[cfe-dev] How to add a new rewriting option

[Vincent R.]

Le 30.07.2013 18:30, Vincent R. a écrit :
> Le 30.07.2013 17:47, jahanian a écrit :
>> Hi Vincent,
>>
>> -rewrite-legacy-objc is out of date. For up to date support for
>> ObjectiveC features and translation of its
>> modern ABI, you may want to look into -rewrite-objc. -rewrite-objc 
>> has
>> simplified the workflow by pre-processing
>> user program and translating it into C++. -rewrite-legacy-objc
>> requires user to do the pre-processing step manually.
>>
>
> Ok but what I would like to achieve is closer to rewrite-legacy-objc
> than rewrite-objc
> because I don't want to compile the code after transformation and I
> don't want preprocessing stage.
>
>
> So now I have modified the Options.td for my new flag
> -rewrite-objc2cs and used the same parameters
> as rewrite-legacy-objc but now the driver tells me : unrecognized
>
> clang -rewrite-objc2cs NSButton.m -c -MMD -MP
> -DGNUSTEP_TARGET_DIR=\".\" -DGNUSTEP_TARGET_CPU=\"x86_64\"
> -DGNUSTEP_TARGET_OS=\"linux-gnu\" -DLIBRARY_COMBO=\"gnu-gnu-gnu\"
> -DBACKEND_BUNDLE=1 -DGNUSTEP -DGNUSTEP_BASE_LIBRARY=1
> -DGNU_GUI_LIBRARY=1 -DGNU_RUNTIME=1 -DGNUSTEP_BASE_LIBRARY=1
> -fno-strict-aliasing -fexceptions -fobjc-exceptions
> -D_NATIVE_OBJC_EXCEPTIONS -fobjc-nonfragile-abi -D_NONFRAGILE_ABI
> -pthread -fPIC -DDEBUG -fno-omit-frame-pointer -Wall -DGSWARN
> -DGSDIAGNOSE -Wno-import -g -fgnu-runtime -Wall
> -fconstant-string-class=NSConstantString -I../Headers/Additions
> -I../Headers -I./. -I. -I/home/vincent/GNUstep/Library/Headers
> -I/GNUstep/Local/Library/Headers -I/GNUstep/System/Library/Headers
> -I/usr/include/libpng12
>
>
> vincent at vincent-virtual-machine ~/objc2cs/gnustep/core/gui/Source $
> clang -v -v -rewrite-objc2cs NSButton.m -c -MMD -MP
> -DGNUSTEP_TARGET_DIR=\".\" -DGNUSTEP_TARGET_CPU=\"x86_64\"
> -DGNUSTEP_TARGET_OS=\"linux-gnu\" -DLIBRARY_COMBO=\"gnu-gnu-gnu\"
> -DBACKEND_BUNDLE=1 -DGNUSTEP -DGNUSTEP_BASE_LIBRARY=1
> -DGNU_GUI_LIBRARY=1 -DGNU_RUNTIME=1 -DGNUSTEP_BASE_LIBRARY=1
> -fno-strict-aliasing -fexceptions -fobjc-exceptions
> -D_NATIVE_OBJC_EXCEPTIONS -fobjc-nonfragile-abi -D_NONFRAGILE_ABI
> -pthread -fPIC -DDEBUG -fno-omit-frame-pointer -Wall -DGSWARN
> -DGSDIAGNOSE -Wno-import -g -fgnu-runtime -Wall
> -fconstant-string-class=NSConstantString -I../Headers/Additions
> -I../Headers -I./. -I. -I/home/vincent/GNUstep/Library/Headers
> -I/GNUstep/Local/Library/Headers -I/GNUstep/System/Library/Headers
> -I/usr/include/libpng12
> clang version 3.3 (186145)
> Target: x86_64-unknown-linux-gnu
> Thread model: posix
>  "/opt/bin/clang-3.3" -cc1 -triple x86_64-unknown-linux-gnu
> -rewrite-objc2cs -disable-free -main-file-name NSButton.m
> -mrelocation-model pic -pic-level 2 -mdisable-fp-elim
> -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases
> -munwind-tables -fuse-init-array -target-cpu x86-64 -v -v -g
> -coverage-file
> /home/vincent/objc2cs/gnustep/core/gui/Source/NSButton.cs
> -resource-dir /opt/bin/../lib/clang/3.3 -dependency-file NSButton.d
> -MT NSButton.o -MP -D "GNUSTEP_TARGET_DIR=\".\"" -D
> "GNUSTEP_TARGET_CPU=\"x86_64\"" -D "GNUSTEP_TARGET_OS=\"linux-gnu\""
> -D "LIBRARY_COMBO=\"gnu-gnu-gnu\"" -D BACKEND_BUNDLE=1 -D GNUSTEP -D
> GNUSTEP_BASE_LIBRARY=1 -D GNU_GUI_LIBRARY=1 -D GNU_RUNTIME=1 -D
> GNUSTEP_BASE_LIBRARY=1 -D _NATIVE_OBJC_EXCEPTIONS -D _NONFRAGILE_ABI
> -D DEBUG -D GSWARN -D GSDIAGNOSE -I ../Headers/Additions -I 
> ../Headers
> -I ./. -I . -I /home/vincent/GNUstep/Library/Headers -I
> /GNUstep/Local/Library/Headers -I /GNUstep/System/Library/Headers -I
> /usr/include/libpng12 -internal-isystem /usr/local/include
> -internal-isystem /opt/bin/../lib/clang/3.3/include
> -internal-externc-isystem /usr/include/x86_64-linux-gnu
> -internal-externc-isystem /include -internal-externc-isystem
> /usr/include -Wall -Wno-import -Wall -fdebug-compilation-dir
> /home/vincent/objc2cs/gnustep/core/gui/Source -fconstant-string-class
> NSConstantString -ferror-limit 19 -fmessage-length 159 -pthread
> -mstackrealign -fblocks -fobjc-runtime=gnustep-1.6
> -fobjc-dispatch-method=non-legacy 
> -fobjc-default-synthesize-properties
> -fno-objc-infer-related-result-type -fobjc-exceptions -fexceptions
> -fdiagnostics-show-option -fcolor-diagnostics -backend-option
> -vectorize-loops -o NSButton.cs -x objective-c NSButton.m
> error: unknown argument: '-rewrite-objc2cs'
>
> Before I use the same arguments as rewrite-legacy-objc, the command
> was working even if the result wasn't what I wanted to (non processed
> file).
> So I suppose I forgot to add my new option somewhere in the code but
> I don't know where ...


And another thing I don't understand because when looking at generated 
code when using -rewrite-legacy-objc
it seems the rewriter used is the one implemented inside 
RewriteModernObjC.cpp.

I don't understand why because if I look int Tools.cpp :

} else if (JA.getType() == types::TY_RewrittenObjC) {
       CmdArgs.push_back("-rewrite-objc");
       rewriteKind = RK_NonFragile;
     } else if (JA.getType() == types::TY_RewrittenLegacyObjC) {
       CmdArgs.push_back("-rewrite-objc");
       rewriteKind = RK_Fragile;
     } else if (JA.getType() == types::TY_RewrittenObjC2Cs) {
       CmdArgs.push_back("-rewrite-objc2cs");
       rewriteKind = RK_Fragile;
     } else {
       assert(JA.getType() == types::TY_PP_Asm &&
              "Unexpected output type!");
     }

the associated rewriteKind of TY_RewrittenLegacyObjC is RK_Fragile BUT 
the code that use RewriteModernObjC is the following :

if (CI.getLangOpts().ObjCRuntime.isNonFragile())
       return CreateModernObjCRewriter(InFile, OS,
                                 CI.getDiagnostics(), CI.getLangOpts(),
                                 CI.getDiagnosticOpts().NoRewriteMacros,
                                 (CI.getCodeGenOpts().getDebugInfo() !=
                                  CodeGenOptions::NoDebugInfo));
     return CreateObjCRewriter(InFile, OS,
                               CI.getDiagnostics(), CI.getLangOpts(),
                               CI.getDiagnosticOpts().NoRewriteMacros);

so does it mean that the fragile meaning of ObjCRuntime.isNonFragile() 
is different from the rewriteKind meaning ?
Because let's say I cannot debug clang and just by reading the code I 
would have thought than when using -rewrite-legacy-objc (RK_Fragile)
it would call the fragile branch ie CreateObjCRewriter() ...


And another question about debugging I tried to put some breakpoints 
inside CreateModernObjCRewriter and CreateObjCRewriter and inside
some other methods inside RewriteModernObjC.cpp but they are never 
triggered. Any idea why ?