make oncevar plugin ignore methods with #ifdef-ery

Change-Id: I8a9cf2c4b81b95bf654f7e90306328d72e3d3408
Reviewed-on: https://gerrit.libreoffice.org/40280Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

compilerplugins/clang/casttovoid.cxx

@@ -414,53 +414,6 @@ private:
                 || compiler.getSourceManager().isMacroBodyExpansion(loc));
     }
 
-    bool containsPreprocessingConditionalInclusion(SourceRange range) {
-        auto const begin = compiler.getSourceManager().getExpansionLoc(
-            range.getBegin());
-        auto const end = compiler.getSourceManager().getExpansionLoc(
-            range.getEnd());
-        assert(begin.isFileID() && end.isFileID());
-        if (!(begin == end
-              || compiler.getSourceManager().isBeforeInTranslationUnit(
-                  begin, end)))
-        {
-            // Conservatively assume "yes" if lexing fails (e.g., due to
-            // macros):
-            return true;
-        }
-        auto hash = false;
-        for (auto loc = begin;;) {
-            Token tok;
-            if (Lexer::getRawToken(
-                    loc, tok, compiler.getSourceManager(),
-                    compiler.getLangOpts(), true))
-            {
-                // Conservatively assume "yes" if lexing fails (e.g., due to
-                // macros):
-                return true;
-            }
-            if (hash && tok.is(tok::raw_identifier)) {
-                auto const id = tok.getRawIdentifier();
-                if (id == "if" || id == "ifdef" || id == "ifndef"
-                    || id == "elif" || id == "else" || id == "endif")
-                {
-                    return true;
-                }
-            }
-            if (loc == range.getEnd()) {
-                break;
-            }
-            hash = tok.is(tok::hash) && tok.isAtStartOfLine();
-            loc = loc.getLocWithOffset(
-                std::max<unsigned>(
-                    Lexer::MeasureTokenLength(
-                        loc, compiler.getSourceManager(),
-                        compiler.getLangOpts()),
-                    1));
-        }
-        return false;
-    }
-
     DeclRefExpr const * checkCast(ExplicitCastExpr const * expr) {
         if (!loplugin::TypeCheck(expr->getTypeAsWritten()).Void()) {
             return nullptr;

compilerplugins/clang/oncevar.cxx

@@ -242,6 +242,7 @@ public:
 
     bool VisitDeclRefExpr( const DeclRefExpr* );
     bool VisitVarDecl( const VarDecl* );
+    bool TraverseFunctionDecl( FunctionDecl* functionDecl );
 
 private:
     std::unordered_set<VarDecl const *> maVarDeclSet;
@@ -287,6 +288,16 @@ private:
     }
 };
 
+bool OnceVar::TraverseFunctionDecl( FunctionDecl* functionDecl )
+{
+    // Ignore functions that contains #ifdef-ery, can be quite tricky
+    // to make useful changes when this plugin fires in such functions
+    if (containsPreprocessingConditionalInclusion(
+            functionDecl->getSourceRange()))
+        return true;
+    return RecursiveASTVisitor::TraverseFunctionDecl(functionDecl);
+}
+
 bool OnceVar::VisitVarDecl( const VarDecl* varDecl )
 {
     if (ignoreLocation(varDecl)) {

compilerplugins/clang/plugin.cxx

@@ -273,6 +273,54 @@ bool Plugin::isUnitTestMode()
     return PluginHandler::isUnitTestMode();
 }
 
+bool Plugin::containsPreprocessingConditionalInclusion(SourceRange range)
+{
+    auto const begin = compiler.getSourceManager().getExpansionLoc(
+        range.getBegin());
+    auto const end = compiler.getSourceManager().getExpansionLoc(
+        range.getEnd());
+    assert(begin.isFileID() && end.isFileID());
+    if (!(begin == end
+          || compiler.getSourceManager().isBeforeInTranslationUnit(
+              begin, end)))
+    {
+        // Conservatively assume "yes" if lexing fails (e.g., due to
+        // macros):
+        return true;
+    }
+    auto hash = false;
+    for (auto loc = begin;;) {
+        Token tok;
+        if (Lexer::getRawToken(
+                loc, tok, compiler.getSourceManager(),
+                compiler.getLangOpts(), true))
+        {
+            // Conservatively assume "yes" if lexing fails (e.g., due to
+            // macros):
+            return true;
+        }
+        if (hash && tok.is(tok::raw_identifier)) {
+            auto const id = tok.getRawIdentifier();
+            if (id == "if" || id == "ifdef" || id == "ifndef"
+                || id == "elif" || id == "else" || id == "endif")
+            {
+                return true;
+            }
+        }
+        if (loc == range.getEnd()) {
+            break;
+        }
+        hash = tok.is(tok::hash) && tok.isAtStartOfLine();
+        loc = loc.getLocWithOffset(
+            std::max<unsigned>(
+                Lexer::MeasureTokenLength(
+                    loc, compiler.getSourceManager(),
+                    compiler.getLangOpts()),
+                1));
+    }
+    return false;
+}
+
 RewritePlugin::RewritePlugin( const InstantiationData& data )
     : Plugin( data )
     , rewriter( data.rewriter )

compilerplugins/clang/plugin.hxx

@@ -80,6 +80,9 @@ protected:
     static void normalizeDotDotInFilePath(std::string&);
 
     static bool isUnitTestMode();
+
+    bool containsPreprocessingConditionalInclusion(SourceRange range);
+
 private:
     static void registerPlugin( Plugin* (*create)( const InstantiationData& ), const char* optionName, bool isPPCallback, bool byDefault );
     template< typename T > static Plugin* createHelper( const InstantiationData& data );