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Diffstat (limited to 'cpp/003trace.cc')
| -rw-r--r-- | cpp/003trace.cc | 478 |
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diff --git a/cpp/003trace.cc b/cpp/003trace.cc deleted file mode 100644 index 77d51fc4..00000000 --- a/cpp/003trace.cc +++ /dev/null @@ -1,478 +0,0 @@ -//: The goal of this skeleton is to make programs more easy to understand and -//: more malleable, easy to rewrite in radical ways without accidentally -//: breaking some corner case. Tests further both goals. They help -//: understandability by letting one make small changes and get feedback. What -//: if I wrote this line like so? What if I removed this function call, is it -//: really necessary? Just try it, see if the tests pass. Want to explore -//: rewriting this bit in this way? Tests put many refactorings on a firmer -//: footing. -//: -//: But the usual way we write tests seems incomplete. Refactorings tend to -//: work in the small, but don't help with changes to function boundaries. If -//: you want to extract a new function you have to manually test-drive it to -//: create tests for it. If you want to inline a function its tests are no -//: longer valid. In both cases you end up having to reorganize code as well as -//: tests, an error-prone activity. -//: -//: This file tries to fix this problem by supporting domain-driven testing -//: We try to focus on the domain of inputs the program should work on. All -//: tests invoke the program in a single way: by calling run() with different -//: inputs. The program operates on the input and logs _facts_ it deduces to a -//: trace: -//: trace("label") << "fact 1: " << val; -//: -//: The tests check for facts: -//: :(scenario foo) -//: 34 # call run() with this input -//: +label: fact 1: 34 # trace should have logged this at the end -//: -label: fact 1: 35 # trace should never contain such a line -//: -//: Since we never call anything but the run() function directly, we never have -//: to rewrite the tests when we reorganize the internals of the program. We -//: just have to make sure our rewrite deduces the same facts about the domain, -//: and that's something we're going to have to do anyway. -//: -//: To avoid the combinatorial explosion of integration tests, we organize the -//: program into different layers, and each fact is logged to the trace with a -//: specific label. Individual tests can focus on specific labels. In essence, -//: validating the facts logged with a specific label is identical to calling -//: some internal subsystem. -//: -//: Traces interact salubriously with layers. Thanks to our ordering -//: directives, each layer can contain its own tests. They may rely on other -//: layers, but when a test fails its usually due to breakage in the same -//: layer. When multiple tests fail, it's usually useful to debug the very -//: first test to fail. This is in contrast with the traditional approach, -//: where changes can cause breakages in faraway subsystems, and picking the -//: right test to debug can be an important skill to pick up. -//: -//: A final wrinkle is for recursive functions; it's often useful to segment -//: calls of different depth in the trace: -//: +eval/1: => 34 # the topmost call to eval should have logged this line -//: (look at new_trace_frame below) -//: -//: To build robust tests, trace facts about your domain rather than details of -//: how you computed them. -//: -//: More details: http://akkartik.name/blog/tracing-tests -//: -//: --- -//: -//: Between layers and domain-driven testing, programming starts to look like a -//: fundamentally different activity. Instead of a) superficial, b) local rules -//: on c) code [like http://blog.bbv.ch/2013/06/05/clean-code-cheat-sheet], -//: we allow programmers to engage with the a) deep, b) global structure of the -//: c) domain. If you can systematically track discontinuities in the domain -//: you don't care if the code used gotos as long as it passed the tests. If -//: tests become more robust to run it becomes easier to try out radically -//: different implementations for the same program. If code is super-easy to -//: rewrite, it becomes less important what indentation style it uses, or that -//: the objects are appropriately encapsulated, or that the functions are -//: referentially transparent. -//: -//: Instead of plumbing, programming becomes building and gradually refining a -//: map of the environment the program must operate under. Whether a program is -//: 'correct' at a given point in time is a red herring; what matters is -//: avoiding regression by monotonically nailing down the more 'eventful' parts -//: of the terrain. It helps readers new and old and rewards curiosity to -//: organize large programs in self-similar hiearchies of example scenarios -//: colocated with the code that makes them work. -//: -//: "Programming properly should be regarded as an activity by which -//: programmers form a mental model, rather than as production of a program." -//: -- Peter Naur (http://alistair.cockburn.us/ASD+book+extract%3A+%22Naur,+Ehn,+Musashi%22) - -:(before "int main") -// End Tracing // hack to ensure most code in this layer comes before anything else - -:(before "End Tracing") -bool Hide_warnings = false; -:(before "End Setup") -//? cerr << "AAA setup\n"; //? 2 -Hide_warnings = false; - -:(before "End Tracing") -struct trace_stream { - vector<pair<string, pair<int, string> > > past_lines; // [(layer label, frame, line)] - map<string, int> frame; - // accumulator for current line - ostringstream* curr_stream; - string curr_layer; - string dump_layer; - trace_stream() :curr_stream(NULL) {} - ~trace_stream() { if (curr_stream) delete curr_stream; } - - ostringstream& stream(string layer) { - newline(); - curr_stream = new ostringstream; - curr_layer = layer; - return *curr_stream; - } - - // be sure to call this before messing with curr_stream or curr_layer or frame - void newline() { - if (!curr_stream) return; - string curr_contents = curr_stream->str(); - curr_contents.erase(curr_contents.find_last_not_of("\r\n")+1); - past_lines.push_back(pair<string, pair<int, string> >(curr_layer, pair<int, string>(frame[curr_layer], curr_contents))); - if (curr_layer == dump_layer || curr_layer == "dump" || dump_layer == "all" || - (!Hide_warnings && curr_layer == "warn")) - cerr << curr_layer << '/' << frame[curr_layer] << ": " << curr_contents << '\n'; - delete curr_stream; - curr_stream = NULL; - } - - // Useful for debugging. - string readable_contents(string layer) { // missing layer = everything, frame, hierarchical layers - newline(); - ostringstream output; - string real_layer, frame; - parse_layer_and_frame(layer, &real_layer, &frame); - for (vector<pair<string, pair<int, string> > >::iterator p = past_lines.begin(); p != past_lines.end(); ++p) - if (layer.empty() || prefix_match(real_layer, p->first)) - output << p->first << "/" << p->second.first << ": " << p->second.second << '\n'; - return output.str(); - } - - // Useful for a newcomer to visualize the program at work. - void dump_browseable_contents(string layer) { - ofstream dump("dump"); - dump << "<div class='frame' frame_index='1'>start</div>\n"; - for (vector<pair<string, pair<int, string> > >::iterator p = past_lines.begin(); p != past_lines.end(); ++p) { - if (p->first != layer) continue; - dump << "<div class='frame"; - if (p->second.first > 1) dump << " hidden"; - dump << "' frame_index='" << p->second.first << "'>"; - dump << p->second.second; - dump << "</div>\n"; - } - dump.close(); - } -}; - - - -trace_stream* Trace_stream = NULL; - -// Top-level helper. IMPORTANT: can't nest. -#define trace(layer) !Trace_stream ? cerr /*print nothing*/ : Trace_stream->stream(layer) -// Warnings should go straight to cerr by default since calls to trace() have -// some unfriendly constraints (they delay printing, they can't nest) -#define raise ((!Trace_stream || !Hide_warnings) ? cerr /*do print*/ : Trace_stream->stream("warn")) - -// A separate helper for debugging. We should only trace domain-specific -// facts. For everything else use log. -#define xlog if (false) log -// To turn on logging replace 'xlog' with 'log'. -#define log cerr - -:(before "End Types") -// raise << die exits after printing -- unless Hide_warnings is set. -struct die {}; -:(before "End Tracing") -ostream& operator<<(ostream& os, unused die) { - if (Hide_warnings) return os; - os << "dying"; - if (Trace_stream) Trace_stream->newline(); - exit(1); -} - -#define CLEAR_TRACE delete Trace_stream, Trace_stream = new trace_stream; - -#define DUMP(layer) if (Trace_stream) cerr << Trace_stream->readable_contents(layer); - -// Trace_stream is a resource, lease_tracer uses RAII to manage it. -string Trace_file; -static string Trace_dir = ".traces/"; -struct lease_tracer { - lease_tracer() { Trace_stream = new trace_stream; } - ~lease_tracer() { -//? cerr << "write to file? " << Trace_file << "$\n"; //? 2 - if (!Trace_file.empty()) { -//? cerr << "writing\n"; //? 2 - ofstream fout((Trace_dir+Trace_file).c_str()); - fout << Trace_stream->readable_contents(""); - fout.close(); - } - delete Trace_stream, Trace_stream = NULL, Trace_file = ""; - } -}; - -// To transparently save traces, start tests with the TEST() macro. -#define TEST(name) void test_##name() { Trace_file = #name; - -#define START_TRACING_UNTIL_END_OF_SCOPE lease_tracer leased_tracer; -:(before "End Test Setup") -START_TRACING_UNTIL_END_OF_SCOPE -//? Trace_stream->dump_layer = "all"; //? 1 - -:(before "End Tracing") -void trace_all(const string& label, const list<string>& in) { - for (list<string>::const_iterator p = in.begin(); p != in.end(); ++p) - trace(label) << *p; -} - -bool check_trace_contents(string FUNCTION, string FILE, int LINE, string expected) { // missing layer == anywhere, frame, hierarchical layers - vector<string> expected_lines = split(expected, ""); - index_t curr_expected_line = 0; - while (curr_expected_line < expected_lines.size() && expected_lines[curr_expected_line].empty()) - ++curr_expected_line; - if (curr_expected_line == expected_lines.size()) return true; - Trace_stream->newline(); - string layer, frame, contents; - parse_layer_frame_contents(expected_lines[curr_expected_line], &layer, &frame, &contents); - for (vector<pair<string, pair<int, string> > >::iterator p = Trace_stream->past_lines.begin(); p != Trace_stream->past_lines.end(); ++p) { - if (!layer.empty() && !prefix_match(layer, p->first)) - continue; - - if (!frame.empty() && strtol(frame.c_str(), NULL, 0) != p->second.first) - continue; - - if (contents != p->second.second) - continue; - - ++curr_expected_line; - while (curr_expected_line < expected_lines.size() && expected_lines[curr_expected_line].empty()) - ++curr_expected_line; - if (curr_expected_line == expected_lines.size()) return true; - parse_layer_frame_contents(expected_lines[curr_expected_line], &layer, &frame, &contents); - } - - ++Num_failures; - cerr << "\nF " << FUNCTION << "(" << FILE << ":" << LINE << "): missing [" << contents << "] in trace:\n"; - DUMP(layer); - Passed = false; - return false; -} - -void parse_layer_frame_contents(const string& orig, string* layer, string* frame, string* contents) { - string layer_and_frame; - parse_contents(orig, ": ", &layer_and_frame, contents); - parse_layer_and_frame(layer_and_frame, layer, frame); -} - -void parse_contents(const string& s, const string& delim, string* prefix, string* contents) { - index_t pos = s.find(delim); - if (pos == NOT_FOUND) { - *prefix = ""; - *contents = s; - } - else { - *prefix = s.substr(0, pos); - *contents = s.substr(pos+delim.size()); - } -} - -void parse_layer_and_frame(const string& orig, string* layer, string* frame) { - index_t last_slash = orig.rfind('/'); - if (last_slash == NOT_FOUND - || orig.find_last_not_of("0123456789") != last_slash) { - *layer = orig; - *frame = ""; - } - else { - *layer = orig.substr(0, last_slash); - *frame = orig.substr(last_slash+1); - } -} - - - -bool check_trace_contents(string FUNCTION, string FILE, int LINE, string layer, string expected) { // empty layer == everything, multiple layers, hierarchical layers - vector<string> expected_lines = split(expected, ""); - index_t curr_expected_line = 0; - while (curr_expected_line < expected_lines.size() && expected_lines[curr_expected_line].empty()) - ++curr_expected_line; - if (curr_expected_line == expected_lines.size()) return true; - Trace_stream->newline(); - vector<string> layers = split(layer, ","); - for (vector<pair<string, pair<int, string> > >::iterator p = Trace_stream->past_lines.begin(); p != Trace_stream->past_lines.end(); ++p) { - if (!layer.empty() && !any_prefix_match(layers, p->first)) - continue; - if (p->second.second != expected_lines[curr_expected_line]) - continue; - ++curr_expected_line; - while (curr_expected_line < expected_lines.size() && expected_lines[curr_expected_line].empty()) - ++curr_expected_line; - if (curr_expected_line == expected_lines.size()) return true; - } - - ++Num_failures; - cerr << "\nF " << FUNCTION << "(" << FILE << ":" << LINE << "): missing [" << expected_lines[curr_expected_line] << "] in trace:\n"; - DUMP(layer); - Passed = false; - return false; -} - -#define CHECK_TRACE_CONTENTS(...) check_trace_contents(__FUNCTION__, __FILE__, __LINE__, __VA_ARGS__) - -int trace_count(string layer) { - return trace_count(layer, ""); -} - -int trace_count(string layer, string line) { - Trace_stream->newline(); - long result = 0; - vector<string> layers = split(layer, ","); - for (vector<pair<string, pair<int, string> > >::iterator p = Trace_stream->past_lines.begin(); p != Trace_stream->past_lines.end(); ++p) { - if (any_prefix_match(layers, p->first)) - if (line == "" || p->second.second == line) - ++result; - } - return result; -} - -int trace_count(string layer, int frame, string line) { - Trace_stream->newline(); - long result = 0; - vector<string> layers = split(layer, ","); - for (vector<pair<string, pair<int, string> > >::iterator p = Trace_stream->past_lines.begin(); p != Trace_stream->past_lines.end(); ++p) { - if (any_prefix_match(layers, p->first) && p->second.first == frame) - if (line == "" || p->second.second == line) - ++result; - } - return result; -} - -#define CHECK_TRACE_WARNS() CHECK(trace_count("warn") > 0) -#define CHECK_TRACE_DOESNT_WARN() \ - if (trace_count("warn") > 0) { \ - ++Num_failures; \ - cerr << "\nF " << __FUNCTION__ << "(" << __FILE__ << ":" << __LINE__ << "): unexpected warnings\n"; \ - DUMP("warn"); \ - Passed = false; \ - return; \ - } - -bool trace_doesnt_contain(string layer, string line) { - return trace_count(layer, line) == 0; -} - -bool trace_doesnt_contain(string expected) { - vector<string> tmp = split(expected, ": "); - return trace_doesnt_contain(tmp[0], tmp[1]); -} - -bool trace_doesnt_contain(string layer, int frame, string line) { - return trace_count(layer, frame, line) == 0; -} - -#define CHECK_TRACE_DOESNT_CONTAIN(...) CHECK(trace_doesnt_contain(__VA_ARGS__)) - - - -// manage layer counts in Trace_stream using RAII -struct lease_trace_frame { - string layer; - lease_trace_frame(string l) :layer(l) { - if (!Trace_stream) return; - Trace_stream->newline(); - ++Trace_stream->frame[layer]; - } - ~lease_trace_frame() { - if (!Trace_stream) return; - Trace_stream->newline(); - --Trace_stream->frame[layer]; - } -}; -#define new_trace_frame(layer) lease_trace_frame leased_frame(layer); - -bool check_trace_contents(string FUNCTION, string FILE, int LINE, string layer, int frame, string expected) { // multiple layers, hierarchical layers - vector<string> expected_lines = split(expected, ""); // hack: doesn't handle newlines in embedded in lines - index_t curr_expected_line = 0; - while (curr_expected_line < expected_lines.size() && expected_lines[curr_expected_line].empty()) - ++curr_expected_line; - if (curr_expected_line == expected_lines.size()) return true; - Trace_stream->newline(); - vector<string> layers = split(layer, ","); - for (vector<pair<string, pair<int, string> > >::iterator p = Trace_stream->past_lines.begin(); p != Trace_stream->past_lines.end(); ++p) { - if (!layer.empty() && !any_prefix_match(layers, p->first)) - continue; - if (p->second.first != frame) - continue; - if (p->second.second != expected_lines[curr_expected_line]) - continue; - ++curr_expected_line; - while (curr_expected_line < expected_lines.size() && expected_lines[curr_expected_line].empty()) - ++curr_expected_line; - if (curr_expected_line == expected_lines.size()) return true; - } - - ++Num_failures; - cerr << "\nF " << FUNCTION << "(" << FILE << ":" << LINE << "): missing [" << expected_lines[curr_expected_line] << "] in trace/" << frame << ":\n"; - DUMP(layer); - Passed = false; - return false; -} - -#define CHECK_TRACE_TOP(layer, expected) CHECK_TRACE_CONTENTS(layer, 1, expected) - - - -vector<string> split(string s, string delim) { - vector<string> result; - index_t begin=0, end=s.find(delim); - while (true) { - if (end == NOT_FOUND) { - result.push_back(string(s, begin, NOT_FOUND)); - break; - } - result.push_back(string(s, begin, end-begin)); - begin = end+delim.size(); - end = s.find(delim, begin); - } - return result; -} - -bool any_prefix_match(const vector<string>& pats, const string& needle) { - if (pats.empty()) return false; - if (*pats[0].rbegin() != '/') - // prefix match not requested - return find(pats.begin(), pats.end(), needle) != pats.end(); - // first pat ends in a '/'; assume all pats do. - for (vector<string>::const_iterator p = pats.begin(); p != pats.end(); ++p) - if (headmatch(needle, *p)) return true; - return false; -} - -bool prefix_match(const string& pat, const string& needle) { - if (*pat.rbegin() != '/') - // prefix match not requested - return pat == needle; - return headmatch(needle, pat); -} - -bool headmatch(const string& s, const string& pat) { - if (pat.size() > s.size()) return false; - return std::mismatch(pat.begin(), pat.end(), s.begin()).first == pat.end(); -} - -:(before "End Includes") -#include<vector> -using std::vector; -#include<list> -using std::list; -#include<utility> -using std::pair; -#include<map> -using std::map; -#include<set> -using std::set; -#include<algorithm> - -#include<iostream> -using std::istream; -using std::ostream; -using std::cin; -using std::cout; -using std::cerr; - -#include<sstream> -using std::istringstream; -using std::ostringstream; - -#include<fstream> -using std::ifstream; -using std::ofstream; - -#define unused __attribute__((unused)) |