From 3350c34a74844e21ea69077e01efff3bae64bdcd Mon Sep 17 00:00:00 2001 From: Kartik Agaram Date: Tue, 23 Mar 2021 17:31:08 -0700 Subject: . --- html/001help.cc.html | 334 --------------------------------------------------- 1 file changed, 334 deletions(-) delete mode 100644 html/001help.cc.html (limited to 'html/001help.cc.html') diff --git a/html/001help.cc.html b/html/001help.cc.html deleted file mode 100644 index 393d7ddc..00000000 --- a/html/001help.cc.html +++ /dev/null @@ -1,334 +0,0 @@ - - - - -Mu - 001help.cc - - - - - - - - - - -https://github.com/akkartik/mu/blob/main/001help.cc -
-  1 //: Everything this project/binary supports.
-  2 //: This should give you a sense for what to look forward to in later layers.
-  3 
-  4 :(before "End Commandline Parsing")
-  5 if (argc <= 1 || is_equal(argv[1], "--help")) {
-  6   //: this is the functionality later layers will provide
-  7   // currently no automated tests for commandline arg parsing
-  8   cerr << get(Help, "usage");
-  9   return 0;
- 10 }
- 11 
- 12 //: Support for option parsing.
- 13 //: Options always begin with '--' and are always the first arguments. An
- 14 //: option will never follow a non-option.
- 15 char** arg = &argv[1];
- 16 while (argc > 1 && starts_with(*arg, "--")) {
- 17   if (false)
- 18     ;  // no-op branch just so any further additions can consistently always start with 'else'
- 19   // End Commandline Options(*arg)
- 20   else
- 21     cerr << "skipping unknown option " << *arg << '\n';
- 22   --argc;  ++argv;  ++arg;
- 23 }
- 24 
- 25 if (is_equal(argv[1], "help")) {
- 26   if (argc == 2) {
- 27     cerr << "help on what?\n";
- 28     help_contents();
- 29     return 0;
- 30   }
- 31   string key(argv[2]);
- 32   // End Help Special-cases(key)
- 33   if (contains_key(Help, key)) {
- 34     cerr << get(Help, key);
- 35     return 0;
- 36   }
- 37   else {
- 38     cerr << "No help found for '" << key << "'\n";
- 39     help_contents();
- 40     cerr << "Please check your command for typos.\n";
- 41     return 1;
- 42   }
- 43 }
- 44 
- 45 :(code)
- 46 void help_contents() {
- 47   cerr << "Available top-level topics:\n";
- 48   cerr << "  usage\n";
- 49   // End Help Contents
- 50 }
- 51 
- 52 :(before "End Globals")
- 53 map<string, string> Help;
- 54 :(before "End Includes")
- 55 #include <map>
- 56 using std::map;
- 57 :(before "End One-time Setup")
- 58 init_help();
- 59 :(code)
- 60 void init_help() {
- 61   put(Help, "usage",
- 62     "bootstrap: the bootstrap translator for SubX.\n"
- 63     "This program also wraps some miscellaneous useful functionality:\n"
- 64     "  - an x86 emulator: `bootstrap run`\n"
- 65     "  - online help: `bootstrap help`\n"
- 66     "\n"
- 67     "== Ways to invoke bootstrap\n"
- 68     "- See this message:\n"
- 69     "    bootstrap --help\n"
- 70     "- Convert a textual SubX program into a standard ELF binary that you can\n"
- 71     "  run on your computer:\n"
- 72     "    bootstrap translate input1.subx input2.subx ... -o <output ELF binary>\n"
- 73     "- Run a SubX binary using SubX itself (for better error messages):\n"
- 74     "    bootstrap run <ELF binary>\n"
- 75     "- Run all bootstrap's unit tests:\n"
- 76     "    bootstrap test\n"
- 77     "- Run a single unit test:\n"
- 78     "    bootstrap test <test name>\n"
- 79     "     e.g. bootstrap test test_copy_imm32_to_EAX\n"
- 80     "\n"
- 81     "== Debugging aids\n"
- 82     "- Add '--trace' to any of these commands to save a trace to disk at the end.\n"
- 83     "  This can run out of memory for long-running commands.\n"
- 84     "- Add '--debug' to emit additional debug information during translation.\n"
- 85     "  'bootstrap --debug translate' will save metadata to disk that\n"
- 86     "  'bootstrap --trace run' uses to make traces more informative.\n"
- 87     "\n"
- 88     "Options starting with '--' must always come before any other arguments.\n"
- 89     "\n"
- 90     "To start learning how to write SubX programs, see Readme.md (particularly\n"
- 91     "the section on the x86 instruction set) and then run:\n"
- 92     "  bootstrap help\n"
- 93   );
- 94   // End Help Texts
- 95 }
- 96 
- 97 :(code)
- 98 bool is_equal(char* s, const char* lit) {
- 99   return strncmp(s, lit, strlen(lit)) == 0;
-100 }
-101 
-102 bool starts_with(const string& s, const string& pat) {
-103   string::const_iterator a=s.begin(), b=pat.begin();
-104   for (/*nada*/;  a!=s.end() && b!=pat.end();  ++a, ++b)
-105     if (*a != *b) return false;
-106   return b == pat.end();
-107 }
-108 
-109 //: I'll throw some style conventions here for want of a better place for them.
-110 //: As a rule I hate style guides. Do what you want, that's my motto. But since
-111 //: we're dealing with C/C++, the one big thing we want to avoid is undefined
-112 //: behavior. If a compiler ever encounters undefined behavior it can make
-113 //: your program do anything it wants.
-114 //:
-115 //: For reference, my checklist of undefined behaviors to watch out for:
-116 //:   out-of-bounds access
-117 //:   uninitialized variables
-118 //:   use after free
-119 //:   dereferencing invalid pointers: null, a new of size 0, others
-120 //:
-121 //:   casting a large number to a type too small to hold it
-122 //:
-123 //:   integer overflow
-124 //:   division by zero and other undefined expressions
-125 //:   left-shift by negative count
-126 //:   shifting values by more than or equal to the number of bits they contain
-127 //:   bitwise operations on signed numbers
-128 //:
-129 //:   Converting pointers to types of different alignment requirements
-130 //:     T* -> void* -> T*: defined
-131 //:     T* -> U* -> T*: defined if non-function pointers and alignment requirements are same
-132 //:     function pointers may be cast to other function pointers
-133 //:
-134 //:       Casting a numeric value into a value that can't be represented by the target type (either directly or via static_cast)
-135 //:
-136 //: To guard against these, some conventions:
-137 //:
-138 //: 0. Initialize all primitive variables in functions and constructors.
-139 //:
-140 //: 1. Minimize use of pointers and pointer arithmetic. Avoid 'new' and
-141 //: 'delete' as far as possible. Rely on STL to perform memory management to
-142 //: avoid use-after-free issues (and memory leaks).
-143 //:
-144 //: 2. Avoid naked arrays to avoid out-of-bounds access. Never use operator[]
-145 //: except with map. Use at() with STL vectors and so on.
-146 //:
-147 //: 3. Valgrind all the things.
-148 //:
-149 //: 4. Avoid unsigned numbers. Not strictly an undefined-behavior issue, but
-150 //: the extra range doesn't matter, and it's one less confusing category of
-151 //: interaction gotchas to worry about.
-152 //:
-153 //: Corollary: don't use the size() method on containers, since it returns an
-154 //: unsigned and that'll cause warnings about mixing signed and unsigned,
-155 //: yadda-yadda. Instead use this macro below to perform an unsafe cast to
-156 //: signed. We'll just give up immediately if a container's ever too large.
-157 //: Basically, Mu is not concerned about this being a little slower than it
-158 //: could be. (https://gist.github.com/rygorous/e0f055bfb74e3d5f0af20690759de5a7)
-159 //:
-160 //: Addendum to corollary: We're going to uniformly use int everywhere, to
-161 //: indicate that we're oblivious to number size, and since Clang on 32-bit
-162 //: platforms doesn't yet support multiplication over 64-bit integers, and
-163 //: since multiplying two integers seems like a more common situation to end
-164 //: up in than integer overflow.
-165 :(before "End Includes")
-166 #define SIZE(X) (assert((X).size() < (1LL<<(sizeof(int)*8-2))), static_cast<int>((X).size()))
-167 
-168 //: 5. Integer overflow is guarded against at runtime using the -ftrapv flag
-169 //: to the compiler, supported by Clang (GCC version only works sometimes:
-170 //: http://stackoverflow.com/questions/20851061/how-to-make-gcc-ftrapv-work).
-171 :(before "atexit(reset)")
-172 initialize_signal_handlers();  // not always necessary, but doesn't hurt
-173 //? cerr << INT_MAX+1 << '\n';  // test overflow
-174 //? assert(false);  // test SIGABRT
-175 :(code)
-176 // based on https://spin.atomicobject.com/2013/01/13/exceptions-stack-traces-c
-177 void initialize_signal_handlers() {
-178   struct sigaction action;
-179   bzero(&action, sizeof(action));
-180   action.sa_sigaction = dump_and_exit;
-181   sigemptyset(&action.sa_mask);
-182   sigaction(SIGABRT, &action, NULL);  // assert() failure or integer overflow on linux (with -ftrapv)
-183   sigaction(SIGILL,  &action, NULL);  // integer overflow on OS X (with -ftrapv)
-184 }
-185 void dump_and_exit(int sig, siginfo_t* /*unused*/, void* /*unused*/) {
-186   switch (sig) {
-187     case SIGABRT:
-188       #ifndef __APPLE__
-189         cerr << "SIGABRT: might be an integer overflow if it wasn't an assert() failure\n";
-190         _Exit(1);
-191       #endif
-192       break;
-193     case SIGILL:
-194       #ifdef __APPLE__
-195         cerr << "SIGILL: most likely caused by integer overflow\n";
-196         _Exit(1);
-197       #endif
-198       break;
-199     default:
-200       break;
-201   }
-202 }
-203 :(before "End Includes")
-204 #include <signal.h>
-205 
-206 //: 6. Map's operator[] being non-const is fucking evil.
-207 :(before "Globals")  // can't generate prototypes for these
-208 // from http://stackoverflow.com/questions/152643/idiomatic-c-for-reading-from-a-const-map
-209 template<typename T> typename T::mapped_type& get(T& map, typename T::key_type const& key) {
-210   typename T::iterator iter(map.find(key));
-211   if (iter == map.end()) {
-212     cerr << "get couldn't find key '" << key << "'\n";
-213     assert(iter != map.end());
-214   }
-215   return iter->second;
-216 }
-217 template<typename T> typename T::mapped_type const& get(const T& map, typename T::key_type const& key) {
-218   typename T::const_iterator iter(map.find(key));
-219   if (iter == map.end()) {
-220     cerr << "get couldn't find key '" << key << "'\n";
-221     assert(iter != map.end());
-222   }
-223   return iter->second;
-224 }
-225 template<typename T> typename T::mapped_type const& put(T& map, typename T::key_type const& key, typename T::mapped_type const& value) {
-226   map[key] = value;
-227   return map[key];
-228 }
-229 template<typename T> bool contains_key(T& map, typename T::key_type const& key) {
-230   return map.find(key) != map.end();
-231 }
-232 template<typename T> typename T::mapped_type& get_or_insert(T& map, typename T::key_type const& key) {
-233   return map[key];
-234 }
-235 template<typename T> typename T::mapped_type const& put_new(T& map, typename T::key_type const& key, typename T::mapped_type const& value) {
-236   assert(map.find(key) == map.end());
-237   map[key] = value;
-238   return map[key];
-239 }
-240 //: The contract: any container that relies on get_or_insert should never call
-241 //: contains_key.
-242 
-243 //: 7. istreams are a royal pain in the arse. You have to be careful about
-244 //: what subclass you try to putback into. You have to watch out for the pesky
-245 //: failbit and badbit. Just avoid eof() and use this helper instead.
-246 :(code)
-247 bool has_data(istream& in) {
-248   return in && !in.eof();
-249 }
-250 
-251 :(before "End Includes")
-252 #include <assert.h>
-253 
-254 #include <iostream>
-255 using std::istream;
-256 using std::ostream;
-257 using std::iostream;
-258 using std::cin;
-259 using std::cout;
-260 using std::cerr;
-261 #include <iomanip>
-262 
-263 #include <string.h>
-264 #include <string>
-265 using std::string;
-266 
-267 #include <algorithm>
-268 using std::min;
-269 using std::max;
-
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