https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61106
lucier at math dot purdue.edu changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |lucier at math dot purdue.edu --- Comment #21 from lucier at math dot purdue.edu --- Regarding: I think this issue may affect other options, not just -Wunused-parameter. I just built mainline gcc and the following bug from 4.8.2 disappeared: gcc -W -Wall -march=native -Wno-unused -Wno-write-strings -O1 -fno-math-errno -fschedule-insns2 -fno-trapping-math -fno-strict-aliasing -fwrapv -fomit-frame-pointer -fPIC -fno-common -mieee-fp -I"../include" -c -o "os_io.o" -I. -DHAVE_CONFIG_H -D___GAMBCDIR="\"/usr/local/Gambit-C/v4.7.3\"" -D___SYS_TYPE_CPU="\"x86_64\"" -D___SYS_TYPE_VENDOR="\"unknown\"" -D___SYS_TYPE_OS="\"linux-gnu\"" -D___CONFIGURE_COMMAND="\"./configure 'CC=gcc -W -Wall -march=native' '--enable-single-host' '--enable-multiple-versions'"\" -D___OBJ_EXTENSION="\".o\"" -D___EXE_EXTENSION="\"\"" -D___BAT_EXTENSION="\"\"" -D___PRIMAL os_io.c -D___LIBRARY os_io.c: In function '___device_stream_setup_from_process': os_io.c:7212:17: warning: ignoring return value of 'write', declared with attribute warn_unused_result [-Wunused-result] write (hdp_errno.writing_fd, &execvp_errno, sizeof (execvp_errno)); so I think it also affects -Wunused-result. Brad