similar to: [LLVMdev] Why clang++ doesn't set 'noreturn' flag on declarations of __cxa_throw and _Unwind_Resume_or_Rethrow ?

On Jul 15, 2010, at 3:31 PM, Yuri wrote: > When I compile some code with the near-trunk clang++ I get this: Please send clang-specific questions to cfe-dev at cs.uiuc.edu. > ... > tail call void @_Unwind_Resume_or_Rethrow(i8* %exn2) noreturn > unreachable > ... > declare void @_Unwind_Resume_or_Rethrow(i8*) > ... > > Same with __cxa_throw. 'noreturn' is

On Jul 15, 2010, at 5:51 PM, John McCall wrote: >> Also can _Unwind_Resume_or_Rethrow actually return? When I run some >> simple exception code in JIT I see that this function actually returns >> and then SEGVs. > > I have no idea what system you're on, but _Unwind_Resume_or_Rethrow really > isn't allowed to return. > It's not. But if the unwind

On 07/15/2010 18:30, Bill Wendling wrote: > It's not. But if the unwind library can't handle something, then the _Unwind_Resume_or_Rethrow could fall out of the function (it would assert in debug mode). Darwin's implementation of _URoR in libunwind does this. > > Isn't unwind library supposed to call terminate() every time it can't handle something? Yuri

On Jul 15, 2010, at 6:52 PM, Yuri wrote: > On 07/15/2010 18:30, Bill Wendling wrote: >> It's not. But if the unwind library can't handle something, then the _Unwind_Resume_or_Rethrow could fall out of the function (it would assert in debug mode). Darwin's implementation of _URoR in libunwind does this. >> > Isn't unwind library supposed to call terminate() every

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, 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* tail call void @llvm.eh.sjlj.longjmp(i8* %0)

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*

+ cfe-dev > On Mar 28, 2016, at 1:23 PM, Harlan Haskins via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hi all, > > Recently I’ve noticed in coverage profiles that llvm_unreachable and the like are considered uncovered because there’s no special behavior in instrumentation to ‘ignore’ noreturn paths. FWIW, Daniel Dunbar and a few others have brought up the lack of a

Dear all, I don't get how llvm handles functions with __attribute__((noreturn)). It seems that LR register is backed up on the stack whilst it will never be used to return from a 'noreturn' function. I have this problem with a home-made backend but it seems that ARM flavour of clang has same behaviour. By the way, SP is also saved, I don't understand why. Is there a syntax error

Hi all, Recently I’ve noticed in coverage profiles that llvm_unreachable and the like are considered uncovered because there’s no special behavior in instrumentation to ‘ignore’ noreturn paths. While I don’t necessarily think it’s ideal to ignore all noreturn decls, I think there’s definitely room for some heuristics around ignoring things like llvm_unreachable (perhaps opt-in?). I’m

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 t = fork(); n++; if (t != 0) join(t); return n; } Produces the following LLVM IR: ; Function Attrs: nounwind uwtable define i32 @f(i32 %n) local_unnamed_addr #0 { entry: %call = call i32

Hello, as of gcc v2.7.2.1, the noreturn attribute needs to be given *after* the prototype declaration and not before, but for gcc v3.x, things changed for this attribute again, since gcc v2.5.x did it the way, newer gcc versions prefer it... I've applied a small unified diff, fixing this stuff. THX for listening. CU Tom. (Thomas M.Ott) Germany -------------- next part -------------- ---

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

Hi Duncan, >>are you trying to get the name "@_ZTIi" or "@__cxa_throw"? yes! i want get the name @_ZTi or @__cxa_throw, the latter @__cxa_throw i can get it throw value->getName(), but the @_ZTi it did n't has name! zhangzw thanks 2009/3/26 Duncan Sands <baldrick at free.fr>: > Hi zhangzw, > >> invoke void @__cxa_throw(i8* %7, i8*

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

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 all, here is a llvm IR : invoke void @__cxa_throw(i8* %7, i8* bitcast (%struct.__fundamental_type_info_pseudo* @_ZTIi to i8*), void (i8*)* null) noreturn to label %invcont unwind label %lpad say I want to get the Invoke's Operand's name, I use getOperand(i)->getName(), it can work for that the Operand hasname, but some Operand hasn't name, So, My problem is how

Hi zhangzw, >> invoke void @__cxa_throw(i8* %7, i8* bitcast >> (%struct.__fundamental_type_info_pseudo* @_ZTIi to i8*), void (i8*)* >> null) >> noreturn to label %invcont unwind label %lpad > > >>are you trying to get the name "@_ZTIi" or "@__cxa_throw"? > > yes! i want get the name @_ZTi or @__cxa_throw, > the latter

Hi zhangzw, > invoke void @__cxa_throw(i8* %7, i8* bitcast > (%struct.__fundamental_type_info_pseudo* @_ZTIi to i8*), void (i8*)* > null) > noreturn to label %invcont unwind label %lpad > > say I want to get the Invoke's Operand's name are you trying to get the name "@_ZTIi" or "@__cxa_throw"? Ciao, Duncan.

Hi, catch_all.cpp: 1 int main() 2 { 3 try { 4 throw 34; 5 } 6 catch (...) {} 7 } llvm-gcc -O3 -S -emit-llvm catch_all.cpp -o catch_all.ll: 1 ; ModuleID = 'catch_all.cpp' 2 target datalayout =