5118 - convert int to string - mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

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author	Kartik Agaram <vc@akkartik.com>	2019-04-23 20:25:04 -0700
committer	Kartik Agaram <vc@akkartik.com>	2019-04-23 20:25:04 -0700
commit	d4e7f835a8cfc84958c4c95f3604c3965337e436 (patch)
tree	c9dbaaf328ee05aeb271ec6f941ae4a8536f92c7 /subx/036global_variables.cc
parent	aa0e9bbe7cc4108773a2e1030b3f16dca52be068 (diff)
download	mu-d4e7f835a8cfc84958c4c95f3604c3965337e436.tar.gz

5118 - convert int to string

Diffstat (limited to 'subx/036global_variables.cc')

0 files changed, 0 insertions, 0 deletions

//: Everything this project/binary supports. //: This should give you a sense for what to look forward to in later layers. :(before "End Commandline Parsing") if (argc <= 1 || is_equal(argv[1], "--help")) { //: this is the functionality later layers will provide // currently no automated tests for commandline arg parsing if (argc <= 1) { cerr << "Please provide a Mu program to run.\n" << "\n"; } cerr << "Usage:\n" << " mu [options] [test] [files]\n" << "or:\n" << " mu [options] [test] [files] -- [ingredients for function/recipe 'main']\n" << "Square brackets surround optional arguments.\n" << "\n" << "Examples:\n" << " To load files and run 'main':\n" << " mu file1.mu file2.mu ...\n" << " To run 'main' and dump a trace of all operations at the end:\n" << " mu --trace file1.mu file2.mu ...\n" << " To run all tests:\n" << " mu test\n" << " To load files and then run all tests:\n" << " mu test file1.mu file2.mu ...\n" << " To run a single Mu scenario:\n" << " mu test file1.mu file2.mu ... scenario\n" << " To run a single Mu scenario and dump a trace at the end:\n" << " mu --trace test file1.mu file2.mu ... scenario\n" << " To load files and run only the tests in explicitly loaded files (for apps):\n" << " mu --test-only-app test file1.mu file2.mu ...\n" << " To load all files with a numeric prefix in a directory:\n" << " mu directory1 directory2 ...\n" << " You can test directories just like files.\n" << " mu test directory1 directory2 ...\n" << " To pass ingredients to a mu program, provide them after '--':\n" << " mu file_or_dir1 file_or_dir2 ... -- ingredient1 ingredient2 ...\n" << " To see where a mu program is spending its time:\n" << " mu --profile file_or_dir1 file_or_dir2 ...\n" << " this slices and dices time spent in various profile.* output files\n" << " To print out the trace to stderr:\n" << " mu --dump file1.mu file2.mu ...\n" << " this is handy when you want to see sandboxed traces alongside the main one\n" << "\n" << " To browse a trace generated by a previous run:\n" << " mu browse-trace file\n" ; return 0; } //: Support for option parsing. //: Options always begin with '--' and are always the first arguments. An //: option will never follow a non-option. :(before "End Commandline Parsing") char** arg = &argv[1]; while (argc > 1 && starts_with(*arg, "--")) { if (false) ; // no-op branch just so any further additions can consistently always start with 'else' // End Commandline Options(*arg) else cerr << "skipping unknown option " << *arg << '\n'; --argc; ++argv; ++arg; } //:: Helper function used by the above fragment of code (and later layers too, //:: who knows?). //: The :(code) directive appends function definitions to the end of the //: project. Regardless of where functions are defined, we can call them //: anywhere we like as long as we format the function header in a specific //: way: put it all on a single line without indent, end the line with ') {' //: and no trailing whitespace. As long as functions uniformly start this //: way, our 'build*' scripts contain a little command to automatically //: generate declarations for them. :(code) bool is_equal(char* s, const char* lit) { return strncmp(s, lit, strlen(lit)) == 0; } bool starts_with(const string& s, const string& pat) { string::const_iterator a=s.begin(), b=pat.begin(); for (/*nada*/; a!=s.end() && b!=pat.end(); ++a, ++b) if (*a != *b) return false; return b == pat.end(); } //: I'll throw some style conventions here for want of a better place for them. //: As a rule I hate style guides. Do what you want, that's my motto. But since //: we're dealing with C/C++, the one big thing we want to avoid is undefined //: behavior. If a compiler ever encounters undefined behavior it can make //: your program do anything it wants. //: //: For reference, my checklist of undefined behaviors to watch out for: //: out-of-bounds access //: uninitialized variables //: use after free //: dereferencing invalid pointers: null, a new of size 0, others //: //: casting a large number to a type too small to hold it //: //: integer overflow //: division by zero and other undefined expressions //: left-shift by negative count //: shifting values by more than or equal to the number of bits they contain //: bitwise operations on signed numbers //: //: Converting pointers to types of different alignment requirements //: T* -> void* -> T*: defined //: T* -> U* -> T*: defined if non-function pointers and alignment requirements are same //: function pointers may be cast to other function pointers //: //: Casting a numeric value into a value that can't be represented by the target type (either directly or via static_cast) //: //: To guard against these, some conventions: //: //: 0. Initialize all primitive variables in functions and constructors. //: //: 1. Minimize use of pointers and pointer arithmetic. Avoid 'new' and //: 'delete' as far as possible. Rely on STL to perform memory management to //: avoid use-after-free issues (and memory leaks). //: //: 2. Avoid naked arrays to avoid out-of-bounds access. Never use operator[] //: except with map. Use at() with STL vectors and so on. //: //: 3. Valgrind all the things. //: //: 4. Avoid unsigned numbers. Not strictly an undefined-behavior issue, but //: the extra range doesn't matter, and it's one less confusing category of //: interaction gotchas to worry about. //: //: Corollary: don't use the size() method on containers, since it returns an //: unsigned and that'll cause warnings about mixing signed and unsigned, //: yadda-yadda. Instead use this macro below to perform an unsafe cast to //: signed. We'll just give up immediately if a container's ever too large. //: Basically, Mu is not concerned about this being a little slower than it //: could be. (https://gist.github.com/rygorous/e0f055bfb74e3d5f0af20690759de5a7) //: //: Addendum to corollary: We're going to uniformly use int everywhere, to //: indicate that we're oblivious to number size, and since Clang on 32-bit //: platforms doesn't yet support multiplication over 64-bit integers, and //: since multiplying two integers seems like a more common situation to end //: up in than integer overflow. :(before "End Includes") #define SIZE(X) (assert((X).size() < (1LL<<(sizeof(int)*8-2))), static_cast<int>((X).size())) //: 5. Integer overflow is guarded against at runtime using the -ftrapv flag //: to the compiler, supported by Clang (GCC version only works sometimes: //: http://stackoverflow.com/questions/20851061/how-to-make-gcc-ftrapv-work). :(before "atexit(reset)") initialize_signal_handlers(); // not always necessary, but doesn't hurt //? cerr << INT_MAX+1 << '\n'; // test overflow //? assert(false); // test SIGABRT :(code) // based on https://spin.atomicobject.com/2013/01/13/exceptions-stack-traces-c void initialize_signal_handlers() { struct sigaction action; bzero(&action, sizeof(action)); action.sa_sigaction = dump_and_exit; sigemptyset(&action.sa_mask); sigaction(SIGABRT, &action, NULL); // assert() failure or integer overflow on linux (with -ftrapv) sigaction(SIGILL, &action, NULL); // integer overflow on OS X (with -ftrapv) } void dump_and_exit(int sig, siginfo_t* /*unused*/, void* /*unused*/) { switch (sig) { case SIGABRT: #ifndef __APPLE__ cerr << "SIGABRT: might be an integer overflow if it wasn't an assert() failure or exception\n"; _Exit(1); #endif break; case SIGILL: #ifdef __APPLE__ cerr << "SIGILL: most likely caused by integer overflow\n"; _Exit(1); #endif break; default: break; } } :(before "End Includes") #include <signal.h> //: For good measure we'll also enable SIGFPE. :(before "atexit(reset)") feenableexcept(FE_OVERFLOW | FE_UNDERFLOW); //? assert(sizeof(int) == 4 && sizeof(float) == 4); //? // | exp | mantissa //? int smallest_subnormal = 0b00000000000000000000000000000001; //? float smallest_subnormal_f = *reinterpret_cast<float*>(&smallest_subnormal); //? cerr << "ε: " << smallest_subnormal_f << '\n'; //? cerr << "ε/2: " << smallest_subnormal_f/2 << " (underflow)\n"; // test SIGFPE :(before "End Includes") #include <fenv.h> :(code) #ifdef __APPLE__ // Public domain polyfill for feenableexcept on OS X // http://www-personal.umich.edu/~williams/archive/computation/fe-handling-example.c int feenableexcept(unsigned int excepts) { static fenv_t fenv; unsigned int new_excepts = excepts & FE_ALL_EXCEPT; unsigned int old_excepts; if (fegetenv(&fenv)) return -1; old_excepts = fenv.__control & FE_ALL_EXCEPT; fenv.__control &= ~new_excepts; fenv.__mxcsr &= ~(new_excepts << 7); return fesetenv(&fenv) ? -1 : old_excepts; } #endif //: 6. Map's operator[] being non-const is fucking evil. :(before "Globals") // can't generate prototypes for these // from http://stackoverflow.com/questions/152643/idiomatic-c-for-reading-from-a-const-map template<typename T> typename T::mapped_type& get(T& map, typename T::key_type const& key) { typename T::iterator iter(map.find(key)); assert(iter != map.end()); return iter->second; } template<typename T> typename T::mapped_type const& get(const T& map, typename T::key_type const& key) { typename T::const_iterator iter(map.find(key)); assert(iter != map.end()); return iter->second; } template<typename T> typename T::mapped_type const& put(T& map, typename T::key_type const& key, typename T::mapped_type const& value) { // map[key] requires mapped_type to have a zero-arg (default) constructor map.insert(std::make_pair(key, value)).first->second = value; return value; } template<typename T> bool contains_key(T& map, typename T::key_type const& key) { return map.find(key) != map.end(); } template<typename T> typename T::mapped_type& get_or_insert(T& map, typename T::key_type const& key) { return map[key]; } //: The contract: any container that relies on get_or_insert should never call //: contains_key. //: 7. istreams are a royal pain in the arse. You have to be careful about //: what subclass you try to putback into. You have to watch out for the pesky //: failbit and badbit. Just avoid eof() and use this helper instead. :(code) bool has_data(istream& in) { return in && !in.eof(); } :(before "End Includes") #include <assert.h> #include <iostream> using std::istream; using std::ostream; using std::iostream; using std::cin; using std::cout; using std::cerr; #include <iomanip> #include <string.h> #include <string> using std::string; #include <algorithm> using std::min; using std::max;


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