[lld] 26cc651 - [ELF] Improve comment of InputSection::file and update getFile. NFC (#79550)

[via llvm-commits]

Author: Fangrui Song
Date: 2024-01-26T10:43:02-08:00
New Revision: 26cc651f1b2a9c74ce332a14f0e35c03db34876b

URL: https://github.com/llvm/llvm-project/commit/26cc651f1b2a9c74ce332a14f0e35c03db34876b
DIFF: https://github.com/llvm/llvm-project/commit/26cc651f1b2a9c74ce332a14f0e35c03db34876b.diff

LOG: [ELF] Improve comment of InputSection::file and update getFile. NFC (#79550)

Clarify a comment after #78944.

All uses of `getFile()` assert `file` is non-null. `getFile` is not used
with a
synthetic section. Replace `cast_or_null` with `cast`.

Added: 
    

Modified: 
    lld/ELF/InputSection.h

Removed: 
    


################################################################################
diff  --git a/lld/ELF/InputSection.h b/lld/ELF/InputSection.h
index dda4242d8be1c1f..bb9dff38ae02995 100644
--- a/lld/ELF/InputSection.h
+++ b/lld/ELF/InputSection.h
@@ -118,9 +118,9 @@ class InputSectionBase : public SectionBase {
 
   static bool classof(const SectionBase *s) { return s->kind() != Output; }
 
-  // The file which contains this section. Its dynamic type is always
-  // ObjFile<ELFT>, but in order to avoid ELFT, we use InputFile as
-  // its static type.
+  // The file which contains this section. Its dynamic type is usually
+  // ObjFile<ELFT>, but may be an InputFile of InternalKind (for a synthetic
+  // section).
   InputFile *file;
 
   // Input sections are part of an output section. Special sections
@@ -132,8 +132,9 @@ class InputSectionBase : public SectionBase {
   // Section index of the relocation section if exists.
   uint32_t relSecIdx = 0;
 
+  // Getter when the dynamic type is ObjFile<ELFT>.
   template <class ELFT> ObjFile<ELFT> *getFile() const {
-    return cast_or_null<ObjFile<ELFT>>(file);
+    return cast<ObjFile<ELFT>>(file);
   }
 
   // Used by --optimize-bb-jumps and RISC-V linker relaxation temporarily to