[llvm] [AArch64][Build Attributes] Improve Parsing and Formatting (PR #126530)

[via llvm-commits]

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@@ -0,0 +1,50 @@
+// RUN: llvm-mc -triple=aarch64 %s -o - | FileCheck %s --check-prefix=ASM
+// RUN: llvm-mc -triple=aarch64 -filetype=obj %s -o - | llvm-readelf --hex-dump=.ARM.attributes - | FileCheck %s --check-prefix=ELF
+
+// ASM: .aeabi_subsection	subsection_a, optional, uleb128
+// ASM: .aeabi_subsection	aeabi_subsection, optional, ntbs
----------------
sivan-shani wrote:

Assembly lines that does not contain a comment emit an extra new line.
Hence some line has an extra new line, and the directive '-NEXT' can not be used.
The cause seems to be `llvm/lib/MC/MCAsmStreamer.cpp`
Assembly lines that do not contain a comment emit an extra newline.
As a result, some lines have an extra newline, making the -NEXT directive unusable.
The issue appears to originate from llvm/lib/MC/MCAsmStreamer.cpp.
"""
  inline void EmitEOL() {
    // Dump Explicit Comments here.
    emitExplicitComments();
    // If we don't have any comments, just emit a \n.
    if (!IsVerboseAsm) {
      OS << '\n';
      return;
    }
    EmitCommentsAndEOL();
  }
  
  void MCAsmStreamer::EmitCommentsAndEOL() {
  if (CommentToEmit.empty() && CommentStream.GetNumBytesInBuffer() == 0) {
    OS << '\n';
    return;
  }
  ...
"""
Removing the extra newline causes a large number of other tests to fail, so it has been left unchanged for now.

https://github.com/llvm/llvm-project/pull/126530