rust-lang · bors · Nov 29, 2016 · Oct 24, 2016 · Nov 23, 2016
diff --git a/src/librustc_errors/emitter.rs b/src/librustc_errors/emitter.rs
diff --git a/src/librustc_errors/snippet.rs b/src/librustc_errors/snippet.rs
@@ -41,6 +41,86 @@ pub struct Line {
    pub annotations: Vec<Annotation>,
 }
+  
+
+  
+#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
+  
+pub struct MultilineAnnotation {
+  
+    pub depth: usize,
+  
+    pub line_start: usize,
+  
+    pub line_end: usize,
+  
+    pub start_col: usize,
+  
+    pub end_col: usize,
+  
+    pub is_primary: bool,
+  
+    pub label: Option<String>,
+  
+}
+  
+
+  
+impl MultilineAnnotation {
+  
+    pub fn increase_depth(&mut self) {
+  
+        self.depth += 1;
+  
+    }
+  
+
+  
+    pub fn as_start(&self) -> Annotation {
+  
+        Annotation {
+  
+            start_col: self.start_col,
+  
+            end_col: self.start_col + 1,
+  
+            is_primary: self.is_primary,
+  
+            label: Some("starting here...".to_owned()),
+  
+            annotation_type: AnnotationType::MultilineStart(self.depth)
+  
+        }
+  
+    }
+  
+
+  
+    pub fn as_end(&self) -> Annotation {
+  
+        Annotation {
+  
+            start_col: self.end_col - 1,
+  
+            end_col: self.end_col,
+  
+            is_primary: self.is_primary,
+  
+            label: match self.label {
+  
+                Some(ref label) => Some(format!("...ending here: {}", label)),
+  
+                None => Some("...ending here".to_owned()),
+  
+            },
+  
+            annotation_type: AnnotationType::MultilineEnd(self.depth)
+  
+        }
+  
+    }
+  
+
+  
+    pub fn as_line(&self) -> Annotation {
+  
+        Annotation {
+  
+            start_col: 0,
+  
+            end_col: 0,
+  
+            is_primary: self.is_primary,
+  
+            label: None,
+  
+            annotation_type: AnnotationType::MultilineLine(self.depth)
+  
+        }
+  
+    }
+  
+}
+  
+
+  
+#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
+  
+pub enum AnnotationType {
+  
+    /// Annotation under a single line of code
+  
+    Singleline,
+  
+
+  
+    /// Annotation under the first character of a multiline span
+  
+    Minimized,
+  
+
+  
+    /// Annotation enclosing the first and last character of a multiline span
+  
+    Multiline(MultilineAnnotation),
+  
+
+  
+    // The Multiline type above is replaced with the following three in order
+  
+    // to reuse the current label drawing code.
+  
+    //
+  
+    // Each of these corresponds to one part of the following diagram:
+  
+    //
+  
+    //     x |   foo(1 + bar(x,
+  
+    //       |  _________^ starting here...           < MultilineStart
+  
+    //     x | |             y),                      < MultilineLine
+  
+    //       | |______________^ ...ending here: label < MultilineEnd
+  
+    //     x |       z);
+  
+    /// Annotation marking the first character of a fully shown multiline span
+  
+    MultilineStart(usize),
+  
+    /// Annotation marking the last character of a fully shown multiline span
+  
+    MultilineEnd(usize),
+  
+    /// Line at the left enclosing the lines of a fully shown multiline span
+  
+    MultilineLine(usize),
+  
+}
+  
+
 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
 pub struct Annotation {
    /// Start column, 0-based indexing -- counting *characters*, not
@@ -55,11 +135,32 @@ pub struct Annotation {
    /// Is this annotation derived from primary span
    pub is_primary: bool,
-  
-    /// Is this a large span minimized down to a smaller span
-  
-    pub is_minimized: bool,
-  
-
    /// Optional label to display adjacent to the annotation.
    pub label: Option<String>,
+  
+
+  
+    /// Is this a single line, multiline or multiline span minimized down to a
+  
+    /// smaller span.
+  
+    pub annotation_type: AnnotationType,
+  
+}
+  
+
+  
+impl Annotation {
+  
+    pub fn is_minimized(&self) -> bool {
+  
+        match self.annotation_type {
+  
+            AnnotationType::Minimized => true,
+  
+            _ => false,
+  
+        }
+  
+    }
+  
+
+  
+    pub fn is_multiline(&self) -> bool {
+  
+        match self.annotation_type {
+  
+            AnnotationType::Multiline(_) |
+  
+            AnnotationType::MultilineStart(_) |
+  
+            AnnotationType::MultilineLine(_) |
+  
+            AnnotationType::MultilineEnd(_) => true,
+  
+            _ => false,
+  
+        }
+  
+    }
+  
+
 }
 #[derive(Debug)]

diff --git a/src/libsyntax/lib.rs b/src/libsyntax/lib.rs
@@ -144,4 +144,7 @@ pub mod ext {
    }
 }
+  
+#[cfg(test)]
+  
+mod test_snippet;
+  
+
 // __build_diagnostic_array! { libsyntax, DIAGNOSTICS }