[lld] r206358 - [Mips] Emit PLT entries for more static relocations.
Simon Atanasyan
simon at atanasyan.com
Tue Apr 15 23:16:33 PDT 2014
Author: atanasyan
Date: Wed Apr 16 01:16:32 2014
New Revision: 206358
URL: http://llvm.org/viewvc/llvm-project?rev=206358&view=rev
Log:
[Mips] Emit PLT entries for more static relocations.
Added:
lld/trunk/test/elf/Mips/Inputs/pic-obj.yaml
lld/trunk/test/elf/Mips/plt-1.test
lld/trunk/test/elf/Mips/plt-2.test
Modified:
lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationPass.cpp
Modified: lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationPass.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationPass.cpp?rev=206358&r1=206357&r2=206358&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationPass.cpp (original)
+++ lld/trunk/lib/ReaderWriter/ELF/Mips/MipsRelocationPass.cpp Wed Apr 16 01:16:32 2014
@@ -182,7 +182,7 @@ private:
void handleReference(Reference &ref);
void handlePlain(Reference &ref);
- void handlePLT(Reference &ref);
+ void handle26(Reference &ref);
void handleGOT(Reference &ref);
const GOTAtom *getLocalGOTEntry(const Reference &ref);
@@ -266,7 +266,7 @@ void RelocationPass<ELFT>::handleReferen
handlePlain(ref);
break;
case R_MIPS_26:
- handlePLT(ref);
+ handle26(ref);
break;
case R_MIPS_GOT16:
case R_MIPS_CALL16:
@@ -287,11 +287,22 @@ void RelocationPass<ELFT>::handlePlain(R
if (!ref.target())
return;
auto sla = dyn_cast<SharedLibraryAtom>(ref.target());
- if (sla && sla->type() == SharedLibraryAtom::Type::Data)
+ if (!sla)
+ return;
+ switch (sla->type()) {
+ case SharedLibraryAtom::Type::Data:
ref.setTarget(getObjectEntry(sla));
+ break;
+ case SharedLibraryAtom::Type::Code:
+ ref.setTarget(getPLTEntry(sla));
+ break;
+ default:
+ // Nothing to do.
+ break;
+ }
}
-template <typename ELFT> void RelocationPass<ELFT>::handlePLT(Reference &ref) {
+template <typename ELFT> void RelocationPass<ELFT>::handle26(Reference &ref) {
if (ref.kindValue() == R_MIPS_26 && !isLocal(ref.target())) {
ref.setKindValue(LLD_R_MIPS_GLOBAL_26);
@@ -299,8 +310,9 @@ template <typename ELFT> void Relocation
const_cast<Reference &>(ref).setTarget(getLA25Entry(ref.target()));
}
- if (isa<SharedLibraryAtom>(ref.target()))
- ref.setTarget(getPLTEntry(ref.target()));
+ const auto *sla = dyn_cast<SharedLibraryAtom>(ref.target());
+ if (sla && sla->type() == SharedLibraryAtom::Type::Code)
+ ref.setTarget(getPLTEntry(sla));
}
template <typename ELFT> void RelocationPass<ELFT>::handleGOT(Reference &ref) {
Added: lld/trunk/test/elf/Mips/Inputs/pic-obj.yaml
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/Mips/Inputs/pic-obj.yaml?rev=206358&view=auto
==============================================================================
--- lld/trunk/test/elf/Mips/Inputs/pic-obj.yaml (added)
+++ lld/trunk/test/elf/Mips/Inputs/pic-obj.yaml Wed Apr 16 01:16:32 2014
@@ -0,0 +1,55 @@
+# Define symbols in the .text (T1, T2, T3) and .data (D1, D2, D3) sections.
+# The object file has PIC, CPIC flags.
+!ELF
+FileHeader: !FileHeader
+ Class: ELFCLASS32
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [EF_MIPS_PIC, EF_MIPS_CPIC]
+
+Sections:
+- Name: .text
+ Type: SHT_PROGBITS
+ Content: "000000000000000000000000"
+ AddressAlign: 16
+ Flags: [SHF_EXECINSTR, SHF_ALLOC]
+
+- Name: .data
+ Type: SHT_PROGBITS
+ Content: "0000000000000000"
+ AddressAlign: 16
+ Flags: [SHF_WRITE, SHF_ALLOC]
+
+Symbols:
+ Global:
+ - Name: T1
+ Section: .text
+ Type: STT_FUNC
+ Value: 0x0
+ Size: 4
+ - Name: T2
+ Section: .text
+ Type: STT_FUNC
+ Value: 0x4
+ Size: 4
+ - Name: T3
+ Section: .text
+ Type: STT_FUNC
+ Value: 0x8
+ Size: 4
+ - Name: D1
+ Section: .data
+ Type: STT_OBJECT
+ Value: 0x0
+ Size: 4
+ - Name: D2
+ Section: .data
+ Type: STT_OBJECT
+ Value: 0x4
+ Size: 4
+ - Name: D3
+ Section: .data
+ Type: STT_OBJECT
+ Value: 0x8
+ Size: 4
Added: lld/trunk/test/elf/Mips/plt-1.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/Mips/plt-1.test?rev=206358&view=auto
==============================================================================
--- lld/trunk/test/elf/Mips/plt-1.test (added)
+++ lld/trunk/test/elf/Mips/plt-1.test Wed Apr 16 01:16:32 2014
@@ -0,0 +1,134 @@
+# Test1. Check PLT entries creation when:
+# a) Linking non-shared executable file
+# b) Relocations' targets are symbols defined in the shared object.
+#
+# RUN: yaml2obj -format=elf %S/Inputs/pic-obj.yaml > %t-so-obj
+# RUN: lld -flavor gnu -target mipsel -shared -o %t-so %t-so-obj
+# RUN: yaml2obj -format=elf %s > %t-obj
+# RUN: lld -flavor gnu -target mipsel -e T0 -o %t1-exe %t-obj %t-so
+# RUN: llvm-objdump -disassemble %t1-exe | FileCheck -check-prefix=PLT1 %s
+
+# PLT1: Disassembly of section .plt:
+# PLT1-NEXT: .plt:
+# PLT1-NEXT: 400210: 40 00 1c 3c lui $gp, 64
+# PLT1-NEXT: 400214: 00 20 99 8f lw $25, 8192($gp)
+# PLT1-NEXT: 400218: 00 20 9c 27 addiu $gp, $gp, 8192
+# PLT1-NEXT: 40021c: 23 c0 1c 03 subu $24, $24, $gp
+# PLT1-NEXT: 400220: 21 78 e0 03 move $15, $ra
+# PLT1-NEXT: 400224: 82 c0 18 00 srl $24, $24, 2
+# PLT1-NEXT: 400228: 09 f8 20 03 jalr $25
+# PLT1-NEXT: 40022c: fe ff 18 27 addiu $24, $24, -2
+#
+# PLT1-NEXT: 400230: 40 00 0f 3c lui $15, 64
+# PLT1-NEXT: 400234: 08 20 f9 8d lw $25, 8200($15)
+# PLT1-NEXT: 400238: 08 00 20 03 jr $25
+# PLT1-NEXT: 40023c: 08 20 f8 25 addiu $24, $15, 8200
+#
+# PLT1-NEXT: 400240: 40 00 0f 3c lui $15, 64
+# PLT1-NEXT: 400244: 0c 20 f9 8d lw $25, 8204($15)
+# PLT1-NEXT: 400248: 08 00 20 03 jr $25
+# PLT1-NEXT: 40024c: 0c 20 f8 25 addiu $24, $15, 8204
+#
+# PLT1-NEXT: 400250: 40 00 0f 3c lui $15, 64
+# PLT1-NEXT: 400254: 10 20 f9 8d lw $25, 8208($15)
+# PLT1-NEXT: 400258: 08 00 20 03 jr $25
+# PLT1-NEXT: 40025c: 10 20 f8 25 addiu $24, $15, 8208
+
+# Test2. Check PLT entries creation when:
+# a) Linking non-shared executable file
+# b) Relocations' targets are undefined symbols
+#
+# R1UN: yaml2obj -format=elf %s > %t-obj
+# R1UN: lld -flavor gnu -target mipsel --noinhibit-exec -e T0 -o %t2-exe %t-obj
+# R1UN: llvm-objdump -disassemble %t2-exe | FileCheck -check-prefix=PLT2 %s
+
+# PLT2-NOT: Disassembly of section .plt:
+
+# Test3. Check PLT entries creation when:
+# a) Linking non-shared executable file
+# b) Relocations' targets are symbols defined in the other object.
+#
+# R1UN: yaml2obj -format=elf %s > %t-obj1
+# R1UN: yaml2obj -format=elf %S/Inputs/pic-obj.yaml > %t-obj2
+# R1UN: lld -flavor gnu -target mipsel -e T0 -o %t3-exe %t-obj1 %t-obj2
+# R1UN: llvm-objdump -disassemble %t3-exe | FileCheck -check-prefix=PLT3 %s
+
+# PLT3-NOT: Disassembly of section .plt:
+
+!ELF
+FileHeader: !FileHeader
+ Class: ELFCLASS32
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [EF_MIPS_CPIC]
+
+Sections:
+- Name: .text
+ Type: SHT_PROGBITS
+ Content: "0000000000000000"
+ AddressAlign: 16
+ Flags: [SHF_EXECINSTR, SHF_ALLOC]
+
+- Name: .data
+ Type: SHT_PROGBITS
+ Content: "0000000000000000"
+ AddressAlign: 16
+ Flags: [SHF_WRITE, SHF_ALLOC]
+
+- Name: .rel.text
+ Type: SHT_REL
+ Info: .text
+ AddressAlign: 4
+ Relocations:
+ - Offset: 0x04
+ Symbol: T3
+ Type: R_MIPS_26
+
+- Name: .rel.data
+ Type: SHT_REL
+ Info: .data
+ AddressAlign: 4
+ Relocations:
+ - Offset: 0x00
+ Symbol: T1
+ Type: R_MIPS_HI16
+ - Offset: 0x00
+ Symbol: T1
+ Type: R_MIPS_LO16
+ - Offset: 0x04
+ Symbol: T2
+ Type: R_MIPS_32
+
+ - Offset: 0x04
+ Symbol: D1
+ Type: R_MIPS_HI16
+ - Offset: 0x04
+ Symbol: D1
+ Type: R_MIPS_LO16
+ - Offset: 0x04
+ Symbol: D2
+ Type: R_MIPS_32
+
+Symbols:
+ Global:
+ - Name: T0
+ Section: .text
+ Type: STT_FUNC
+ Value: 0x0
+ Size: 8
+ - Name: T1
+ Type: STT_FUNC
+ - Name: T2
+ Type: STT_FUNC
+ - Name: T3
+ Type: STT_FUNC
+ - Name: D0
+ Section: .data
+ Type: STT_OBJECT
+ Value: 0x0
+ Size: 8
+ - Name: D1
+ Type: STT_OBJECT
+ - Name: D2
+ Type: STT_OBJECT
Added: lld/trunk/test/elf/Mips/plt-2.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/Mips/plt-2.test?rev=206358&view=auto
==============================================================================
--- lld/trunk/test/elf/Mips/plt-2.test (added)
+++ lld/trunk/test/elf/Mips/plt-2.test Wed Apr 16 01:16:32 2014
@@ -0,0 +1,48 @@
+# Test1. Check PLT entries creation when:
+# a) Linking shared object file
+# b) Relocations' targets are undefined symbols
+#
+# RUN: yaml2obj -format=elf %s > %t-obj
+# RUN: lld -flavor gnu -target mipsel -shared --noinhibit-exec -o %t1-so %t-obj
+# RUN: llvm-objdump -disassemble %t1-so | FileCheck -check-prefix=PLT1 %s
+
+# PLT1-NOT: Disassembly of section .plt:
+
+!ELF
+FileHeader: !FileHeader
+ Class: ELFCLASS32
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_MIPS
+ Flags: [EF_MIPS_PIC, EF_MIPS_CPIC]
+
+Sections:
+- Name: .text
+ Type: SHT_PROGBITS
+ Content: "0000000000000000"
+ AddressAlign: 16
+ Flags: [SHF_EXECINSTR, SHF_ALLOC]
+
+- Name: .data
+ Type: SHT_PROGBITS
+ Content: "0000000000000000"
+ AddressAlign: 16
+ Flags: [SHF_WRITE, SHF_ALLOC]
+
+- Name: .rel.text
+ Type: SHT_REL
+ Info: .text
+ AddressAlign: 4
+ Relocations:
+ - Offset: 0x00
+ Symbol: T1
+ Type: R_MIPS_32
+
+Symbols:
+ Global:
+ - Name: T0
+ Section: .text
+ Type: STT_FUNC
+ Value: 0x0
+ Size: 4
+ - Name: T1
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