Rollup merge of #47481 - estebank:unused-args, r=arielb1

Point at unused arguments for format string

Avoid overlapping spans by only pointing at the arguments that are not
being used in the argument string. Enable libsyntax to have diagnostics
with multiple primary spans by accepting `Into<MultiSpan>` instead of
`Span`.

Partially addresses #41850.

1 files changed, 15 insertions, 10 deletions

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index e7565d35739..3d58104260f 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -42,7 +42,7 @@ use ast::{BinOpKind, UnOp};
 use ast::{RangeEnd, RangeSyntax};
 use {ast, attr};
 use codemap::{self, CodeMap, Spanned, respan};
-use syntax_pos::{self, Span, BytePos, FileName, DUMMY_SP};
+use syntax_pos::{self, Span, MultiSpan, BytePos, FileName, DUMMY_SP};
 use errors::{self, DiagnosticBuilder};
 use parse::{self, classify, token};
 use parse::common::SeqSep;
@@ -447,7 +447,9 @@ pub enum Error {
 }
 
 impl Error {
-    pub fn span_err(self, sp: Span, handler: &errors::Handler) -> DiagnosticBuilder {
+    pub fn span_err<S: Into<MultiSpan>>(self,
+                                        sp: S,
+                                        handler: &errors::Handler) -> DiagnosticBuilder {
         match self {
             Error::FileNotFoundForModule { ref mod_name,
                                            ref default_path,
@@ -1266,13 +1268,16 @@ impl<'a> Parser<'a> {
     pub fn fatal(&self, m: &str) -> DiagnosticBuilder<'a> {
         self.sess.span_diagnostic.struct_span_fatal(self.span, m)
     }
-    pub fn span_fatal(&self, sp: Span, m: &str) -> DiagnosticBuilder<'a> {
+    pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
         self.sess.span_diagnostic.struct_span_fatal(sp, m)
     }
-    pub fn span_fatal_err(&self, sp: Span, err: Error) -> DiagnosticBuilder<'a> {
+    pub fn span_fatal_err<S: Into<MultiSpan>>(&self, sp: S, err: Error) -> DiagnosticBuilder<'a> {
         err.span_err(sp, self.diagnostic())
     }
-    pub fn span_fatal_help(&self, sp: Span, m: &str, help: &str) -> DiagnosticBuilder<'a> {
+    pub fn span_fatal_help<S: Into<MultiSpan>>(&self,
+                                            sp: S,
+                                            m: &str,
+                                            help: &str) -> DiagnosticBuilder<'a> {
         let mut err = self.sess.span_diagnostic.struct_span_fatal(sp, m);
         err.help(help);
         err
@@ -1283,21 +1288,21 @@ impl<'a> Parser<'a> {
     pub fn warn(&self, m: &str) {
         self.sess.span_diagnostic.span_warn(self.span, m)
     }
-    pub fn span_warn(&self, sp: Span, m: &str) {
+    pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, m: &str) {
         self.sess.span_diagnostic.span_warn(sp, m)
     }
-    pub fn span_err(&self, sp: Span, m: &str) {
+    pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) {
         self.sess.span_diagnostic.span_err(sp, m)
     }
-    pub fn struct_span_err(&self, sp: Span, m: &str) -> DiagnosticBuilder<'a> {
+    pub fn struct_span_err<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> DiagnosticBuilder<'a> {
         self.sess.span_diagnostic.struct_span_err(sp, m)
     }
-    pub fn span_err_help(&self, sp: Span, m: &str, h: &str) {
+    pub fn span_err_help<S: Into<MultiSpan>>(&self, sp: S, m: &str, h: &str) {
         let mut err = self.sess.span_diagnostic.mut_span_err(sp, m);
         err.help(h);
         err.emit();
     }
-    pub fn span_bug(&self, sp: Span, m: &str) -> ! {
+    pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, m: &str) -> ! {
         self.sess.span_diagnostic.span_bug(sp, m)
     }
     pub fn abort_if_errors(&self) {