search for: dwarfexception

Hello, Renato > Are you actively working in that area? No, I started to experiment with ARM EH ~year ago, but never had anything complete, unfortunately > My main concern is that DwarfException is not extensible at all. I can't inherit from it (DwarfWriter creates it directly) and there are no call backs to target-specific code (nor registration of such mechanism). Why do you need this? My feeling that this will not be required. I might be mistaken though. -- With best regards, Anto...

.... I have some patched uncommitted for > EH on ARM but they are too far from being complete. Hi Anton, Are you actively working in that area? I did some experiments and managed to understand how LLVM does the exception handling, but my changes are also far from working. My main concern is that DwarfException is not extensible at all. I can't inherit from it (DwarfWriter creates it directly) and there are no call backs to target-specific code (nor registration of such mechanism). To change that in line with AsmWriter would be a major change and passing a ARMException reference through AsmWriter woul...

> Is it safe to say the MC work provides a (new) foundation for > implementing ARM EH? Or, is providing ARM EH independent of the ARM-MC > work? The latter. MC stuff helps somehow though. -- With best regards, Anton Korobeynikov Faculty of Mathematics and Mechanics, Saint Petersburg State University

On Mon, Sep 27, 2010 at 09:14:05AM -0700, Jason Kim wrote: > On Mon, Sep 27, 2010 at 8:50 AM, Dennis Taul <dtaul at codeaurora.org> wrote: > > > > I am new to LLVM but have perused the code alongside using llvm-gcc > > and CLANG to build ARM EABI objects. > > > > Based on this superficial analysis it appears that LLVM currently does > > not support the

On May 19, 2010, at 2:37 AM, Renato Golin wrote: >> -----Original Message----- >>> My main concern is that DwarfException is not extensible at all. I >>> can't inherit from it (DwarfWriter creates it directly) and there are >>> no call backs to target-specific code (nor registration of such >>> mechanism). >> >> Why do you need this? My feeling that this will not be required...

...sics mismatch, EH call table) were present, but the general execution flow seems very similar. If I compile the resulting asm with GCC ("-T generic-hosted.ld") and run, it breaks completely. GCC's run flawlessly. Anyone has any idea on the status of exception handling in clang/LLVM? DwarfException cannot be easily overwritten, and adding target specific code to it seems wrong... Attached is my example compiled with Codesourcery's GCC (2009q3) and clang (2.7). cheers, --renato -------------- next part -------------- A non-text attachment was scrubbed... Name: exception-clang-example.ta...

Hello, Renato > Anyone has any idea on the status of exception handling in clang/LLVM? > DwarfException cannot be easily overwritten, and adding target specific > code to it seems wrong... Neither llvm-gcc nor clang support exceptions on ARM (except, maybe, sjlj excheptions on arm/darwin). I have some patched uncommitted for EH on ARM but they are too far from being complete. -- With best regard...

...unwind_pr_common after "switch (((offset & 1) << 1) | (len & 1))" control reaches default: return _URC_FAILURE. offset was == 0x808f and len was == 0xff. (((offset & 1) << 1) | (len & 1)) was == 3. 3 is an undefined descriptor as per ARM EHABI spec section 9.2. DwarfException::EmitExceptionTable Asm->EmitULEB128(TTypeBaseOffset, "@TType base offset", SizeAlign); was generating ".asciz  "\217\200"             @ @TType base offset" in .s file leading to the problem.           I would like to know whether anyone managed to use ARM EHABI suc...

On 31/03/13 19:28, Duncan Sands wrote: >> How would I go about getting a custom data format stored at the >> exception landing pads (the location _Unwind_GetLanguageSpecificData >> returns)? The Dwarf encoded format is not well suited for the type of >> exception handling I wish to do in my language. > I didn't understand the question, can you please be more explicit

Hi Bill, First, I like the idea of being more expressive in IR, since the old exception handling style didn't quite express exception handling, but alternate paths (resume/unwind). That made DwarfException.cpp a big hack. ;) It also makes the front-end engineer's life a lot easier, since there is less need to keep a long list of global state for all current landing pads, clean up areas, terminate handlers, etc. If I got it right, the dispatch instruction will tell the instructions/calls to unw...

...with each document. But I would look to understand why the FDE looks like it does or what the format of the exception handling table means (-fverbose-asm gives extra information to help with this). For specifics on how LLVM generates this information, look at these files: * lib/CodeGen/AsmPrinter/DwarfException.cpp This outputs the CIE, FDE, and exception handling tables. * lib/Target/X86/X86RegisterInfo.cpp The "X86RegisterInfo::emitPrologue" method shows how it constructs the "machine move" information that's used to create the FDE. The front-end parses and generates the ex...

Dear all, AFAIK, ARM EHABI is not ready for both asm and obj emitter. Some people including me what to implement them. My question is, to avoid duplicate effort, does someone take charge of this part? or does anyone is already implementing this currently? BTW, any suggestion on this effort? I'm very appreciated! Thanks in advance! -- Best regards, Wen-Han Gu (Nowar) -------------- next

Hi, I'm trying to learn all that I can about exception handling from the compiler's point of view. Although much has been written about compiler theory in general -- parsing, code generation, you name it -- I can find almost nothing on the specific problem of exception handling support. In fact, the most informative document I've been able to find so far is "Bill's

Hi everyone! I've been silently working on the previous exception handling proposal I published last year (http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-November/027311.html). However, there were some major deficiencies in it. After discussing this further with Jim Grosbach and John McCall, we've come up with another proposal. As you can see, it incorporates the idea of

...in, this is a requirement for problem 1, but it'd need to be fixed after 3. 3. Unwinding code Currently, even when no exception handling are needed, the exception code is used to generate Dwarf unwinding directives (CFI) for the debugger. Both DwarfCFIException and ARMException inherit from DwarfException, and they are called to do the debug info about the stack unwinding, which is (at least) misplaced. The consensus is that this code should be factored out. The part that is relevant to this thread is that, today, if -arm-disable-ehabi is requested, ARMException will not be used and we won't ha...

...after 3. > > > 3. Unwinding code > > Currently, even when no exception handling are needed, the exception code is > used to generate Dwarf unwinding directives (CFI) for the debugger. This is because the 2 are so similar. > Both DwarfCFIException and ARMException inherit from DwarfException, and they > are called to do the debug info about the stack unwinding, which is (at least) > misplaced. The consensus is that this code should be factored out. There is some interaction in that if you are generating a .eh_frame section for exception handling then there is little sense is gen...

On Nov 24, 2010, at 2:59 AM, Renato Golin wrote: > Hi Bill, > > First, I like the idea of being more expressive in IR, since the old > exception handling style didn't quite express exception handling, but > alternate paths (resume/unwind). That made DwarfException.cpp a big > hack. ;) > > It also makes the front-end engineer's life a lot easier, since there > is less need to keep a long list of global state for all current > landing pads, clean up areas, terminate handlers, etc. > That's a big goal of this rewrite. :-) > If I...

...ForGlobal(llvm::GlobalValue const*, llvm::SectionKind, llvm::Mangler*, llvm::TargetMachine const&) constin libLLVMCodeGen.a(TargetLoweringObjectFileImpl.cpp.o) "llvm::UnwindTablesMandatory", referenced from: __ZN4llvm21UnwindTablesMandatoryE$non_lazy_ptr in libLLVMAsmPrinter.a(DwarfException.cpp.o) "llvm::TargetData::init(llvm::StringRef)", referenced from: llvm::TargetData::TargetData(llvm::StringRef)in libLLVMEBCCodeGen.a(EBCTargetMachine.cpp.o) "llvm::TargetLoweringObjectFile::getKindForGlobal(llvm::GlobalValue const*, llvm::TargetMachine const&)",...