[Bug middle-end/91395] Report an uninitialized variable on its initialization statement (setjmp)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91395 --- Comment #5 from joseph at codesourcery dot com --- It's *accessible objects* whose value on second return from setjmp is the same as when longjmp is called (unless non-volatile, automatic storage duration and changed between setjmp and longjmp). The point is that when longjmp is called, save_exception_stack may not be an accessible object (because of having gone out of scope), so has no defined value, so it's just like goto jumping into the block where save_exception_stack is declared and thus bypassing its initialization - it's valid to jump into the scope like that (unless jumping into the scope of a declaration with variably modified type), but the variable is uninitialized.
[Bug middle-end/91395] Report an uninitialized variable on its initialization statement (setjmp)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91395 --- Comment #4 from Adam --- (In reply to Andrew Pinski from comment #3) > In theory other can cause a call to longjmp but gcc does not know it cannot. Thanks for the quick reply. I got the longjmp() part, it could be called anytime. The part I don't get is why it reports since gcc could tell that no one changes the save_exception_stack (it has a certain short life). The POSIX's statement as I know has two facts: "a local not-volatile variable" and "it's been changed between setjmp() and longjmp()". Have I missed anything?
[Bug middle-end/91395] Report an uninitialized variable on its initialization statement (setjmp)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91395 --- Comment #3 from Andrew Pinski --- In theory other can cause a call to longjmp but gcc does not know it cannot.
[Bug middle-end/91395] Report an uninitialized variable on its initialization statement (setjmp)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91395 --- Comment #2 from Adam --- I got the point "The local variables that do not have the volatile type and have been changed between the setjmp() invocation and longjmp() call are indeterminate" But save_exception_stack is not changed between the setjmp() invocation and longjmp() call, it is defined every time. Still looks expected?
[Bug middle-end/91395] Report an uninitialized variable on its initialization statement (setjmp)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91395 Andrew Pinski changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED Component|c |middle-end Resolution|--- |INVALID --- Comment #1 from Andrew Pinski --- The warning is correct due to the way sigsetjmp works. You need to mark save_exception_stack as volatile to fix the issue. Basically any non-volatile variable in the function scope can be incorrect. This is what the POSIX (and C standard for setjmp) says. GCC is just taking into account this now.
