From 480054a094d0b71fb0984e7c87f97d39c55d46e7 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <jolesen@mozilla.com>
Date: Wed, 14 Sep 2016 13:14:43 -0700
Subject: [PATCH] Add a utility read_to_string() function.

---
 src/tools/cat.rs         | 11 +++--------
 src/tools/main.rs        |  1 +
 src/tools/print_cfg.rs   |  9 +++------
 src/tools/rsfilecheck.rs |  8 ++------
 src/tools/utils.rs       | 13 +++++++++++++
 5 files changed, 22 insertions(+), 20 deletions(-)
 create mode 100644 src/tools/utils.rs

diff --git a/src/tools/cat.rs b/src/tools/cat.rs
index a41b5b5f27..566997c403 100644
--- a/src/tools/cat.rs
+++ b/src/tools/cat.rs
@@ -3,11 +3,9 @@
 //! Read a sequence of Cretonne IL files and print them again to stdout. This has the effect of
 //! normalizing formatting and removing comments.
 
-use std::fs::File;
-use std::io::{self, Read};
-
+use std::io;
 use CommandResult;
-
+use utils::read_to_string;
 use cton_reader::parse_functions;
 use cretonne::write::write_function;
 
@@ -22,10 +20,7 @@ pub fn run(files: Vec<String>) -> CommandResult {
 }
 
 fn cat_one(filename: String) -> CommandResult {
-    let mut file = try!(File::open(&filename).map_err(|e| format!("{}: {}", filename, e)));
-    let mut buffer = String::new();
-    try!(file.read_to_string(&mut buffer)
-        .map_err(|e| format!("Couldn't read {}: {}", filename, e)));
+    let buffer = try!(read_to_string(&filename).map_err(|e| format!("{}: {}", filename, e)));
     let items = try!(parse_functions(&buffer).map_err(|e| format!("{}: {}", filename, e)));
 
     for (idx, func) in items.into_iter().enumerate() {
diff --git a/src/tools/main.rs b/src/tools/main.rs
index 5abfa89462..af7a092394 100644
--- a/src/tools/main.rs
+++ b/src/tools/main.rs
@@ -10,6 +10,7 @@ use docopt::Docopt;
 use std::io::{self, Write};
 use std::process;
 
+mod utils;
 mod filetest;
 mod cat;
 mod print_cfg;
diff --git a/src/tools/print_cfg.rs b/src/tools/print_cfg.rs
index 649d87fb9f..1c57710b29 100644
--- a/src/tools/print_cfg.rs
+++ b/src/tools/print_cfg.rs
@@ -2,10 +2,10 @@
 //!
 //! Read a series of Cretonne IL files and print their control flow graphs
 //! in graphviz format.
-use std::fs::File;
-use std::io::{Read, Write, stdout};
+use std::io::{Write, stdout};
 
 use CommandResult;
+use utils::read_to_string;
 use cretonne::ir::Function;
 use cretonne::cfg::ControlFlowGraph;
 use cretonne::ir::instructions::InstructionData;
@@ -156,10 +156,7 @@ impl<T: Write> CFGPrinter<T> {
 }
 
 fn print_cfg(filename: String) -> CommandResult {
-    let mut file = try!(File::open(&filename).map_err(|e| format!("{}: {}", filename, e)));
-    let mut buffer = String::new();
-    try!(file.read_to_string(&mut buffer)
-        .map_err(|e| format!("Couldn't read {}: {}", filename, e)));
+    let buffer = try!(read_to_string(&filename).map_err(|e| format!("{}: {}", filename, e)));
     let items = try!(parse_functions(&buffer).map_err(|e| format!("{}: {}", filename, e)));
 
     let mut cfg_printer = CFGPrinter::new(stdout());
diff --git a/src/tools/rsfilecheck.rs b/src/tools/rsfilecheck.rs
index b64a86283e..5ff6c596d1 100644
--- a/src/tools/rsfilecheck.rs
+++ b/src/tools/rsfilecheck.rs
@@ -1,6 +1,6 @@
 use CommandResult;
+use utils::read_to_string;
 use filecheck::{CheckerBuilder, Checker, NO_VARIABLES};
-use std::fs::File;
 use std::io::{self, Read};
 
 pub fn run(files: Vec<String>, verbose: bool) -> CommandResult {
@@ -40,11 +40,7 @@ pub fn run(files: Vec<String>, verbose: bool) -> CommandResult {
 }
 
 fn read_checkfile(filename: &str) -> Result<Checker, String> {
-    let mut file = try!(File::open(&filename).map_err(|e| format!("{}: {}", filename, e)));
-    let mut buffer = String::new();
-    try!(file.read_to_string(&mut buffer)
-        .map_err(|e| format!("Couldn't read {}: {}", filename, e)));
-
+    let buffer = try!(read_to_string(&filename).map_err(|e| format!("{}: {}", filename, e)));
     let mut builder = CheckerBuilder::new();
     try!(builder.text(&buffer).map_err(|e| format!("{}: {}", filename, e)));
     Ok(builder.finish())
diff --git a/src/tools/utils.rs b/src/tools/utils.rs
new file mode 100644
index 0000000000..5973f25814
--- /dev/null
+++ b/src/tools/utils.rs
@@ -0,0 +1,13 @@
+//! Utility functions.
+
+use std::path::Path;
+use std::fs::File;
+use std::io::{Result, Read};
+
+/// Read an entire file into a string.
+pub fn read_to_string<P: AsRef<Path>>(path: P) -> Result<String> {
+    let mut file = try!(File::open(path));
+    let mut buffer = String::new();
+    try!(file.read_to_string(&mut buffer));
+    Ok(buffer)
+}