Thanks Ian. Makes sense now. I was scratching my brain to figure out possible ways that lack of optimization could cause actual failures.The Go team does an amazing job.
On Friday, July 9, 2021 at 11:02:59 PM UTC-4 Ian Lance Taylor wrote: > On Fri, Jul 9, 2021 at 8:33 AM jake...@gmail.com <jake...@gmail.com> > wrote: > > > > On Thursday, July 8, 2021 at 11:45:19 PM UTC-4 Ian Lance Taylor wrote: > >> > >> On Thu, Jul 8, 2021 at 8:41 PM 董⼀峰 <dongyif...@bytedance.com> wrote: > >> > > >> > Thanks for replying. > >> > So golang only supports debugging optimized golang runtime? > >> > >> Well, Go requires that the runtime package be built with optimization > >> (when using the gc compiler, which is the default). So, yes, when > >> running runtime code under the debugger you will be looking at > >> optimized code. > > > > > > Is this just to keep people from accidentally making a slow version of > the runtime, or is there an actual technical reason why it would not work? > If the check were removed ( > https://github.com/golang/go/blob/ef57834360cf69f2e8b52b32c7a05d96bf6bbba7/src/cmd/compile/internal/base/flag.go#L226) > > is there any reason to believe that the runtime would not function > correctly (albeit slowly)? > > Yes, there are cases that will fail if the runtime is compiled without > optimization. The Go compiler and runtime cooperate to ensure that > there is a certain amount of stack space available at all times. > Certain parts of the runtime can't copy the stack for various reasons > (these functions are marked with "//go:nosplit" in the runtime Go code > and with NOSPLIT in the runtime assembly code). Those parts of the > runtime are constrained to run within the amount of stack space that > is always available. When the runtime is compiled without > optimization, functions use more stack space, and in some cases there > are sequences of nosplit function calls that run over the amount of > stack space they have available. > > Ian > -- 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/81f1df27-43e3-4eae-8d5e-a60141a844f5n%40googlegroups.com.
