[PATCH] D68598: [IA] Recognize hexadecimal escape sequences

[Bill Wendling via Phabricator via llvm-commits]

This revision was not accepted when it landed; it landed in state "Needs Review".
This revision was automatically updated to reflect the committed changes.
Closed by commit rL374018: [IA] Recognize hexadecimal escape sequences (authored by void, committed by ).

Changed prior to commit:
  https://reviews.llvm.org/D68598?vs=223666&id=223787#toc

Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D68598/new/

https://reviews.llvm.org/D68598

Files:
  llvm/trunk/lib/MC/MCParser/AsmParser.cpp
  llvm/trunk/test/MC/AsmParser/directive_ascii.s


Index: llvm/trunk/lib/MC/MCParser/AsmParser.cpp
===================================================================
--- llvm/trunk/lib/MC/MCParser/AsmParser.cpp
+++ llvm/trunk/lib/MC/MCParser/AsmParser.cpp
@@ -2914,11 +2914,27 @@
     }
 
     // Recognize escaped characters. Note that this escape semantics currently
-    // loosely follows Darwin 'as'. Notably, it doesn't support hex escapes.
+    // loosely follows Darwin 'as'.
     ++i;
     if (i == e)
       return TokError("unexpected backslash at end of string");
 
+    // Recognize hex sequences similarly to GNU 'as'.
+    if (Str[i] == 'x' || Str[i] == 'X') {
+      size_t length = Str.size();
+      if (i + 1 >= length || !isHexDigit(Str[i + 1]))
+        return TokError("invalid hexadecimal escape sequence");
+
+      // Consume hex characters. GNU 'as' reads all hexadecimal characters and
+      // then truncates to the lower 16 bits. Seems reasonable.
+      unsigned Value = 0;
+      while (i + 1 < length && isHexDigit(Str[i + 1]))
+        Value = Value * 16 + hexDigitValue(Str[++i]);
+
+      Data += (unsigned char)(Value & 0xFF);
+      continue;
+    }
+
     // Recognize octal sequences.
     if ((unsigned)(Str[i] - '0') <= 7) {
       // Consume up to three octal characters.
Index: llvm/trunk/test/MC/AsmParser/directive_ascii.s
===================================================================
--- llvm/trunk/test/MC/AsmParser/directive_ascii.s
+++ llvm/trunk/test/MC/AsmParser/directive_ascii.s
@@ -39,3 +39,8 @@
 # CHECK: .byte 0
 TEST6:
         .string "B", "C"
+
+# CHECK: TEST7:
+# CHECK: .ascii "dk"
+TEST7:
+        .ascii "\x64\Xa6B"


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