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Make signed overflow behave "correctly" #4624

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1ce7059
Make signed overflow behave "correctly"
cousteaulecommandant Feb 28, 2016
c90073f
Apply fix to sam as well
cousteaulecommandant Feb 28, 2016
e906856
Merge remote-tracking branch 'upstream/master' into patch-1
cousteaulecommandant Nov 8, 2016
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Make signed overflow behave "correctly" 
Fix for issue #4511
In short, the documentation says that signed integer overflow causes the value to "roll over".  Actually, this results in undefined behavior, with potentially unpredictable results.  This patch adds a GCC option to treat signed integers the "right" way so that they roll over as the documentation claims.
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cousteaulecommandant committed Feb 28, 2016
commit 1ce70592d60893deabe1fca12e260f35043d32e3
4 changes: 2 additions & 2 deletions hardware/arduino/avr/platform.txt
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Expand Up @@ -20,14 +20,14 @@ compiler.warning_flags.all=-Wall -Wextra
# Default "compiler.path" is correct, change only if you want to overidde the initial value
compiler.path={runtime.tools.avr-gcc.path}/bin/
compiler.c.cmd=avr-gcc
compiler.c.flags=-c -g -Os {compiler.warning_flags} -std=gnu11 -ffunction-sections -fdata-sections -MMD
compiler.c.flags=-c -g -Os {compiler.warning_flags} -std=gnu11 -fwrapv -ffunction-sections -fdata-sections -MMD
# -w flag added to avoid printing a wrong warning http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59396
# This is fixed in gcc 4.8.3 and will be removed as soon as we update the toolchain
compiler.c.elf.flags={compiler.warning_flags} -Os -Wl,--gc-sections
compiler.c.elf.cmd=avr-gcc
compiler.S.flags=-c -g -x assembler-with-cpp
compiler.cpp.cmd=avr-g++
compiler.cpp.flags=-c -g -Os {compiler.warning_flags} -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD
compiler.cpp.flags=-c -g -Os {compiler.warning_flags} -std=gnu++11 -fwrapv -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD
compiler.ar.cmd=avr-ar
compiler.ar.flags=rcs
compiler.objcopy.cmd=avr-objcopy
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