[MC] - llvm-mc hangs on non-english characters.

[grimar]

Summary

This fixes PR33255.

Currently llvm-mc just hangs inside infinite loop while trying to parse file
which has ".section .с" inside, where section name is non-english character.

In this patch I also moved content of non-english-characters.s to test/MC/AsmParser/Inputs folder
so that non-english-characters.s becomes a single testcase for all invalid inputs
containing non-english symbols. That is convinent because llvm-mc otherwise tries
to parse and tokenize the whole testcase file with tools invocations and it is harder to isolate the issue.

[rnk]

lgtm

[grimar]

In D38545#888290, @rnk wrote:

lgtm

Thanks for review ! Going to commit it tomorrow.

[davide]

sounds good.

lib/MC/MCParser/ELFAsmParser.cpp

bool ELFAsmParser::ParseSectionName(StringRef &SectionName) {
   unsigned Size = 0;
 
   if (getLexer().is(AsmToken::String)) {
     SectionName = getTok().getIdentifier();
     Lex();
     return false;
   }
 
-  while (true) {
+  while (!getParser().hasPendingError()) {
     SMLoc PrevLoc = getLexer().getLoc();
     if (getLexer().is(AsmToken::Comma) ||
       getLexer().is(AsmToken::EndOfStatement))
       break;
     
     unsigned CurSize;
     if (getLexer().is(AsmToken::String)) {
       CurSize = getTok().getIdentifier().size() + 2;

test/MC/AsmParser/Inputs/non-english-characters-comments.s

+# 0bﾑ
+# 0xﾑ
+# .ﾑ4
+# .Xﾑ
+# .1ﾑ
+# .1eﾑ
+# 0x.ﾑ
+# 0x0pﾑ
+.intel_syntax
+# 1ﾑ

test/MC/AsmParser/Inputs/non-english-characters-section-name.s

+.section .ñ

test/MC/AsmParser/non-english-characters.s

-# RUN: llvm-mc -triple i386-linux-gnu -filetype=obj -o %t %s
+# RUN: llvm-mc -triple i386-linux-gnu -filetype=obj -o %t \
+# RUN:   %S/Inputs/non-english-characters-comments.s
 # RUN: llvm-readobj %t | FileCheck %s
 # CHECK: Format: ELF32-i386
 
-# 0bﾑ
-# 0xﾑ
-# .ﾑ4
-# .Xﾑ
-# .1ﾑ
-# .1eﾑ
-# 0x.ﾑ
-# 0x0pﾑ
-.intel_syntax
-# 1ﾑ
+# RUN: not llvm-mc -triple i386-linux-gnu -filetype=obj -o %t \
+# RUN:   %S/Inputs/non-english-characters-section-name.s 2>&1 | \
+# RUN:     FileCheck %s --check-prefix=ERR
+# ERR: invalid character in input