Clang plugin to re-write SvStream operator<< to non-overloaded methods

Use a clang rewriter to rewrite SvStream::operator<< to methods
like WriteUInt32.
Note that the rewriter is not perfect, and hand-tweaking the output
is necessary.

Change-Id: I0291c8192ca74d6334ed3cf8cb713212b2f0c67d
Reviewed-on: https://gerrit.libreoffice.org/7307
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>

3 files changed, 341 insertions, 38 deletions

diff --git a/compilerplugins/clang/svstreamoutputoperators.cxx b/compilerplugins/clang/svstreamoutputoperators.cxx
new file mode 100644
index 000000000000..579ca6fda5e9
--- /dev/null
+++ b/compilerplugins/clang/svstreamoutputoperators.cxx
@@ -0,0 +1,181 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * Based on LLVM/Clang.
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ */
+
+/*
+This is a rewriter.
+
+It changes the SvStream operator<< calls into calls to more explicitly named
+methods, which reduces the casting needed, and makes it less likely that we
+will accidentally write data to a file using the wrong data-type-size.
+
+TODO we don't currently cope with macro expansion e.g. if the constant on the RHS is a #define
+
+TODO we don't currently cope with code like "(*this) << 1;"
+
+TODO we don't currently cope with code like "aStream << x << endl;" the "endl" parts ends up dangling.
+
+TODO we don't currently cope with custom overloads of operator<< in some of the use-sites.
+*/
+
+#include "plugin.hxx"
+#include <clang/Lex/Lexer.h>
+#include <iostream>
+
+namespace loplugin
+{
+
+class SvStreamOutputOperators
+    : public RecursiveASTVisitor< SvStreamOutputOperators >
+    , public RewritePlugin
+{
+    public:
+        explicit SvStreamOutputOperators( CompilerInstance& compiler, Rewriter& rewriter );
+        virtual void run() override;
+        bool VisitCallExpr( const CallExpr* call );
+   private:
+        SourceLocation after(const SourceLocation& loc);
+};
+
+SvStreamOutputOperators::SvStreamOutputOperators( CompilerInstance& compiler, Rewriter& rewriter )
+    : RewritePlugin( compiler, rewriter )
+{
+}
+
+void SvStreamOutputOperators::run()
+{
+    TraverseDecl( compiler.getASTContext().getTranslationUnitDecl());
+}
+
+bool SvStreamOutputOperators::VisitCallExpr( const CallExpr* callExpr )
+{
+    if( ignoreLocation( callExpr ))
+        return true;
+    if( callExpr->getNumArgs() < 2 )
+        return true;
+    const FunctionDecl* func = dyn_cast_or_null< FunctionDecl >( callExpr->getCalleeDecl() );
+    if ( func == NULL )
+        return true;
+    if( func->getNumParams() != 1 )
+        return true;
+    string qualifiedName = func->getQualifiedNameAsString();
+    if( qualifiedName != "SvStream::operator<<" )
+        return true;
+
+    string arg0 = func->getParamDecl( 0 )->getType().getAsString();
+    string newWriteMethod;
+    if( arg0 == "sal_uInt16" )
+        newWriteMethod = "WriteUInt16";
+    else if( arg0 == "sal_uInt32" )
+        newWriteMethod = "WriteUInt32";
+    else if( arg0 == "sal_uInt64" )
+        newWriteMethod = "WriteUInt64";
+    else if( arg0 == "sal_Int16" )
+        newWriteMethod = "WriteInt16";
+    else if( arg0 == "sal_Int32" )
+        newWriteMethod = "WriteInt32";
+    else if( arg0 == "sal_Int64" )
+        newWriteMethod = "WriteInt64";
+    else if( arg0 == "sal_uInt8" )
+        newWriteMethod = "WriteUInt8";
+    else if( arg0 == "sal_Unicode" )
+        newWriteMethod = "WriteUnicode";
+    else if( arg0 == "rtl::OString" )
+        newWriteMethod = "WriteOString";
+    else if( arg0 == "bool" )
+        newWriteMethod = "WriteBool";
+    else if( arg0 == "signed char" )
+        newWriteMethod = "WriteSChar";
+    else if( arg0 == "char" )
+        newWriteMethod = "WriteChar";
+    else if( arg0 == "unsigned char" )
+        newWriteMethod = "WriteUChar";
+    else if( arg0 == "float" )
+        newWriteMethod = "WriteFloat";
+    else if( arg0 == "double" )
+        newWriteMethod = "WriteDouble";
+    else if( arg0 == "const double &" )
+        newWriteMethod = "WriteDouble";
+    else if( arg0 == "const char *" )
+        newWriteMethod = "WriteCharPtr";
+    else if( arg0 == "char *" )
+        newWriteMethod = "WriteCharPtr";
+    else if( arg0 == "const unsigned char *" )
+        newWriteMethod = "WriteUCharPtr";
+    else if( arg0 == "unsigned char *" )
+        newWriteMethod = "WriteUCharPtr";
+    else if( arg0 == "class SvStream &" )
+        newWriteMethod = "WriteStream";
+    else
+    {
+        report( DiagnosticsEngine::Warning,
+                "found call to operator<< that I cannot convert with type: " + arg0,
+                callExpr->getLocStart());
+        return true;
+    }
+
+    // CallExpr overrides the children() method from Stmt, but not the const variant of it, so we need to cast const away.
+    StmtRange range = const_cast<CallExpr*>(callExpr)->children();
+    const Stmt* child1 = *range; // ImplicitCastExpr
+    ++range;
+    const Stmt* child2 = *range; // ImplicitCastExpr
+
+    if( dyn_cast_or_null< UnaryOperator >( child2 ) != NULL )
+    {
+        // remove the "*" before the stream variable
+        if( !replaceText( callExpr->getLocStart(), 1, "" ) )
+            return true;
+        if( !replaceText( child1->getLocStart().getLocWithOffset(-1), 4, "->" ) )
+            return true;
+    }
+    else
+    {
+        if( !replaceText( child1->getLocStart().getLocWithOffset(-1), 4, "." ) )
+            return true;
+    }
+
+    if( !insertTextBefore( callExpr->getArg( 1 )->getLocStart(), newWriteMethod + "( " ) )
+        return true;
+    if( !insertTextAfter( after( callExpr->getLocEnd() ), " )" ) )
+        return true;
+
+//TODO for some reason this is currently removing too much text
+    // if there was a cast e.g. "r << (sal_Int32) 1", then remove the cast
+//    const CStyleCastExpr* cast = dyn_cast_or_null< CStyleCastExpr >( callExpr->getArg(1) );
+//    if (cast != NULL)
+//    {
+//        replaceText( SourceRange( cast->getLParenLoc(), cast->getRParenLoc() ), "" );
+//    }
+
+    // if there was already parentheses around the expression, remove them
+    const ParenExpr* paren = dyn_cast_or_null< ParenExpr >( callExpr->getArg(1) );
+    if (paren != NULL)
+    {
+        if( !replaceText( paren->getLocStart(), 1, "" ) )
+             return true;
+        if( !replaceText( paren->getLocEnd(), 1, "" ) )
+            return true;
+    }
+
+//    report( DiagnosticsEngine::Note, "found", callExpr->getLocStart());
+    return true;
+}
+
+SourceLocation SvStreamOutputOperators::after( const SourceLocation& loc )
+{
+    return Lexer::getLocForEndOfToken( loc, 0, compiler.getASTContext().getSourceManager(), compiler.getASTContext().getLangOpts() );
+}
+
+
+static Plugin::Registration< SvStreamOutputOperators > X( "svstreamoutputoperators" );
+
+} // namespace
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/include/tools/stream.hxx b/include/tools/stream.hxx
index e390407a274e..7551a59d0dc0 100644
--- a/include/tools/stream.hxx
+++ b/include/tools/stream.hxx
@@ -315,24 +315,57 @@ public:
     SvStream&       operator>>( double& rDouble );
     SvStream&       operator>>( SvStream& rStream );
 
-    SvStream&       operator<<( sal_uInt16 nUInt16 );
-    SvStream&       operator<<( sal_uInt32 nUInt32 );
-    SvStream&       operator<<( sal_uInt64 nuInt64 );
-    SvStream&       operator<<( sal_Int16 nInt16 );
-    SvStream&       operator<<( sal_Int32 nInt32 );
+    SvStream&       operator<<( sal_uInt16 nUInt16 )
+                        { return WriteUInt16(nUInt16); }
+    SvStream&       operator<<( sal_uInt32 nUInt32 )
+                        { return WriteUInt32(nUInt32); }
+    SvStream&       operator<<( sal_uInt64 nuInt64 )
+                        { return WriteUInt64(nuInt64); }
+    SvStream&       operator<<( sal_Int16 nInt16 )
+                        { return WriteInt16(nInt16); }
+    SvStream&       operator<<( sal_Int32 nInt32 )
+                        { return WriteInt32(nInt32); }
     SvStream&       operator<<( sal_Int64 nInt64 ) SAL_DELETED_FUNCTION;
-    SvStream&       WriteInt64(sal_Int64 nInt64);
-
     SvStream&       operator<<( bool b )
                         { return operator<<(static_cast< sal_Bool >(b)); }
-    SvStream&       operator<<( signed char nChar );
-    SvStream&       operator<<( char nChar );
-    SvStream&       operator<<( unsigned char nChar );
-    SvStream&       operator<<( float nFloat );
-    SvStream&       operator<<( const double& rDouble );
-    SvStream&       operator<<( const char* pBuf );
-    SvStream&       operator<<( const unsigned char* pBuf );
-    SvStream&       operator<<( SvStream& rStream );
+    SvStream&       operator<<( signed char nChar )
+                        { return WriteSChar(nChar); }
+    SvStream&       operator<<( char nChar )
+                        { return WriteChar(nChar); }
+    SvStream&       operator<<( unsigned char nChar )
+                        { return WriteUChar(nChar); }
+    SvStream&       operator<<( float nFloat )
+                        { return WriteFloat(nFloat); }
+    SvStream&       operator<<( const double& rDouble )
+                        { return WriteDouble(rDouble); }
+    SvStream&       operator<<( const char* pBuf )
+                        { return WriteCharPtr(pBuf); }
+    SvStream&       operator<<( const unsigned char* pBuf )
+                        { return WriteUCharPtr(pBuf); }
+    SvStream&       operator<<( SvStream& rStream )
+                        { return WriteStream(rStream); }
+
+    SvStream&       WriteUInt16( sal_uInt16 nUInt16 );
+    SvStream&       WriteUInt32( sal_uInt32 nUInt32 );
+    SvStream&       WriteUInt64( sal_uInt64 nuInt64 );
+    SvStream&       WriteInt16( sal_Int16 nInt16 );
+    SvStream&       WriteInt32( sal_Int32 nInt32 );
+    SvStream&       WriteInt64( sal_Int64 nInt64 );
+    SvStream&       WriteUInt8( sal_uInt8 nuInt8 );
+    SvStream&       WriteUnicode( sal_Unicode );
+    SvStream&       WriteOString(const OString& rStr)
+                        { return WriteCharPtr(rStr.getStr()); }
+    SvStream&       WriteStream( SvStream& rStream );
+
+    SvStream&       WriteBool( bool b )
+                        { return WriteUChar(static_cast< sal_Bool >(b)); }
+    SvStream&       WriteSChar( signed char nChar );
+    SvStream&       WriteChar( char nChar );
+    SvStream&       WriteUChar( unsigned char nChar );
+    SvStream&       WriteFloat( float nFloat );
+    SvStream&       WriteDouble( const double& rDouble );
+    SvStream&       WriteCharPtr( const char* pBuf );
+    SvStream&       WriteUCharPtr( const unsigned char* pBuf );
 
     SvStream&       WriteNumber( sal_uInt32 nUInt32 );
     SvStream&       WriteNumber( sal_Int32 nInt32 );
@@ -585,6 +618,18 @@ sal_Size write_lenPrefixed_uInt16s_FromOUString(SvStream& rStrm,
     return streamdetail::write_lenPrefixed_seq_From_str<prefix, OUString, write_uInt16s_FromOUString>(rStrm, rStr);
 }
 
+/// Attempt to write a pascal-style length (of type prefix) prefixed sequence
+/// of 16bit units from an OUString, returned value is number of bytes written
+/// (including byte-count of prefix)
+TOOLS_DLLPUBLIC sal_Size write_uInt32_lenPrefixed_uInt16s_FromOUString(SvStream& rStrm,
+                                                const OUString &rStr);
+
+/// Attempt to write a pascal-style length (of type prefix) prefixed sequence
+/// of 16bit units from an OUString, returned value is number of bytes written
+/// (including byte-count of prefix)
+TOOLS_DLLPUBLIC sal_Size write_uInt16_lenPrefixed_uInt16s_FromOUString(SvStream& rStrm,
+                                                const OUString &rStr);
+
 /// Attempt to read 8bit units to an OString until a zero terminator is
 /// encountered, returned OString's length is number of units *definitely*
 /// successfully read, check SvStream::good() to see if null terminator was
@@ -650,6 +695,22 @@ sal_Size write_lenPrefixed_uInt8s_FromOUString(SvStream& rStrm,
     return write_lenPrefixed_uInt8s_FromOString<prefix>(rStrm, OUStringToOString(rStr, eEnc));
 }
 
+/// Attempt to write a pascal-style length (of type prefix) prefixed
+/// sequence of units from a string-type, returned value is number of bytes
+/// written (including byte-count of prefix)
+TOOLS_DLLPUBLIC sal_Size write_uInt16_lenPrefixed_uInt8s_FromOString(SvStream& rStrm,
+                                              const OString &rStr);
+
+/// Attempt to write a pascal-style length (of type prefix) prefixed sequence
+/// of 8bit units from an OUString, returned value is number of bytes written
+/// (including byte-count of prefix)
+TOOLS_DLLPUBLIC inline sal_Size write_uInt16_lenPrefixed_uInt8s_FromOUString(SvStream& rStrm,
+                                               const OUString &rStr,
+                                               rtl_TextEncoding eEnc)
+{
+    return write_uInt16_lenPrefixed_uInt8s_FromOString(rStrm, OUStringToOString(rStr, eEnc));
+}
+
 // FileStream
 
 class TOOLS_DLLPUBLIC SvFileStream : public SvStream
diff --git a/tools/source/stream/stream.cxx b/tools/source/stream/stream.cxx
index 808008919398..f02b5a00e200 100644
--- a/tools/source/stream/stream.cxx
+++ b/tools/source/stream/stream.cxx
@@ -790,7 +790,7 @@ bool SvStream::WriteLine(const OString& rStr)
 bool SvStream::WriteUniOrByteChar( sal_Unicode ch, rtl_TextEncoding eDestCharSet )
 {
     if ( eDestCharSet == RTL_TEXTENCODING_UNICODE )
-        *this << ch;
+        WriteChar(ch);
     else
     {
         OString aStr(&ch, 1, eDestCharSet);
@@ -805,7 +805,7 @@ bool SvStream::StartWritingUnicodeText()
     // BOM, Byte Order Mark, U+FEFF, see
     // http://www.unicode.org/faq/utf_bom.html#BOM
     // Upon read: 0xfeff(-257) => no swap; 0xfffe(-2) => swap
-    *this << sal_uInt16( 0xfeff );
+    WriteUInt16( 0xfeff );
     return nError == SVSTREAM_OK;
 }
 
@@ -1055,7 +1055,7 @@ SvStream& SvStream::operator>> ( SvStream& rStream )
     return *this;
 }
 
-SvStream& SvStream::operator<< ( sal_uInt16 v )
+SvStream& SvStream::WriteUInt16( sal_uInt16 v )
 {
     if( bSwap )
         SwapUShort(v);
@@ -1063,7 +1063,7 @@ SvStream& SvStream::operator<< ( sal_uInt16 v )
     return *this;
 }
 
-SvStream& SvStream::operator<<  ( sal_uInt32 v )
+SvStream& SvStream::WriteUInt32( sal_uInt32 v )
 {
     if( bSwap )
         SwapULong(v);
@@ -1071,7 +1071,7 @@ SvStream& SvStream::operator<<  ( sal_uInt32 v )
     return *this;
 }
 
-SvStream& SvStream::operator<<  ( sal_uInt64 v )
+SvStream& SvStream::WriteUInt64( sal_uInt64 v )
 {
     if( bSwap )
         SwapUInt64(v);
@@ -1079,7 +1079,7 @@ SvStream& SvStream::operator<<  ( sal_uInt64 v )
     return *this;
 }
 
-SvStream& SvStream::operator<< ( sal_Int16 v )
+SvStream& SvStream::WriteInt16( sal_Int16 v )
 {
     if( bSwap )
         SwapShort(v);
@@ -1087,7 +1087,7 @@ SvStream& SvStream::operator<< ( sal_Int16 v )
     return *this;
 }
 
-SvStream& SvStream::operator<<  ( sal_Int32 v )
+SvStream& SvStream::WriteInt32( sal_Int32 v )
 {
     if( bSwap )
         SwapLongInt(v);
@@ -1103,7 +1103,7 @@ SvStream& SvStream::WriteInt64  (sal_Int64 v)
     return *this;
 }
 
-SvStream& SvStream::operator<<  ( signed char v )
+SvStream& SvStream::WriteSChar( signed char v )
 {
     //SDO
     if(bIoWrite && sizeof(signed char) <= nBufFree )
@@ -1123,7 +1123,7 @@ SvStream& SvStream::operator<<  ( signed char v )
 
 // Special treatment for Chars due to PutBack
 
-SvStream& SvStream::operator<<  ( char v )
+SvStream& SvStream::WriteChar( char v )
 {
     //SDO
     if(bIoWrite && sizeof(char) <= nBufFree )
@@ -1141,7 +1141,7 @@ SvStream& SvStream::operator<<  ( char v )
     return *this;
 }
 
-SvStream& SvStream::operator<<  ( unsigned char v )
+SvStream& SvStream::WriteUChar( unsigned char v )
 {
 //SDO
     if(bIoWrite && sizeof(char) <= nBufFree )
@@ -1159,7 +1159,17 @@ SvStream& SvStream::operator<<  ( unsigned char v )
     return *this;
 }
 
-SvStream& SvStream::operator<< ( float v )
+SvStream& SvStream::WriteUInt8( sal_uInt8 v )
+{
+    return WriteUChar(v);
+}
+
+SvStream& SvStream::WriteUnicode( sal_Unicode v )
+{
+    return WriteUInt16(v);
+}
+
+SvStream& SvStream::WriteFloat( float v )
 {
 #ifdef UNX
     if( bSwap )
@@ -1169,7 +1179,7 @@ SvStream& SvStream::operator<< ( float v )
     return *this;
 }
 
-SvStream& SvStream::operator<< ( const double& r )
+SvStream& SvStream::WriteDouble ( const double& r )
 {
 #if defined UNX
     if( bSwap )
@@ -1187,19 +1197,19 @@ SvStream& SvStream::operator<< ( const double& r )
     return *this;
 }
 
-SvStream& SvStream::operator<<  ( const char* pBuf )
+SvStream& SvStream::WriteCharPtr( const char* pBuf )
 {
     Write( pBuf, strlen( pBuf ) );
     return *this;
 }
 
-SvStream& SvStream::operator<<  ( const unsigned char* pBuf )
+SvStream& SvStream::WriteUCharPtr( const unsigned char* pBuf )
 {
     Write( (char*)pBuf, strlen( (char*)pBuf ) );
     return *this;
 }
 
-SvStream& SvStream::operator<< ( SvStream& rStream )
+SvStream& SvStream::WriteStream( SvStream& rStream )
 {
     const sal_uInt32 cBufLen = 0x8000;
     char* pBuf = new char[ cBufLen ];
@@ -1225,9 +1235,9 @@ SvStream& SvStream::WriteUniOrByteString( const OUString& rStr, rtl_TextEncoding
 {
     // write UTF-16 string directly into stream ?
     if (eDestCharSet == RTL_TEXTENCODING_UNICODE)
-        write_lenPrefixed_uInt16s_FromOUString<sal_uInt32>(*this, rStr);
+        write_uInt32_lenPrefixed_uInt16s_FromOUString(*this, rStr);
     else
-        write_lenPrefixed_uInt8s_FromOUString<sal_uInt16>(*this, rStr, eDestCharSet);
+        write_uInt16_lenPrefixed_uInt8s_FromOUString(*this, rStr, eDestCharSet);
     return *this;
 }
 
@@ -1627,11 +1637,11 @@ SvStream& endl( SvStream& rStr )
 {
     LineEnd eDelim = rStr.GetLineDelimiter();
     if ( eDelim == LINEEND_CR )
-        rStr << '\r';
+        rStr.WriteChar('\r');
     else if( eDelim == LINEEND_LF )
-        rStr << '\n';
+        rStr.WriteChar('\n');
     else
-        rStr << '\r' << '\n';
+        rStr.WriteChar('\r').WriteChar('\n');
     return rStr;
 }
 
@@ -1640,13 +1650,13 @@ SvStream& endlu( SvStream& rStrm )
     switch ( rStrm.GetLineDelimiter() )
     {
         case LINEEND_CR :
-            rStrm << sal_Unicode('\r');
+            rStrm.WriteUnicode('\r');
         break;
         case LINEEND_LF :
-            rStrm << sal_Unicode('\n');
+            rStrm.WriteUnicode('\n');
         break;
         default:
-            rStrm << sal_Unicode('\r') << sal_Unicode('\n');
+            rStrm.WriteUnicode('\r').WriteUnicode('\n');
     }
     return rStrm;
 }
@@ -2170,4 +2180,55 @@ OUString convertLineEnd(const OUString &rIn, LineEnd eLineEnd)
     return tmpl_convertLineEnd<OUString, OUStringBuffer>(rIn, eLineEnd);
 }
 
+sal_Size write_uInt32_lenPrefixed_uInt16s_FromOUString(SvStream& rStrm,
+                                                const OUString &rStr)
+{
+    sal_Size nWritten = 0;
+    sal_uInt32 nUnits = std::min<sal_Size>(rStr.getLength(), std::numeric_limits<sal_uInt32>::max());
+    SAL_WARN_IF(static_cast<sal_Size>(nUnits) != static_cast<sal_Size>(rStr.getLength()),
+        "tools.stream",
+        "string too long for prefix count to fit in output type");
+    rStrm.WriteUInt32(nUnits);
+    if (rStrm.good())
+    {
+        nWritten += sizeof(sal_uInt32);
+        nWritten += write_uInt16s_FromOUString(rStrm, rStr, nUnits);
+    }
+    return nWritten;
+}
+
+sal_Size write_uInt16_lenPrefixed_uInt16s_FromOUString(SvStream& rStrm,
+                                                const OUString &rStr)
+{
+    sal_Size nWritten = 0;
+    sal_uInt16 nUnits = std::min<sal_Size>(rStr.getLength(), std::numeric_limits<sal_uInt16>::max());
+    SAL_WARN_IF(nUnits != rStr.getLength(),
+        "tools.stream",
+        "string too long for prefix count to fit in output type");
+    rStrm.WriteUInt16(nUnits);
+    if (rStrm.good())
+    {
+        nWritten += sizeof(nUnits);
+        nWritten += write_uInt16s_FromOUString(rStrm, rStr, nUnits);
+    }
+    return nWritten;
+}
+
+sal_Size write_uInt16_lenPrefixed_uInt8s_FromOString(SvStream& rStrm,
+                                              const OString &rStr)
+{
+    sal_Size nWritten = 0;
+    sal_uInt16 nUnits = std::min<sal_Size>(rStr.getLength(), std::numeric_limits<sal_uInt16>::max());
+    SAL_WARN_IF(static_cast<sal_Size>(nUnits) != static_cast<sal_Size>(rStr.getLength()),
+        "tools.stream",
+        "string too long for sal_uInt16 count to fit in output type");
+    rStrm.WriteUInt16( nUnits );
+    if (rStrm.good())
+    {
+        nWritten += sizeof(sal_uInt16);
+        nWritten += write_uInt8s_FromOString(rStrm, rStr, nUnits);
+    }
+    return nWritten;
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */