Hi Kurtis, Thank you for your input.
I am searching how do languages handle stack overflow. Languages like rust, handle this by catching SIGSEGV. In golang, as I found, it was handled by increasing the stack[1], [2] (Sorry if my terms are wrong). I have generated object dump(objdump -d) for go source code (just a function call) I can see that at the beginning of every function call it checks for the stack overflow and try to increase the stack(see //go:nosplit section of [2]). I am lloking how does gollvm handle this. *00000000004871a0 <main.foo>:* * 4871a0: 64 48 8b 0c 25 f8 ff mov %fs:0xfffffffffffffff8,%rcx* * 4871a7: ff ff * * 4871a9: 48 8d 44 24 f8 lea -0x8(%rsp),%rax* * 4871ae: 48 3b 41 10 cmp 0x10(%rcx),%rax* * 4871b2: 0f 86 e1 00 00 00 jbe 487299 <main.foo+0xf9>* * ........* * 487299: e8 62 80 fc ff callq 44f300 <runtime.morestack_noctxt>* * 48729e: e9 fd fe ff ff jmpq 4871a0 <main.foo>* [1]: https://github.com/golang/go/blob/02ab8d1a1dc82ce019969221313bfa28911f54a1/src/runtime/stack.go#L28 [2]: https://dave.cheney.net/2018/01/08/gos-hidden-pragmas On Thursday, 24 June 2021 at 08:17:33 UTC+5:30 Kurtis Rader wrote: > This might be an XY Problem <https://xyproblem.info/>, or your question > simply needs more context. Your sample program is an example of infinite > recursion. How that is detected is platform specific. It might be done via > a special signal. Or it might be done by a syscall to grow the stack > returning an error. So my question is, why are you asking how infinite > recursion is handled? > > On Wed, Jun 23, 2021 at 7:33 PM Kavindu Gimhan Zoysa <kavin...@gmail.com> > wrote: > >> Hi all, >> >> *package main* >> >> *func main() {* >> * foo()* >> *}* >> >> *func foo() {* >> * a := 5* >> * _ = a* >> * foo()* >> *}* >> >> I have generated the below llvm ir using the command `./bin/llvm-goc -S >> test.go -dump-ir`. I expected there are some llvm intrinsics that have been >> used to handle stack overflow. But it is not there. How does gollvm handle >> stackoverflow? >> >> *define void @main.main(i8* nest %nest.0) #0 !dbg !14 {* >> *entry:* >> * call void @main.foo(i8* nest undef), !dbg !15* >> * ret void* >> *}* >> >> *define void @main.foo(i8* nest %nest.1) #0 !dbg !16 {* >> *entry:* >> * %a = alloca i64, align 8* >> * %0 = bitcast i64* %a to i8** >> * call void @llvm.lifetime.start.p0i8(i64 8, i8* %0)* >> * store i64 5, i64* %a, align 8* >> * call void @llvm.dbg.declare(metadata i64* %a, metadata !17, metadata >> !DIExpression()), !dbg !20* >> * %a.ld.0 = load i64, i64* %a, align 8, !dbg !21* >> * call void @main.foo(i8* nest undef), !dbg !22* >> * %1 = bitcast i64* %a to i8** >> * call void @llvm.lifetime.end.p0i8(i64 8, i8* %1)* >> * ret void* >> *}* >> >> -- >> You received this message because you are subscribed to the Google Groups >> "golang-nuts" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to golang-nuts...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/golang-nuts/0bbb1347-5ceb-4ed2-9622-cb695d29bc6dn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/golang-nuts/0bbb1347-5ceb-4ed2-9622-cb695d29bc6dn%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > Kurtis Rader > Caretaker of the exceptional canines Junior and Hank > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/53de3903-83a2-4b31-b73d-4d46504ca28cn%40googlegroups.com.
