Run the filetests as part of "cargo test".

Refactor the filetests harness so that it can be run as part of
`cargo test`. And begin reorganizing the test harness code in preparation
for moving it out of the src directory.
 - Test subcommand files are now named `test_*.rs`.
 - cton-util subcommand files now just export their `run` and nothing else.
 - src/filetest/mod.rs now also just exports `run` and nothing else.
 - Tests are now run in release mode (with debug assertions enabled).

cranelift/src/print_cfg.rs

@@ -3,15 +3,9 @@
 //! Read a series of Cretonne IL files and print their control flow graphs
 //! in graphviz format.
 
-use std::borrow::Cow;
-use std::fmt::{Result, Write, Display, Formatter};
-
 use CommandResult;
-use cretonne::flowgraph::ControlFlowGraph;
-use cretonne::ir::Function;
-use cretonne::ir::instructions::BranchInfo;
-use cton_reader::{parse_functions, TestCommand};
-use filetest::subtest::{self, SubTest, Context, Result as STResult};
+use cretonne::cfg_printer::CFGPrinter;
+use cton_reader::parse_functions;
 use utils::read_to_string;
 
 pub fn run(files: Vec<String>) -> CommandResult {
@@ -24,72 +18,6 @@ pub fn run(files: Vec<String>) -> CommandResult {
     Ok(())
 }
 
-struct CFGPrinter<'a> {
-    func: &'a Function,
-    cfg: ControlFlowGraph,
-}
-
-impl<'a> CFGPrinter<'a> {
-    pub fn new(func: &'a Function) -> CFGPrinter<'a> {
-        CFGPrinter {
-            func,
-            cfg: ControlFlowGraph::with_function(func),
-        }
-    }
-
-    /// Write the CFG for this function to `w`.
-    pub fn write(&self, w: &mut Write) -> Result {
-        self.header(w)?;
-        self.ebb_nodes(w)?;
-        self.cfg_connections(w)?;
-        writeln!(w, "}}")
-    }
-
-    fn header(&self, w: &mut Write) -> Result {
-        writeln!(w, "digraph \"{}\" {{", self.func.name)?;
-        if let Some(entry) = self.func.layout.entry_block() {
-            writeln!(w, "    {{rank=min; {}}}", entry)?;
-        }
-        Ok(())
-    }
-
-    fn ebb_nodes(&self, w: &mut Write) -> Result {
-        for ebb in &self.func.layout {
-            write!(w, "    {} [shape=record, label=\"{{{}", ebb, ebb)?;
-            // Add all outgoing branch instructions to the label.
-            for inst in self.func.layout.ebb_insts(ebb) {
-                let idata = &self.func.dfg[inst];
-                match idata.analyze_branch(&self.func.dfg.value_lists) {
-                    BranchInfo::SingleDest(dest, _) => {
-                        write!(w, " | <{}>{} {}", inst, idata.opcode(), dest)?
-                    }
-                    BranchInfo::Table(table) => {
-                        write!(w, " | <{}>{} {}", inst, idata.opcode(), table)?
-                    }
-                    BranchInfo::NotABranch => {}
-                }
-            }
-            writeln!(w, "}}\"]")?
-        }
-        Ok(())
-    }
-
-    fn cfg_connections(&self, w: &mut Write) -> Result {
-        for ebb in &self.func.layout {
-            for (parent, inst) in self.cfg.pred_iter(ebb) {
-                writeln!(w, "    {}:{} -> {}", parent, inst, ebb)?;
-            }
-        }
-        Ok(())
-    }
-}
-
-impl<'a> Display for CFGPrinter<'a> {
-    fn fmt(&self, f: &mut Formatter) -> Result {
-        self.write(f)
-    }
-}
-
 fn print_cfg(filename: String) -> CommandResult {
     let buffer = read_to_string(&filename).map_err(
         |e| format!("{}: {}", filename, e),
@@ -107,29 +35,3 @@ fn print_cfg(filename: String) -> CommandResult {
 
     Ok(())
 }
-
-/// Object implementing the `test print-cfg` sub-test.
-struct TestPrintCfg;
-
-pub fn subtest(parsed: &TestCommand) -> STResult<Box<SubTest>> {
-    assert_eq!(parsed.command, "print-cfg");
-    if !parsed.options.is_empty() {
-        Err(format!("No options allowed on {}", parsed))
-    } else {
-        Ok(Box::new(TestPrintCfg))
-    }
-}
-
-impl SubTest for TestPrintCfg {
-    fn name(&self) -> Cow<str> {
-        Cow::from("print-cfg")
-    }
-
-    fn needs_verifier(&self) -> bool {
-        false
-    }
-
-    fn run(&self, func: Cow<Function>, context: &Context) -> STResult<()> {
-        subtest::run_filecheck(&CFGPrinter::new(&func).to_string(), context)
-    }
-}