Add support for the .base64 directive (fixes #165499)

[kenballus]

Starting in version 15, GCC emits a .base64 directive instead of .string or .ascii for char arrays of length >= 3.

See this godbolt link for an example.

This patch adds support for the .base64 directive to AsmParser.cpp, so tools like llvm-mc can process the output of GCC more effectively.

This addresses #165499.

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[llvmbot]

@llvm/pr-subscribers-llvm-mc

Author: Ben Kallus (kenballus)

Changes

Starting in version 15, GCC emits a .base64 directive instead of .string or .ascii for char arrays of length >= 3.

See this godbolt link for an example.

This patch adds support for the .base64 directive to AsmParser.cpp, so tools like llvm-mc can process the output of GCC more effectively.

This addresses #165499.

---

Full diff: https://github.com/llvm/llvm-project/pull/165549.diff

1 Files Affected:

• (modified) llvm/lib/MC/MCParser/AsmParser.cpp (+21)

diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp index dd1bc2be5feb4..54bb1451a5a73 100644 --- a/llvm/lib/MC/MCParser/AsmParser.cpp +++ b/llvm/lib/MC/MCParser/AsmParser.cpp @@ -46,6 +46,7 @@ #include "llvm/MC/MCSymbolMachO.h" #include "llvm/MC/MCTargetOptions.h" #include "llvm/MC/MCValue.h" +#include "llvm/Support/Base64.h" #include "llvm/Support/Casting.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/ErrorHandling.h" @@ -530,6 +531,7 @@ class AsmParser : public MCAsmParser { DK_LTO_SET_CONDITIONAL, DK_CFI_MTE_TAGGED_FRAME, DK_MEMTAG, + DK_BASE64, DK_END }; @@ -552,6 +554,7 @@ class AsmParser : public MCAsmParser { // ".ascii", ".asciz", ".string" bool parseDirectiveAscii(StringRef IDVal, bool ZeroTerminated); + bool parseDirectiveBase64(); // ".base64" bool parseDirectiveReloc(SMLoc DirectiveLoc); // ".reloc" bool parseDirectiveValue(StringRef IDVal, unsigned Size); // ".byte", ".long", ... @@ -1953,6 +1956,8 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info, case DK_ASCIZ: case DK_STRING: return parseDirectiveAscii(IDVal, true); + case DK_BASE64: + return parseDirectiveBase64(); case DK_BYTE: case DK_DC_B: return parseDirectiveValue(IDVal, 1); @@ -3076,6 +3081,21 @@ bool AsmParser::parseDirectiveAscii(StringRef IDVal, bool ZeroTerminated) { return parseMany(parseOp); } +/// parseDirectiveBase64: +// ::= .base64 "string" +bool AsmParser::parseDirectiveBase64() { + std::vector<char> Decoded; + + std::string str; + + if (parseEscapedString(str) || str.empty() || decodeBase64(str, Decoded)) { + return true; + } + + getStreamer().emitBytes(std::string(Decoded.begin(), Decoded.end())); + return false; +} + /// parseDirectiveReloc /// ::= .reloc expression , identifier [ , expression ] bool AsmParser::parseDirectiveReloc(SMLoc DirectiveLoc) { @@ -5345,6 +5365,7 @@ void AsmParser::initializeDirectiveKindMap() { DirectiveKindMap[".asciz"] = DK_ASCIZ; DirectiveKindMap[".string"] = DK_STRING; DirectiveKindMap[".byte"] = DK_BYTE; + DirectiveKindMap[".base64"] = DK_BASE64; DirectiveKindMap[".short"] = DK_SHORT; DirectiveKindMap[".value"] = DK_VALUE; DirectiveKindMap[".2byte"] = DK_2BYTE; 

[lenary]

Please add tests.