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[ELF] - Properly handle R_386_GOTPC relocation. 

This is PR33243. R_GOTONLY_PC_FROM_END was not in a list of link time constant
expressions and that was a result of confusiing messages like PR shows:

/usr/bin/ld.lld: error: /usr/lib/go/src/runtime/alg.go:47: 
can't create dynamic relocation R_386_GOTPC against local symbol in readonly segment defined in /tmp/nice/go-link-597453838/go.o

Though in reality we just should not have try to create a dynamic relocation for this case at all.

Patch fixes the issue.

Differential revision: https://reviews.llvm.org/D33717

llvm-svn: 304393
This commit is contained in:
George Rimar 2017-06-01 07:53:58 +00:00
parent b940f65cd2
commit d602987271
2 changed files with 35 additions and 3 deletions
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6
lld/ELF/Relocations.cpp
View File

@ -360,9 +360,9 @@ static bool isStaticLinkTimeConstant(RelExpr E, uint32_t Type,
// These expressions always compute a constant
if (isRelExprOneOf<R_SIZE, R_GOT_FROM_END, R_GOT_OFF, R_MIPS_GOT_LOCAL_PAGE,
R_MIPS_GOT_OFF, R_MIPS_GOT_OFF32, R_MIPS_GOT_GP_PC,
R_MIPS_TLSGD, R_GOT_PAGE_PC, R_GOT_PC, R_PLT_PC,
R_TLSGD_PC, R_TLSGD, R_PPC_PLT_OPD, R_TLSDESC_CALL,
R_TLSDESC_PAGE, R_HINT>(E))
R_MIPS_TLSGD, R_GOT_PAGE_PC, R_GOT_PC,
R_GOTONLY_PC_FROM_END, R_PLT_PC, R_TLSGD_PC, R_TLSGD,
R_PPC_PLT_OPD, R_TLSDESC_CALL, R_TLSDESC_PAGE, R_HINT>(E))
return true;
// These never do, except if the entire file is position dependent or if

32
lld/test/ELF/i386-gotpc-dynamic.s Normal file
View File

@ -0,0 +1,32 @@
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=i686-pc-linux %s -o %t.o
# RUN: ld.lld %t.o -o %t.so -shared
# RUN: llvm-readobj -s %t.so | FileCheck %s
# RUN: llvm-objdump -d %t.so | FileCheck --check-prefix=DISASM %s
# CHECK: Section {
# CHECK: Index: 7
# CHECK-NEXT: Name: .got
# CHECK-NEXT: Type: SHT_PROGBITS
# CHECK-NEXT: Flags [
# CHECK-NEXT: SHF_ALLOC
# CHECK-NEXT: SHF_WRITE
# CHECK-NEXT: ]
# CHECK-NEXT: Address: 0x2030
# CHECK-NEXT: Offset:
# CHECK-NEXT: Size:
# CHECK-NEXT: Link:
# CHECK-NEXT: Info:
# CHECK-NEXT: AddressAlignment:
# CHECK-NEXT: EntrySize:
# CHECK-NEXT: }
## 0x1000 + 4144 = 0x2030
# DISASM: 1000: {{.*}} movl $4144, %eax
.section .foo,"ax",@progbits
foo:
movl $bar@got-., %eax # R_386_GOTPC
.local bar
bar: