[lld] r275374 - Set sh_addralign to 1 instead of 0.

[Rui Ueyama via llvm-commits]

Author: ruiu
Date: Thu Jul 14 00:46:24 2016
New Revision: 275374

URL: http://llvm.org/viewvc/llvm-project?rev=275374&view=rev
Log:
Set sh_addralign to 1 instead of 0.

ELF spec says that alignment of 0 is equivalent to 1.
Previously, we arbitrary set to 0 or 1, but always setting to 1
makes our program simpler.

Modified:
    lld/trunk/ELF/OutputSections.cpp
    lld/trunk/ELF/OutputSections.h
    lld/trunk/test/ELF/eh-frame-hdr.s

Modified: lld/trunk/ELF/OutputSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.cpp?rev=275374&r1=275373&r2=275374&view=diff
==============================================================================
--- lld/trunk/ELF/OutputSections.cpp (original)
+++ lld/trunk/ELF/OutputSections.cpp Thu Jul 14 00:46:24 2016
@@ -37,6 +37,7 @@ OutputSectionBase<ELFT>::OutputSectionBa
   memset(&Header, 0, sizeof(Elf_Shdr));
   Header.sh_type = Type;
   Header.sh_flags = Flags;
+  Header.sh_addralign = 1;
 }
 
 template <class ELFT>
@@ -393,7 +394,6 @@ template <class ELFT>
 InterpSection<ELFT>::InterpSection()
     : OutputSectionBase<ELFT>(".interp", SHT_PROGBITS, SHF_ALLOC) {
   this->Header.sh_size = Config->DynamicLinker.size() + 1;
-  this->Header.sh_addralign = 1;
 }
 
 template <class ELFT> void InterpSection<ELFT>::writeTo(uint8_t *Buf) {
@@ -1247,9 +1247,7 @@ template <class ELFT>
 StringTableSection<ELFT>::StringTableSection(StringRef Name, bool Dynamic)
     : OutputSectionBase<ELFT>(Name, SHT_STRTAB,
                               Dynamic ? (uintX_t)SHF_ALLOC : 0),
-      Dynamic(Dynamic) {
-  this->Header.sh_addralign = 1;
-}
+      Dynamic(Dynamic) {}
 
 // Adds a string to the string table. If HashIt is true we hash and check for
 // duplicates. It is optional because the name of global symbols are already

Modified: lld/trunk/ELF/OutputSections.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.h?rev=275374&r1=275373&r2=275374&view=diff
==============================================================================
--- lld/trunk/ELF/OutputSections.h (original)
+++ lld/trunk/ELF/OutputSections.h Thu Jul 14 00:46:24 2016
@@ -67,12 +67,9 @@ public:
   void setSize(uintX_t Val) { Header.sh_size = Val; }
   uintX_t getFlags() const { return Header.sh_flags; }
   uintX_t getFileOff() const { return Header.sh_offset; }
-  uintX_t getAlignment() const {
-    // The ELF spec states that a value of 0 means the section has no alignment
-    // constraits.
-    return std::max<uintX_t>(Header.sh_addralign, 1);
-  }
+  uintX_t getAlignment() const { return Header.sh_addralign; }
   uint32_t getType() const { return Header.sh_type; }
+
   void updateAlignment(uintX_t Alignment) {
     if (Alignment > Header.sh_addralign)
       Header.sh_addralign = Alignment;

Modified: lld/trunk/test/ELF/eh-frame-hdr.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/eh-frame-hdr.s?rev=275374&r1=275373&r2=275374&view=diff
==============================================================================
--- lld/trunk/test/ELF/eh-frame-hdr.s (original)
+++ lld/trunk/test/ELF/eh-frame-hdr.s Thu Jul 14 00:46:24 2016
@@ -89,7 +89,7 @@ _start:
 // HDR-NEXT:    Size: 36
 // HDR-NEXT:    Link: 0
 // HDR-NEXT:    Info: 0
-// HDR-NEXT:    AddressAlignment: 0
+// HDR-NEXT:    AddressAlignment: 1
 // HDR-NEXT:    EntrySize: 0
 // HDR-NEXT:    SectionData (
 // HDR-NEXT:      0000: 011B033B 9CFFFFFF 03000000 480E0000  |