MC: Move useCodeAlign from MCSection to MCAsmInfo

MaskRay · MaskRay · commit e9de1ee9f57c · 2025-07-26T11:34:10.000-07:00
To centralize assembly-related virtual functions to MCAsmInfo and move
toward making MCSection non-virtual.
diff --git a/llvm/include/llvm/MC/MCAsmInfo.h b/llvm/include/llvm/MC/MCAsmInfo.h
@@ -494,6 +494,10 @@ class LLVM_ABI MCAsmInfo {
   /// returns true  => .text
   virtual bool shouldOmitSectionDirective(StringRef SectionName) const;
 
+  // Return true if a .align directive should use "optimized nops" to fill
+  // instead of 0s.
+  virtual bool useCodeAlign(const MCSection &Sec) const { return false; }
+
   bool usesSunStyleELFSectionSwitchSyntax() const {
     return SunStyleELFSectionSwitchSyntax;
   }
diff --git a/llvm/include/llvm/MC/MCAsmInfoCOFF.h b/llvm/include/llvm/MC/MCAsmInfoCOFF.h
@@ -15,6 +15,7 @@ namespace llvm {
 
 class MCAsmInfoCOFF : public MCAsmInfo {
   virtual void anchor();
+  bool useCodeAlign(const MCSection &Sec) const final;
 
 protected:
   explicit MCAsmInfoCOFF();
diff --git a/llvm/include/llvm/MC/MCAsmInfoDarwin.h b/llvm/include/llvm/MC/MCAsmInfoDarwin.h
@@ -21,6 +21,7 @@ namespace llvm {
 class MCAsmInfoDarwin : public MCAsmInfo {
 public:
   explicit MCAsmInfoDarwin();
+  bool useCodeAlign(const MCSection &Sec) const final;
 
   /// True if the section is atomized using the symbols in it.
   /// This is false if the section is atomized based on its contents (MachO' __TEXT,__cstring for
diff --git a/llvm/include/llvm/MC/MCAsmInfoELF.h b/llvm/include/llvm/MC/MCAsmInfoELF.h
@@ -16,6 +16,7 @@ namespace llvm {
 class MCAsmInfoELF : public MCAsmInfo {
   virtual void anchor();
   MCSection *getNonexecutableStackSection(MCContext &Ctx) const final;
+  bool useCodeAlign(const MCSection &Sec) const final;
 
 protected:
   MCAsmInfoELF();
diff --git a/llvm/include/llvm/MC/MCAsmInfoXCOFF.h b/llvm/include/llvm/MC/MCAsmInfoXCOFF.h
@@ -14,10 +14,9 @@
 namespace llvm {
 
 class MCAsmInfoXCOFF : public MCAsmInfo {
-  virtual void anchor();
-
 protected:
   MCAsmInfoXCOFF();
+  bool useCodeAlign(const MCSection &Sec) const final;
 
 public:
   // Return true only when C is an acceptable character inside a
diff --git a/llvm/include/llvm/MC/MCSection.h b/llvm/include/llvm/MC/MCSection.h
@@ -652,10 +652,6 @@ class LLVM_ABI MCSection {
                                     raw_ostream &OS,
                                     uint32_t Subsection) const = 0;
 
-  /// Return true if a .align directive should use "optimized nops" to fill
-  /// instead of 0s.
-  virtual bool useCodeAlign() const { return false; }
-
   /// Check whether this section is "virtual", that is has no actual object
   /// file contents.
   bool isBssSection() const { return IsBss; }
diff --git a/llvm/include/llvm/MC/MCSectionCOFF.h b/llvm/include/llvm/MC/MCSectionCOFF.h
@@ -81,7 +81,6 @@ class MCSectionCOFF final : public MCSection {
   void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
                             raw_ostream &OS,
                             uint32_t Subsection) const override;
-  bool useCodeAlign() const override;
 
   unsigned getOrAssignWinCFISectionID(unsigned *NextID) const {
     if (WinCFISectionID == ~0U)
diff --git a/llvm/include/llvm/MC/MCSectionELF.h b/llvm/include/llvm/MC/MCSectionELF.h
@@ -83,7 +83,6 @@ class MCSectionELF final : public MCSection {
   void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
                             raw_ostream &OS,
                             uint32_t Subsection) const override;
-  bool useCodeAlign() const override;
 
   bool isUnique() const { return UniqueID != NonUniqueID; }
   unsigned getUniqueID() const { return UniqueID; }
diff --git a/llvm/include/llvm/MC/MCSectionMachO.h b/llvm/include/llvm/MC/MCSectionMachO.h
@@ -79,7 +79,6 @@ class LLVM_ABI MCSectionMachO final : public MCSection {
   void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
                             raw_ostream &OS,
                             uint32_t Subsection) const override;
-  bool useCodeAlign() const override;
 
   void allocAtoms();
   const MCSymbol *getAtom(size_t I) const;
diff --git a/llvm/include/llvm/MC/MCSectionWasm.h b/llvm/include/llvm/MC/MCSectionWasm.h
@@ -67,7 +67,6 @@ class MCSectionWasm final : public MCSection {
   void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
                             raw_ostream &OS,
                             uint32_t Subsection) const override;
-  bool useCodeAlign() const override;
 
   bool isWasmData() const { return IsWasmData; }
   bool isMetadata() const { return IsMetadata; }
diff --git a/llvm/include/llvm/MC/MCSectionXCOFF.h b/llvm/include/llvm/MC/MCSectionXCOFF.h
@@ -114,7 +114,6 @@ class MCSectionXCOFF final : public MCSection {
   void printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
                             raw_ostream &OS,
                             uint32_t Subsection) const override;
-  bool useCodeAlign() const override;
   StringRef getSymbolTableName() const { return SymbolTableName; }
   void setSymbolTableName(StringRef STN) { SymbolTableName = STN; }
   bool isMultiSymbolsAllowed() const { return MultiSymbolsAllowed; }
diff --git a/llvm/lib/MC/MCAsmInfoCOFF.cpp b/llvm/lib/MC/MCAsmInfoCOFF.cpp
@@ -13,6 +13,7 @@
 
 #include "llvm/MC/MCAsmInfoCOFF.h"
 #include "llvm/MC/MCDirectives.h"
+#include "llvm/MC/MCSection.h"
 
 using namespace llvm;
 
@@ -49,6 +50,10 @@ MCAsmInfoCOFF::MCAsmInfoCOFF() {
   HasCOFFComdatConstants = true;
 }
 
+bool MCAsmInfoCOFF::useCodeAlign(const MCSection &Sec) const {
+  return Sec.isText();
+}
+
 void MCAsmInfoMicrosoft::anchor() {}
 
 MCAsmInfoMicrosoft::MCAsmInfoMicrosoft() = default;
diff --git a/llvm/lib/MC/MCAsmInfoDarwin.cpp b/llvm/lib/MC/MCAsmInfoDarwin.cpp
@@ -85,3 +85,8 @@ MCAsmInfoDarwin::MCAsmInfoDarwin() {
   DwarfUsesRelocationsAcrossSections = false;
   SetDirectiveSuppressesReloc = true;
 }
+
+bool MCAsmInfoDarwin::useCodeAlign(const MCSection &Sec) const {
+  return static_cast<const MCSectionMachO &>(Sec).hasAttribute(
+      MachO::S_ATTR_PURE_INSTRUCTIONS);
+}
diff --git a/llvm/lib/MC/MCAsmInfoELF.cpp b/llvm/lib/MC/MCAsmInfoELF.cpp
@@ -28,6 +28,10 @@ MCSection *MCAsmInfoELF::getNonexecutableStackSection(MCContext &Ctx) const {
   return Ctx.getELFSection(".note.GNU-stack", ELF::SHT_PROGBITS, 0);
 }
 
+bool MCAsmInfoELF::useCodeAlign(const MCSection &Sec) const {
+  return static_cast<const MCSectionELF &>(Sec).getFlags() & ELF::SHF_EXECINSTR;
+}
+
 MCAsmInfoELF::MCAsmInfoELF() {
   HasIdentDirective = true;
   WeakRefDirective = "\t.weak\t";
diff --git a/llvm/lib/MC/MCAsmInfoXCOFF.cpp b/llvm/lib/MC/MCAsmInfoXCOFF.cpp
@@ -8,6 +8,7 @@
 
 #include "llvm/MC/MCAsmInfoXCOFF.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/MC/MCSectionXCOFF.h"
 #include "llvm/Support/CommandLine.h"
 
 using namespace llvm;
@@ -16,8 +17,6 @@ namespace llvm {
 extern cl::opt<cl::boolOrDefault> UseLEB128Directives;
 }
 
-void MCAsmInfoXCOFF::anchor() {}
-
 MCAsmInfoXCOFF::MCAsmInfoXCOFF() {
   IsAIX = true;
   IsLittleEndian = false;
@@ -56,3 +55,7 @@ bool MCAsmInfoXCOFF::isAcceptableChar(char C) const {
   // any combination of these.
   return isAlnum(C) || C == '_' || C == '.';
 }
+
+bool MCAsmInfoXCOFF::useCodeAlign(const MCSection &Sec) const {
+  return static_cast<const MCSectionXCOFF &>(Sec).getKind().isText();
+}
diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -3413,7 +3413,7 @@ bool AsmParser::parseDirectiveAlign(bool IsPow2, uint8_t ValueSize) {
 
   // Check whether we should use optimal code alignment for this .align
   // directive.
-  if (Section->useCodeAlign() && !HasFillExpr) {
+  if (MAI.useCodeAlign(*Section) && !HasFillExpr) {
     getStreamer().emitCodeAlignment(
         Align(Alignment), &getTargetParser().getSTI(), MaxBytesToFill);
   } else {
diff --git a/llvm/lib/MC/MCParser/MasmParser.cpp b/llvm/lib/MC/MCParser/MasmParser.cpp
@@ -4228,8 +4228,7 @@ bool MasmParser::emitAlignTo(int64_t Alignment) {
     // Check whether we should use optimal code alignment for this align
     // directive.
     const MCSection *Section = getStreamer().getCurrentSectionOnly();
-    assert(Section && "must have section to emit alignment");
-    if (Section->useCodeAlign()) {
+    if (MAI.useCodeAlign(*Section)) {
       getStreamer().emitCodeAlignment(Align(Alignment),
                                       &getTargetParser().getSTI(),
                                       /*MaxBytesToEmit=*/0);
diff --git a/llvm/lib/MC/MCSectionCOFF.cpp b/llvm/lib/MC/MCSectionCOFF.cpp
@@ -113,5 +113,3 @@ void MCSectionCOFF::printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
 
   OS << '\n';
 }
-
-bool MCSectionCOFF::useCodeAlign() const { return isText(); }
diff --git a/llvm/lib/MC/MCSectionELF.cpp b/llvm/lib/MC/MCSectionELF.cpp
@@ -211,7 +211,3 @@ void MCSectionELF::printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
     OS << '\n';
   }
 }
-
-bool MCSectionELF::useCodeAlign() const {
-  return getFlags() & ELF::SHF_EXECINSTR;
-}
diff --git a/llvm/lib/MC/MCSectionMachO.cpp b/llvm/lib/MC/MCSectionMachO.cpp
@@ -169,10 +169,6 @@ void MCSectionMachO::printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
   OS << '\n';
 }
 
-bool MCSectionMachO::useCodeAlign() const {
-  return hasAttribute(MachO::S_ATTR_PURE_INSTRUCTIONS);
-}
-
 /// ParseSectionSpecifier - Parse the section specifier indicated by "Spec".
 /// This is a string that can appear after a .section directive in a mach-o
 /// flavored .s file.  If successful, this fills in the specified Out
diff --git a/llvm/lib/MC/MCSectionWasm.cpp b/llvm/lib/MC/MCSectionWasm.cpp
@@ -97,5 +97,3 @@ void MCSectionWasm::printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
   if (Subsection)
     OS << "\t.subsection\t" << Subsection << '\n';
 }
-
-bool MCSectionWasm::useCodeAlign() const { return false; }
diff --git a/llvm/lib/MC/MCSectionXCOFF.cpp b/llvm/lib/MC/MCSectionXCOFF.cpp
@@ -130,5 +130,3 @@ void MCSectionXCOFF::printSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
 
   report_fatal_error("Printing for this SectionKind is unimplemented.");
 }
-
-bool MCSectionXCOFF::useCodeAlign() const { return getKind().isText(); }
diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -12327,7 +12327,7 @@ bool ARMAsmParser::parseDirectiveEven(SMLoc L) {
   }
 
   assert(Section && "must have section to emit alignment");
-  if (Section->useCodeAlign())
+  if (getContext().getAsmInfo()->useCodeAlign(*Section))
     getStreamer().emitCodeAlignment(Align(2), &getSTI());
   else
     getStreamer().emitValueToAlignment(Align(2));
@@ -12525,7 +12525,7 @@ bool ARMAsmParser::parseDirectiveAlign(SMLoc L) {
     // '.align' is target specifically handled to mean 2**2 byte alignment.
     const MCSection *Section = getStreamer().getCurrentSectionOnly();
     assert(Section && "must have section to emit alignment");
-    if (Section->useCodeAlign())
+    if (getContext().getAsmInfo()->useCodeAlign(*Section))
       getStreamer().emitCodeAlignment(Align(4), &getSTI(), 0);
     else
       getStreamer().emitValueToAlignment(Align(4), 0, 1, 0);
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
@@ -969,7 +969,7 @@ void MipsTargetELFStreamer::finish() {
 
       Align Alignment = Section.getAlign();
       S.switchSection(&Section);
-      if (Section.useCodeAlign())
+      if (getContext().getAsmInfo()->useCodeAlign(Section))
         S.emitCodeAlignment(Alignment, &STI, Alignment.value());
       else
         S.emitValueToAlignment(Alignment, 0, 1, Alignment.value());
diff --git a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.cpp b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.cpp
@@ -220,8 +220,6 @@ bool PPCELFMCAsmInfo::evaluateAsRelocatableImpl(const MCSpecifierExpr &Expr,
   return evaluateAsRelocatable(Expr, Res, Asm);
 }
 
-void PPCXCOFFMCAsmInfo::anchor() {}
-
 PPCXCOFFMCAsmInfo::PPCXCOFFMCAsmInfo(bool Is64Bit, const Triple &T) {
   if (T.getArch() == Triple::ppc64le || T.getArch() == Triple::ppcle)
     report_fatal_error("XCOFF is not supported for little-endian targets");
diff --git a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.h b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCMCAsmInfo.h
@@ -33,8 +33,6 @@ class PPCELFMCAsmInfo : public MCAsmInfoELF {
 };
 
 class PPCXCOFFMCAsmInfo : public MCAsmInfoXCOFF {
-  void anchor() override;
-
 public:
   explicit PPCXCOFFMCAsmInfo(bool is64Bit, const Triple &);
   void printSpecifierExpr(raw_ostream &OS,
diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -4803,7 +4803,7 @@ bool X86AsmParser::parseDirectiveEven(SMLoc L) {
     getStreamer().initSections(false, getSTI());
     Section = getStreamer().getCurrentSectionOnly();
   }
-  if (Section->useCodeAlign())
+  if (getContext().getAsmInfo()->useCodeAlign(*Section))
     getStreamer().emitCodeAlignment(Align(2), &getSTI(), 0);
   else
     getStreamer().emitValueToAlignment(Align(2), 0, 1, 0);
