Auto merge of #29780 - KyleMayes:quote-ext, r=nrc

This is my first code contribution to Rust, so I'm sure there are some issues with the changes I've made.

I've added the `quote_arg!`, `quote_block!`, `quote_path!`, and `quote_meta_item!` quasiquoting macros. From my experience trying to build AST in compiler plugins, I would like to be able to build any AST piece with a quasiquoting macro (e.g., `quote_struct_field!` or `quote_variant!`) and then use those AST pieces in other quasiquoting macros, but this pull request just adds some of the low-hanging fruit.

I'm not sure if these additions are desirable, and I'm sure these macros can be implemented in an external crate if not.

2 files changed, 51 insertions, 10 deletions

diff --git a/src/test/compile-fail-fulldeps/gated-quote.rs b/src/test/compile-fail-fulldeps/gated-quote.rs
index 6a5cd88a591..cd801fbcd88 100644
--- a/src/test/compile-fail-fulldeps/gated-quote.rs
+++ b/src/test/compile-fail-fulldeps/gated-quote.rs
@@ -37,14 +37,18 @@ impl ParseSess {
 
 pub fn main() {
     let ecx = &ParseSess;
-    let x = quote_tokens!(ecx, 3);   //~ ERROR macro undefined: 'quote_tokens!'
-    let x = quote_expr!(ecx, 3);     //~ ERROR macro undefined: 'quote_expr!'
-    let x = quote_ty!(ecx, 3);       //~ ERROR macro undefined: 'quote_ty!'
-    let x = quote_method!(ecx, 3);   //~ ERROR macro undefined: 'quote_method!'
-    let x = quote_item!(ecx, 3);     //~ ERROR macro undefined: 'quote_item!'
-    let x = quote_pat!(ecx, 3);      //~ ERROR macro undefined: 'quote_pat!'
-    let x = quote_arm!(ecx, 3);      //~ ERROR macro undefined: 'quote_arm!'
-    let x = quote_stmt!(ecx, 3);     //~ ERROR macro undefined: 'quote_stmt!'
-    let x = quote_matcher!(ecx, 3);  //~ ERROR macro undefined: 'quote_matcher!'
-    let x = quote_attr!(ecx, 3);     //~ ERROR macro undefined: 'quote_attr!'
+    let x = quote_tokens!(ecx, 3);    //~ ERROR macro undefined: 'quote_tokens!'
+    let x = quote_expr!(ecx, 3);      //~ ERROR macro undefined: 'quote_expr!'
+    let x = quote_ty!(ecx, 3);        //~ ERROR macro undefined: 'quote_ty!'
+    let x = quote_method!(ecx, 3);    //~ ERROR macro undefined: 'quote_method!'
+    let x = quote_item!(ecx, 3);      //~ ERROR macro undefined: 'quote_item!'
+    let x = quote_pat!(ecx, 3);       //~ ERROR macro undefined: 'quote_pat!'
+    let x = quote_arm!(ecx, 3);       //~ ERROR macro undefined: 'quote_arm!'
+    let x = quote_stmt!(ecx, 3);      //~ ERROR macro undefined: 'quote_stmt!'
+    let x = quote_matcher!(ecx, 3);   //~ ERROR macro undefined: 'quote_matcher!'
+    let x = quote_attr!(ecx, 3);      //~ ERROR macro undefined: 'quote_attr!'
+    let x = quote_arg!(ecx, 3);       //~ ERROR macro undefined: 'quote_arg!'
+    let x = quote_block!(ecx, 3);     //~ ERROR macro undefined: 'quote_block!'
+    let x = quote_meta_item!(ecx, 3); //~ ERROR macro undefined: 'quote_meta_item!'
+    let x = quote_path!(ecx, 3);      //~ ERROR macro undefined: 'quote_path!'
 }
diff --git a/src/test/run-pass-fulldeps/qquote.rs b/src/test/run-pass-fulldeps/qquote.rs
index ba713bb98f8..edaa88452c4 100644
--- a/src/test/run-pass-fulldeps/qquote.rs
+++ b/src/test/run-pass-fulldeps/qquote.rs
@@ -63,4 +63,41 @@ fn main() {
 
     let attr = quote_attr!(cx, #![cfg(foo = "bar")]);
     check!(attribute_to_string, attr, quote_attr!(cx, $attr); r#"#![cfg(foo = "bar")]"#);
+
+    // quote_arg!
+
+    let arg = quote_arg!(cx, foo: i32);
+    check!(arg_to_string, arg, quote_arg!(cx, $arg); "foo: i32");
+
+    let function = quote_item!(cx, fn f($arg) { }).unwrap();
+    check!(item_to_string, function; "fn f(foo: i32) { }");
+
+    let args = vec![arg, quote_arg!(cx, bar: u32)];
+    let args = &args[..];
+    let function = quote_item!(cx, fn f($args) { }).unwrap();
+    check!(item_to_string, function; "fn f(foo: i32, bar: u32) { }");
+
+    // quote_block!
+
+    let block = quote_block!(cx, { $stmt let y = 40u32; });
+    check!(block_to_string, block, *quote_block!(cx, $block); "{ let x = 20u16; let y = 40u32; }");
+
+    let function = quote_item!(cx, fn f() $block).unwrap();
+    check!(item_to_string, function; "fn f() { let x = 20u16; let y = 40u32; }");
+
+    // quote_path!
+
+    let path = quote_path!(cx, ::syntax::ptr::P<MetaItem>);
+    check!(path_to_string, path, quote_path!(cx, $path); "::syntax::ptr::P<MetaItem>");
+
+    let ty = quote_ty!(cx, $path);
+    check!(ty_to_string, ty; "::syntax::ptr::P<MetaItem>");
+
+    // quote_meta_item!
+
+    let meta = quote_meta_item!(cx, cfg(foo = "bar"));
+    check!(meta_item_to_string, meta, *quote_meta_item!(cx, $meta); r#"cfg(foo = "bar")"#);
+
+    let attr = quote_attr!(cx, #![$meta]);
+    check!(attribute_to_string, attr; r#"#![cfg(foo = "bar")]"#);
 }