similar to: [LLVMdev] llvm-gcc4 and setjmp

Hi Anton, > > I would expect llvm-gcc to use LLVM's setjmp/longjmp intrinsics and > > then to run the LowerSetJmp pass to turn the intrinsic calls into uses > > of invoke and unwind. At that point, the control flow is explicit, > > isn't it? > Unfortunately, no. You can call setjmp/longjmp on the same jump buffer > multiple times. So, in general it's not

Hello, Jay. > the resulting bitcode doesn't use LLVM's exception handling > intrinsics, it just has a call to a function called "_setjmp". And > there doesn't seem to be any provision for returning the current value > of the volatile variable v if setjmp returns non-zero - the bitcode > always returns zero, whereas the spec for setjmp() says that f() >

I'm trying to make sense in the support for setjmp/longjmp in Clang and LLVM, with only partial success. I'll try to summarize my findings in the hope that someone can shed some light on why things are the way they are and what I'm missing. Clang. Clang recognizes two forms of setjmp (all I say here applies to longjmp similarly): * __builtin_setjmp: gets lowered to calling the

On 30/09/16 20:10, Reid Kleckner wrote: > On Mon, Sep 19, 2016 at 4:42 AM, Jonas Maebe <jonas-devlists at watlock.be > <mailto:jonas-devlists at watlock.be>> wrote: > > So, can I use invoke and landingpad without using any of the other > exception handling intrinsics? (in combination with a dummy personality > function) Or will LLVM in all cases insist on

Hi, In our (non-C) compiler we use setjmp/longjmp to implement exception handling. For the initial implementation LLVM backend, I'm keeping that model. In order to ensure that changes performed in a try/setjmp==0 block survive the longjmp, the changes must be done via volatile operations. Given that volatility is a property of individual load/store instructions rather than of memory slots in

On Mon, Sep 19, 2016 at 4:42 AM, Jonas Maebe <jonas-devlists at watlock.be> wrote: > Reid Kleckner wrote: > > On Fri, Sep 16, 2016 at 10:13 AM, Jonas Maebe via llvm-dev > > <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: > > > > model. In order to ensure that changes performed in a try/setjmp==0 > > block survive

First I try it with bytecodes: ~/compiler/temp$ llvmgcc sjmp01.c -o sjmp01 ~/compiler/temp$ ./sjmp01 Hello World! Abort trap Same results for lli sjmp01.bc Now I try converting to native code: ~/compiler/temp$ llc sjmp01.bc -enable-correct-eh-support -o sjmp01.s ~/compiler/temp$ gcc sjmp01.s -o sjmp01.native ~/compiler/temp$ ./sjmp01.native Hello World! Bus error ~/compiler/temp$ On Apr 20,

Hi, I would like to build an x86 executable consisting of a number of subsystems (mostly legacy C code). One subsystem will be compiled to native code using llvm. It calls, and is called by, the other subsystems, many of which have to be compiled using gcc because they use small amounts of inline assembly. All of the subsystems catch and throw errors to one another using setjmp/longjmp. When

Hi, I have some code which has sigsetjmp / longjmp. After a longjmp, unreachable is inserted, which is fine. The problem is that in the backend before calling longjmp, some register was spilled to a stack location which is live across the jmp. I mean, it will be live after jumping. The stack location was initialized before the call to setjmp, and is used afterwards. Is there any bug in handling

On Apr 27, 2011, at 4:08 PM, Joerg Sonnenberger wrote: > On Wed, Apr 27, 2011 at 03:55:53PM -0700, Jim Grosbach wrote: >> The builtins are for internal compiler use in the context of SjLj >> exception handling. Any other use, including any direct calls of the >> builtins in user code, are a bad idea with no guaranteed behaviour. >> That they're exposed at all is,

I'm trying to get unwind to work. I was unable to get an unwind example to work directly, so I decided to compile a c program that uses setjmp and longjmp and work backwards. I keep running into a "Abort trap" problem, whatever "Abort trap" is. Anyway, here's an example of a C program that compiles and works properly under normal gcc, but that fails with an

It seems straightforward to implement, if it just needs to be functionally correct. I have another question about setjmp/longjmp. When the following program is compiled and run with argument 10 (./a.out 10), should it print 10 or 23? I am asking this question because it prints 23 when compiled with gcc and prints 10 when compiled with clang. If it is supposed to return 23, it seems to me that

Dear list, I want to add SJLJ exception handling to my frontend. Unfortunately, there doesn't seem to be any examples in the documentation as to how to use the intrinsics @llvm.eh.sjlj.setjmp @llvm.eh.sjlj.longjmp @llvm.eh.sjlj.lsda @llvm.eh.sjlj.callsite Is there a way to force Clang to use SJLJ exception handling for C++? That way I would be able to look at its output to learn how to use

On Oct 4, 2011, at 3:53 PM, Eli Friedman wrote: > On Tue, Oct 4, 2011 at 3:10 PM, Khaled ElWazeer > <khalid.alwazeer at gmail.com> wrote: >> Hi, >> >> I have some code which has sigsetjmp / longjmp. After a longjmp, unreachable >> is inserted, which is fine. The problem is that in the backend before >> calling longjmp, some register was spilled to a

That code should do it, but I realized you only detect setjmp functions by name. My code is calling "__sigsetjmp" not "segsetjmp". You only support these functions: static const char *ReturnsTwiceFns[] = { "_setjmp", "setjmp", "sigsetjmp", "setjmp_syscall", "savectx", "qsetjmp",

On Tue, Oct 4, 2011 at 3:10 PM, Khaled ElWazeer <khalid.alwazeer at gmail.com> wrote: > Hi, > > I have some code which has sigsetjmp / longjmp. After a longjmp, unreachable > is inserted, which is fine. The problem is that in the backend before > calling longjmp, some register was spilled to a stack location which is live > across the jmp. I mean, it will be live after

Hi,I'm trying to prevent llvm instruction motion around an intrinsic function call. Throughout my experimenting, I was told that setjmp could create fake entry points into a region of code and that might prevent code motion.What I found is something surprising, and probably is a misuse of setjmp but I couldn't find an explanation for it.Consider this:#include <csetjmp> std::jmp_buf

Commit-ID: d7d16afbdae9bdea83aeb26ac572e6fc4d7d4940 Gitweb: http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=d7d16afbdae9bdea83aeb26ac572e6fc4d7d4940 Author: Steve McIntyre <steve at einval.com> AuthorDate: Fri, 29 Jun 2012 18:13:34 +0100 Committer: maximilian attems <max at stro.at> CommitDate: Sun, 1 Jul 2012 22:51:00 +0200 [klibc] arm/setjmp.S: fix longjmp

On Wed, 20 Apr 2005, Greg Pettyjohn wrote: > I'm trying to get unwind to work. > > I was unable to get an unwind example to work directly, > so I decided to compile a c program that uses setjmp > and longjmp and work backwards. > > I keep running into a "Abort trap" problem, whatever "Abort trap" is. > > Anyway, here's an example of a C

Okay. I understand builtin functions do not have to behave exactly the same way as standard library functions. What I wanted to know is what should the code generated by llvm (clang + llc) look like (I am working on the Mips back-end now). I guess there should be a behavior users expect to see who are using __builtin_setjmp/longjmp even they aren't the same as library functions. If the code