MC: Overhaul handling of .lcomm
- Darwin lied about not supporting .lcomm and turned it into zerofill in the
asm parser. Push the zerofill-conversion down into macho-specific code.
- This makes the tri-state LCOMMType enum superfluous, there are no targets
without .lcomm.
- Do proper error reporting when trying to use .lcomm with alignment on a target
that doesn't support it.
- .comm and .lcomm alignment was parsed in bytes on COFF, should be power of 2.
- Fixes PR13755 (.lcomm crashes on ELF).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163395 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCAsmInfo.cpp b/lib/MC/MCAsmInfo.cpp
index 8da2e0e..11e368c 100644
--- a/lib/MC/MCAsmInfo.cpp
+++ b/lib/MC/MCAsmInfo.cpp
@@ -68,8 +68,8 @@
GlobalDirective = "\t.globl\t";
HasSetDirective = true;
HasAggressiveSymbolFolding = true;
- LCOMMDirectiveType = LCOMM::None;
COMMDirectiveAlignmentIsInBytes = true;
+ LCOMMDirectiveSupportsAlignment = false;
HasDotTypeDotSizeDirective = true;
HasSingleParameterDotFile = true;
HasNoDeadStrip = false;
diff --git a/lib/MC/MCAsmInfoCOFF.cpp b/lib/MC/MCAsmInfoCOFF.cpp
index 678e75a..2637be7 100644
--- a/lib/MC/MCAsmInfoCOFF.cpp
+++ b/lib/MC/MCAsmInfoCOFF.cpp
@@ -20,7 +20,7 @@
MCAsmInfoCOFF::MCAsmInfoCOFF() {
GlobalPrefix = "_";
COMMDirectiveAlignmentIsInBytes = false;
- LCOMMDirectiveType = LCOMM::ByteAlignment;
+ LCOMMDirectiveSupportsAlignment = true;
HasDotTypeDotSizeDirective = false;
HasSingleParameterDotFile = false;
PrivateGlobalPrefix = "L"; // Prefix for private global symbols
diff --git a/lib/MC/MCAsmInfoDarwin.cpp b/lib/MC/MCAsmInfoDarwin.cpp
index 8e0ac23..99520d4 100644
--- a/lib/MC/MCAsmInfoDarwin.cpp
+++ b/lib/MC/MCAsmInfoDarwin.cpp
@@ -32,6 +32,7 @@
AlignmentIsInBytes = false;
COMMDirectiveAlignmentIsInBytes = false;
+ LCOMMDirectiveSupportsAlignment = true;
InlineAsmStart = " InlineAsm Start";
InlineAsmEnd = " InlineAsm End";
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 394f049..804e38e 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -517,13 +517,16 @@
/// @param Size - The size of the common symbol.
void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlign) {
- assert(MAI.getLCOMMDirectiveType() != LCOMM::None &&
- "Doesn't have .lcomm, can't emit it!");
OS << "\t.lcomm\t" << *Symbol << ',' << Size;
if (ByteAlign > 1) {
- assert(MAI.getLCOMMDirectiveType() == LCOMM::ByteAlignment &&
- "Alignment not supported on .lcomm!");
- OS << ',' << ByteAlign;
+ assert(MAI.getLCOMMDirectiveSupportsAlignment() &&
+ "alignment not supported on .lcomm!");
+ if (MAI.getCOMMDirectiveAlignmentIsInBytes()) {
+ OS << ',' << ByteAlign;
+ } else {
+ assert(isPowerOf2_32(ByteAlign) && "alignment must be a power of 2");
+ OS << ',' << Log2_32(ByteAlign);
+ }
}
EmitEOL();
}
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index b75fe2c..74f6dc6 100644
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -70,9 +70,7 @@
llvm_unreachable("macho doesn't support this directive");
}
virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
- unsigned ByteAlignment) {
- llvm_unreachable("macho doesn't support this directive");
- }
+ unsigned ByteAlignment);
virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
uint64_t Size = 0, unsigned ByteAlignment = 0);
virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
@@ -325,6 +323,15 @@
SD.setCommon(Size, ByteAlignment);
}
+void MCMachOStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
+ unsigned ByteAlignment) {
+ // '.lcomm' is equivalent to '.zerofill'.
+ return EmitZerofill(getContext().getMachOSection("__DATA", "__bss",
+ MCSectionMachO::S_ZEROFILL,
+ 0, SectionKind::getBSS()),
+ Symbol, Size, ByteAlignment);
+}
+
void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment) {
MCSectionData &SectData = getAssembler().getOrCreateSectionData(*Section);
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index d60a270..271fee0 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -2280,8 +2280,11 @@
if (ParseAbsoluteExpression(Pow2Alignment))
return true;
+ if (IsLocal && !Lexer.getMAI().getLCOMMDirectiveSupportsAlignment())
+ return Error(Pow2AlignmentLoc, "alignment not supported on this target");
+
// If this target takes alignments in bytes (not log) validate and convert.
- if (Lexer.getMAI().getAlignmentIsInBytes()) {
+ if (Lexer.getMAI().getCOMMDirectiveAlignmentIsInBytes()) {
if (!isPowerOf2_64(Pow2Alignment))
return Error(Pow2AlignmentLoc, "alignment must be a power of 2");
Pow2Alignment = Log2_64(Pow2Alignment);
@@ -2309,13 +2312,9 @@
if (!Sym->isUndefined())
return Error(IDLoc, "invalid symbol redefinition");
- // '.lcomm' is equivalent to '.zerofill'.
// Create the Symbol as a common or local common with Size and Pow2Alignment
if (IsLocal) {
- getStreamer().EmitZerofill(Ctx.getMachOSection(
- "__DATA", "__bss", MCSectionMachO::S_ZEROFILL,
- 0, SectionKind::getBSS()),
- Sym, Size, 1 << Pow2Alignment);
+ getStreamer().EmitLocalCommonSymbol(Sym, Size, 1 << Pow2Alignment);
return false;
}