From c1034a85d08d61bd344b3923fdaaf7903fc329e4 Mon Sep 17 00:00:00 2001 From: George Rimar Date: Tue, 1 Mar 2016 19:12:35 +0000 Subject: [PATCH] [ELF] - do not create special symbols when creating relocatable output __start_/__end_ symbols and other specials like: preinit_array_start/end init_array_start/end fini_array_start/end should not be created by linker when creating relocatable files. Differential revision: http://reviews.llvm.org/D17774 llvm-svn: 262366 --- lld/ELF/Writer.cpp | 8 +- lld/test/ELF/relocatable-symbols.s | 183 +++++++++++++++++++++++++++++ 2 files changed, 188 insertions(+), 3 deletions(-) create mode 100644 lld/test/ELF/relocatable-symbols.s diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp index 1277994e6f35..cfb49203f786 100644 --- a/lld/ELF/Writer.cpp +++ b/lld/ELF/Writer.cpp @@ -1001,9 +1001,11 @@ template bool Writer::createSections() { // The linker needs to define SECNAME_start, SECNAME_end and SECNAME_stop // symbols for sections, so that the runtime can get the start and end // addresses of each section by section name. Add such symbols. - addStartEndSymbols(); - for (OutputSectionBase *Sec : RegularSections) - addStartStopSymbols(Sec); + if (!Config->Relocatable) { + addStartEndSymbols(); + for (OutputSectionBase *Sec : RegularSections) + addStartStopSymbols(Sec); + } if (isOutputDynamic()) Symtab.addSynthetic("_DYNAMIC", *Out::Dynamic, 0, STV_HIDDEN); diff --git a/lld/test/ELF/relocatable-symbols.s b/lld/test/ELF/relocatable-symbols.s new file mode 100644 index 000000000000..75ed17ec5f6f --- /dev/null +++ b/lld/test/ELF/relocatable-symbols.s @@ -0,0 +1,183 @@ +# REQUIRES: x86 +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t +# RUN: ld.lld -r %t -o %tout +# RUN: llvm-objdump -d %tout | FileCheck -check-prefix=DISASM %s +# RUN: llvm-readobj -symbols -r %tout | FileCheck -check-prefix=SYMBOL %s + +# DISASM: _start: +# DISASM-NEXT: 0: {{.*}} callq 0 +# DISASM-NEXT: 5: {{.*}} callq 0 +# DISASM-NEXT: a: {{.*}} callq 0 +# DISASM-NEXT: f: {{.*}} callq 0 +# DISASM-NEXT: 14: {{.*}} callq 0 +# DISASM-NEXT: 19: {{.*}} callq 0 +# DISASM-NEXT: 1e: {{.*}} callq 0 +# DISASM-NEXT: 23: {{.*}} callq 0 +# DISASM-NEXT: 28: {{.*}} callq 0 +# DISASM-NEXT: 2d: {{.*}} callq 0 +# DISASM-NEXT: 32: {{.*}} callq 0 +# DISASM-NEXT: 37: {{.*}} callq 0 +# DISASM-NEXT: Disassembly of section foo: +# DISASM-NEXT: foo: +# DISASM-NEXT: 0: 90 nop +# DISASM-NEXT: 1: 90 nop +# DISASM-NEXT: 2: 90 nop +# DISASM-NEXT: Disassembly of section bar: +# DISASM-NEXT: bar: +# DISASM-NEXT: 0: 90 nop +# DISASM-NEXT: 1: 90 nop +# DISASM-NEXT: 2: 90 nop + +# SYMBOL: Relocations [ +# SYMBOL-NEXT: Section ({{.*}}) .rela.text { +# SYMBOL-NEXT: 0x1 R_X86_64_PC32 __start_foo 0x0 +# SYMBOL-NEXT: 0x6 R_X86_64_PC32 __stop_foo 0x0 +# SYMBOL-NEXT: 0xB R_X86_64_PC32 __start_bar 0x0 +# SYMBOL-NEXT: 0x10 R_X86_64_PC32 __stop_bar 0x0 +# SYMBOL-NEXT: 0x15 R_X86_64_PC32 __start_doo 0x0 +# SYMBOL-NEXT: 0x1A R_X86_64_PC32 __stop_doo 0x0 +# SYMBOL-NEXT: 0x1F R_X86_64_PC32 __preinit_array_start 0x0 +# SYMBOL-NEXT: 0x24 R_X86_64_PC32 __preinit_array_end 0x0 +# SYMBOL-NEXT: 0x29 R_X86_64_PC32 __init_array_start 0x0 +# SYMBOL-NEXT: 0x2E R_X86_64_PC32 __init_array_end 0x0 +# SYMBOL-NEXT: 0x33 R_X86_64_PC32 __fini_array_start 0x0 +# SYMBOL-NEXT: 0x38 R_X86_64_PC32 __fini_array_end 0x0 +# SYMBOL-NEXT: } +# SYMBOL-NEXT: ] +# SYMBOL: Symbol { +# SYMBOL: Name: __fini_array_end +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __fini_array_start +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __init_array_end +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __init_array_start +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __preinit_array_end +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __preinit_array_start +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __start_bar +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __start_doo +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __start_foo +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __stop_bar +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __stop_doo +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } +# SYMBOL-NEXT: Symbol { +# SYMBOL-NEXT: Name: __stop_foo +# SYMBOL-NEXT: Value: 0x0 +# SYMBOL-NEXT: Size: 0 +# SYMBOL-NEXT: Binding: Global +# SYMBOL-NEXT: Type: None +# SYMBOL-NEXT: Other: 0 +# SYMBOL-NEXT: Section: Undefined +# SYMBOL-NEXT: } + +.global _start +.text +_start: + call __start_foo + call __stop_foo + + call __start_bar + call __stop_bar + + call __start_doo + call __stop_doo + + call __preinit_array_start + call __preinit_array_end + call __init_array_start + call __init_array_end + call __fini_array_start + call __fini_array_end + +.section foo,"ax" + nop + nop + nop + +.section bar,"ax" + nop + nop + nop