QDoc: Move `CodeParser::parseHeaderFile` to `ClangCodeParser`

QDoc parses a series of source file in different languages and formats
to find the user-provided documentation.

The base parsing interface for elements that perform this process is
given by the `CodeParser` class, with the concrete implementation of the
process for different languages/formats give by its child classes.

`CodeParser`, as part of its interface, provides certain methods that
are only meaningful when processing specific programming languages
source.

For example, it exposes `CodeParser::parseHeaderFile` whose purpose it
to provide an entry point for parsing C++ header files.

The method is only meaningfully implemented and used in the
`ClangCodeParser` child class, the class that actually implements the
processing of C++ source files.

Hence, the method is now removed from `CodeParser`'s interface and
directly exposed as part of the interface of `ClangCodeParser`, to
reduce the surface of the method and to reduce the dependencies between
`ClangCodeParser` and the `CodeParser` interface, which is generally
expected to be removed in the future.

`CodeParser` are, currently and temporarily, mostly initialized
statically and then retrieved through certain methods of the
`CodeParser` interface.
`CodeParser::parserForHeaderFile` is one such method that would retrieve
a `CodeParser` or child class instance that is able to parse an header
file.

Due to the removal of `parseHeaderFile` from `CodeParser` interface and
the fact that only one specific parser is able, and should be able, to
parse header files, `CodeParser::parserForHeaderFile` was removed.

Its only usage in "main.cpp", where it was called to retrieve the
already available `ClangCodeParser`, was modified to make use of
`ClangCodeParser` directly.

An auxiliary method, `CodeParser::headerFileNameFilter`, previously used
only by `CodeParser::parserForHeaderFile`, which provided a list of
extensions to identify what files could be accepted by a certain parser
as header files, is now removed as dead code.
A non-meaningful reimplementation of the `headerFileNameFilter` method
in `CppCodeParser`, a child class of `CodeParser`, was removed as of
consequence.

Similarly, the same method implementation in `ClangCodeParser` was
removed.
The filtering functionality that the method indirectly provided when
used by `CodeParser::parserForHeaderFile`, which is to be retained for
backward compatibility reasons, was moved to
`processQdocconfFile` in "main.cpp", where the header files that should
be parsed are gathered.
Instead of using the `headerFileNameFilter` method, the data that was
provided by it is now exposed as a static member of `ClangCodeParser`
and accessed directly when filtering is necessary.

Change-Id: Iff9a204627675aa7b34232c114945afceb8313ff
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

7 files changed, 16 insertions, 56 deletions

diff --git a/src/qdoc/clangcodeparser.cpp b/src/qdoc/clangcodeparser.cpp
index d2338ee32..e3984e502 100644
--- a/src/qdoc/clangcodeparser.cpp
+++ b/src/qdoc/clangcodeparser.cpp
@@ -41,6 +41,10 @@
 
 QT_BEGIN_NAMESPACE
 
+const QStringList ClangCodeParser::accepted_header_file_extensions{
+    "ch", "h", "h++", "hh", "hpp", "hxx"
+};
+
 // We're printing diagnostics in ClangCodeParser::printDiagnostics,
 // so avoid clang itself printing them.
 static const auto kClangDontDisplayDiagnostics = 0;
@@ -1240,19 +1244,6 @@ QString ClangCodeParser::language()
 }
 
 /*!
-  Returns a list of extensions for header files.
- */
-QStringList ClangCodeParser::headerFileNameFilter()
-{
-    return QStringList() << "*.ch"
-                         << "*.h"
-                         << "*.h++"
-                         << "*.hh"
-                         << "*.hpp"
-                         << "*.hxx";
-}
-
-/*!
   Returns a list of extensions for source files, i.e. not
   header files.
  */
diff --git a/src/qdoc/clangcodeparser.h b/src/qdoc/clangcodeparser.h
index 30d639f9f..24c793714 100644
--- a/src/qdoc/clangcodeparser.h
+++ b/src/qdoc/clangcodeparser.h
@@ -7,6 +7,7 @@
 #include "cppcodeparser.h"
 
 #include <QtCore/qtemporarydir.h>
+#include <QtCore/QStringList>
 
 typedef struct CXTranslationUnitImpl *CXTranslationUnit;
 
@@ -15,14 +16,16 @@ QT_BEGIN_NAMESPACE
 class ClangCodeParser : public CppCodeParser
 {
 public:
+    static const QStringList accepted_header_file_extensions;
+
+public:
     ~ClangCodeParser() override = default;
 
     void initializeParser() override;
     void terminateParser() override;
     QString language() override;
-    QStringList headerFileNameFilter() override;
     QStringList sourceFileNameFilter() override;
-    void parseHeaderFile(const Location &location, const QString &filePath) override;
+    void parseHeaderFile(const Location &location, const QString &filePath);
     void parseSourceFile(const Location &location, const QString &filePath) override;
     void precompileHeaders();
     Node *parseFnArg(const Location &location, const QString &fnSignature, const QString &idTag) override;
diff --git a/src/qdoc/codeparser.cpp b/src/qdoc/codeparser.cpp
index 72d1139e4..3c1ceabd1 100644
--- a/src/qdoc/codeparser.cpp
+++ b/src/qdoc/codeparser.cpp
@@ -50,16 +50,6 @@ void CodeParser::terminateParser()
     // nothing.
 }
 
-QStringList CodeParser::headerFileNameFilter()
-{
-    return sourceFileNameFilter();
-}
-
-void CodeParser::parseHeaderFile(const Location &location, const QString &filePath)
-{
-    parseSourceFile(location, filePath);
-}
-
 /*!
   All the code parsers in the static list are initialized here,
   after the qdoc configuration variables have been set.
@@ -88,21 +78,6 @@ CodeParser *CodeParser::parserForLanguage(const QString &language)
     return nullptr;
 }
 
-CodeParser *CodeParser::parserForHeaderFile(const QString &filePath)
-{
-    QString fileName = QFileInfo(filePath).fileName();
-
-    for (const auto &parser : std::as_const(s_parsers)) {
-        const QStringList headerPatterns = parser->headerFileNameFilter();
-        for (const auto &pattern : headerPatterns) {
-            auto re = QRegularExpression::fromWildcard(pattern, Qt::CaseInsensitive);
-            if (re.match(fileName).hasMatch())
-                return parser;
-        }
-    }
-    return nullptr;
-}
-
 CodeParser *CodeParser::parserForSourceFile(const QString &filePath)
 {
     QString fileName = QFileInfo(filePath).fileName();
diff --git a/src/qdoc/codeparser.h b/src/qdoc/codeparser.h
index ebd433dae..17fd43574 100644
--- a/src/qdoc/codeparser.h
+++ b/src/qdoc/codeparser.h
@@ -23,9 +23,7 @@ public:
     virtual void initializeParser();
     virtual void terminateParser();
     virtual QString language() = 0;
-    virtual QStringList headerFileNameFilter();
     virtual QStringList sourceFileNameFilter() = 0;
-    virtual void parseHeaderFile(const Location &location, const QString &filePath);
     virtual void parseSourceFile(const Location &location, const QString &filePath) = 0;
     virtual Node *parseFnArg(const Location &, const QString &, const QString & = QString())
     {
diff --git a/src/qdoc/cppcodeparser.cpp b/src/qdoc/cppcodeparser.cpp
index 3e16626fc..82753cb61 100644
--- a/src/qdoc/cppcodeparser.cpp
+++ b/src/qdoc/cppcodeparser.cpp
@@ -136,14 +136,6 @@ void CppCodeParser::terminateParser()
 }
 
 /*!
-  Returns a list of extensions for header files.
- */
-QStringList CppCodeParser::headerFileNameFilter()
-{
-    return QStringList();
-}
-
-/*!
   Returns a list of extensions for source files, i.e. not
   header files.
  */
diff --git a/src/qdoc/cppcodeparser.h b/src/qdoc/cppcodeparser.h
index b6d718eb9..14ab48661 100644
--- a/src/qdoc/cppcodeparser.h
+++ b/src/qdoc/cppcodeparser.h
@@ -30,7 +30,6 @@ public:
     void initializeParser() override;
     void terminateParser() override;
     QString language() override { return QStringLiteral("Cpp"); }
-    QStringList headerFileNameFilter() override;
     QStringList sourceFileNameFilter() override;
     FunctionNode *parseMacroArg(const Location &location, const QString &macroArg);
     FunctionNode *parseOtherFuncArg(const QString &topic, const Location &location,
diff --git a/src/qdoc/main.cpp b/src/qdoc/main.cpp
index d2e0b2625..1d0af6078 100644
--- a/src/qdoc/main.cpp
+++ b/src/qdoc/main.cpp
@@ -480,8 +480,13 @@ static void processQdocconfFile(const QString &fileName)
         for (const auto &header : headerList) {
             if (header.contains(QLatin1String("doc/snippets")))
                 continue;
+
             if (headers.contains(header))
                 continue;
+
+            if (!ClangCodeParser::accepted_header_file_extensions.contains(QFileInfo{header}.suffix()))
+                continue;
+
             headers.insert(header, header);
             QString t = header.mid(header.lastIndexOf('/') + 1);
             headerFileNames.insert(t, t);
@@ -521,11 +526,8 @@ static void processQdocconfFile(const QString &fileName)
 
         qCDebug(lcQdoc, "Parsing header files");
         for (auto it = headers.constBegin(); it != headers.constEnd(); ++it) {
-            CodeParser *codeParser = CodeParser::parserForHeaderFile(it.key());
-            if (codeParser) {
-                qCDebug(lcQdoc, "Parsing %s", qPrintable(it.key()));
-                codeParser->parseHeaderFile(config.location(), it.key());
-            }
+            qCDebug(lcQdoc, "Parsing %s", qPrintable(it.key()));
+            clangParser_->parseHeaderFile(config.location(), it.key());
         }
 
         clangParser_->precompileHeaders();