fix Makefile and README.md for 2015/schweikhardt
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@@ -1,36 +1,52 @@
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#!/usr/bin/env make
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#
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# 2015 makefile
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# IOCCC 2015 winning entry - schweikhardt
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################################################################################
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#
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# This work by Landon Curt Noll, Simon Cooper, and Leonid A. Broukhis
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# is licensed under:
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# Regarding individual entries:
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||||
#
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||||
# IOCCC winning entry code may not work on your system. Even with standards,
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||||
# conditions and build environments change, especially when it comes to more
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# extreme code such you might find in an IOCCC winner. Moreover, what was
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# allowed and liked in one IOCCC contest may no longer be liked/allowed in
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# later IOCCC years.
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#
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# Corrections on winning author and fixing typos in remarks are VERY WELCOME.
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#
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# GitHub pull requests are welcome:
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#
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# If you have a patch that might make running an entry work in modern Unix-like
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# environments, please create a GitHub pull request for the IOCCC judges to
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# consider.
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#
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||||
# Suggestions and corrections regarding Makefiles, winning author information,
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# fixing typos in remarks, and code patches are welcome via opening a GitHub
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# issue or better yet, by creating a GitHub pull request for the IOCCC judges
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# to consider. To form a GitHub issue or GitHub pull, please visit:
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#
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# https://github.com/ioccc-src/winner
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#
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################################################################################
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# This work by Landon Curt Noll and Leonid A. Broukhis is licensed under:
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#
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# Creative Commons Attribution-ShareAlike 3.0 Unported License.
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#
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# See: http://creativecommons.org/licenses/by-sa/3.0/
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################
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# tool locations
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################
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#############################
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# shell used by this Makefile
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#############################
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#
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#SHELL= bash
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CP= cp
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CPP= cpp
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GUNZIP= gunzip
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||||
BUNZIP2= bunzip2
|
||||
LD= ld
|
||||
MAKE= make
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||||
RM= rm
|
||||
SED= sed
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||||
TAR= tar
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TRUE= true
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||||
MKDIR= mkdir
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||||
MV= mv
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||||
TR= tr
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||||
GREP= grep
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SORT= sort
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UNIQ= uniq
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SHELL= bash
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#######################
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# common tool locations
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#######################
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#
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include ../../var.mk
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# Set X11_LIBDIR to the directory where the X11 library resides
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#
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@@ -44,49 +60,51 @@ X11_LIBDIR= /opt/X11/lib
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#X11_INCDIR= /usr/X11/include
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X11_INCDIR= /opt/X11/include
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# Compiler warnings
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#
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#CWARN=
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#CWARN= -Wall
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#CWARN= -Wall -Wextra
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CWARN= -Wall -Wextra -pedantic ${CSILENCE}
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#CWARN= -Wall -Wextra -Weverything
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#CWARN= -Wall -Wextra -Weverything -pedantic
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#CWARN= -Wall -Wextra -Weverything -pedantic ${CSILENCE}
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||||
|
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# Silence warnings that ${CWARN} would normally complain about
|
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# Common C compiler warnings to silence
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#
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CSILENCE=
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#CSILENCE= -Wno-implicit-int
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|
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# compiler standard
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# Common C compiler warning flags
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#
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#CWARN= ${CSILENCE}
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#CWARN= -Wall ${CSILENCE}
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#CWARN= -Wall -Wextra ${CSILENCE}
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CWARN= -Wall -Wextra -pedantic ${CSILENCE}
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# Compiler standard
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#
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#CSTD=
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#CSTD= -ansi
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CSTD= -std=c11
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#CSTD= -std=c99
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CSTD= -std=gnu11
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# compiler bit architecture
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# Compiler bit architecture
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#
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||||
# Some entries require 32-bitness:
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# ARCH= -m32
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#
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# Some entries require 64-bitess:
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# Some entries require 64-bitness:
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# ARCH= -m64
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#
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# By default we assume nothing:
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#
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ARCH=
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# defines that are needed to compile
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# Defines that are needed to compile
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#
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#CDEFINE=
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CDEFINE= -Dtyp=uint64_t
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# include files that are needed to compile
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# Include files that are needed to compile
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#
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CINCLUDE=
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#CINCLUDE= -include stdlib.h
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#CINCLUDE= -include stdio.h
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#CINCLUDE= -include stdlib.h -include stdio.h
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#CINCLUDE= -I ${X11_INCDIR} -I ${X11_INCDIR}/X11
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#CINCLUDE= `${SDL2_CONFIG} --cflags`
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|
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# optimization
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# Optimization
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#
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# Most compiles will safely use -O2. Some can use only -O1 or -O.
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# A few compilers have broken optimizers or this entry make break
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@@ -99,56 +117,77 @@ CINCLUDE=
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#OPT= -O2
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OPT= -O3
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# default flags for ANSI C compilation
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# Default flags for ANSI C compilation
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#
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CFLAGS= ${CWARN} ${CSTD} ${ARCH} ${CDEFINE} ${CINCLUDE} ${OPT}
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CFLAGS= ${CSTD} ${CWARN} ${ARCH} ${CDEFINE} ${CINCLUDE} ${OPT}
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# Libraries needed to build
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#
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LIBS=
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#LIBS= -lm
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#LIBS= -L ${X11_LIBDIR} -lX11
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#LIBS= `${SDL2_CONFIG} --libs`
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# ANSI compiler
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#
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# Set CC to the name of your ANSI compiler.
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#
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# Some entries seem to need gcc. If you have gcc, set
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# both CC and MAY_NEED_GCC to gcc.
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#
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# If you do not have gcc, set CC to the name of your ANSI compiler, and
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# set MAY_NEED_GCC to either ${CC} (and hope for the best) or to just :
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# to disable such programs.
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# C compiler to use
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#
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CC= cc
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#CC=clang
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MAY_NEED_GCC= gcc
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#CC=gcc
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# Compiler add-ons or replacements for clang only
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#
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ifeq ($(CC),clang)
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#
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CSILENCE+= -Wno-poison-system-directories
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#
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CWARN+= -Weverything
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#
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endif
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||||
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||||
# Specific add-ons or replacements for gcc only
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#
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ifeq ($(CC),gcc)
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#
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#CSILENCE+=
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#
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#CWARN+=
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#
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endif
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##############################
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# Special flags for this entry
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##############################
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#
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ENTRY= prog
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CSRC= ${ENTRY}.c
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OBJ= ${ENTRY}.o
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ENTRY= schweikhardt
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PROG= prog
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#
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OBJ= ${PROG}.o
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CSRC= ${PROG}.o
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DATA=
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TARGET= ${PROG}
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#
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ALT_OBJ=
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ALT_ENTRY=
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TARGET= ${ENTRY}
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ALT_TARGET=
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||||
|
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#################
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# build the entry
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||||
#################
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||||
#
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all: ${TARGET} ${DATA}
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all: data ${TARGET}
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@${TRUE}
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${ENTRY}: ${CSRC}
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.PHONY: all alt data everything clean clobber install \
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love haste waste maker easter_egg sandwich \
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supernova deep_magic magic charon pluto
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${PROG}: ${PROG}.c
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${CC} ${CFLAGS} $< -o $@ ${LIBS}
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|
||||
# alternative executable
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||||
#
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alt: ${ALT_ENTRY}
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alt: data ${ALT_TARGET}
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@${TRUE}
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# data files
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@@ -156,33 +195,51 @@ alt: ${ALT_ENTRY}
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data: ${DATA}
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@${TRUE}
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# both all and alt
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#
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everything: all alt
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###############
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# utility rules
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||||
###############
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#
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everything: all alt
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clean:
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${RM} -f ${OBJ} ${ALT_OBJ}
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@-if [ -f indent.c ]; then \
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echo ${RM} -f indent.c; \
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${RM} -f indent.c; \
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fi
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clobber: clean
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${RM} -f ${TARGET} ${ALT_ENTRY}
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nuke: clobber
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@${TRUE}
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dist_clean: nuke
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@${TRUE}
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${RM} -f ${TARGET} ${ALT_TARGET}
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@-if [ -e sandwich ]; then \
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${RM} -f sandwich; \
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echo 'ate sandwich'; \
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fi
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install:
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||||
@echo "Surely we are joking Dr. May!"
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@echo "Dr. Spock says that is not logical!"
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@${TRUE}
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# backwards compatibility
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# you may be able to misunderstand the source by reading indent.c
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#
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build: all
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@${TRUE}
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indent.c: ${PROG}.c
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@if which "${GINDENT}" >/dev/null 2>&1; then \
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echo ${RM} -f $@; \
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${RM} -f $@; \
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echo "${GINDENT} < $< > $@"; \
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${GINDENT} < $< > $@; \
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elif which "${INDENT}" >/dev/null 2>&1; then \
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echo ${RM} -f $@; \
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${RM} -f $@; \
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echo "${INDENT} < $< > $@"; \
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${INDENT} < $< > $@; \
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else \
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echo "no intent tool found, ident $< yourself, sorry"; \
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echo "exit 1"; \
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exit 1; \
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fi
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||||
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##################
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@@ -201,54 +258,69 @@ waste:
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@echo 'haste'
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@${TRUE}
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make:
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||||
@echo 'Attend a maker faire'
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maker:
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@echo 'Participate in a maker faire'
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@${TRUE}
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easter_egg:
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||||
@echo you expected to sometimes mis-understand this $${RANDOM} magic
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||||
@echo chongo '<was here>' "/\\oo/\\"
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||||
@echo Readers shall not be disallowed from not failing to be unable to not partly misunderstand this particular final echo.
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@echo "you expected to often misunderstand this $${RANDOM} magic"
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||||
@echo "chongo '<was here>' /\\oo/\\"
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@echo "Eggy"
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sandwich: easter_egg
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@if [ `id -u` -eq 0 ]; then \
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echo 'Okay.'; \
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echo "$${RANDOM}`date +%s`$${RANDOM}" > $@; \
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||||
else \
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echo 'What? Make it yourself.'; \
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exit 1; \
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fi
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||||
# Understand the history of the Homebrew Computer Club
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# as well as the West Coast Computer Faire and
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||||
# you might be confused different. :-)
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||||
#
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||||
supernova: nuke
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supernova: sandwich
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@-if [ -r .code_anal ]; then \
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${RM} -f .code_anal_v5; \
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||||
${RM} -f .code_anal_v6; \
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||||
else \
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echo "planet deniers, like the IAU, are amusing"; \
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echo "planet deniers, like some members of the IAU, are so cute when they try to defend their logic"; \
|
||||
fi
|
||||
@echo A $@ helps ${MAKE} the elements that help form planets
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||||
@echo "A $@ helps ${MAKE} the elements that help form planets"
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||||
@${TRUE}
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||||
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||||
deep_magic:
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||||
deep_magic: supernova
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||||
@-if [ -r .code_anal ]; then \
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||||
ccode_analysis --deep_magic 2ed3582ec5c094a093fea2a6bcb9f19439892873c9cc45ed1ceaafe08b7d52e1b2c7cd524be3b0b2 --FNV1a_hash_512_bit "${ENTRY}"; \
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||||
ccode_analysis --deep_magic 7889066cdbdf09b0408021754586e895be641cc9be29e7eafd3ca65359541f17 \
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||||
--FNV1a_hash_512_bit -v2 "${PROG}" "${PROG}.c"; \
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||||
else \
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||||
echo "You are holding it wrong!"; \
|
||||
echo "Wrong! Do it again!"; \
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||||
sleep 2; \
|
||||
echo "Wrong! Do it again!"; \
|
||||
sleep 2; \
|
||||
echo "Wrong! Do it again!"; \
|
||||
fi
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||||
@${TRUE}
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||||
|
||||
magic: deep_magic
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||||
@-if [ -r .code_anal ]; then \
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||||
ccode_analysis --mode 216091 --level 216193 --FNV1a_hash_512_bit "${ENTRY}"; \
|
||||
ccode_analysis --level 20003 --mode 5717175 --FNV1a_hash_512_bit -v2 "${PROG}" "${PROG}.c"; \
|
||||
else \
|
||||
echo "These aren't the primes you're looking for Pauline!"; \
|
||||
echo "If you don't eat yer meat, you can't have any pudding!"; \
|
||||
echo "How can you have any pudding if you don't eat yer meat?!"; \
|
||||
fi
|
||||
@${TRUE}
|
||||
|
||||
# The IOCCC resident astronomer states
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||||
#
|
||||
charon: supernova
|
||||
@echo $@ is a dwarf planet
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||||
@echo dwarf is a type of planet
|
||||
@echo $@ is a planet
|
||||
charon: magic
|
||||
@echo "$@ is a dwarf planet"
|
||||
@echo "dwarf is a type of planet"
|
||||
@echo "therefore IAU, $@ is a planet"
|
||||
|
||||
pluto: supernova
|
||||
pluto: charon
|
||||
${MAKE} charon
|
||||
@echo $@ is a dwarf planet
|
||||
@echo dwarf is a type of planet
|
||||
@echo $@ is a planet
|
||||
@echo get used to having lots of planets becasue supernovae can ${MAKE} a lot of them
|
||||
@echo "$@ is a dwarf planet"
|
||||
@echo "dwarf is a type of planet"
|
||||
@echo "therefore, $@ is a planet"
|
||||
@echo "having lots of planets is good feature because supernovae can help ${MAKE} a lot of them"
|
||||
+203
-184
@@ -1,29 +1,36 @@
|
||||
# Best Documented
|
||||
|
||||
Jens Schweikhardt
|
||||
<http://www.schweikhardt.net>
|
||||
Jens Schweikhardt
|
||||
<http://www.schweikhardt.net>
|
||||
|
||||
# To build:
|
||||
|
||||
## Judges' comments:
|
||||
### To use:
|
||||
```sh
|
||||
make
|
||||
```
|
||||
|
||||
make
|
||||
### To run:
|
||||
|
||||
./prog n
|
||||
```sh
|
||||
./prog n
|
||||
```
|
||||
|
||||
where n is a base 16 number of any size
|
||||
where n is a base 16 number of any size.
|
||||
|
||||
### Try:
|
||||
|
||||
./prog 19
|
||||
```sh
|
||||
./prog 19
|
||||
```
|
||||
|
||||
|
||||
### Selected Judges Remarks:
|
||||
## Judges' comments:
|
||||
|
||||
This code is clean. When you compile with all warnings enabled,
|
||||
such as with clang:
|
||||
|
||||
cc -Weverything -pedantic -std=c11 -Dtyp=uint64\_t -O3 prog.c -o prog
|
||||
```sh
|
||||
cc -Weverything -pedantic -std=c11 -Dtyp=uint64\_t -O3 prog.c -o prog
|
||||
```
|
||||
|
||||
The code compiles without warnings on the systems that we tested!
|
||||
|
||||
@@ -33,9 +40,11 @@ static source checkers.
|
||||
This tool references a problem that David I. Bell once described
|
||||
as having one of the largest "yummo quotients" in number theory:
|
||||
|
||||
complexity of the solution
|
||||
yummo quotient = -----------------------------------
|
||||
complexity of the problem statement
|
||||
```
|
||||
complexity of the solution
|
||||
yummo quotient = -----------------------------------
|
||||
complexity of the problem statement
|
||||
```
|
||||
|
||||
Erdős privately told one of the IOCCC judges:
|
||||
|
||||
@@ -45,15 +54,17 @@ to begin to work on the [Collatz conjecture](https://en.wikipedia.org/wiki/Colla
|
||||
|
||||
You may explore this famous conjecture using this entry:
|
||||
|
||||
./prog 2410
|
||||
./prog abfff
|
||||
./prog 27f8cebf
|
||||
./prog 246f8fddf
|
||||
./prog 2e95ab51ffea9de
|
||||
./prog e6a5c22fd7bde9f
|
||||
./prog 1b7dd73a937485bf
|
||||
./prog 7d3237680d190a77e53751b
|
||||
./prog 302ab3d052fb87c06228d249581be0e4
|
||||
```sh
|
||||
./prog 2410
|
||||
./prog abfff
|
||||
./prog 27f8cebf
|
||||
./prog 246f8fddf
|
||||
./prog 2e95ab51ffea9de
|
||||
./prog e6a5c22fd7bde9f
|
||||
./prog 1b7dd73a937485bf
|
||||
./prog 7d3237680d190a77e53751b
|
||||
./prog 302ab3d052fb87c06228d249581be0e4
|
||||
```
|
||||
|
||||
When you first look at the source, the code looks fairly straightforward.
|
||||
But look again. Like the Collatz conjecture, simplicity is deceptive!
|
||||
@@ -67,8 +78,8 @@ p.s. We appreciated that apart from a few powers of 2, the source
|
||||
code is magic number free.
|
||||
|
||||
## Author's comments:
|
||||
The TL;DR version
|
||||
-----------------
|
||||
|
||||
### The TL;DR version
|
||||
|
||||
This is the cleanest program ever submitted. If for some input it enters
|
||||
a non-terminating loop or runs out of memory you will be insta-famous.
|
||||
@@ -80,8 +91,7 @@ The program illustrates the bloat caused by adherence to too many rules,
|
||||
each of which may sound sane in isolation, but in their entirety lead to
|
||||
an obfuscated, hard to read and understand monster.
|
||||
|
||||
What this program does.
|
||||
-----------------------
|
||||
### What this program does.
|
||||
|
||||
The program tests whether a given natural number satisfies the
|
||||
[Collatz Conjecture](https://en.wikipedia.org/wiki/Collatz_conjecture):
|
||||
@@ -116,23 +126,27 @@ prefix) as the first argument. The program prints the given number in
|
||||
zero-padded hex and each iteration along with a line count in decimal.
|
||||
The example above looks like this (compiled with 64 bit word size):
|
||||
|
||||
$ ./prog 6
|
||||
0000000000000006
|
||||
0000000000000003 1
|
||||
000000000000000A 2
|
||||
0000000000000005 3
|
||||
0000000000000010 4
|
||||
0000000000000008 5
|
||||
0000000000000004 6
|
||||
0000000000000002 7
|
||||
0000000000000001 8
|
||||
```sh
|
||||
$ ./prog 6
|
||||
0000000000000006
|
||||
0000000000000003 1
|
||||
000000000000000A 2
|
||||
0000000000000005 3
|
||||
0000000000000010 4
|
||||
0000000000000008 5
|
||||
0000000000000004 6
|
||||
0000000000000002 7
|
||||
0000000000000001 8
|
||||
## Judges' comments:
|
||||
|
||||
The size of *n* is only limited by the argument size limit of your
|
||||
shell/OS (the program implements arbitrary size bignums).
|
||||
To query this on your POSIX system, run
|
||||
|
||||
$ getconf ARG_MAX
|
||||
262144
|
||||
```sh
|
||||
$ getconf ARG_MAX
|
||||
262144
|
||||
```
|
||||
|
||||
which reports the limit in bytes, here 256KB. This allows to test
|
||||
whether a [Googol](https://en.wikipedia.org/wiki/Googol), which is
|
||||
@@ -141,12 +155,12 @@ Fear not,
|
||||
[bc(1)](http://pubs.opengroup.org/onlinepubs/9699919799/utilities/bc.html)
|
||||
to the rescue:
|
||||
|
||||
$ printf 'obase=16;10^100\n' | bc
|
||||
1249AD2594C37CEB0B2784C4CE0BF38ACE408E211A7CAAB24308A82E8F1000000000\
|
||||
0000000000000000
|
||||
$ ./prog 1249AD2594C37CEB0B2784C4CE0BF38ACE408E211A7CAAB24308A82E8F10000000000000000000000000 \
|
||||
| less
|
||||
[...]
|
||||
$ printf 'obase=16;10^100\n' | bc
|
||||
1249AD2594C37CEB0B2784C4CE0BF38ACE408E211A7CAAB24308A82E8F1000000000\
|
||||
0000000000000000
|
||||
$ ./prog 1249AD2594C37CEB0B2784C4CE0BF38ACE408E211A7CAAB24308A82E8F10000000000000000000000000 \
|
||||
| less
|
||||
[...]
|
||||
|
||||
Observe how the first 100 iterations melt the zeros to the right. Can you explain
|
||||
why?
|
||||
@@ -154,58 +168,54 @@ why?
|
||||
For a given *n* the program behavior is one of the following 3:
|
||||
|
||||
1. The sequence stops at 1. No fame. No money. Thanks for playing. Computational
|
||||
mathematicians have tested all *n* < 4FFDD776055A0000 (~10<sup>18</sup>)
|
||||
so don't try anything less than that.
|
||||
mathematicians have tested all *n* < 4FFDD776055A0000 (~10<sup>18</sup>)
|
||||
so don't try anything less than that.
|
||||
2. The chosen *n* leads to a sequence with ever bigger numbers,
|
||||
so that eventually the bignum cannot be stored in memory. If this happens,
|
||||
the program outputs `laugh` (more likely) or `throw up` (less likely) and
|
||||
stops. You *might* have found
|
||||
a number for which the sequence *diverges*. If confirmed, this disproves the
|
||||
conjecture.
|
||||
so that eventually the bignum cannot be stored in memory. If this happens,
|
||||
the program outputs `laugh` (more likely) or `throw up` (less likely) and
|
||||
stops. You *might* have found
|
||||
a number for which the sequence *diverges*. If confirmed, this disproves the
|
||||
conjecture.
|
||||
3. The chosen *n* leads to a cycle not including 1 (i.e. runs forever,
|
||||
repeating the same sequence over and over). You have disproved the
|
||||
conjecture and should certainly submit a paper to the nearest
|
||||
mathematical journal.
|
||||
repeating the same sequence over and over). You have disproved the
|
||||
conjecture and should certainly submit a paper to the nearest
|
||||
mathematical journal.
|
||||
|
||||
|
||||
Design objectives
|
||||
-----------------
|
||||
### Design objectives
|
||||
|
||||
I gave myself the following objectives. Like in real world programming,
|
||||
not all of them can be met 100%. Think of them as a multidimensional
|
||||
continuum, where trade-offs have to be made.
|
||||
|
||||
1. No arbitrary limits on the input number. 64 bits might be enough
|
||||
for everybody, but is not enough for exploring new Collatz-territory.
|
||||
Thus bignums are required.
|
||||
for everybody, but is not enough for exploring new Collatz-territory.
|
||||
Thus bignums are required.
|
||||
2. Ultra-portable. Must run on C89 systems and self-adapt to C99 and C11
|
||||
features like exact width types.
|
||||
features like exact width types.
|
||||
3. Super-efficient. Must be able to run with the widest type as the
|
||||
base of the bignums. Make the user select the widest type supported
|
||||
by the implementation and then crunch away. If a non-standard
|
||||
128bit type is available, it should be usable.
|
||||
base of the bignums. Make the user select the widest type supported
|
||||
by the implementation and then crunch away. If a non-standard
|
||||
128bit type is available, it should be usable.
|
||||
4. Pentagon level lint cleanliness and MISRA compliance.
|
||||
5. Easy to understand, self-documenting clear code. A joy for maintenance
|
||||
programmers. The epitome of best practice demonstration for all
|
||||
future textbooks on C.
|
||||
programmers. The epitome of best practice demonstration for all
|
||||
future textbooks on C.
|
||||
|
||||
Program Obfuscation
|
||||
===================
|
||||
### Program Obfuscation
|
||||
|
||||
In the following I address all the *tests* as specified by your honors in the
|
||||
*guidelines*.
|
||||
|
||||
* look at the original source
|
||||
* convert ANSI tri-graphs to ASCII
|
||||
* C pre-process the source ignoring `#include` lines
|
||||
* C pre-process the source ignoring `#define` and `#include` lines
|
||||
* run it through a C beautifier
|
||||
* examine the algorithm
|
||||
* compile it (with flags to enable all warnings)
|
||||
* execute it
|
||||
* look at the original source
|
||||
* convert ANSI tri-graphs to ASCII
|
||||
* C pre-process the source ignoring `#include` lines
|
||||
* C pre-process the source ignoring `#define` and `#include` lines
|
||||
* run it through a C beautifier
|
||||
* examine the algorithm
|
||||
* compile it (with flags to enable all warnings)
|
||||
* execute it
|
||||
|
||||
Look at the original source
|
||||
---------------------------
|
||||
### Look at the original source
|
||||
|
||||
Using one letter identifiers is quite old. I decided to use TLI (three
|
||||
letter identifiers). Not the random kind, rather with a connection to
|
||||
@@ -214,27 +224,27 @@ the myriad of possible amino acids there are 23 from which proteins are
|
||||
built. In biochemistry, each is assigned a TLI (see [Proteinogenic amino
|
||||
acid](https://en.wikipedia.org/wiki/Proteinogenic_amino_acid)):
|
||||
|
||||
ala Alanine
|
||||
cys Cysteine
|
||||
asp Aspartic acid
|
||||
glu Glutamic acid
|
||||
phe Phenylalanine
|
||||
gly Glycine
|
||||
his Histidine
|
||||
ile Isoleucine
|
||||
lys Lysine
|
||||
leu Leucine
|
||||
met Methionine
|
||||
asn Asparagine
|
||||
pyl Pyrrolysine
|
||||
pro Proline
|
||||
gln Glutamine
|
||||
arg Arginine
|
||||
ser Serine
|
||||
thr Threonine
|
||||
sec Selenocysteine
|
||||
val Valine
|
||||
trp Tryptophan
|
||||
ala Alanine
|
||||
cys Cysteine
|
||||
asp Aspartic acid
|
||||
glu Glutamic acid
|
||||
phe Phenylalanine
|
||||
gly Glycine
|
||||
his Histidine
|
||||
ile Isoleucine
|
||||
lys Lysine
|
||||
leu Leucine
|
||||
met Methionine
|
||||
asn Asparagine
|
||||
pyl Pyrrolysine
|
||||
pro Proline
|
||||
gln Glutamine
|
||||
arg Arginine
|
||||
ser Serine
|
||||
thr Threonine
|
||||
sec Selenocysteine
|
||||
val Valine
|
||||
trp Tryptophan
|
||||
tyr Tyrosine
|
||||
asx Asparagine or Aspartic acid
|
||||
glx Glutamic acid or Glutamine
|
||||
@@ -258,19 +268,16 @@ counter), `gly` means "Grow Larger memorY", `gln` is "Grown Larger Now"
|
||||
is the "UNit (Known as 1)", `trp` is the "Tabula Rasa Product" (zero),
|
||||
`phe` is "Print HEx" and so on.
|
||||
|
||||
Convert ANSI tri-graphs to ASCII
|
||||
--------------------------------
|
||||
### Convert ANSI tri-graphs to ASCII
|
||||
|
||||
Huh??!
|
||||
|
||||
C pre-process the source ignoring '#include' lines
|
||||
--------------------------------------------------
|
||||
### C pre-process the source ignoring '#include' lines
|
||||
|
||||
Wow, an identity operation (except for the `<stdint.h>` and `EOF + __STDC__`
|
||||
trivialities). Did you gain any insight through this?
|
||||
|
||||
C pre-process the source ignoring '#define' and '#include' lines
|
||||
----------------------------------------------------------------
|
||||
### C pre-process the source ignoring '#define' and '#include' lines
|
||||
|
||||
`#define`? Which `#define` directives? How many 4K source files do you
|
||||
see that neither use a single `#define` directive *nor* abuse the build
|
||||
@@ -278,13 +285,13 @@ file? Even though the "no `#define`" rule I submitted myself to made it
|
||||
hard, I could use `__LINE__` and stdio macros `EOF`, `L_tmpnam`,
|
||||
`BUFSIZ`, `FILENAME_MAX`, `TMP_MAX` to obfuscate at least something.
|
||||
|
||||
Run it through a C beautifier
|
||||
-----------------------------
|
||||
### Run it through a C beautifier
|
||||
|
||||
Another identity operation. I've done it for you already. Use this
|
||||
`.indent.pro` with FreeBSD indent:
|
||||
|
||||
$ cat .indent.pro
|
||||
```sh
|
||||
$ cat .indent.pro
|
||||
-bad /* blank line after decls */
|
||||
-bap /* blank line after functions */
|
||||
-br /* braces on if line */
|
||||
@@ -302,6 +309,7 @@ Another identity operation. I've done it for you already. Use this
|
||||
-Tpro
|
||||
-Tser
|
||||
-Tala
|
||||
```
|
||||
|
||||
It looks like a perfect program should:
|
||||
|
||||
@@ -325,39 +333,41 @@ as (256 + 128 + 4 + 2) * 512 minimizes the character count. That's what
|
||||
judges get when they don't like programs that are longer than they need
|
||||
to be.
|
||||
|
||||
Examine the algorithm
|
||||
---------------------
|
||||
### Examine the algorithm
|
||||
|
||||
Spoilers ahead. Duh!
|
||||
|
||||
Pseudocode, with comments matching those in the C source:
|
||||
|
||||
/* run */
|
||||
if (non-NULL and nonempty argv[1]) {
|
||||
n = convert(argv[1])
|
||||
print n /* 2hx */
|
||||
while (n != 1) { /* one */
|
||||
if (n is odd) { /* odd */
|
||||
m = deep copy of n /* cpy */
|
||||
n <<= 1 /* shl */
|
||||
n += m /* add */
|
||||
increment n /* inc */
|
||||
} else { /* eve */
|
||||
n >>= 1 /* shr */
|
||||
}
|
||||
print n /* 2hx */
|
||||
```c
|
||||
/* run */
|
||||
if (non-NULL and nonempty argv[1]) {
|
||||
n = convert(argv[1])
|
||||
print n /* 2hx */
|
||||
while (n != 1) { /* one */
|
||||
if (n is odd) { /* odd */
|
||||
m = deep copy of n /* cpy */
|
||||
n <<= 1 /* shl */
|
||||
n += m /* add */
|
||||
increment n /* inc */
|
||||
} else { /* eve */
|
||||
n >>= 1 /* shr */
|
||||
}
|
||||
}
|
||||
print n /* 2hx */
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Bignums are represented as the two member structs
|
||||
|
||||
typedef struct {
|
||||
size_t places; /* number of places in base 2<sup>8*sizeof(type)</sup> */
|
||||
type *number; /* dynamically allocated memory for number */
|
||||
} bignum
|
||||
```c
|
||||
typedef struct {
|
||||
size_t places; /* number of places in base 2<sup>8*sizeof(type)</sup> */
|
||||
type *number; /* dynamically allocated memory for number */
|
||||
} bignum
|
||||
```
|
||||
|
||||
Compile it (with flags to enable all warnings)
|
||||
----------------------------------------------
|
||||
### Compile it (with flags to enable all warnings)
|
||||
|
||||
Here's where the program shines brighter than a [gamma-ray
|
||||
burst](https://en.wikipedia.org/wiki/Gamma-ray_burst)!
|
||||
@@ -368,9 +378,7 @@ analyzers at my program and make it find the slightest of issues.
|
||||
Is `clang -Wall -Wextra -Weverything -Dtyp=uint32_t prog.c` all you can
|
||||
do? Clang has implemented a new warning? Bring it on!
|
||||
|
||||
|
||||
Execute it
|
||||
----------
|
||||
### Execute it
|
||||
|
||||
May you win the jackpot!
|
||||
|
||||
@@ -383,21 +391,22 @@ This means however, that the program accepts __any string__, turns it
|
||||
into a starting number (which is output as the first line), and starts
|
||||
crunching. Nothing stops you from executing
|
||||
|
||||
$ ./prog "$(cat prog.c)" # Kind of quine?
|
||||
$ ./prog "$(cat rules guidelines)" # A jackpot? Maybe next year...
|
||||
$ ./prog "$(cat /bin/ls)" # Number cut short at first NUL byte.
|
||||
```sh
|
||||
./prog "$(cat prog.c)" # Kind of quine?
|
||||
./prog "$(cat rules guidelines)" # A jackpot? Maybe next year...
|
||||
./prog "$(cat /bin/ls)" # Number cut short at first NUL byte.
|
||||
```
|
||||
|
||||
In a certain way, the program is character set and encoding agnostic.
|
||||
|
||||
Assumptions made
|
||||
----------------
|
||||
### Assumptions made
|
||||
|
||||
* The `EOF` macro from `<stdio.h>` must expand to negative one since it is used
|
||||
to decrement a pointer and do some other math.
|
||||
None of the tools catches this one. The program self-protects against unusual
|
||||
systems with `#if EOF + __STDC__` followed by `#error goofy!`. In the rare event
|
||||
your system is goofy, replace all `EOF` tokens with `(-1)` and remove the
|
||||
`#error` directive.
|
||||
to decrement a pointer and do some other math.
|
||||
None of the tools catches this one. The program self-protects against unusual
|
||||
systems with `#if EOF + __STDC__` followed by `#error goofy!`. In the rare event
|
||||
your system is goofy, replace all `EOF` tokens with `(-1)` and remove the
|
||||
`#error` directive.
|
||||
|
||||
|
||||
While the program works best when bytes/characters are octets and the
|
||||
@@ -406,9 +415,7 @@ on 24bit or 36bit systems with 9 bits/byte, or systems where
|
||||
`sizeof(typ)` is 1 even for `int` and so on. On such systems, it will only
|
||||
use 8 * `sizeof(typ)` bits per place. It does not work when `CHAR_BIT <= 7`.
|
||||
|
||||
|
||||
Results of various checkers
|
||||
---------------------------
|
||||
### Results of various checkers
|
||||
|
||||
### cppcheck
|
||||
|
||||
@@ -416,7 +423,9 @@ The open source static checker [cppcheck](http://cppcheck.sourceforge.net/)
|
||||
checks various problems with respect to style, performance, portability
|
||||
and general fishiness. To enable all checks, run
|
||||
|
||||
$ cppcheck --enable=all --force -I/usr/include -Dtyp=uint32_t prog.c
|
||||
```sh
|
||||
cppcheck --enable=all --force -I/usr/include -Dtyp=uint32_t prog.c
|
||||
```
|
||||
|
||||
No issues found.
|
||||
|
||||
@@ -427,16 +436,17 @@ checks various problems with respect to security like buffer overflows,
|
||||
function arguments to known troublemaker functions and more. It doesn't need to
|
||||
pre-process code, so can be run without the `typ` macro being defined:
|
||||
|
||||
$ flawfinder prog.c
|
||||
Flawfinder version 1.31, (C) 2001-2014 David A. Wheeler.
|
||||
Number of rules (primarily dangerous function names) in C/C++ ruleset: 169
|
||||
Examining prog.c
|
||||
FINAL RESULTS:
|
||||
ANALYSIS SUMMARY:
|
||||
No hits found.
|
||||
$
|
||||
```sh
|
||||
$ flawfinder prog.c
|
||||
Flawfinder version 1.31, (C) 2001-2014 David A. Wheeler.
|
||||
Number of rules (primarily dangerous function names) in C/C++ ruleset: 169
|
||||
Examining prog.c
|
||||
FINAL RESULTS:
|
||||
ANALYSIS SUMMARY:
|
||||
No hits found.
|
||||
```
|
||||
|
||||
### valgrind
|
||||
#### valgrind
|
||||
|
||||
The open source dynamic checker [valgrind](http://valgrind.org/)
|
||||
runs an executable and verifies all memory accesses and (de)allocations for
|
||||
@@ -511,7 +521,7 @@ So I `fclose(stdout)` before returning and now:
|
||||
|
||||
A squeaky clean valgrind result!
|
||||
|
||||
### FlexeLint
|
||||
#### FlexeLint
|
||||
|
||||
FlexeLint is a commercial lint tool by [Gimpel
|
||||
Software](http://www.gimpel.com/html/index.htm). It supports nearly a
|
||||
@@ -629,9 +639,7 @@ what remained:
|
||||
-esym(9058,__*) // tag not used outside typedef
|
||||
-e9092 // NULL does not expand to a pointer (but plain 0)
|
||||
|
||||
|
||||
Compulsory obfuscations
|
||||
-----------------------
|
||||
### Compulsory obfuscations
|
||||
|
||||
Which of the rules cause which obfuscation?
|
||||
|
||||
@@ -641,7 +649,9 @@ expressions other than assignments to `char` objects. A consequence is
|
||||
that printing digits with `'0' + digit` is not allowed (even though
|
||||
`'0'` is technically an `int`!) so I am forced to output hex digits with
|
||||
|
||||
printf("%c", (met)tyr + 32 + 16 + ((8 + EOF) * ((met)tyr / (8 + 2))));
|
||||
```c
|
||||
printf("%c", (met)tyr + 32 + 16 + ((8 + EOF) * ((met)tyr / (8 + 2))));
|
||||
```
|
||||
|
||||
because of the "no magic numbers other than powers of two" rule. How is this
|
||||
an improvement over `printf("%c", '0' + tyr + 7 * (tyr / 10)`, MISRA?
|
||||
@@ -664,9 +674,10 @@ precedence rules in expressions." This requires parentheses for almost
|
||||
all expressions involving more than one operator, especially those for which
|
||||
a cast is required, leading to hard to understand expressions such as
|
||||
|
||||
const ser glx = (ser)((asx > (ser)64u) ? (ser)((ser)asx + (ser)8u + (ser)1u) : (ser)asx);
|
||||
not.not[leu] = (and)((and)not.not[leu] | (and)(((and)glx % (and)16u) << (and)lys));
|
||||
|
||||
```c
|
||||
const ser glx = (ser)((asx > (ser)64u) ? (ser)((ser)asx + (ser)8u + (ser)1u) : (ser)asx);
|
||||
not.not[leu] = (and)((and)not.not[leu] | (and)(((and)glx % (and)16u) << (and)lys));
|
||||
```
|
||||
|
||||
MISRA 14.7, "A function shall have a single point of exit at the end of
|
||||
the function." Sigh. Since I must use eloquent prototypes (8.1, 16.3,
|
||||
@@ -676,20 +687,23 @@ useless indent level*. The first three `if` statements in `main` cause a
|
||||
silly 24 character indent. The maximum indent is forced to 8, which is way
|
||||
too high for a sane function.
|
||||
|
||||
|
||||
MISRA 16.10, "If a function returns error information, then that error
|
||||
information shall be tested." A cast to void would draw a lint warning, so
|
||||
I use the `printf` result in expressions,
|
||||
|
||||
lys -= 4 * printf("%c", (met)tyr + 32 + 16 + ((8 + EOF) * ((met)tyr / (8 + 2))));
|
||||
val += printf("\n") / ((__LINE__ * L_tmpnam) + TMP_MAX);
|
||||
val -= (printf(" %d\n", val) > BUFSIZ) ? FILENAME_MAX : EOF;
|
||||
```c
|
||||
lys -= 4 * printf("%c", (met)tyr + 32 + 16 + ((8 + EOF) * ((met)tyr / (8 + 2))));
|
||||
val += printf("\n") / ((__LINE__ * L_tmpnam) + TMP_MAX);
|
||||
val -= (printf(" %d\n", val) > BUFSIZ) ? FILENAME_MAX : EOF;
|
||||
```
|
||||
|
||||
which are, in the absence of errors, equivalent to
|
||||
|
||||
lys -= 4;
|
||||
/*nop*/
|
||||
++val;
|
||||
```c
|
||||
lys -= 4;
|
||||
/*nop*/
|
||||
++val;
|
||||
```
|
||||
|
||||
|
||||
MISRA 13.1, "Assignment operators shall not be used in expressions that
|
||||
@@ -702,9 +716,11 @@ declared as pointer to const if the pointer is not used to modify the
|
||||
addressed object." in conjunction with lint's "Note 952: Parameter could
|
||||
be declared const" causes const-poisoning for all functions,
|
||||
|
||||
static void phe(const ala not);
|
||||
static void gly(ala *const not, const and his);
|
||||
met main(met val, const pro *const his[]);
|
||||
```c
|
||||
static void phe(const ala not);
|
||||
static void gly(ala *const not, const and his);
|
||||
met main(met val, const pro *const his[]);
|
||||
```
|
||||
|
||||
and quite a number of automatic variables.
|
||||
|
||||
@@ -718,15 +734,19 @@ up :-) (humor really helps!)"
|
||||
If your compiler supports a 128 bit wide type (e.g. clang, gcc) then
|
||||
you can use it via the `typ` macro:
|
||||
|
||||
clang -Dtyp=__uint128_t -o prog prog.c
|
||||
```sh
|
||||
clang -Dtyp=__uint128_t -o prog prog.c
|
||||
```
|
||||
|
||||
Indeed, the program can use (and lints clean for) all of
|
||||
|
||||
clang -Dtyp=uint8_t -o prog8 prog.c
|
||||
clang -Dtyp=uint16_t -o prog16 prog.c
|
||||
clang -Dtyp=uint32_t -o prog32 prog.c
|
||||
clang -Dtyp=uint64_t -o prog64 prog.c
|
||||
clang -std=c89 -Dtyp="unsigned long" -o prog89 prog.c
|
||||
```sh
|
||||
clang -Dtyp=uint8_t -o prog8 prog.c
|
||||
clang -Dtyp=uint16_t -o prog16 prog.c
|
||||
clang -Dtyp=uint32_t -o prog32 prog.c
|
||||
clang -Dtyp=uint64_t -o prog64 prog.c
|
||||
clang -std=c89 -Dtyp="unsigned long" -o prog89 prog.c
|
||||
```
|
||||
|
||||
This works because the program has no need for corresponding `SCN` or
|
||||
`PRI` macros to do the scanning and printing of variables of these
|
||||
@@ -761,11 +781,10 @@ memory resources with the ulimit(1) built-in of your shell.
|
||||
|
||||
For all intents and purposes, the *Not Overflowing Type* keeps the promise!
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
<!--
|
||||
## Copyright:
|
||||
|
||||
(c) Copyright 1984-2016, [Leo Broukhis, Simon Cooper, Landon Curt Noll][judges] - All rights reserved
|
||||
This work is licensed under a [Creative Commons Attribution-ShareAlike 3.0 Unported License][cc].
|
||||
|
||||
[judges]: http://www.ioccc.org/judges.html
|
||||
[cc]: http://creativecommons.org/licenses/by-sa/3.0/
|
||||
-->
|
||||
Reference in new issue
Block a user