On Mon, 2020-05-18 at 16:47 +0200, Mark Wielaard wrote: > Hi David, > > On Mon, May 18, 2020 at 08:45:36AM -0400, David Malcolm wrote: > > Also, m_unsafe_fndecl is a field of signal_unsafe_call, so we can > > delay > > calling replacement_fn until inside signal_unsafe_call::emit, after > > the > > warning has been emitted. > > > > It could even become a member function of signal_unsafe_call, > > giving > > something like this for signal_unsafe_call::emit: > > Thanks for all the hints. I adopted all your suggestions and the > warning plus note now looks like: > > /opt/local/gcc/bin/gcc -g -O2 -fanalyzer -c bzip2.c > bzip2.c: In function ‘mySIGSEGVorSIGBUScatcher’: > bzip2.c:874:4: warning: call to ‘exit’ from within signal handler > [CWE-479] [-Wanalyzer-unsafe-call-within-signal-handler] > 874 | exit(exitValue); > | ^~~~~~~~~~~~~~~ > ‘main’: events 1-2 > | > | 1784 | IntNative main ( IntNative argc, Char *argv[] ) > | | ^~~~ > | | | > | | (1) entry to ‘main’ > |...... > | 1800 | smallMode = False; > | | ~~~~~~~~~ > | | | > | | (2) registering ‘mySIGSEGVorSIGBUScatcher’ as signal > handler > | > event 3 > | > |cc1: > | (3): later on, when the signal is delivered to the process > | > +--> ‘mySIGSEGVorSIGBUScatcher’: events 4-5 > | > | 816 | void mySIGSEGVorSIGBUScatcher ( IntNative n ) > | | ^~~~~~~~~~~~~~~~~~~~~~~~ > | | | > | | (4) entry to ‘mySIGSEGVorSIGBUScatcher’ > |...... > | 874 | exit(exitValue); > | | ~~~~~~~~~~~~~~~ > | | | > | | (5) call to ‘exit’ from within signal handler > | > bzip2.c:874:4: note: ‘_exit’ is a possible signal-safe alternative > for ‘exit’ > 874 | exit(exitValue); > | ^~~~~~~~~~~~~~~ > | _exit > > I also added a testcase. How about the attached?
Thanks Mark. Overall, I like it, but it looks like there's a problem with the location of the fix-it hint: it looks like it might be replacing the whole of the underlined section of the call, argument, parentheses and all, with "_exit", rather than just the "exit" token. I wonder if the location of that token is still available in the middle-end by the time the analyzer runs. What does -fdiagnostics-generate-patch emit? David
