From e644a2ab6a99951ac8d367f7a6bac985cf16f9cc Mon Sep 17 00:00:00 2001
From: Veikka Tuominen <git@vexu.eu>
Date: Sun, 10 Jul 2022 16:58:25 +0300
Subject: [PATCH] Compilation: do not repeat same source line for notes

---
 lib/std/zig.zig     |  4 ++++
 src/Compilation.zig | 16 ++++++++--------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/lib/std/zig.zig b/lib/std/zig.zig
index 0d3c94d37b..b8f75f649e 100644
--- a/lib/std/zig.zig
+++ b/lib/std/zig.zig
@@ -49,6 +49,10 @@ pub const Loc = struct {
     column: usize,
     /// Does not include the trailing newline.
     source_line: []const u8,
+
+    pub fn eql(a: Loc, b: Loc) bool {
+        return a.line == b.line and a.column == b.column and std.mem.eql(u8, a.source_line, b.source_line);
+    }
 };
 
 pub fn findLineColumn(source: []const u8, byte_offset: usize) Loc {
diff --git a/src/Compilation.zig b/src/Compilation.zig
index b00f135813..48a287d40b 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -505,6 +505,9 @@ pub const AllErrors = struct {
             Message.HashContext,
             std.hash_map.default_max_load_percentage,
         ).init(allocator);
+        const err_source = try module_err_msg.src_loc.file_scope.getSource(module.gpa);
+        const err_byte_offset = try module_err_msg.src_loc.byteOffset(module.gpa);
+        const err_loc = std.zig.findLineColumn(err_source.bytes, err_byte_offset);
 
         for (module_err_msg.notes) |module_note| {
             const source = try module_note.src_loc.file_scope.getSource(module.gpa);
@@ -519,7 +522,7 @@ pub const AllErrors = struct {
                     .byte_offset = byte_offset,
                     .line = @intCast(u32, loc.line),
                     .column = @intCast(u32, loc.column),
-                    .source_line = try allocator.dupe(u8, loc.source_line),
+                    .source_line = if (err_loc.eql(loc)) null else try allocator.dupe(u8, loc.source_line),
                 },
             };
             const gop = try seen_notes.getOrPut(note);
@@ -537,19 +540,16 @@ pub const AllErrors = struct {
             });
             return;
         }
-        const source = try module_err_msg.src_loc.file_scope.getSource(module.gpa);
-        const byte_offset = try module_err_msg.src_loc.byteOffset(module.gpa);
-        const loc = std.zig.findLineColumn(source.bytes, byte_offset);
         const file_path = try module_err_msg.src_loc.file_scope.fullPath(allocator);
         try errors.append(.{
             .src = .{
                 .src_path = file_path,
                 .msg = try allocator.dupe(u8, module_err_msg.msg),
-                .byte_offset = byte_offset,
-                .line = @intCast(u32, loc.line),
-                .column = @intCast(u32, loc.column),
+                .byte_offset = err_byte_offset,
+                .line = @intCast(u32, err_loc.line),
+                .column = @intCast(u32, err_loc.column),
                 .notes = notes_buf[0..note_i],
-                .source_line = try allocator.dupe(u8, loc.source_line),
+                .source_line = try allocator.dupe(u8, err_loc.source_line),
             },
         });
     }