feat(diagnostics): print source diagnostics in gcc file:line: layout

Lexer, parser, driver and codegen diagnostics now read
"<path>:<line>: error: <message>" instead of "error: <message> at line N
in <path>". The path is always printed as given on the command line.
Call sites pass the bare message to cps::sourceError/sourceWarning, which
carry printf format checking; reportError routes through the same helper.

The suite iii harness parses the new layout and matches the reason
against the message only. iii/template-class-pack-field passed only
because its reason regex matched the case path, so it is now
case-insensitive.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 8 insertions, 5 deletions

diff --git a/tests/run.pl b/tests/run.pl
index 86eff4f..2835d5e 100644
--- a/tests/run.pl
+++ b/tests/run.pl
@@ -113,18 +113,21 @@ sub check_diagnostics {
     if (length($result->{stdout})) {
         push @errors, 'unexpected stdout: ' . show_bytes(substr($result->{stdout}, 0, 1000));
     }
-    # ASCII markers (error:, line N) are matched on raw bytes; the compiler
-    # emits UTF-8 and ASCII patterns are unaffected by decoding.
+    # Diagnostics use the gcc layout "<path>:<line>: error: <message>" and are
+    # matched on raw bytes; the compiler emits UTF-8 and ASCII patterns are
+    # unaffected by decoding. The non-greedy path keeps Windows "D:/" intact.
     my @lines = split_records(normalized($result->{stderr}));
     for my $expectation (@{$expectations}) {
         my $reason = $expectation->{reason};
         my $line_no = $expectation->{line};
+        my $file = $expectation->{file};
         my @matching = grep { /error:/ && /$reason/ } @lines;
         my $found = 0;
         for my $line (@matching) {
-            my $file = $expectation->{file};
-            if ($line =~ /\bline $line_no\b/ &&
-                (!defined($file) || $line =~ /\bline $line_no in \Q$file\E(?:\s|$)/)) {
+            next unless $line =~ /^(.+?):(\d+): error: (.*)$/;
+            my ($path, $number, $message) = ($1, $2, $3);
+            if ($number == $line_no && $message =~ /$reason/ &&
+                (!defined($file) || $path eq $file)) {
                 $found = 1;
                 last;
             }