[clang] 3184fb9 - [clang][Diagnostics] Print empty lines in multiline snippets

[Timm Bäder via cfe-commits]

Author: Timm Bäder
Date: 2023-05-31T10:21:24+02:00
New Revision: 3184fb958091f6b119c878e2eab894d799432686

URL: https://github.com/llvm/llvm-project/commit/3184fb958091f6b119c878e2eab894d799432686
DIFF: https://github.com/llvm/llvm-project/commit/3184fb958091f6b119c878e2eab894d799432686.diff

LOG: [clang][Diagnostics] Print empty lines in multiline snippets

We should preserve empty lines in output snippets.

Differential Revision: https://reviews.llvm.org/D151301

Added: 
    clang/test/Misc/diag-style.cpp

Modified: 
    clang/lib/Frontend/TextDiagnostic.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Frontend/TextDiagnostic.cpp b/clang/lib/Frontend/TextDiagnostic.cpp
index d285b8873977..d2cbb55dea87 100644
--- a/clang/lib/Frontend/TextDiagnostic.cpp
+++ b/clang/lib/Frontend/TextDiagnostic.cpp
@@ -1225,7 +1225,7 @@ void TextDiagnostic::emitSnippetAndCaret(
     // to produce easily machine parsable output.  Add a space before the
     // source line and the caret to make it trivial to tell the main diagnostic
     // line from what the user is intended to see.
-    if (DiagOpts->ShowSourceRanges) {
+    if (DiagOpts->ShowSourceRanges && !SourceLine.empty()) {
       SourceLine = ' ' + SourceLine;
       CaretLine = ' ' + CaretLine;
     }
@@ -1262,9 +1262,6 @@ void TextDiagnostic::emitSnippetAndCaret(
 void TextDiagnostic::emitSnippet(StringRef SourceLine,
                                  unsigned MaxLineNoDisplayWidth,
                                  unsigned LineNo) {
-  if (SourceLine.empty())
-    return;
-
   // Emit line number.
   if (MaxLineNoDisplayWidth > 0) {
     unsigned LineNoDisplayWidth = getNumDisplayWidth(LineNo);

diff  --git a/clang/test/Misc/diag-style.cpp b/clang/test/Misc/diag-style.cpp
new file mode 100644
index 000000000000..b12afb2cd923
--- /dev/null
+++ b/clang/test/Misc/diag-style.cpp
@@ -0,0 +1,12 @@
+// RUN: not %clang_cc1 -fsyntax-only %s 2>&1 | FileCheck -strict-whitespace %s
+
+/// empty lines in multi-line diagnostic snippets are preserved.
+static_assert(false &&
+
+              true, "");
+// CHECK: static assertion failed
+// CHECK-NEXT: {{^}}    4 | static_assert(false &&{{$}}
+// CHECK-NEXT: {{^}}      |               ^~~~~~~~{{$}}
+// CHECK-NEXT: {{^}}    5 | {{$}}
+// CHECK-NEXT: {{^}}    6 |               true, "");{{$}}
+// CHECK-NEXT: {{^}}      |               ~~~~{{$}}