpp>
+#include <fstream>
 #include <optional>
 #include <vector>
 
@@ -70,10 +74,35 @@ build(
     if(! ex)
         return ex.error();
 
-    MultiPageVisitor visitor(*ex, outputPath, corpus);
+    std::string path = files::appendPath(outputPath, "reference.tag.xml");
+    if(auto err = files::createDirectory(outputPath)) 
+    {
+        return err;
+    }
+
+    std::ofstream os;
+    try
+    {
+        os.open(path,
+            std::ios_base::binary |
+                std::ios_base::out |
+                std::ios_base::trunc // | std::ios_base::noreplace
+            );
+    }
+    catch(std::exception const& ex)
+    {
+        return formatError("std::ofstream(\"{}\") threw \"{}\"", path, ex.what());
+    }    
+
+    RawOstream raw_os(os);
+    auto tagfileWriter = TagfileWriter(raw_os, corpus);
+    tagfileWriter.initialize();
+
+    MultiPageVisitor visitor(*ex, outputPath, corpus, tagfileWriter);
     visitor(corpus.globalNamespace());
 
     auto errors = ex->wait();
+    tagfileWriter.finalize();
     if(! errors.empty())
         return Error(errors);
     return Error::success();
@@ -83,8 +112,12 @@ Error
 AdocGenerator::
 buildOne(
     std::ostream& os,
-    Corpus const& corpus) const
+    Corpus const& corpus,
+    std::string_view outputPath) const
 {
+    namespace path = llvm::sys::path;
+    using SmallString = llvm::SmallString<0>;
+
     auto options = loadOptions(corpus);
     if(! options)
         return options.error();
@@ -106,9 +139,36 @@ buildOne(
     if(! errors.empty())
         return {errors};
 
-    SinglePageVisitor visitor(*ex, corpus, os);
+    SmallString fileName(outputPath);
+    path::replace_extension(fileName, "tag.xml");
+    auto parentDir = files::getParentDir(fileName.str());
+    if(auto err = files::createDirectory(parentDir)) 
+    {
+        return err;
+    }
+
+    std::ofstream osTagfile;
+    try
+    {
+        osTagfile.open(fileName.str().str(),
+            std::ios_base::binary |
+                std::ios_base::out |
+                std::ios_base::trunc // | std::ios_base::noreplace
+            );
+    }
+    catch(std::exception const& ex)
+    {
+        return formatError("std::ofstream(\"{}\") threw \"{}\"", fileName.str().str(), ex.what());
+    }    
+
+    RawOstream raw_os(osTagfile);
+    auto tagfileWriter = TagfileWriter(raw_os, corpus);
+    tagfileWriter.initialize();
+
+    SinglePageVisitor visitor(*ex, corpus, os, outputPath, tagfileWriter);
     visitor(corpus.globalNamespace());
     errors = ex->wait();
+    tagfileWriter.finalize();
     if(! errors.empty())
         return {errors};
 

src/lib/Gen/adoc/AdocGenerator.hpp

@@ -49,7 +49,8 @@ class AdocGenerator
     Error
     buildOne(
         std::ostream& os,
-        Corpus const& corpus) const override;
+        Corpus const& corpus,
+        std::string_view fileName) const override;
 };
 
 } // adoc

src/lib/Gen/adoc/MultiPageVisitor.cpp

@@ -50,8 +50,12 @@ operator()(T const& I)
 {
     ex_.async([this, &I](Builder& builder)
     {
-        if(const auto r = builder(I))
-            writePage(*r, builder.domCorpus.getXref(I));
+        if(const auto r = builder(I)) 
+        {
+            auto const xref = builder.domCorpus.getXref(I);
+            writePage(*r, xref);
+            tagfileWriter_(I, xref);
+        }
         else
             r.error().Throw();
         if constexpr(

src/lib/Gen/adoc/MultiPageVisitor.hpp

@@ -12,6 +12,7 @@
 #define MRDOCS_LIB_GEN_ADOC_MULTIPAGEVISITOR_HPP
 
 #include "Builder.hpp"
+#include <lib/Lib/TagfileWriter.hpp>
 #include <mrdocs/Support/ExecutorGroup.hpp>
 #include <mutex>
 #include <ostream>
@@ -29,6 +30,7 @@ class MultiPageVisitor
     ExecutorGroup<Builder>& ex_;
     std::string_view outputPath_;
     Corpus const& corpus_;
+    TagfileWriter& tagfileWriter_;
 
     void
     writePage(
@@ -39,10 +41,12 @@ class MultiPageVisitor
     MultiPageVisitor(
         ExecutorGroup<Builder>& ex,
         std::string_view outputPath,
-        Corpus const& corpus) noexcept
+        Corpus const& corpus,
+        TagfileWriter& tagfileWriter) noexcept
         : ex_(ex)
         , outputPath_(outputPath)
         , corpus_(corpus)
+        , tagfileWriter_(tagfileWriter)
     {
     }
 

src/lib/Gen/adoc/SinglePageVisitor.cpp

@@ -22,8 +22,11 @@ operator()(T const& I)
 {
     ex_.async([this, &I, page = numPages_++](Builder& builder)
     {
-        if(auto r = builder(I))
+        if(auto r = builder(I)) 
+        {
             writePage(*r, page);
+            tagfileWriter_(I, fileName_);
+        }
         else
             r.error().Throw();
     });

src/lib/Gen/adoc/SinglePageVisitor.hpp

@@ -13,6 +13,7 @@
 
 #include "Builder.hpp"
 #include <mrdocs/MetadataFwd.hpp>
+#include <lib/Lib/TagfileWriter.hpp>
 #include <mrdocs/Support/ExecutorGroup.hpp>
 #include <mutex>
 #include <ostream>
@@ -35,16 +36,22 @@ class SinglePageVisitor
     std::size_t topPage_ = 0;
     std::vector<std::optional<
         std::string>> pages_;
+    std::string fileName_;
+    TagfileWriter& tagfileWriter_;
 
     void writePage(std::string pageText, std::size_t pageNumber);
 public:
     SinglePageVisitor(
         ExecutorGroup<Builder>& ex,
         Corpus const& corpus,
-        std::ostream& os) noexcept
+        std::ostream& os,
+        std::string_view fileName,
+        TagfileWriter& tagfileWriter) noexcept
         : ex_(ex)
         , corpus_(corpus)
         , os_(os)
+        , fileName_(fileName)
+        , tagfileWriter_(tagfileWriter)
     {
     }
 

src/lib/Gen/html/HTMLGenerator.cpp

@@ -15,9 +15,13 @@
 #include "MultiPageVisitor.hpp"
 #include "SinglePageVisitor.hpp"
 #include "lib/Support/LegibleNames.hpp"
+#include "lib/Support/RawOstream.hpp"
+#include <llvm/Support/FileSystem.h>
+#include <llvm/Support/Path.h>
 #include <mrdocs/Metadata/DomMetadata.hpp>
 #include <mrdocs/Support/Error.hpp>
 #include <mrdocs/Support/Path.hpp>
+#include <fstream>
 #include <optional>
 #include <vector>
 
@@ -67,9 +71,34 @@ build(
     if(! ex)
         return ex.error();
 
-    MultiPageVisitor visitor(*ex, outputPath, corpus);
+    std::string path = files::appendPath(outputPath, "reference.tag.xml");
+    if(auto err = files::createDirectory(outputPath)) 
+    {
+        return err;
+    }
+
+    std::ofstream os;
+    try
+    {
+        os.open(path,
+            std::ios_base::binary |
+                std::ios_base::out |
+                std::ios_base::trunc // | std::ios_base::noreplace
+            );
+    }
+    catch(std::exception const& ex)
+    {
+        return formatError("std::ofstream(\"{}\") threw \"{}\"", path, ex.what());
+    }    
+
+    RawOstream raw_os(os);
+    auto tagfileWriter = TagfileWriter(raw_os, corpus);
+    tagfileWriter.initialize();        
+
+    MultiPageVisitor visitor(*ex, outputPath, corpus, tagfileWriter);
     visitor(corpus.globalNamespace());
     auto errors = ex->wait();
+    tagfileWriter.finalize();
     if(! errors.empty())
         return Error(errors);
     return Error::success();
@@ -79,8 +108,12 @@ Error
 HTMLGenerator::
 buildOne(
     std::ostream& os,
-    Corpus const& corpus) const
+    Corpus const& corpus,
+    std::string_view outputPath) const
 {
+    namespace path = llvm::sys::path;
+    using SmallString = llvm::SmallString<0>;
+
     HTMLCorpus domCorpus(corpus);
     auto ex = createExecutors(domCorpus);
     if(! ex)
@@ -98,9 +131,36 @@ buildOne(
     if(! errors.empty())
         return Error(errors);
 
-    SinglePageVisitor visitor(*ex, corpus, os);
+    SmallString fileName(outputPath);
+    path::replace_extension(fileName, "tag.xml");
+    auto parentDir = files::getParentDir(fileName.str());
+    if(auto err = files::createDirectory(parentDir)) 
+    {
+        return err;
+    }
+
+    std::ofstream osTagfile;
+    try
+    {
+        osTagfile.open(fileName.str().str(),
+            std::ios_base::binary |
+                std::ios_base::out |
+                std::ios_base::trunc // | std::ios_base::noreplace
+            );
+    }
+    catch(std::exception const& ex)
+    {
+        return formatError("std::ofstream(\"{}\") threw \"{}\"", fileName.str().str(), ex.what());
+    }    
+
+    RawOstream raw_os(osTagfile);
+    auto tagfileWriter = TagfileWriter(raw_os, corpus);
+    tagfileWriter.initialize();
+
+    SinglePageVisitor visitor(*ex, corpus, os, outputPath, tagfileWriter);
     visitor(corpus.globalNamespace());
     errors = ex->wait();
+    tagfileWriter.finalize();
     if(! errors.empty())
         return Error(errors);
 

src/lib/Gen/html/HTMLGenerator.hpp

@@ -49,7 +49,8 @@ class HTMLGenerator
     Error
     buildOne(
         std::ostream& os,
-        Corpus const& corpus) const override;
+        Corpus const& corpus,
+        std::string_view fileName) const override;
 };
 
 } // html

src/lib/Gen/html/MultiPageVisitor.cpp

@@ -50,6 +50,7 @@ renderPage(
                         std::ios_base::trunc // | std::ios_base::noreplace
                     );
                 os.write(pageText.data(), pageText.size());
+                tagfileWriter_(I, fileName);
             }
             catch(std::exception const& ex)
             {