diff --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index 4b4d7d6db93cd5..e83cca31105d48 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -348,7 +348,7 @@ static std::string createFileLineMsg(StringRef path, unsigned line) {
 
 template <class ELFT>
 static std::string getSrcMsgAux(ObjFile<ELFT> &file, const Symbol &sym,
-                                InputSectionBase &sec, uint64_t offset) {
+                                const InputSectionBase &sec, uint64_t offset) {
   // In DWARF, functions and variables are stored to different places.
   // First, look up a function for a given offset.
   if (std::optional<DILineInfo> info = file.getDILineInfo(&sec, offset))
@@ -363,7 +363,7 @@ static std::string getSrcMsgAux(ObjFile<ELFT> &file, const Symbol &sym,
   return std::string(file.sourceFile);
 }
 
-std::string InputFile::getSrcMsg(const Symbol &sym, InputSectionBase &sec,
+std::string InputFile::getSrcMsg(const Symbol &sym, const InputSectionBase &sec,
                                  uint64_t offset) {
   if (kind() != ObjKind)
     return "";
@@ -474,8 +474,8 @@ ObjFile<ELFT>::getVariableLoc(StringRef name) {
 // Returns source line information for a given offset
 // using DWARF debug info.
 template <class ELFT>
-std::optional<DILineInfo> ObjFile<ELFT>::getDILineInfo(InputSectionBase *s,
-                                                       uint64_t offset) {
+std::optional<DILineInfo>
+ObjFile<ELFT>::getDILineInfo(const InputSectionBase *s, uint64_t offset) {
   // Detect SectionIndex for specified section.
   uint64_t sectionIndex = object::SectionedAddress::UndefSection;
   ArrayRef<InputSectionBase *> sections = s->file->getSections();
@@ -1822,7 +1822,7 @@ template <class ELFT> void ObjFile<ELFT>::parseLazy() {
   }
 }
 
-bool InputFile::shouldExtractForCommon(StringRef name) {
+bool InputFile::shouldExtractForCommon(StringRef name) const {
   if (isa<BitcodeFile>(this))
     return isBitcodeNonCommonDef(mb, name, archiveName);
 
diff --git a/lld/ELF/InputFiles.h b/lld/ELF/InputFiles.h
index 41c2ba4e307b36..ab98d78fcf1455 100644
--- a/lld/ELF/InputFiles.h
+++ b/lld/ELF/InputFiles.h
@@ -101,7 +101,7 @@ class InputFile {
 
   // Check if a non-common symbol should be extracted to override a common
   // definition.
-  bool shouldExtractForCommon(StringRef name);
+  bool shouldExtractForCommon(StringRef name) const;
 
   // .got2 in the current file. This is used by PPC32 -fPIC/-fPIE to compute
   // offsets in PLT call stubs.
@@ -133,7 +133,7 @@ class InputFile {
   // True if this is an argument for --just-symbols. Usually false.
   bool justSymbols = false;
 
-  std::string getSrcMsg(const Symbol &sym, InputSectionBase &sec,
+  std::string getSrcMsg(const Symbol &sym, const InputSectionBase &sec,
                         uint64_t offset);
 
   // On PPC64 we need to keep track of which files contain small code model
@@ -255,7 +255,8 @@ template <class ELFT> class ObjFile : public ELFFileBase {
     return getSymbol(symIndex);
   }
 
-  std::optional<llvm::DILineInfo> getDILineInfo(InputSectionBase *, uint64_t);
+  std::optional<llvm::DILineInfo> getDILineInfo(const InputSectionBase *,
+                                                uint64_t);
   std::optional<std::pair<std::string, unsigned>>
   getVariableLoc(StringRef name);
 
diff --git a/lld/ELF/InputSection.cpp b/lld/ELF/InputSection.cpp
index e4ce050a789dfb..e6942a928787a5 100644
--- a/lld/ELF/InputSection.cpp
+++ b/lld/ELF/InputSection.cpp
@@ -242,7 +242,8 @@ InputSection *InputSectionBase::getLinkOrderDep() const {
 }
 
 // Find a symbol that encloses a given location.
-Defined *InputSectionBase::getEnclosingSymbol(uint64_t offset, uint8_t type) {
+Defined *InputSectionBase::getEnclosingSymbol(uint64_t offset,
+                                              uint8_t type) const {
   for (Symbol *b : file->getSymbols())
     if (Defined *d = dyn_cast<Defined>(b))
       if (d->section == this && d->value <= offset &&
@@ -252,7 +253,7 @@ Defined *InputSectionBase::getEnclosingSymbol(uint64_t offset, uint8_t type) {
 }
 
 // Returns an object file location string. Used to construct an error message.
-std::string InputSectionBase::getLocation(uint64_t offset) {
+std::string InputSectionBase::getLocation(uint64_t offset) const {
   std::string secAndOffset =
       (name + "+0x" + Twine::utohexstr(offset) + ")").str();
 
@@ -273,7 +274,8 @@ std::string InputSectionBase::getLocation(uint64_t offset) {
 //   foo.c:42 (/home/alice/possibly/very/long/path/foo.c:42)
 //
 //  Returns an empty string if there's no way to get line info.
-std::string InputSectionBase::getSrcMsg(const Symbol &sym, uint64_t offset) {
+std::string InputSectionBase::getSrcMsg(const Symbol &sym,
+                                        uint64_t offset) const {
   return file->getSrcMsg(sym, *this, offset);
 }
 
@@ -286,7 +288,7 @@ std::string InputSectionBase::getSrcMsg(const Symbol &sym, uint64_t offset) {
 // or
 //
 //   path/to/foo.o:(function bar) in archive path/to/bar.a
-std::string InputSectionBase::getObjMsg(uint64_t off) {
+std::string InputSectionBase::getObjMsg(uint64_t off) const {
   std::string filename = std::string(file->getName());
 
   std::string archive;
diff --git a/lld/ELF/InputSection.h b/lld/ELF/InputSection.h
index 7570901b4ef942..fbaea57bd586b0 100644
--- a/lld/ELF/InputSection.h
+++ b/lld/ELF/InputSection.h
@@ -191,15 +191,15 @@ class InputSectionBase : public SectionBase {
 
   // Get a symbol that encloses this offset from within the section. If type is
   // not zero, return a symbol with the specified type.
-  Defined *getEnclosingSymbol(uint64_t offset, uint8_t type = 0);
-  Defined *getEnclosingFunction(uint64_t offset) {
+  Defined *getEnclosingSymbol(uint64_t offset, uint8_t type = 0) const;
+  Defined *getEnclosingFunction(uint64_t offset) const {
     return getEnclosingSymbol(offset, llvm::ELF::STT_FUNC);
   }
 
   // Returns a source location string. Used to construct an error message.
-  std::string getLocation(uint64_t offset);
-  std::string getSrcMsg(const Symbol &sym, uint64_t offset);
-  std::string getObjMsg(uint64_t offset);
+  std::string getLocation(uint64_t offset) const;
+  std::string getSrcMsg(const Symbol &sym, uint64_t offset) const;
+  std::string getObjMsg(uint64_t offset) const;
 
   // Each section knows how to relocate itself. These functions apply
   // relocations, assuming that Buf points to this section's copy in