Add structopt dependency in version 0.3.7

This patch series replaces argparse with structopt in the argument
handling code. As a first step, we need structopt as a dependency.

Import subrepo structopt/:structopt at efbdda4753592e27bc430fb01f7b9650b2f3174d
Import subrepo bitflags/:bitflags at 30668016aca6bd3b02c766e8347e0b4080d4c296
Import subrepo clap/:clap at 784524f7eb193e35f81082cc69454c8c21b948f7
Import subrepo heck/:heck at 093d56fbf001e1506e56dbfa38631d99b1066df1
Import subrepo proc-macro-error/:proc-macro-error at 6c4cfe79a622c5de8ae68557993542be46eacae2
Import subrepo proc-macro2/:proc-macro2 at d5d48eddca4566e5438e8a2cbed4a74e049544de
Import subrepo quote/:quote at 727436c6c137b20f0f34dde5d8fda2679b9747ad
Import subrepo rustversion/:rustversion at 0c5663313516263059ce9059ef81fc7a1cf655ca
Import subrepo syn-mid/:syn-mid at 5d3d85414a9e6674e1857ec22a87b96e04a6851a
Import subrepo syn/:syn at e87c27e87f6f4ef8919d0372bdb056d53ef0d8f3
Import subrepo textwrap/:textwrap at abcd618beae3f74841032aa5b53c1086b0a57ca2
Import subrepo unicode-segmentation/:unicode-segmentation at 637c9874c4fe0c205ff27787faf150a40295c6c3
Import subrepo unicode-width/:unicode-width at 3033826f8bf05e82724140a981d5941e48fce393
Import subrepo unicode-xid/:unicode-xid at 4baae9fffb156ba229665b972a9cd5991787ceb7

1 files changed, 32 insertions, 0 deletions

diff --git a/syn/codegen/src/file.rs b/syn/codegen/src/file.rs
new file mode 100644
index 0000000..5521d75
--- /dev/null
+++ b/syn/codegen/src/file.rs
@@ -0,0 +1,32 @@
+use anyhow::Result;
+use proc_macro2::TokenStream;
+use std::fs;
+use std::io::Write;
+use std::path::Path;
+
+pub fn write<P: AsRef<Path>>(path: P, content: TokenStream) -> Result<()> {
+    let mut formatted = Vec::new();
+    writeln!(
+        formatted,
+        "// This file is @generated by syn-internal-codegen."
+    )?;
+    writeln!(formatted, "// It is not intended for manual editing.")?;
+    writeln!(formatted)?;
+
+    let mut config = rustfmt::Config::default();
+    config.set().emit_mode(rustfmt::EmitMode::Stdout);
+    config.set().verbose(rustfmt::Verbosity::Quiet);
+    config.set().format_macro_matchers(true);
+    config.set().normalize_doc_attributes(true);
+
+    let mut session = rustfmt::Session::new(config, Some(&mut formatted));
+    session.format(rustfmt::Input::Text(content.to_string()))?;
+    drop(session);
+
+    if path.as_ref().is_file() && fs::read(&path)? == formatted {
+        return Ok(());
+    }
+
+    fs::write(path, formatted)?;
+    Ok(())
+}