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Differential D94887

MC: fix AsmLexer not understanding some escapes (notably '\r' and '\f')
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Authored by Ferdi265 on Jan 17 2021, 11:59 AM.
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Summary

This patch fixes Bug 48781.

llvm-mc, or also the integrated assembler in clang (which uses the same parser), doesn't understand the escapes '\r' and '\f'. This patch fixes that.

Reproducer: llvm-mc <(echo ".byte '\\r'")
Expected: .text .byte 13
Actual: .text .byte 114

After Bug 8615, support was added for basic character escapes, but '\r' and '\f' were seemingly forgotten.
By adding those two escapes to llvm-mc, LLVM would achieve feature parity with GNU as for character constants as described by the info as manual.

Diff Detail

Event Timeline

Ferdi265 created this revision.Jan 17 2021, 11:59 AM
Herald added a subscriber: hiraditya. · View Herald TranscriptJan 17 2021, 11:59 AM
Ferdi265 requested review of this revision.Jan 17 2021, 11:59 AM
Herald added a project: Restricted Project. · View Herald TranscriptJan 17 2021, 11:59 AM
Herald added a subscriber: llvm-commits. · View Herald Transcript
Harbormaster completed remote builds in B85538: Diff 317243.Jan 17 2021, 1:02 PM
c-rhodes added a subscriber: c-rhodes.Sep 9 2021, 6:17 AM

Hi @Ferdi265, it looks like this has since been fixed by D99609.

Revision Contents

PathSize
llvm/
lib/
MC/
MCParser/
2 lines

Diff 317243

llvm/lib/MC/MCParser/AsmLexer.cpp

Context not available.
case 't': Value = '\t'; break; case 't': Value = '\t'; break;
case 'n': Value = '\n'; break; case 'n': Value = '\n'; break;
case 'b': Value = '\b'; break; case 'b': Value = '\b'; break;
case 'r': Value = '\r'; break;
Lint: Pre-merge checks
Inline Actions

clang-format: please reformat the code

-      case 'r': Value = '\r'; break;
-      case 'f': Value = '\f'; break;
+      case 'r':
+        Value = '\r';
+        break;
+      case 'f':
+        Value = '\f';
+        break;
Lint: Pre-merge checks: clang-format: please reformat the code ``` - case 'r': Value = '\r'; break; - case…
case 'f': Value = '\f'; break;
} }
} else } else
Value = TokStart[1]; Value = TokStart[1];
Context not available.