fuzzer.rs is now a pseudo-fuzzer that takes an AST and replaces expressions inside it

Author: jruderman

src/fuzzer/fuzzer.rs

@@ -7,28 +7,127 @@ import std::getopts::optopt;
 import std::getopts::opt_present;
 import std::getopts::opt_str;
 import std::io;
+import std::io::stdout;
 import std::vec;
 import std::ivec;
 import std::str;
+import std::uint;
 
-import rustc::back::link;
 import rustc::syntax::ast;
+import rustc::syntax::fold;
+import rustc::syntax::walk;
+import rustc::syntax::codemap;
+import rustc::syntax::print::pprust;
+
 import driver = rustc::driver::rustc; // see https://github.com/graydon/rust/issues/624
+import rustc::back::link;
+import rustc::driver::rustc::time;
 import rustc::driver::session;
 
+/*
+// Imports for "the rest of driver::compile_input"
+import rustc::metadata::creader;
+import rustc::metadata::cstore;
+import rustc::syntax::parse::parser;
+import rustc::syntax::parse::token;
+import rustc::front;
+import rustc::front::attr;
+import rustc::middle;
+import rustc::middle::trans;
+import rustc::middle::resolve;
+import rustc::middle::ty;
+import rustc::middle::typeck;
+import rustc::middle::tstate::ck;
+import rustc::syntax::print::pp;
+import rustc::util::ppaux;
+import rustc::lib::llvm;
+*/
 
-fn find_rust_files(&mutable str[] files, str root) {
-    for (str filename in fs::list_dir(root)) {
-        if (str::ends_with(filename, ".rs")) {
-           files += ~[filename];
+fn file_contains(&str filename, &str needle) -> bool {
+    auto r = io::file_reader(filename);
+    auto contents = str::unsafe_from_bytes(r.read_whole_stream());
+    ret str::find(contents, needle) != -1;
+}
+
+fn find_rust_files(&mutable str[] files, str path) {
+    if (str::ends_with(path, ".rs")) {
+        if (file_contains(path, "xfail-stage1")) {
+            //log_err "Skipping " + path + " because it is marked as xfail-stage1";
+        } else if (
+            !str::ends_with(path, "constrained-type.rs") &&     // https://github.com/graydon/rust/issues/653
+             str::find(path, "utf8") != -1 &&  // https://github.com/graydon/rust/issues/654
+             true) {
+            //log_err "Skipping " + path + " because of a known bug";
+        } else {
+            files += ~[path];
+        }
+    } else if (fs::file_is_dir(path) && str::find(path, "compile-fail") == -1) {
+        for (str p in fs::list_dir(path)) {
+            find_rust_files(files, p);
+        }
+    }
+}
+
+fn steal_exprs(&ast::crate crate) -> ast::expr[] {
+    let @mutable ast::expr[] exprs = @mutable ~[];
+    // "Stash" cannot be type-parameterized because of https://github.com/graydon/rust/issues/375
+    fn stash_expr(@mutable ast::expr[] es, &@ast::expr e) { *es += ~[*e]; }
+    auto v = rec(visit_expr_pre = bind stash_expr(exprs, _) with walk::default_visitor());
+    walk::walk_crate(v, crate);
+    *exprs
+}
+
+// https://github.com/graydon/rust/issues/652
+fn safe_to_replace(ast::expr_ e) -> bool {
+    alt (e) {
+        case (ast::expr_if(_, _, _)) { false }
+        case (ast::expr_block(_)) { false }
+        case (_) { true }
+    }
+}
+
+// Replace the |i|th expr (in fold order) of |crate| with |newexpr|.
+fn replace_expr_in_crate(&ast::crate crate, uint i, ast::expr_ newexpr) -> ast::crate {
+    let @mutable uint j = @mutable 0u;
+    fn fold_expr_rep(@mutable uint j_, uint i_, &ast::expr_ newexpr_, &ast::expr_ original, fold::ast_fold fld) -> ast::expr_ {
+      *j_ += 1u;
+      if (i_ + 1u == *j_ && safe_to_replace(original)) {
+        newexpr_
+      } else {
+        fold::noop_fold_expr(original, fld)
+      }
+    }
+    auto afp = rec(fold_expr = bind fold_expr_rep(j, i, newexpr, _, _) with *fold::default_ast_fold());
+    auto af = fold::make_fold(afp);
+    let @ast::crate crate2 = @af.fold_crate(crate);
+    fold::dummy_out(af); // work around a leak (https://github.com/graydon/rust/issues/651)
+    *crate2
+}
+
+iter under(uint n) -> uint { let uint i = 0u; while (i < n) { put i; i += 1u; } }
+
+fn devnull() -> io::writer { std::io::string_writer().get_writer() }
+
+fn pp_variants(&ast::crate crate, &session::session sess, &str filename) {
+    auto exprs = steal_exprs(crate);
+    auto exprsL = ivec::len(exprs);
+    if (exprsL < 100u) {
+        for each (uint i in under(uint::min(exprsL, 20u))) {
+            log_err "Replacing... " + pprust::expr_to_str(@exprs.(i));
+            for each (uint j in under(uint::min(exprsL, 5u))) {
+                log_err "With... " + pprust::expr_to_str(@exprs.(j));
+                auto crate2 = @replace_expr_in_crate(crate, i, exprs.(j).node);
+                pprust::print_crate(sess.get_codemap(), crate2, filename, devnull(), pprust::no_ann());
+            }
         }
     }
 }
 
 fn main(vec[str] args) {
     auto files = ~[];
-    auto root = "/Users/jruderman/code/rust/src/lib/"; // XXX
-    find_rust_files(files, root); // not using driver::time here because that currently screws with passing-a-mutable-array
+    auto root = "/Users/jruderman/code/rust/src/"; // XXX
+    find_rust_files(files, root); // not using time here because that currently screws with passing-a-mutable-array
+    log_err uint::str(ivec::len(files)) + " files";
 
     auto binary = vec::shift[str](args);
     auto binary_dir = fs::dirname(binary);
@@ -50,14 +149,12 @@ fn main(vec[str] args) {
              cfg=~[],
              test=false);
 
-    let session::session sess = driver::build_session(sopts);
-
-    log_err ivec::len(files);
     for (str file in files) {
-        log_err file;
-        // Can't use parse_input here because of https://github.com/graydon/rust/issues/632 :(
-        //auto crate = driver::parse_input(sess, ~[], file);
-        //let @ast::crate crate = driver::time(true, "parsing " + file, bind driver::parse_input(sess, ~[], file));
+        log_err "=== " + file + " ===";
+        let session::session sess = driver::build_session(sopts);
+        let @ast::crate crate = time(true, "parsing " + file, bind driver::parse_input(sess, ~[], file));
+        pprust::print_crate(sess.get_codemap(), crate, file, devnull(), pprust::no_ann());
+        pp_variants(*crate, sess, file);
     }
 }