[PATCH] D27041: [ELF] - Disable emiting multiple output sections when merging is disabled.

[George Rimar via llvm-commits]

grimar updated this revision to Diff 79289.
grimar added a comment.

- Addressed review comments.


https://reviews.llvm.org/D27041

Files:
  ELF/InputSection.cpp
  test/ELF/merge-string.s
  test/ELF/no-merge.s


Index: test/ELF/no-merge.s
===================================================================
--- test/ELF/no-merge.s
+++ test/ELF/no-merge.s
@@ -0,0 +1,25 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+# RUN: echo "SECTIONS { .data : {*(.data.*)} }" > %t0.script
+# RUN: ld.lld %t.o -o %t0.out --script %t0.script
+# RUN: llvm-objdump -s %t0.out | FileCheck %s --check-prefix=OPT
+# OPT:      Contents of section .data:
+# OPT-NEXT:   0000 01
+# OPT-NEXT: Contents of section .data:
+# OPT-NEXT:   0001 6100
+# OPT-NEXT: Contents of section .data:
+# OPT-NEXT:   0003 03
+
+# RUN: ld.lld -O0 %t.o -o %t1.out --script %t0.script
+# RUN: llvm-objdump -s %t1.out | FileCheck %s --check-prefix=NOOPT
+# NOOPT:      Contents of section .data:
+# NOOPT-NEXT:   0000 01610003
+
+.section .data.aw,"aw", at progbits
+.byte 1
+
+.section .data.ams,"aMS", at progbits,1
+.asciz "a"
+
+.section .data.am,"aM", at progbits,1
+.byte 3
Index: test/ELF/merge-string.s
===================================================================
--- test/ELF/merge-string.s
+++ test/ELF/merge-string.s
@@ -61,8 +61,6 @@
 // NOMERGE-NEXT: Type:    SHT_PROGBITS
 // NOMERGE-NEXT: Flags [
 // NOMERGE-NEXT:   SHF_ALLOC
-// NOMERGE-NEXT:   SHF_MERGE
-// NOMERGE-NEXT:   SHF_STRINGS
 // NOMERGE-NEXT: ]
 // NOMERGE-NEXT: Address:         0x1C8
 // NOMERGE-NEXT: Offset:  0x1C8
Index: ELF/InputSection.cpp
===================================================================
--- ELF/InputSection.cpp
+++ ELF/InputSection.cpp
@@ -53,6 +53,15 @@
   return (Flags & SHF_COMPRESSED) || Name.startswith(".zdebug");
 }
 
+// We do not do merge of sections in case when optimization is disabled,
+// drop the flags in that case to stop produce multiple output sections.
+template <class ELFT>
+static typename ELFT::uint filter(typename ELFT::uint Flags) {
+  if (Config->Optimize == 0)
+    return Flags & ~(SHF_MERGE | SHF_STRINGS);
+  return Flags;
+}
+
 template <class ELFT>
 InputSectionBase<ELFT>::InputSectionBase(elf::ObjectFile<ELFT> *File,
                                          uintX_t Flags, uint32_t Type,
@@ -62,8 +71,8 @@
                                          Kind SectionKind)
     : InputSectionData(SectionKind, Name, Data, isCompressed<ELFT>(Flags, Name),
                        !Config->GcSections || !(Flags & SHF_ALLOC)),
-      File(File), Flags(Flags), Entsize(Entsize), Type(Type), Link(Link),
-      Info(Info), Repl(this) {
+      File(File), Flags(filter<ELFT>(Flags)), Entsize(Entsize), Type(Type),
+      Link(Link), Info(Info), Repl(this) {
   NumRelocations = 0;
   AreRelocsRela = false;
 


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