[PATCH] D32016: [ELF] - Linkerscript: make section with no content to be SHT_PROGBITS by default.

[George Rimar via Phabricator via llvm-commits]

grimar created this revision.

Imagine next script:

  SECTIONS { BYTE(0x11); }

Section content written to disk will be 0x11. Previous LLD behavior was to make this
section SHT_NOBITS. What is not correct because section has content.
ld.bfd makes such sections SHT_PROGBITS, this patch do the same.

This fixes PR32537


https://reviews.llvm.org/D32016

Files:
  ELF/LinkerScript.cpp
  test/ELF/linkerscript/orphan-first-cmd.s
  test/ELF/linkerscript/symbol-only.s


Index: test/ELF/linkerscript/symbol-only.s
===================================================================
--- test/ELF/linkerscript/symbol-only.s
+++ test/ELF/linkerscript/symbol-only.s
@@ -12,7 +12,7 @@
 # CHECK:      Sections:
 # CHECK-NEXT: Idx Name          Size      Address
 # CHECK-NEXT:   0               00000000 0000000000000000
-# CHECK:          abc           00000000 [[ADDR:[0-9a-f]*]] BSS
+# CHECK:          abc           00000000 [[ADDR:[0-9a-f]*]] DATA
 # CHECK-NEXT:     bar           00000000 0000000000001000 DATA
 
 # CHECK: SYMBOL TABLE:
Index: test/ELF/linkerscript/orphan-first-cmd.s
===================================================================
--- test/ELF/linkerscript/orphan-first-cmd.s
+++ test/ELF/linkerscript/orphan-first-cmd.s
@@ -4,7 +4,7 @@
 # RUN:         foo = 123; \
 # RUN:         . = 0x1000; \
 # RUN:         . = 0x2000; \
-# RUN:         .bar : { . = . + 1; } \
+# RUN:         .bar : { *(.bar) } \
 # RUN:       }" > %t.script
 # RUN: ld.lld -o %t -T %t.script %t.o -shared
 # RUN: llvm-readobj -s %t | FileCheck %s
@@ -16,3 +16,5 @@
 # CHECK-NEXT:   SHF_EXECINSTR
 # CHECK-NEXT: ]
 # CHECK-NEXT: Address: 0x1000
+
+.section .bar, "aw"
Index: ELF/LinkerScript.cpp
===================================================================
--- ELF/LinkerScript.cpp
+++ ELF/LinkerScript.cpp
@@ -627,7 +627,7 @@
   // '.' is assigned to, but creating these section should not have any bad
   // consequeces and gives us a section to put the symbol in.
   uint64_t Flags = SHF_ALLOC;
-  uint32_t Type = SHT_NOBITS;
+  uint32_t Type = SHT_PROGBITS;
   for (BaseCommand *Base : Opt.Commands) {
     auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
     if (!Cmd)


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