[llvm] 6201761 - MC: Rename isVirtualSection to isBssSection
Fangrui Song via llvm-commits
llvm-commits at lists.llvm.org
Sun Jul 20 10:39:22 PDT 2025
Author: Fangrui Song
Date: 2025-07-20T10:39:17-07:00
New Revision: 6201761e961f4d7ed08352d55134e6ef58ee5eb2
URL: https://github.com/llvm/llvm-project/commit/6201761e961f4d7ed08352d55134e6ef58ee5eb2
DIFF: https://github.com/llvm/llvm-project/commit/6201761e961f4d7ed08352d55134e6ef58ee5eb2.diff
LOG: MC: Rename isVirtualSection to isBssSection
The term BSS (Block Started by Symbol) is a standard, widely recognized
term, available in the a.out object file format and adopted by formats
like COFF, XCOFF, Mach-O (called S_ZEROFILL while `__bss` is also used),
and ELF. To avoid introducing unfamiliar terms, we should use
isBSSSection instead of isVirtualSection.
Added:
Modified:
llvm/include/llvm/MC/MCSection.h
llvm/include/llvm/MC/MCSectionGOFF.h
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
llvm/lib/MC/MCAssembler.cpp
llvm/lib/MC/MCMachOStreamer.cpp
llvm/lib/MC/MCParser/AsmParser.cpp
llvm/lib/MC/MCSection.cpp
llvm/lib/MC/MachObjectWriter.cpp
llvm/lib/ObjCopy/MachO/MachOObject.h
llvm/lib/ObjCopy/MachO/MachOWriter.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/MC/MCSection.h b/llvm/include/llvm/MC/MCSection.h
index fe8c13d108c2c..68fc8767d6bce 100644
--- a/llvm/include/llvm/MC/MCSection.h
+++ b/llvm/include/llvm/MC/MCSection.h
@@ -91,8 +91,7 @@ class LLVM_ABI MCSection {
bool IsRegistered : 1;
bool IsText : 1;
-
- bool IsVirtual : 1;
+ bool IsBss : 1;
/// Whether the section contains linker-relaxable fragments. If true, the
/// offset between two locations may not be fully resolved.
@@ -176,9 +175,9 @@ class LLVM_ABI MCSection {
/// instead of 0s.
virtual bool useCodeAlign() const = 0;
- /// Check whether this section is "virtual", that is has no actual object
- /// file contents.
- bool isVirtualSection() const { return IsVirtual; }
+ /// Return true if this is a BSS section (e.g., ELF .bss or .tbss) that does
+ /// not store content and is typically initialized to zeroes by the runtime.
+ bool isBssSection() const { return IsBss; }
virtual StringRef getVirtualSectionKind() const;
};
diff --git a/llvm/include/llvm/MC/MCSectionGOFF.h b/llvm/include/llvm/MC/MCSectionGOFF.h
index 9e3f95e82a14c..b166397b5d370 100644
--- a/llvm/include/llvm/MC/MCSectionGOFF.h
+++ b/llvm/include/llvm/MC/MCSectionGOFF.h
@@ -111,7 +111,7 @@ class LLVM_ABI MCSectionGOFF final : public MCSection {
// Returns the text style for a section. Only defined for ED and PR sections.
GOFF::ESDTextStyle getTextStyle() const {
- assert((isED() || isPR() || isVirtualSection()) && "Expect ED or PR section");
+ assert((isED() || isPR() || isBssSection()) && "Expect ED or PR section");
if (isED())
return EDAttributes.TextStyle;
if (isPR())
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 76a1d8c931605..10bdb81e4fb49 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -809,7 +809,7 @@ void AsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
// If we have a bss global going to a section that supports the
// zerofill directive, do so here.
- if (GVKind.isBSS() && MAI->isMachO() && TheSection->isVirtualSection()) {
+ if (GVKind.isBSS() && MAI->isMachO() && TheSection->isBssSection()) {
if (Size == 0)
Size = 1; // zerofill of 0 bytes is undefined.
emitLinkage(GV, GVSym);
diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index 674adc92257c9..317ba8128cff1 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -362,7 +362,7 @@ uint64_t MCAssembler::getSectionAddressSize(const MCSection &Sec) const {
uint64_t MCAssembler::getSectionFileSize(const MCSection &Sec) const {
// Virtual sections have no file size.
- if (Sec.isVirtualSection())
+ if (Sec.isBssSection())
return 0;
return getSectionAddressSize(Sec);
}
@@ -559,7 +559,7 @@ void MCAssembler::writeSectionData(raw_ostream &OS,
const MCSection *Sec) const {
assert(getBackendPtr() && "Expected assembler backend");
- if (Sec->isVirtualSection()) {
+ if (Sec->isBssSection()) {
assert(getSectionFileSize(*Sec) == 0 && "Invalid size for section!");
// Ensure no fixups or non-zero bytes are written to BSS sections, catching
diff --git a/llvm/lib/MC/MCMachOStreamer.cpp b/llvm/lib/MC/MCMachOStreamer.cpp
index 08d2b931858a6..e8bbb53b98dd0 100644
--- a/llvm/lib/MC/MCMachOStreamer.cpp
+++ b/llvm/lib/MC/MCMachOStreamer.cpp
@@ -393,7 +393,7 @@ void MCMachOStreamer::emitZerofill(MCSection *Section, MCSymbol *Symbol,
// On darwin all virtual sections have zerofill type. Disallow the usage of
// .zerofill in non-virtual functions. If something similar is needed, use
// .space or .zero.
- if (!Section->isVirtualSection()) {
+ if (!Section->isBssSection()) {
getContext().reportError(
Loc, "The usage of .zerofill is restricted to sections of "
"ZEROFILL type. Use .zero or .space instead.");
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 77bf84364c5a3..4c55e97f0c1fc 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -3404,7 +3404,7 @@ bool AsmParser::parseDirectiveAlign(bool IsPow2, uint8_t ValueSize) {
const MCSection *Section = getStreamer().getCurrentSectionOnly();
assert(Section && "must have section to emit alignment");
- if (HasFillExpr && FillExpr != 0 && Section->isVirtualSection()) {
+ if (HasFillExpr && FillExpr != 0 && Section->isBssSection()) {
ReturnVal |=
Warning(FillExprLoc, "ignoring non-zero fill value in " +
Section->getVirtualSectionKind() +
diff --git a/llvm/lib/MC/MCSection.cpp b/llvm/lib/MC/MCSection.cpp
index 93671450c0c2f..fd1d072cf4152 100644
--- a/llvm/lib/MC/MCSection.cpp
+++ b/llvm/lib/MC/MCSection.cpp
@@ -21,7 +21,7 @@ using namespace llvm;
MCSection::MCSection(SectionVariant V, StringRef Name, bool IsText,
bool IsVirtual, MCSymbol *Begin)
: Begin(Begin), HasInstructions(false), IsRegistered(false), IsText(IsText),
- IsVirtual(IsVirtual), LinkerRelaxable(false), Name(Name), Variant(V) {
+ IsBss(IsVirtual), LinkerRelaxable(false), Name(Name), Variant(V) {
// The initial subsection number is 0. Create a fragment list.
CurFragList = &Subsections.emplace_back(0u, FragList{}).second;
}
diff --git a/llvm/lib/MC/MachObjectWriter.cpp b/llvm/lib/MC/MachObjectWriter.cpp
index 3291dd774c1e0..3298eef5d41af 100644
--- a/llvm/lib/MC/MachObjectWriter.cpp
+++ b/llvm/lib/MC/MachObjectWriter.cpp
@@ -131,7 +131,7 @@ uint64_t MachObjectWriter::getPaddingSize(const MCAssembler &Asm,
return 0;
const MCSection &NextSec = *SectionOrder[Next];
- if (NextSec.isVirtualSection())
+ if (NextSec.isBssSection())
return 0;
return offsetToAlignment(EndAddr, NextSec.getAlign());
}
@@ -267,7 +267,7 @@ void MachObjectWriter::writeSection(const MCAssembler &Asm,
const MCSectionMachO &Section = cast<MCSectionMachO>(Sec);
// The offset is unused for virtual sections.
- if (Section.isVirtualSection()) {
+ if (Section.isBssSection()) {
assert(Asm.getSectionFileSize(Sec) == 0 && "Invalid file size!");
FileOffset = 0;
}
@@ -682,13 +682,13 @@ void MachObjectWriter::computeSectionAddresses(const MCAssembler &Asm) {
unsigned i = 0;
// Compute the section layout order. Virtual sections must go last.
for (MCSection &Sec : Asm) {
- if (!Sec.isVirtualSection()) {
+ if (!Sec.isBssSection()) {
SectionOrder.push_back(&Sec);
cast<MCSectionMachO>(Sec).setLayoutOrder(i++);
}
}
for (MCSection &Sec : Asm) {
- if (Sec.isVirtualSection()) {
+ if (Sec.isBssSection()) {
SectionOrder.push_back(&Sec);
cast<MCSectionMachO>(Sec).setLayoutOrder(i++);
}
@@ -883,7 +883,7 @@ uint64_t MachObjectWriter::writeObject() {
VMSize = std::max(VMSize, Address + Size);
- if (Sec.isVirtualSection())
+ if (Sec.isBssSection())
continue;
SectionDataSize = std::max(SectionDataSize, Address + Size);
@@ -915,7 +915,7 @@ uint64_t MachObjectWriter::writeObject() {
unsigned Flags = Sec.getTypeAndAttributes();
if (Sec.hasInstructions())
Flags |= MachO::S_ATTR_SOME_INSTRUCTIONS;
- if (!cast<MCSectionMachO>(Sec).isVirtualSection() &&
+ if (!cast<MCSectionMachO>(Sec).isBssSection() &&
!isUInt<32>(SectionStart)) {
getContext().reportError(
SMLoc(), "cannot encode offset of section; object file too large");
diff --git a/llvm/lib/ObjCopy/MachO/MachOObject.h b/llvm/lib/ObjCopy/MachO/MachOObject.h
index 8f9444f5fb025..86c6b120fa6c3 100644
--- a/llvm/lib/ObjCopy/MachO/MachOObject.h
+++ b/llvm/lib/ObjCopy/MachO/MachOObject.h
@@ -64,14 +64,14 @@ struct Section {
return static_cast<MachO::SectionType>(Flags & MachO::SECTION_TYPE);
}
- bool isVirtualSection() const {
+ bool isBssSection() const {
return (getType() == MachO::S_ZEROFILL ||
getType() == MachO::S_GB_ZEROFILL ||
getType() == MachO::S_THREAD_LOCAL_ZEROFILL);
}
bool hasValidOffset() const {
- return !(isVirtualSection() || OriginalOffset == 0);
+ return !(isBssSection() || OriginalOffset == 0);
}
};
diff --git a/llvm/lib/ObjCopy/MachO/MachOWriter.cpp b/llvm/lib/ObjCopy/MachO/MachOWriter.cpp
index 7c24d1277dc8d..89c1df8699298 100644
--- a/llvm/lib/ObjCopy/MachO/MachOWriter.cpp
+++ b/llvm/lib/ObjCopy/MachO/MachOWriter.cpp
@@ -112,7 +112,7 @@ size_t MachOWriter::totalSize() const {
for (const std::unique_ptr<Section> &S : LC.Sections) {
if (!S->hasValidOffset()) {
assert((S->Offset == 0) && "Skipped section's offset must be zero");
- assert((S->isVirtualSection() || S->Size == 0) &&
+ assert((S->isBssSection() || S->Size == 0) &&
"Non-zero-fill sections with zero offset must have zero size");
continue;
}
@@ -240,7 +240,7 @@ void MachOWriter::writeSections() {
for (const std::unique_ptr<Section> &Sec : LC.Sections) {
if (!Sec->hasValidOffset()) {
assert((Sec->Offset == 0) && "Skipped section's offset must be zero");
- assert((Sec->isVirtualSection() || Sec->Size == 0) &&
+ assert((Sec->isBssSection() || Sec->Size == 0) &&
"Non-zero-fill sections with zero offset must have zero size");
continue;
}
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