Point at macro definition when no rules expect token

rust-lang · Oct 24, 2018 · 8227a93 · 8227a93
1 parent a66dc8a
commit 8227a93
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Showing 21 changed files with 256 additions and 82 deletions.
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
@@ -247,8 +247,13 @@ impl<F> AttrProcMacro for F
 
 /// Represents a thing that maps token trees to Macro Results
 pub trait TTMacroExpander {
-    fn expand<'cx>(&self, ecx: &'cx mut ExtCtxt, span: Span, input: TokenStream)
-                   -> Box<dyn MacResult+'cx>;
+    fn expand<'cx>(
+        &self,
+        ecx: &'cx mut ExtCtxt,
+        span: Span,
+        input: TokenStream,
+        def_span: Option<Span>,
+    ) -> Box<dyn MacResult+'cx>;
 }
 
 pub type MacroExpanderFn =
@@ -259,8 +264,13 @@ impl<F> TTMacroExpander for F
     where F: for<'cx> Fn(&'cx mut ExtCtxt, Span, &[tokenstream::TokenTree])
     -> Box<dyn MacResult+'cx>
 {
-    fn expand<'cx>(&self, ecx: &'cx mut ExtCtxt, span: Span, input: TokenStream)
-                   -> Box<dyn MacResult+'cx> {
+    fn expand<'cx>(
+        &self,
+        ecx: &'cx mut ExtCtxt,
+        span: Span,
+        input: TokenStream,
+        _def_span: Option<Span>,
+    ) -> Box<dyn MacResult+'cx> {
         struct AvoidInterpolatedIdents;
 
         impl Folder for AvoidInterpolatedIdents {

diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
@@ -764,7 +764,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                                                                     edition) {
                     dummy_span
                 } else {
-                    kind.make_from(expander.expand(self.cx, span, mac.node.stream()))
+                    kind.make_from(expander.expand(self.cx, span, mac.node.stream(), None))
                 }
             }
 
@@ -785,7 +785,12 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                                                                     edition) {
                     dummy_span
                 } else {
-                    kind.make_from(expander.expand(self.cx, span, mac.node.stream()))
+                    kind.make_from(expander.expand(
+                        self.cx,
+                        span,
+                        mac.node.stream(),
+                        def_info.map(|(_, s)| s),
+                    ))
                 }
             }
 

diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
@@ -74,16 +74,19 @@ struct MacroRulesMacroExpander {
 }
 
 impl TTMacroExpander for MacroRulesMacroExpander {
-    fn expand<'cx>(&self,
-                   cx: &'cx mut ExtCtxt,
-                   sp: Span,
-                   input: TokenStream)
-                   -> Box<dyn MacResult+'cx> {
+    fn expand<'cx>(
+        &self,
+        cx: &'cx mut ExtCtxt,
+        sp: Span,
+        input: TokenStream,
+        def_span: Option<Span>,
+    ) -> Box<dyn MacResult+'cx> {
         if !self.valid {
             return DummyResult::any(sp);
         }
         generic_extension(cx,
                           sp,
+                          def_span,
                           self.name,
                           input,
                           &self.lhses,
@@ -99,6 +102,7 @@ fn trace_macros_note(cx: &mut ExtCtxt, sp: Span, message: String) {
 /// Given `lhses` and `rhses`, this is the new macro we create
 fn generic_extension<'cx>(cx: &'cx mut ExtCtxt,
                           sp: Span,
+                          def_span: Option<Span>,
                           name: ast::Ident,
                           arg: TokenStream,
                           lhses: &[quoted::TokenTree],
@@ -178,7 +182,14 @@ fn generic_extension<'cx>(cx: &'cx mut ExtCtxt,
     }
 
     let best_fail_msg = parse_failure_msg(best_fail_tok.expect("ran no matchers"));
-    let mut err = cx.struct_span_err(best_fail_spot.substitute_dummy(sp), &best_fail_msg);
+    let span = best_fail_spot.substitute_dummy(sp);
+    let mut err = cx.struct_span_err(span, &best_fail_msg);
+    err.span_label(span, best_fail_msg);
+    if let Some(sp) = def_span {
+        if cx.source_map().span_to_filename(sp).is_real() && !sp.is_dummy() {
+            err.span_label(sp, "when calling this macro");
+        }
+    }
 
     // Check whether there's a missing comma in this macro call, like `println!("{}" a);`
     if let Some((arg, comma_span)) = arg.add_comma() {
@@ -189,7 +200,7 @@ fn generic_extension<'cx>(cx: &'cx mut ExtCtxt,
             };
             match TokenTree::parse(cx, lhs_tt, arg.clone()) {
                 Success(_) => {
-                    if comma_span == DUMMY_SP {
+                    if comma_span.is_dummy() {
                         err.note("you might be missing a comma");
                     } else {
                         err.span_suggestion_short_with_applicability(

diff --git a/src/test/run-pass-fulldeps/auxiliary/plugin_args.rs b/src/test/run-pass-fulldeps/auxiliary/plugin_args.rs
@@ -38,7 +38,8 @@ impl TTMacroExpander for Expander {
     fn expand<'cx>(&self,
                    ecx: &'cx mut ExtCtxt,
                    sp: Span,
-                   _: TokenStream) -> Box<MacResult+'cx> {
+                   _: TokenStream,
+                   _: Option<Span>) -> Box<MacResult+'cx> {
         let args = self.args.iter().map(|i| pprust::meta_list_item_to_string(i))
             .collect::<Vec<_>>().join(", ");
         MacEager::expr(ecx.expr_str(sp, Symbol::intern(&args)))

diff --git a/src/test/ui/editions/edition-keywords-2015-2015-parsing.stderr b/src/test/ui/editions/edition-keywords-2015-2015-parsing.stderr
@@ -2,13 +2,13 @@ error: no rules expected the token `r#async`
   --> $DIR/edition-keywords-2015-2015-parsing.rs:22:31
    |
 LL |     r#async = consumes_async!(r#async); //~ ERROR no rules expected the token `r#async`
-   |                               ^^^^^^^
+   |                               ^^^^^^^ no rules expected the token `r#async`
 
 error: no rules expected the token `async`
   --> $DIR/edition-keywords-2015-2015-parsing.rs:23:35
    |
 LL |     r#async = consumes_async_raw!(async); //~ ERROR no rules expected the token `async`
-   |                                   ^^^^^
+   |                                   ^^^^^ no rules expected the token `async`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/editions/edition-keywords-2015-2018-parsing.stderr b/src/test/ui/editions/edition-keywords-2015-2018-parsing.stderr
@@ -2,13 +2,13 @@ error: no rules expected the token `r#async`
   --> $DIR/edition-keywords-2015-2018-parsing.rs:22:31
    |
 LL |     r#async = consumes_async!(r#async); //~ ERROR no rules expected the token `r#async`
-   |                               ^^^^^^^
+   |                               ^^^^^^^ no rules expected the token `r#async`
 
 error: no rules expected the token `async`
   --> $DIR/edition-keywords-2015-2018-parsing.rs:23:35
    |
 LL |     r#async = consumes_async_raw!(async); //~ ERROR no rules expected the token `async`
-   |                                   ^^^^^
+   |                                   ^^^^^ no rules expected the token `async`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/editions/edition-keywords-2018-2015-parsing.stderr b/src/test/ui/editions/edition-keywords-2018-2015-parsing.stderr
@@ -14,13 +14,13 @@ error: no rules expected the token `r#async`
   --> $DIR/edition-keywords-2018-2015-parsing.rs:22:31
    |
 LL |     r#async = consumes_async!(r#async); //~ ERROR no rules expected the token `r#async`
-   |                               ^^^^^^^
+   |                               ^^^^^^^ no rules expected the token `r#async`
 
 error: no rules expected the token `async`
   --> $DIR/edition-keywords-2018-2015-parsing.rs:23:35
    |
 LL |     r#async = consumes_async_raw!(async); //~ ERROR no rules expected the token `async`
-   |                                   ^^^^^
+   |                                   ^^^^^ no rules expected the token `async`
 
 error: expected one of `move`, `|`, or `||`, found `<eof>`
   --> <::edition_kw_macro_2015::passes_ident macros>:1:22

diff --git a/src/test/ui/editions/edition-keywords-2018-2018-parsing.stderr b/src/test/ui/editions/edition-keywords-2018-2018-parsing.stderr
@@ -14,13 +14,13 @@ error: no rules expected the token `r#async`
   --> $DIR/edition-keywords-2018-2018-parsing.rs:22:31
    |
 LL |     r#async = consumes_async!(r#async); //~ ERROR no rules expected the token `r#async`
-   |                               ^^^^^^^
+   |                               ^^^^^^^ no rules expected the token `r#async`
 
 error: no rules expected the token `async`
   --> $DIR/edition-keywords-2018-2018-parsing.rs:23:35
    |
 LL |     r#async = consumes_async_raw!(async); //~ ERROR no rules expected the token `async`
-   |                                   ^^^^^
+   |                                   ^^^^^ no rules expected the token `async`
 
 error: expected one of `move`, `|`, or `||`, found `<eof>`
   --> <::edition_kw_macro_2018::passes_ident macros>:1:22

diff --git a/src/test/ui/empty/empty-comment.stderr b/src/test/ui/empty/empty-comment.stderr
@@ -1,8 +1,13 @@
 error: unexpected end of macro invocation
   --> $DIR/empty-comment.rs:20:5
    |
-LL |     one_arg_macro!(/**/); //~ ERROR unexpected end
-   |     ^^^^^^^^^^^^^^^^^^^^^
+LL | / macro_rules! one_arg_macro {
+LL | |     ($fmt:expr) => (print!(concat!($fmt, "/n")));
+LL | | }
+   | |_- when calling this macro
+...
+LL |       one_arg_macro!(/**/); //~ ERROR unexpected end
+   |       ^^^^^^^^^^^^^^^^^^^^^ unexpected end of macro invocation
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/fail-simple.stderr b/src/test/ui/fail-simple.stderr
@@ -2,7 +2,7 @@ error: no rules expected the token `@`
   --> $DIR/fail-simple.rs:12:12
    |
 LL |     panic!(@); //~ ERROR no rules expected the token `@`
-   |            ^
+   |            ^ no rules expected the token `@`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-7970a.stderr b/src/test/ui/issues/issue-7970a.stderr
@@ -1,8 +1,13 @@
 error: unexpected end of macro invocation
   --> $DIR/issue-7970a.rs:16:5
    |
-LL |     one_arg_macro!();
-   |     ^^^^^^^^^^^^^^^^^
+LL | / macro_rules! one_arg_macro {
+LL | |     ($fmt:expr) => (print!(concat!($fmt, "/n")));
+LL | | }
+   | |_- when calling this macro
+...
+LL |       one_arg_macro!();
+   |       ^^^^^^^^^^^^^^^^^ unexpected end of macro invocation
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/macros/macro-at-most-once-rep-2018-feature-gate.stderr b/src/test/ui/macros/macro-at-most-once-rep-2018-feature-gate.stderr
@@ -51,20 +51,41 @@ LL |     ($(a)?*) => {}
 error: no rules expected the token `?`
   --> $DIR/macro-at-most-once-rep-2018-feature-gate.rs:41:11
    |
-LL |     foo!(a?); //~ ERROR no rules expected the token `?`
-   |           ^
+LL | / macro_rules! foo {
+LL | |     ($(a)?) => {}
+LL | |     //~^ERROR using the `?` macro Kleene operator for
+LL | |     //~|ERROR expected `*` or `+`
+LL | | }
+   | |_- when calling this macro
+...
+LL |       foo!(a?); //~ ERROR no rules expected the token `?`
+   |             ^ no rules expected the token `?`
 
 error: no rules expected the token `?`
   --> $DIR/macro-at-most-once-rep-2018-feature-gate.rs:42:11
    |
-LL |     foo!(a?a); //~ ERROR no rules expected the token `?`
-   |           ^
+LL | / macro_rules! foo {
+LL | |     ($(a)?) => {}
+LL | |     //~^ERROR using the `?` macro Kleene operator for
+LL | |     //~|ERROR expected `*` or `+`
+LL | | }
+   | |_- when calling this macro
+...
+LL |       foo!(a?a); //~ ERROR no rules expected the token `?`
+   |             ^ no rules expected the token `?`
 
 error: no rules expected the token `?`
   --> $DIR/macro-at-most-once-rep-2018-feature-gate.rs:43:11
    |
-LL |     foo!(a?a?a); //~ ERROR no rules expected the token `?`
-   |           ^
+LL | / macro_rules! foo {
+LL | |     ($(a)?) => {}
+LL | |     //~^ERROR using the `?` macro Kleene operator for
+LL | |     //~|ERROR expected `*` or `+`
+LL | | }
+   | |_- when calling this macro
+...
+LL |       foo!(a?a?a); //~ ERROR no rules expected the token `?`
+   |             ^ no rules expected the token `?`
 
 error: aborting due to 10 previous errors