Add a Context::compile() function which runs all compiler passes.

This is the main entry point to the code generator. It returns the
computed size of the functions code.

Also add a 'test compile' command which runs the whole code generation
pipeline.

cranelift/src/filetest/compile.rs

@@ -0,0 +1,98 @@
+//! Test command for testing the code generator pipeline
+//!
+//! The `compile` test command runs each function through the full code generator pipeline
+
+use cretonne::binemit;
+use cretonne::ir;
+use cretonne;
+use cton_reader::TestCommand;
+use filetest::subtest::{SubTest, Context, Result};
+use std::borrow::Cow;
+use utils::pretty_error;
+
+struct TestCompile;
+
+pub fn subtest(parsed: &TestCommand) -> Result<Box<SubTest>> {
+    assert_eq!(parsed.command, "compile");
+    if !parsed.options.is_empty() {
+        Err(format!("No options allowed on {}", parsed))
+    } else {
+        Ok(Box::new(TestCompile))
+    }
+}
+
+impl SubTest for TestCompile {
+    fn name(&self) -> Cow<str> {
+        Cow::from("compile")
+    }
+
+    fn is_mutating(&self) -> bool {
+        true
+    }
+
+    fn needs_isa(&self) -> bool {
+        true
+    }
+
+    fn run(&self, func: Cow<ir::Function>, context: &Context) -> Result<()> {
+        let isa = context.isa.expect("compile needs an ISA");
+
+        // Create a compilation context, and drop in the function.
+        let mut comp_ctx = cretonne::Context::new();
+        comp_ctx.func = func.into_owned();
+
+        let code_size = comp_ctx
+            .compile(isa)
+            .map_err(|e| pretty_error(&comp_ctx.func, context.isa, e))?;
+
+        dbg!("Generated {} bytes of code:\n{}",
+             code_size,
+             comp_ctx.func.display(isa));
+
+        // Finally verify that the returned code size matches the emitted bytes.
+        let mut sink = SizeSink { offset: 0 };
+        for ebb in comp_ctx.func.layout.ebbs() {
+            assert_eq!(sink.offset, comp_ctx.func.offsets[ebb]);
+            for inst in comp_ctx.func.layout.ebb_insts(ebb) {
+                isa.emit_inst(&comp_ctx.func, inst, &mut sink);
+            }
+        }
+
+        if sink.offset != code_size {
+            return Err(format!("Expected code size {}, got {}", code_size, sink.offset));
+        }
+
+        Ok(())
+    }
+}
+
+// Code sink that simply counts bytes.
+struct SizeSink {
+    offset: binemit::CodeOffset,
+}
+
+impl binemit::CodeSink for SizeSink {
+    fn offset(&self) -> binemit::CodeOffset {
+        self.offset
+    }
+
+    fn put1(&mut self, _: u8) {
+        self.offset += 1;
+    }
+
+    fn put2(&mut self, _: u16) {
+        self.offset += 2;
+    }
+
+    fn put4(&mut self, _: u32) {
+        self.offset += 4;
+    }
+
+    fn put8(&mut self, _: u64) {
+        self.offset += 8;
+    }
+
+    fn reloc_ebb(&mut self, _reloc: binemit::Reloc, _ebb: ir::Ebb) {}
+    fn reloc_func(&mut self, _reloc: binemit::Reloc, _fref: ir::FuncRef) {}
+    fn reloc_jt(&mut self, _reloc: binemit::Reloc, _jt: ir::JumpTable) {}
+}