[llvm] r315346 - [llvm-objcopy] Add support for removing sections
Jake Ehrlich via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 10 11:47:09 PDT 2017
Author: jakehehrlich
Date: Tue Oct 10 11:47:09 2017
New Revision: 315346
URL: http://llvm.org/viewvc/llvm-project?rev=315346&view=rev
Log:
[llvm-objcopy] Add support for removing sections
This change adds support for removing sections using the -R field (as
GNU objcopy does as well). This change should let us add many helpful
tests and is a proper stepping stone for adding more general kinds of
stripping.
Differential Revision: https://reviews.llvm.org/D38260
Added:
llvm/trunk/test/tools/llvm-objcopy/dynsym-error-remove-strtab.test
llvm/trunk/test/tools/llvm-objcopy/reloc-error-remove-symtab.test
llvm/trunk/test/tools/llvm-objcopy/remove-section-with-symbol.test
llvm/trunk/test/tools/llvm-objcopy/remove-section.test
llvm/trunk/test/tools/llvm-objcopy/remove-shstrtab-error.test
llvm/trunk/test/tools/llvm-objcopy/remove-symtab.test
llvm/trunk/test/tools/llvm-objcopy/segment-shift-section-remove.test
llvm/trunk/test/tools/llvm-objcopy/segment-test-remove-section.test
llvm/trunk/test/tools/llvm-objcopy/symtab-error-on-remove-strtab.test
Modified:
llvm/trunk/tools/llvm-objcopy/Object.cpp
llvm/trunk/tools/llvm-objcopy/Object.h
llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp
Added: llvm/trunk/test/tools/llvm-objcopy/dynsym-error-remove-strtab.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/dynsym-error-remove-strtab.test?rev=315346&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/dynsym-error-remove-strtab.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/dynsym-error-remove-strtab.test Tue Oct 10 11:47:09 2017
@@ -0,0 +1,3 @@
+# RUN: not llvm-objcopy -R .dynstr %p/Inputs/dynsym.so %t 2>&1 >/dev/null | FileCheck %s
+
+# CHECK: String table .dynstr cannot be removed because it is referenced by the section .dynsym
Added: llvm/trunk/test/tools/llvm-objcopy/reloc-error-remove-symtab.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/reloc-error-remove-symtab.test?rev=315346&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/reloc-error-remove-symtab.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/reloc-error-remove-symtab.test Tue Oct 10 11:47:09 2017
@@ -0,0 +1,32 @@
+# RUN: yaml2obj %s > %t
+# RUN: not llvm-objcopy -R .symtab %t %t2 2>&1 >/dev/null | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+Sections:
+ - Name: .text
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Address: 0x1000
+ AddressAlign: 0x0000000000000010
+ Content: "0000000000000000"
+ - Name: .rel.text
+ Type: SHT_REL
+ Link: .symtab
+ Info: .text
+ Relocations:
+ - Offset: 0x1000
+ Symbol: foo
+ Type: R_X86_64_PC32
+
+Symbols:
+ Global:
+ - Name: foo
+ Type: STT_FUNC
+ Size: 4
+
+# CHECK: Symbol table .symtab cannot be removed because it is referenced by the relocation section .rel.text.
Added: llvm/trunk/test/tools/llvm-objcopy/remove-section-with-symbol.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/remove-section-with-symbol.test?rev=315346&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/remove-section-with-symbol.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/remove-section-with-symbol.test Tue Oct 10 11:47:09 2017
@@ -0,0 +1,54 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy -R .test %t %t2
+# RUN: llvm-readobj -file-headers -symbols %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+Sections:
+ - Name: .test
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC ]
+ - Name: .test2
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC ]
+Symbols:
+ Global:
+ - Name: test
+ Type: STT_FUNC
+ Section: .test
+ Value: 0x1000
+ Size: 4
+ - Name: test2
+ Type: STT_FUNC
+ Section: .test2
+ Value: 0x1000
+ Size: 4
+
+# The sections counted here should be .test, .symtab, .strtab, and .shstrtab.
+# The 5th section is the null section.
+#CHECK: SectionHeaderCount: 5
+
+#CHECK: Symbols [
+#CHECK-NEXT: Symbol {
+#CHECK-NEXT: Name:
+#CHECK-NEXT: Value: 0x0
+#CHECK-NEXT: Size: 0
+#CHECK-NEXT: Binding: Local
+#CHECK-NEXT: Type: None
+#CHECK-NEXT: Other: 0
+#CHECK-NEXT: Section: Undefined
+#CHECK-NEXT: }
+#CHECK-NEXT: Symbol {
+#CHECK-NEXT: Name: test2
+#CHECK-NEXT: Value: 0x1000
+#CHECK-NEXT: Size: 4
+#CHECK-NEXT: Binding: Global
+#CHECK-NEXT: Type: Function
+#CHECK-NEXT: Other: 0
+#CHECK-NEXT: Section: .test2
+#CHECK-NEXT: }
+#CHECK-NEXT:]
Added: llvm/trunk/test/tools/llvm-objcopy/remove-section.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/remove-section.test?rev=315346&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/remove-section.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/remove-section.test Tue Oct 10 11:47:09 2017
@@ -0,0 +1,109 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy -R=.test2 %t %t2
+# RUN: llvm-readobj -file-headers -sections %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+Sections:
+ - Name: .test1
+ Type: SHT_PROGBITS
+ Flags: [ ]
+ - Name: .test2
+ Type: SHT_PROGBITS
+ Flags: [ ]
+ - Name: .test3
+ Type: SHT_PROGBITS
+ Flags: [ ]
+
+# CHECK: SectionHeaderCount: 6
+
+# CHECK: Sections [
+# CHECK: Section {
+# CHECK: Index: 0
+# CHECK: Name: (0)
+# CHECK: Type: SHT_NULL (0x0)
+# CHECK: Flags [ (0x0)
+# CHECK: ]
+# CHECK: Address: 0x0
+# CHECK: Offset:
+# CHECK: Size:
+# CHECK: Link: 0
+# CHECK: Info: 0
+# CHECK: AddressAlignment: 0
+# CHECK: EntrySize: 0
+# CHECK: }
+# CHECK: Section {
+# CHECK: Index: 1
+# CHECK: Name: .test1
+# CHECK: Type: SHT_PROGBITS (0x1)
+# CHECK: Flags [ (0x0)
+# CHECK: ]
+# CHECK: Address: 0x0
+# CHECK: Offset:
+# CHECK: Size:
+# CHECK: Link: 0
+# CHECK: Info: 0
+# CHECK: AddressAlignment: 0
+# CHECK: EntrySize: 0
+# CHECK: }
+# CHECK: Section {
+# CHECK: Index: 2
+# CHECK: Name: .test3
+# CHECK: Type: SHT_PROGBITS (0x1)
+# CHECK: Flags [ (0x0)
+# CHECK: ]
+# CHECK: Address: 0x0
+# CHECK: Offset:
+# CHECK: Size:
+# CHECK: Link: 0
+# CHECK: Info: 0
+# CHECK: AddressAlignment: 0
+# CHECK: EntrySize: 0
+# CHECK: }
+# CHECK: Section {
+# CHECK: Index: 3
+# CHECK: Name: .symtab
+# CHECK: Type: SHT_SYMTAB (0x2)
+# CHECK: Flags [ (0x0)
+# CHECK: ]
+# CHECK: Address: 0x0
+# CHECK: Offset:
+# CHECK: Size:
+# CHECK: Link: 4
+# CHECK: Info: 1
+# CHECK: AddressAlignment: 8
+# CHECK: EntrySize: 24
+# CHECK: }
+# CHECK: Section {
+# CHECK: Index: 4
+# CHECK: Name: .strtab
+# CHECK: Type: SHT_STRTAB (0x3)
+# CHECK: Flags [ (0x0)
+# CHECK: ]
+# CHECK: Address: 0x0
+# CHECK: Offset:
+# CHECK: Size:
+# CHECK: Link: 0
+# CHECK: Info: 0
+# CHECK: AddressAlignment: 1
+# CHECK: EntrySize: 0
+# CHECK: }
+# CHECK: Section {
+# CHECK: Index: 5
+# CHECK: Name: .shstrtab
+# CHECK: Type: SHT_STRTAB (0x3)
+# CHECK: Flags [ (0x0)
+# CHECK: ]
+# CHECK: Address: 0x0
+# CHECK: Offset:
+# CHECK: Size:
+# CHECK: Link: 0
+# CHECK: Info: 0
+# CHECK: AddressAlignment: 1
+# CHECK: EntrySize: 0
+# CHECK: }
+# CHECK: ]
Added: llvm/trunk/test/tools/llvm-objcopy/remove-shstrtab-error.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/remove-shstrtab-error.test?rev=315346&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/remove-shstrtab-error.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/remove-shstrtab-error.test Tue Oct 10 11:47:09 2017
@@ -0,0 +1,11 @@
+# RUN: yaml2obj %s > %t
+# RUN: not llvm-objcopy -R .shstrtab %t %t2 2>&1 >/dev/null | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+
+# CHECK: Cannot remove .shstrtab because it is the section header string table.
Added: llvm/trunk/test/tools/llvm-objcopy/remove-symtab.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/remove-symtab.test?rev=315346&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/remove-symtab.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/remove-symtab.test Tue Oct 10 11:47:09 2017
@@ -0,0 +1,57 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy -R .symtab %t %t2
+# RUN: llvm-readobj -file-headers -sections %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+
+#CHECK: SectionHeaderCount: 3
+
+#CHECK: Sections [
+#CHECK-NEXT: Section {
+#CHECK-NEXT: Index: 0
+#CHECK-NEXT: Name: (0)
+#CHECK-NEXT: Type: SHT_NULL (0x0)
+#CHECK-NEXT: Flags [ (0x0)
+#CHECK-NEXT: ]
+#CHECK-NEXT: Address: 0x0
+#CHECK-NEXT: Offset: 0x0
+#CHECK-NEXT: Size: 0
+#CHECK-NEXT: Link: 0
+#CHECK-NEXT: Info: 0
+#CHECK-NEXT: AddressAlignment: 0
+#CHECK-NEXT: EntrySize: 0
+#CHECK-NEXT: }
+#CHECK-NEXT: Section {
+#CHECK-NEXT: Index: 1
+#CHECK-NEXT: Name: .strtab
+#CHECK-NEXT: Type: SHT_STRTAB (0x3)
+#CHECK-NEXT: Flags [ (0x0)
+#CHECK-NEXT: ]
+#CHECK-NEXT: Address: 0x0
+#CHECK-NEXT: Offset:
+#CHECK-NEXT: Size: 1
+#CHECK-NEXT: Link: 0
+#CHECK-NEXT: Info: 0
+#CHECK-NEXT: AddressAlignment: 1
+#CHECK-NEXT: EntrySize: 0
+#CHECK-NEXT: }
+#CHECK-NEXT: Section {
+#CHECK-NEXT: Index: 2
+#CHECK-NEXT: Name: .shstrtab (1)
+#CHECK-NEXT: Type: SHT_STRTAB (0x3)
+#CHECK-NEXT: Flags [ (0x0)
+#CHECK-NEXT: ]
+#CHECK-NEXT: Address: 0x0
+#CHECK-NEXT: Offset:
+#CHECK-NEXT: Size:
+#CHECK-NEXT: Link: 0
+#CHECK-NEXT: Info: 0
+#CHECK-NEXT: AddressAlignment: 1
+#CHECK-NEXT: EntrySize: 0
+#CHECK-NEXT: }
+#CHECK-NEXT: ]
Added: llvm/trunk/test/tools/llvm-objcopy/segment-shift-section-remove.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/segment-shift-section-remove.test?rev=315346&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/segment-shift-section-remove.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/segment-shift-section-remove.test Tue Oct 10 11:47:09 2017
@@ -0,0 +1,164 @@
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-objcopy -R .text2 %t %t2
+# RUN: llvm-readobj -file-headers -sections -program-headers %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_EXEC
+ Machine: EM_X86_64
+Sections:
+ - Name: .text
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Address: 0x1000
+ AddressAlign: 0x1000
+ Size: 0x1000
+ - Name: .text2
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Address: 0x2000
+ AddressAlign: 0x1000
+ Size: 0x1000
+ - Name: .text3
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Address: 0x3000
+ AddressAlign: 0x1000
+ Size: 0x1000
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_R ]
+ VAddr: 0x1000
+ PAddr: 0x1000
+ Sections:
+ - Section: .text
+ - Type: PT_LOAD
+ Flags: [ PF_X, PF_R ]
+ VAddr: 0x3000
+ PAddr: 0x3000
+ Sections:
+ - Section: .text3
+
+#CHECK: SectionHeaderCount: 6
+
+# CHECK: Sections [
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 0
+# CHECK-NEXT: Name: (0)
+# CHECK-NEXT: Type: SHT_NULL (0x0)
+# CHECK-NEXT: Flags [ (0x0)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x0
+# CHECK-NEXT: Offset: 0x0
+# CHECK-NEXT: Size: 0
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 0
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 1
+# CHECK-NEXT: Name: .text
+# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
+# CHECK-NEXT: Flags [ (0x6)
+# CHECK-NEXT: SHF_ALLOC (0x2)
+# CHECK-NEXT: SHF_EXECINSTR (0x4)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x1000
+# CHECK-NEXT: Offset: 0x1000
+# CHECK-NEXT: Size: 4096
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 4096
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 2
+# CHECK-NEXT: Name: .text3
+# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
+# CHECK-NEXT: Flags [ (0x6)
+# CHECK-NEXT: SHF_ALLOC (0x2)
+# CHECK-NEXT: SHF_EXECINSTR (0x4)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x3000
+# CHECK-NEXT: Offset: 0x2000
+# CHECK-NEXT: Size: 4096
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 4096
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 3
+# CHECK-NEXT: Name: .symtab
+# CHECK-NEXT: Type: SHT_SYMTAB (0x2)
+# CHECK-NEXT: Flags [ (0x0)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x0
+# CHECK-NEXT: Offset: 0x3000
+# CHECK-NEXT: Size: 24
+# CHECK-NEXT: Link: 4
+# CHECK-NEXT: Info: 1
+# CHECK-NEXT: AddressAlignment: 8
+# CHECK-NEXT: EntrySize: 24
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 4
+# CHECK-NEXT: Name: .strtab
+# CHECK-NEXT: Type: SHT_STRTAB (0x3)
+# CHECK-NEXT: Flags [ (0x0)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x0
+# CHECK-NEXT: Offset: 0x3018
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 1
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 5
+# CHECK-NEXT: Name: .shstrtab
+# CHECK-NEXT: Type: SHT_STRTAB (0x3)
+# CHECK-NEXT: Flags [ (0x0)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x0
+# CHECK-NEXT: Offset:
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 1
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: ]
+
+
+# CHECK: ProgramHeaders [
+# CHECK-NEXT: ProgramHeader {
+# CHECK-NEXT: Type: PT_LOAD (0x1)
+# CHECK-NEXT: Offset: 0x1000
+# CHECK-NEXT: VirtualAddress: 0x1000
+# CHECK-NEXT: PhysicalAddress: 0x1000
+# CHECK-NEXT: FileSize: 4096
+# CHECK-NEXT: MemSize: 4096
+# CHECK-NEXT: Flags [ (0x4)
+# CHECK-NEXT: PF_R (0x4)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Alignment: 4096
+# CHECK-NEXT: }
+# CHECK-NEXT: ProgramHeader {
+# CHECK-NEXT: Type: PT_LOAD (0x1)
+# CHECK-NEXT: Offset: 0x2000
+# CHECK-NEXT: VirtualAddress: 0x3000
+# CHECK-NEXT: PhysicalAddress: 0x3000
+# CHECK-NEXT: FileSize: 4096
+# CHECK-NEXT: MemSize: 4096
+# CHECK-NEXT: Flags [ (0x5)
+# CHECK-NEXT: PF_R (0x4)
+# CHECK-NEXT: PF_X (0x1)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Alignment: 4096
+# CHECK-NEXT: }
+# CHECK-NEXT:]
Added: llvm/trunk/test/tools/llvm-objcopy/segment-test-remove-section.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/segment-test-remove-section.test?rev=315346&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/segment-test-remove-section.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/segment-test-remove-section.test Tue Oct 10 11:47:09 2017
@@ -0,0 +1,156 @@
+# This test is checking to ensure that if a section is removed in the presence
+# of a segment that the segment maintains its shape and properties and that any
+# section inside that segment maintains the relative positioning it had in the
+# segment. Note worthy is that .text3 keeps its offset despite it being
+# possible to place it after .text when .text2 is removed.
+
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-objcopy -R .text2 %t %t2
+# RUN: llvm-readobj -file-headers -program-headers -sections %t2 | FileCheck %s
+# RUN: od -t x1 -j 8192 %t2 | FileCheck %s --check-prefix=DATA
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_EXEC
+ Machine: EM_X86_64
+Sections:
+ - Name: .text
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Address: 0x1000
+ AddressAlign: 0x1000
+ Size: 4096
+ - Name: .text2
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Address: 0x2000
+ AddressAlign: 0x1000
+ Size: 4096
+ Content: "DEADBEEF"
+ - Name: .text3
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Address: 0x3000
+ AddressAlign: 0x1000
+ Size: 4096
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_X, PF_R ]
+ Sections:
+ - Section: .text
+ - Section: .text2
+ - Section: .text3
+
+# Make sure that when we remove a section we overwrite it with zeros
+# DATA: 0020000 00 00 00 00
+
+#CHECK: SectionHeaderCount: 6
+
+# CHECK: Sections [
+# CHECK: Section {
+# CHECK-NEXT: Index: 0
+# CHECK-NEXT: Name: (0)
+# CHECK-NEXT: Type: SHT_NULL (0x0)
+# CHECK-NEXT: Flags [ (0x0)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x0
+# CHECK-NEXT: Offset:
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 0
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 1
+# CHECK-NEXT: Name: .text
+# CHECK-NEXT: Type: SHT_PROGBITS
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: SHF_ALLOC
+# CHECK-NEXT: SHF_EXECINSTR
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x1000
+# CHECK-NEXT: Offset: 0x1000
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 4096
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 2
+# CHECK-NEXT: Name: .text3
+# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: SHF_ALLOC
+# CHECK-NEXT: SHF_EXECINSTR
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x3000
+# CHECK-NEXT: Offset: 0x3000
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 4096
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 3
+# CHECK-NEXT: Name: .symtab
+# CHECK-NEXT: Type: SHT_SYMTAB (0x2)
+# CHECK-NEXT: Flags [ (0x0)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x0
+# CHECK-NEXT: Offset:
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Link: 4
+# CHECK-NEXT: Info: 1
+# CHECK-NEXT: AddressAlignment: 8
+# CHECK-NEXT: EntrySize: 24
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 4
+# CHECK-NEXT: Name: .strtab
+# CHECK-NEXT: Type: SHT_STRTAB (0x3)
+# CHECK-NEXT: Flags [ (0x0)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x0
+# CHECK-NEXT: Offset:
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 1
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: Section {
+# CHECK-NEXT: Index: 5
+# CHECK-NEXT: Name: .shstrtab
+# CHECK-NEXT: Type: SHT_STRTAB (0x3)
+# CHECK-NEXT: Flags [ (0x0)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x0
+# CHECK-NEXT: Offset:
+# CHECK-NEXT: Size:
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 1
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: }
+# CHECK-NEXT: ]
+
+#CHECK: ProgramHeaders [
+#CHECK-NEXT: ProgramHeader {
+#CHECK-NEXT: Type: PT_LOAD (0x1)
+#CHECK-NEXT: Offset: 0x1000
+#CHECK-NEXT: VirtualAddress: 0x0
+#CHECK-NEXT: PhysicalAddress: 0x0
+#CHECK-NEXT: FileSize: 12288
+#CHECK-NEXT: MemSize: 12288
+#CHECK-NEXT: Flags [ (0x5)
+#CHECK-NEXT: PF_R (0x4)
+#CHECK-NEXT: PF_X (0x1)
+#CHECK-NEXT: ]
+#CHECK-NEXT: Alignment: 4096
+#CHECK-NEXT: }
+#CHECK-NEXT:]
Added: llvm/trunk/test/tools/llvm-objcopy/symtab-error-on-remove-strtab.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/symtab-error-on-remove-strtab.test?rev=315346&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/symtab-error-on-remove-strtab.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/symtab-error-on-remove-strtab.test Tue Oct 10 11:47:09 2017
@@ -0,0 +1,11 @@
+# RUN: yaml2obj %s > %t
+# RUN: not llvm-objcopy -R .strtab %t %t2 2>&1 >/dev/null | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+
+# CHECK: String table .strtab cannot be removed because it is referenced by the symbol table .symtab
Modified: llvm/trunk/tools/llvm-objcopy/Object.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/Object.cpp?rev=315346&r1=315345&r2=315346&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/Object.cpp (original)
+++ llvm/trunk/tools/llvm-objcopy/Object.cpp Tue Oct 10 11:47:09 2017
@@ -37,6 +37,7 @@ void Segment::writeSegment(FileOutputBuf
std::copy(std::begin(Contents), std::end(Contents), Buf);
}
+void SectionBase::removeSectionReferences(const SectionBase *Sec) {}
void SectionBase::initialize(SectionTableRef SecTable) {}
void SectionBase::finalize() {}
@@ -138,6 +139,19 @@ void SymbolTableSection::addSymbol(Strin
Size += this->EntrySize;
}
+void SymbolTableSection::removeSectionReferences(const SectionBase *Sec) {
+ if (SymbolNames == Sec) {
+ error("String table " + SymbolNames->Name +
+ " cannot be removed because it is referenced by the symbol table " +
+ this->Name);
+ }
+ auto Iter =
+ std::remove_if(std::begin(Symbols), std::end(Symbols),
+ [=](const SymPtr &Sym) { return Sym->DefinedIn == Sec; });
+ Size -= (std::end(Symbols) - Iter) * this->EntrySize;
+ Symbols.erase(Iter, std::end(Symbols));
+}
+
void SymbolTableSection::initialize(SectionTableRef SecTable) {
Size = 0;
setStrTab(SecTable.getSectionOfType<StringTableSection>(
@@ -195,7 +209,19 @@ void SymbolTableSectionImpl<ELFT>::write
}
template <class SymTabType>
-void RelocationSectionBase<SymTabType>::initialize(SectionTableRef SecTable) {
+void RelocSectionWithSymtabBase<SymTabType>::removeSectionReferences(
+ const SectionBase *Sec) {
+ if (Symbols == Sec) {
+ error("Symbol table " + Symbols->Name + " cannot be removed because it is "
+ "referenced by the relocation "
+ "section " +
+ this->Name);
+ }
+}
+
+template <class SymTabType>
+void RelocSectionWithSymtabBase<SymTabType>::initialize(
+ SectionTableRef SecTable) {
setSymTab(SecTable.getSectionOfType<SymTabType>(
Link,
"Link field value " + Twine(Link) + " in section " + Name + " is invalid",
@@ -210,7 +236,8 @@ void RelocationSectionBase<SymTabType>::
setSection(nullptr);
}
-template <class SymTabType> void RelocationSectionBase<SymTabType>::finalize() {
+template <class SymTabType>
+void RelocSectionWithSymtabBase<SymTabType>::finalize() {
this->Link = Symbols->Index;
if (SecToApplyRel != nullptr)
this->Info = SecToApplyRel->Index;
@@ -249,6 +276,14 @@ void DynamicRelocationSection::writeSect
Out.getBufferStart() + Offset);
}
+void SectionWithStrTab::removeSectionReferences(const SectionBase *Sec) {
+ if (StrTab == Sec) {
+ error("String table " + StrTab->Name + " cannot be removed because it is "
+ "referenced by the section " +
+ this->Name);
+ }
+}
+
bool SectionWithStrTab::classof(const SectionBase *S) {
return isa<DynamicSymbolTableSection>(S) || isa<DynamicSection>(S);
}
@@ -589,6 +624,41 @@ void Object<ELFT>::writeSectionData(File
Section->writeSection(Out);
}
+template <class ELFT>
+void Object<ELFT>::removeSections(
+ std::function<bool(const SectionBase &)> ToRemove) {
+
+ auto Iter = std::stable_partition(
+ std::begin(Sections), std::end(Sections), [=](const SecPtr &Sec) {
+ if (ToRemove(*Sec))
+ return false;
+ if (auto RelSec = dyn_cast<RelocationSectionBase>(Sec.get()))
+ return !ToRemove(*RelSec->getSection());
+ return true;
+ });
+ if (SymbolTable != nullptr && ToRemove(*SymbolTable))
+ SymbolTable = nullptr;
+ if (ToRemove(*SectionNames)) {
+ // Right now llvm-objcopy always outputs section headers. This will not
+ // always be the case. Eventully the section header table will become
+ // optional and if no section header is output then there dosn't need to be
+ // a section header string table.
+ error("Cannot remove " + SectionNames->Name +
+ " because it is the section header string table.");
+ }
+ // Now make sure there are no remaining references to the sections that will
+ // be removed. Sometimes it is impossible to remove a reference so we emit
+ // an error here instead.
+ for (auto &RemoveSec : make_range(Iter, std::end(Sections))) {
+ for (auto &Segment : Segments)
+ Segment->removeSection(RemoveSec.get());
+ for (auto &KeepSec : make_range(std::begin(Sections), Iter))
+ KeepSec->removeSectionReferences(RemoveSec.get());
+ }
+ // Now finally get rid of them all togethor.
+ Sections.erase(Iter, std::end(Sections));
+}
+
template <class ELFT> void ELFObject<ELFT>::sortSections() {
// Put all sections in offset order. Maintain the ordering as closely as
// possible while meeting that demand however.
@@ -692,7 +762,8 @@ template <class ELFT> void ELFObject<ELF
this->SectionNames->addString(Section->Name);
}
// Make sure we add the names of all the symbols.
- this->SymbolTable->addSymbolNames();
+ if (this->SymbolTable != nullptr)
+ this->SymbolTable->addSymbolNames();
sortSections();
assignOffsets();
Modified: llvm/trunk/tools/llvm-objcopy/Object.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/Object.h?rev=315346&r1=315345&r2=315346&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/Object.h (original)
+++ llvm/trunk/tools/llvm-objcopy/Object.h Tue Oct 10 11:47:09 2017
@@ -58,6 +58,7 @@ public:
virtual ~SectionBase() {}
virtual void initialize(SectionTableRef SecTable);
virtual void finalize();
+ virtual void removeSectionReferences(const SectionBase *Sec);
template <class ELFT> void writeHeader(llvm::FileOutputBuffer &Out) const;
virtual void writeSection(llvm::FileOutputBuffer &Out) const = 0;
};
@@ -98,7 +99,8 @@ public:
return *Sections.begin();
return nullptr;
}
- void addSection(const SectionBase *sec) { Sections.insert(sec); }
+ void removeSection(const SectionBase *Sec) { Sections.erase(Sec); }
+ void addSection(const SectionBase *Sec) { Sections.insert(Sec); }
template <class ELFT> void writeHeader(llvm::FileOutputBuffer &Out) const;
void writeSegment(llvm::FileOutputBuffer &Out) const;
};
@@ -164,6 +166,8 @@ protected:
std::vector<std::unique_ptr<Symbol>> Symbols;
StringTableSection *SymbolNames = nullptr;
+ typedef std::unique_ptr<Symbol> SymPtr;
+
public:
void setStrTab(StringTableSection *StrTab) { SymbolNames = StrTab; }
void addSymbol(llvm::StringRef Name, uint8_t Bind, uint8_t Type,
@@ -171,6 +175,7 @@ public:
uint64_t Sz);
void addSymbolNames();
const Symbol *getSymbolByIndex(uint32_t Index) const;
+ void removeSectionReferences(const SectionBase *Sec) override;
void initialize(SectionTableRef SecTable) override;
void finalize() override;
static bool classof(const SectionBase *S) {
@@ -190,20 +195,49 @@ struct Relocation {
uint32_t Type;
};
-template <class SymTabType> class RelocationSectionBase : public SectionBase {
+// All relocation sections denote relocations to apply to another section.
+// However, some relocation sections use a dynamic symbol table and others use
+// a regular symbol table. Because the types of the two symbol tables differ in
+// our system (because they should behave differently) we can't uniformly
+// represent all relocations with the same base class if we expose an interface
+// that mentions the symbol table type. So we split the two base types into two
+// different classes, one which handles the section the relocation is applied to
+// and another which handles the symbol table type. The symbol table type is
+// taken as a type parameter to the class (see RelocSectionWithSymtabBase).
+class RelocationSectionBase : public SectionBase {
+protected:
+ SectionBase *SecToApplyRel = nullptr;
+
+public:
+ const SectionBase *getSection() const { return SecToApplyRel; }
+ void setSection(SectionBase *Sec) { SecToApplyRel = Sec; }
+
+ static bool classof(const SectionBase *S) {
+ return S->Type == llvm::ELF::SHT_REL || S->Type == llvm::ELF::SHT_RELA;
+ }
+};
+
+// Takes the symbol table type to use as a parameter so that we can deduplicate
+// that code between the two symbol table types.
+template <class SymTabType>
+class RelocSectionWithSymtabBase : public RelocationSectionBase {
private:
SymTabType *Symbols = nullptr;
- SectionBase *SecToApplyRel = nullptr;
+
+protected:
+ RelocSectionWithSymtabBase() {}
public:
void setSymTab(SymTabType *StrTab) { Symbols = StrTab; }
- void setSection(SectionBase *Sec) { SecToApplyRel = Sec; }
+
+ void removeSectionReferences(const SectionBase *Sec) override;
void initialize(SectionTableRef SecTable) override;
void finalize() override;
};
template <class ELFT>
-class RelocationSection : public RelocationSectionBase<SymbolTableSection> {
+class RelocationSection
+ : public RelocSectionWithSymtabBase<SymbolTableSection> {
private:
typedef typename ELFT::Rel Elf_Rel;
typedef typename ELFT::Rela Elf_Rela;
@@ -230,6 +264,7 @@ private:
public:
SectionWithStrTab(llvm::ArrayRef<uint8_t> Data) : Section(Data) {}
void setStrTab(StringTableSection *StringTable) { StrTab = StringTable; }
+ void removeSectionReferences(const SectionBase *Sec) override;
void initialize(SectionTableRef SecTable) override;
void finalize() override;
static bool classof(const SectionBase *S);
@@ -253,7 +288,7 @@ public:
};
class DynamicRelocationSection
- : public RelocationSectionBase<DynamicSymbolTableSection> {
+ : public RelocSectionWithSymtabBase<DynamicSymbolTableSection> {
private:
llvm::ArrayRef<uint8_t> Contents;
@@ -304,6 +339,7 @@ public:
uint32_t Flags;
Object(const llvm::object::ELFObjectFile<ELFT> &Obj);
+ void removeSections(std::function<bool(const SectionBase &)> ToRemove);
virtual size_t totalSize() const = 0;
virtual void finalize() = 0;
virtual void write(llvm::FileOutputBuffer &Out) const = 0;
Modified: llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp?rev=315346&r1=315345&r2=315346&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp (original)
+++ llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp Tue Oct 10 11:47:09 2017
@@ -56,17 +56,24 @@ cl::opt<std::string> OutputFilename(cl::
cl::opt<std::string>
OutputFormat("O", cl::desc("set output format to one of the following:"
"\n\tbinary"));
+// TODO: make this a cl::list to support removing multiple sections
+cl::opt<std::string> ToRemove("remove-section",
+ cl::desc("Remove a specific section"));
+cl::alias ToRemoveA("R", cl::desc("Alias for remove-section"), cl::aliasopt(ToRemove));
void CopyBinary(const ELFObjectFile<ELF64LE> &ObjFile) {
std::unique_ptr<FileOutputBuffer> Buffer;
std::unique_ptr<Object<ELF64LE>> Obj;
if (!OutputFormat.empty() && OutputFormat != "binary")
error("invalid output format '" + OutputFormat + "'");
-
if (!OutputFormat.empty() && OutputFormat == "binary")
Obj = llvm::make_unique<BinaryObject<ELF64LE>>(ObjFile);
else
Obj = llvm::make_unique<ELFObject<ELF64LE>>(ObjFile);
+ if (!ToRemove.empty()) {
+ Obj->removeSections(
+ [&](const SectionBase &Sec) { return ToRemove == Sec.Name; });
+ }
Obj->finalize();
ErrorOr<std::unique_ptr<FileOutputBuffer>> BufferOrErr =
FileOutputBuffer::create(OutputFilename, Obj->totalSize(),
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