[LLVM][inline-asm] Altmacro string escape character '!'

This patch is the fourth patch in a series of reviews for the Altmacro feature. 
This patch introduces a new escape character '!' and it depends on D32701.

according to https://sourceware.org/binutils/docs/as/Altmacro.html:
"single-character string escape
To include any single character literally in a string (even if the character would otherwise have some special meaning), you can prefix the character with !' (an exclamation mark). For example, you can write <4.3 !> 5.4!!>' to get the literal text `4.3 > 5.4!'. "

Differential Revision: https://reviews.llvm.org/D32792



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302652 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Michael Zuckerman 2017-05-10 13:08:11 +00:00
parent 80d9dea549
commit 6361a0b8e9
2 changed files with 50 additions and 0 deletions

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@ -288,6 +288,7 @@ public:
private:
bool isAltmacroString(SMLoc &StrLoc, SMLoc &EndLoc);
void altMacroString(StringRef AltMacroStr, std::string &Res);
bool parseStatement(ParseStatementInfo &Info,
MCAsmParserSemaCallback *SI);
bool parseCurlyBlockScope(SmallVectorImpl<AsmRewrite>& AsmStrRewrites);
@ -1209,6 +1210,8 @@ bool AsmParser::isAltmacroString(SMLoc &StrLoc, SMLoc &EndLoc) {
const char *CharPtr = StrLoc.getPointer();
while ((*CharPtr != '>') && (*CharPtr != '\n') &&
(*CharPtr != '\r') && (*CharPtr != '\0')){
if(*CharPtr == '!')
CharPtr++;
CharPtr++;
}
if (*CharPtr == '>') {
@ -1218,6 +1221,15 @@ bool AsmParser::isAltmacroString(SMLoc &StrLoc, SMLoc &EndLoc) {
return false;
}
/// \brief creating a string without the escape characters '!'.
void AsmParser::altMacroString(StringRef AltMacroStr,std::string &Res) {
for (int Pos = 0; Pos < AltMacroStr.size(); Pos++) {
if (AltMacroStr[Pos] == '!')
Pos++;
Res += AltMacroStr[Pos];
}
}
/// \brief Parse an expression and return it.
///
/// expr ::= expr &&,|| expr -> lowest.
@ -2309,6 +2321,15 @@ bool AsmParser::expandMacro(raw_svector_ostream &OS, StringRef Body,
(*(Token.getString().begin()) == '%') && Token.is(AsmToken::Integer))
// Emit an integer value to the buffer.
OS << Token.getIntVal();
// Only Token that was validated as a string and begins with '<'
// is considered altMacroString!!!
else if ((Lexer.IsaAltMacroMode()) &&
(*(Token.getString().begin()) == '<') &&
Token.is(AsmToken::String)) {
std::string Res;
altMacroString(Token.getStringContents(), Res);
OS << Res;
}
// We expect no quotes around the string's contents when
// parsing for varargs.
else if (Token.isNot(AsmToken::String) || VarargParameter)

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@ -0,0 +1,29 @@
# RUN: llvm-mc -triple i386-linux-gnu %s| FileCheck %s
.altmacro
# single-character string escape
# To include any single character literally in a string
# (even if the character would otherwise have some special meaning),
# you can prefix the character with `!'.
# For example, you can write `<4.3 !> 5.4!!>' to get the literal text `4.3 > 5.4!'.
# CHECK: workForFun:
.macro fun1 number
.if \number=5
lableNotWork:
.else
workForFun:
.endif
.endm
# CHECK: workForFun2:
.macro fun2 string
.if \string
workForFun2:
.else
notworkForFun2:
.endif
.endm
fun1 <5!!>
fun2 <5!>4>