[llvm] r241674 - [yaml2obj] Align section content using AddressAlign field's value

[Simon Atanasyan]

Author: atanasyan
Date: Wed Jul  8 05:12:40 2015
New Revision: 241674

URL: http://llvm.org/viewvc/llvm-project?rev=241674&view=rev
Log:
[yaml2obj] Align section content using AddressAlign field's value

Use AddressAlign field's value to properly align sections content in the
yaml2obj tool. Before this change the yaml2obj ignored AddressAlign and
always aligned section on 16 bytes boundary.

Added:
    llvm/trunk/test/Object/yaml2obj-elf-alignment.yaml
Modified:
    llvm/trunk/tools/yaml2obj/yaml2elf.cpp

Added: llvm/trunk/test/Object/yaml2obj-elf-alignment.yaml
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/yaml2obj-elf-alignment.yaml?rev=241674&view=auto
==============================================================================
--- llvm/trunk/test/Object/yaml2obj-elf-alignment.yaml (added)
+++ llvm/trunk/test/Object/yaml2obj-elf-alignment.yaml Wed Jul  8 05:12:40 2015
@@ -0,0 +1,53 @@
+# Check that yaml2obj takes in account section AddressAlign field.
+
+# RUN: yaml2obj -format=elf %s > %t
+# RUN: llvm-readobj -s %t | FileCheck %s
+
+# CHECK:      Section {
+# CHECK:        Index: 2
+# CHECK-NEXT:   Name: .data
+# CHECK-NEXT:   Type: SHT_PROGBITS
+# CHECK-NEXT:   Flags [
+# CHECK-NEXT:     SHF_ALLOC
+# CHECK-NEXT:     SHF_WRITE
+# CHECK-NEXT:   ]
+# CHECK-NEXT:   Address: 0x0
+# CHECK-NEXT:   Offset: 0x{{[0-9A-F]*}}00
+# CHECK-NEXT:   Size: 4
+# CHECK-NEXT:   Link: 0
+# CHECK-NEXT:   Info: 0
+# CHECK-NEXT:   AddressAlignment: 256
+# CHECK-NEXT:   EntrySize: 0
+# CHECK-NEXT: }
+
+---
+FileHeader:
+  Class:    ELFCLASS32
+  Data:     ELFDATA2LSB
+  Type:     ET_REL
+  Machine:  EM_MIPS
+  Flags:    [ EF_MIPS_CPIC, EF_MIPS_ABI_O32, EF_MIPS_ARCH_32 ]
+
+Sections:
+  - Name:          .text
+    Type:          SHT_PROGBITS
+    Flags:         [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:  8
+    Size:          4
+  - Name:          .data
+    Type:          SHT_PROGBITS
+    Flags:         [ SHF_WRITE, SHF_ALLOC ]
+    AddressAlign:  256
+    Size:          4
+
+Symbols:
+  Global:
+    - Name:     T0
+      Type:     STT_FUNC
+      Section:  .text
+      Size:     4
+    - Name:     D0
+      Type:     STT_OBJECT
+      Section:  .data
+      Size:     4
+...

Modified: llvm/trunk/tools/yaml2obj/yaml2elf.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/yaml2obj/yaml2elf.cpp?rev=241674&r1=241673&r2=241674&view=diff
==============================================================================
--- llvm/trunk/tools/yaml2obj/yaml2elf.cpp (original)
+++ llvm/trunk/tools/yaml2obj/yaml2elf.cpp Wed Jul  8 05:12:40 2015
@@ -35,6 +35,8 @@ class ContiguousBlobAccumulator {
 
   /// \returns The new offset.
   uint64_t padToAlignment(unsigned Align) {
+    if (Align == 0)
+      Align = 1;
     uint64_t CurrentOffset = InitialOffset + OS.tell();
     uint64_t AlignedOffset = RoundUpToAlignment(CurrentOffset, Align);
     for (; CurrentOffset != AlignedOffset; ++CurrentOffset)
@@ -46,7 +48,7 @@ public:
   ContiguousBlobAccumulator(uint64_t InitialOffset_)
       : InitialOffset(InitialOffset_), Buf(), OS(Buf) {}
   template <class Integer>
-  raw_ostream &getOSAndAlignedOffset(Integer &Offset, unsigned Align = 16) {
+  raw_ostream &getOSAndAlignedOffset(Integer &Offset, unsigned Align) {
     Offset = padToAlignment(Align);
     return OS;
   }
@@ -246,7 +248,7 @@ bool ELFState<ELFT>::initSectionHeaders(
       SHeader.sh_size = S->Size;
       // SHT_NOBITS section does not have content
       // so just to setup the section offset.
-      CBA.getOSAndAlignedOffset(SHeader.sh_offset);
+      CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
     } else
       llvm_unreachable("Unknown section type");
 
@@ -287,8 +289,9 @@ void ELFState<ELFT>::initSymtabSectionHe
   addSymbols(Doc.Symbols.Global, Syms, ELF::STB_GLOBAL);
   addSymbols(Doc.Symbols.Weak, Syms, ELF::STB_WEAK);
 
-  writeArrayData(CBA.getOSAndAlignedOffset(SHeader.sh_offset),
-                 makeArrayRef(Syms));
+  writeArrayData(
+      CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign),
+      makeArrayRef(Syms));
   SHeader.sh_size = arrayDataSize(makeArrayRef(Syms));
 }
 
@@ -299,7 +302,8 @@ void ELFState<ELFT>::initStrtabSectionHe
   zero(SHeader);
   SHeader.sh_name = DotShStrtab.getOffset(Name);
   SHeader.sh_type = ELF::SHT_STRTAB;
-  CBA.getOSAndAlignedOffset(SHeader.sh_offset) << STB.data();
+  CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign)
+      << STB.data();
   SHeader.sh_size = STB.data().size();
   SHeader.sh_addralign = 1;
 }
@@ -337,7 +341,8 @@ ELFState<ELFT>::writeSectionContent(Elf_
                                     ContiguousBlobAccumulator &CBA) {
   assert(Section.Size >= Section.Content.binary_size() &&
          "Section size and section content are inconsistent");
-  raw_ostream &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset);
+  raw_ostream &OS =
+      CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
   Section.Content.writeAsBinary(OS);
   for (auto i = Section.Content.binary_size(); i < Section.Size; ++i)
     OS.write(0);
@@ -364,7 +369,7 @@ ELFState<ELFT>::writeSectionContent(Elf_
   SHeader.sh_entsize = IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel);
   SHeader.sh_size = SHeader.sh_entsize * Section.Relocations.size();
 
-  auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset);
+  auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
 
   for (const auto &Rel : Section.Relocations) {
     unsigned SymIdx = 0;
@@ -402,7 +407,7 @@ bool ELFState<ELFT>::writeSectionContent
   SHeader.sh_entsize = sizeof(Elf_Word);
   SHeader.sh_size = SHeader.sh_entsize * Section.Members.size();
 
-  auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset);
+  auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
 
   for (auto member : Section.Members) {
     Elf_Word SIdx;
@@ -433,7 +438,7 @@ bool ELFState<ELFT>::writeSectionContent
   SHeader.sh_entsize = sizeof(Flags);
   SHeader.sh_size = SHeader.sh_entsize;
 
-  auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset);
+  auto &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset, SHeader.sh_addralign);
   Flags.version = Section.Version;
   Flags.isa_level = Section.ISALevel;
   Flags.isa_rev = Section.ISARevision;