similar to: [LLVMdev] noreturn attribute on a call instruction vs noreturn on a function

You can use CallInst::hasFnAttr(). It checks for attributes in the instruction and in the function decl. http://llvm.org/docs/doxygen/html/Instructions_8cpp_source.html#l00345 Nuno ----- Original Message ----- > Hi, > > Building the following C code I get a call instruction that has no > noreturn > attribute, while the function itself does have it. > > void foo(void **b)

Hi Kostya, On 28/11/12 14:47, Kostya Serebryany wrote: > Hi, > > Building the following C code I get a call instruction that has no noreturn > attribute, while the function itself does have it. > > void foo(void **b) { > __builtin_longjmp(b, 1); > } > > > define void @_Z3fooPPv(i8** %b) noreturn nounwind uwtable { > entry: > %0 = bitcast i8** %b to i8*

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 Fri, Nov 3, 2017 at 5:39 PM, Hal Finkel <hfinkel at anl.gov> wrote: > > On 11/03/2017 07:20 PM, Alexandre Isoard via llvm-dev wrote: > > Hello, > > I am not sure about the semantic (if any) of returns_twice and noreturn > attributes. > > int fork() __attribute__((returns_twice)); > void join(int) __attribute__((noreturn)); > > int f(int n) { > int

On 11/03/2017 07:57 PM, Yichao Yu wrote: > On Fri, Nov 3, 2017 at 8:54 PM, Alexandre Isoard via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> On Fri, Nov 3, 2017 at 5:39 PM, Hal Finkel <hfinkel at anl.gov> wrote: >>> On 11/03/2017 07:20 PM, Alexandre Isoard via llvm-dev wrote: >>> >>> Hello, >>> >>> I am not sure about the

Hi, I'm trying to understand how __builtin_setjmp/longjmp are supposed to interact with the frame pointer on x86_64. In particular, what is the expected behavior when the compiler chooses not to use rsp or rbp to address local variables? When built with Clang, the following program will segfault, but it is fine when built with GCC. The target is x86_64 linux. int main(int argc, char

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

hi, list, i am making a llvm compiler for shader-like programs. as we known, shader programs are short and have less function calls. i found that i have to save/restore callee-saved register(CSR) in prolog and epilog. because I can violate ABI from driver(c code) and shader, i plan to append the attribute 'noreturn' to all shader functions. in PrologEpilogInserter.cpp, you can find that

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, again, for historical purposes. Don't use them. -Jim On Apr 27, 2011, at 3:45 PM, Akira Hatanaka wrote: > Okay. I understand builtin functions do not

Do the LLVM Setjmp/Longjmp intrinsics interact with C++ exception handling and execute C++ cleanup actions? I compiled a small example using setjmp/longjmp using clang and they did not execute C++ cleanup actions and calling longjmp bypassed calling destructors on objects that were allocated between the call to setjmp and longjmp. I’m wondering if the LLVM intrinsics behave differently from

Okay. Are you saying that you shouldn't use __builtin functions in general in your program or just __builtin_setjmp/longjmp? Also, are there any warnings issued by either clang or llvm if they are used in your program? On Wed, Apr 27, 2011 at 3:55 PM, Jim Grosbach <grosbach at apple.com> wrote: > The builtins are for internal compiler use in the context of SjLj exception >

Hi In llvm src the file llvm/lib/Transforms/IPO/LowerSetJmp.cpp, it seems for sjlj-eh ? but this pass has no effect about c++ sjlj-eh. this pass is for future extend? zhangzw

On 28 April 2015 at 00:30, Reid Kleckner <rnk at google.com> wrote: > I think Paweł identified the problem. The frames on the stack between the > setjmp and longjmp must have valid unwind information, which is described > here: > https://msdn.microsoft.com/en-us/library/ft9x1kdx.aspx?f=255&MSPPError=-2147217396 > > In particular, it has this line about JITed code: >

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 Sun, Dec 18, 2016 at 02:23:01PM +0100, Jonas Maebe via llvm-dev wrote: > Recap: we use setjmp/longjmp for our exception handling on all platforms in > our regular (non-LLVM) code generators. I'd like to use the same > infrastructure with the LLVM code generator for code interoperability > purposes (the LLVM SjLj personality is not binary-compatible with our > existing

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, again, for historical purposes. Don't use them. Why is longjmp converted

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 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

I have the following C source: extern unsigned int donut; void f1(); void f2(); void f1() { unsigned int *magic = &donut; if (*magic != 286529877) { f2(); } } void f2() { /* Loop here forever if application is built with wrong version of ROM image */ while(1) { ; } } The -O2 level PruneEH pass uses SimplifyFunction() which contains this code: for

On 6 March 2014 18:09, Mark Seaborn <mseaborn at chromium.org> wrote: > LowerAtomic "lowers atomic intrinsics to non-atomic form for use in a > known non-preemptible environment". LowerInvoke strips out exception > handling by converting invokes to calls, so that landingpads, resumes, etc. > become dead and can be removed by a later pass. > > (As an aside,