[PATCH] D42911: [ELF] - Make defsym to work correctly with reserved symbols.

[Rafael Avila de Espindola via llvm-commits]

LGTM

George Rimar via Phabricator <reviews at reviews.llvm.org> writes:

> grimar updated this revision to Diff 132949.
> grimar added a comment.
>
> - Updated.
>
>
> https://reviews.llvm.org/D42911
>
> Files:
>   ELF/LinkerScript.cpp
>   test/ELF/defsym-reserved-syms.s
>
>
> Index: test/ELF/defsym-reserved-syms.s
> ===================================================================
> --- test/ELF/defsym-reserved-syms.s
> +++ test/ELF/defsym-reserved-syms.s
> @@ -0,0 +1,30 @@
> +# REQUIRES: x86
> +# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
> +# RUN: ld.lld -o %t %t.o --defsym=foo2=etext
> +# RUN: llvm-readobj -t -s %t | FileCheck %s
> +
> +## Check 'foo2' value is equal to value of 'etext'.
> +# CHECK:     Symbol {
> +# CHECK:      Name: foo2
> +# CHECK-NEXT:  Value: 0x[[VAL:.*]]
> +# CHECK:     Symbol {
> +# CHECK:      Name: etext
> +# CHECK-NEXT:  Value: 0x[[VAL]]
> +
> +## Check 'foo2' value set correctly when using
> +## reserved symbol 'etext' in expression.
> +# RUN: ld.lld -o %t %t.o --defsym=foo2=etext+2
> +# RUN: llvm-readobj -t -s %t | FileCheck %s --check-prefix=EXPR
> +# EXPR:     Symbol {
> +# EXPR:      Name: foo2
> +# EXPR-NEXT:  Value: 0x201007
> +# EXPR:     Symbol {
> +# EXPR:      Name: etext
> +# EXPR-NEXT:  Value: 0x201005
> +
> +.globl foo1
> + foo1 = 0x123
> +
> +.global _start
> +_start:
> +  movl $foo2, %edx
> Index: ELF/LinkerScript.cpp
> ===================================================================
> --- ELF/LinkerScript.cpp
> +++ ELF/LinkerScript.cpp
> @@ -74,7 +74,7 @@
>    // If the alignment is trivial, we don't have to compute the full
>    // value to know the offset. This allows this function to succeed in
>    // cases where the output section is not yet known.
> -  if (Alignment == 1)
> +  if (Alignment == 1 && (!Sec || !Sec->getOutputSection()))
>      return Val;
>    return getValue() - getSecAddr();
>  }
>
>
> Index: test/ELF/defsym-reserved-syms.s
> ===================================================================
> --- test/ELF/defsym-reserved-syms.s
> +++ test/ELF/defsym-reserved-syms.s
> @@ -0,0 +1,30 @@
> +# REQUIRES: x86
> +# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
> +# RUN: ld.lld -o %t %t.o --defsym=foo2=etext
> +# RUN: llvm-readobj -t -s %t | FileCheck %s
> +
> +## Check 'foo2' value is equal to value of 'etext'.
> +# CHECK:     Symbol {
> +# CHECK:      Name: foo2
> +# CHECK-NEXT:  Value: 0x[[VAL:.*]]
> +# CHECK:     Symbol {
> +# CHECK:      Name: etext
> +# CHECK-NEXT:  Value: 0x[[VAL]]
> +
> +## Check 'foo2' value set correctly when using
> +## reserved symbol 'etext' in expression.
> +# RUN: ld.lld -o %t %t.o --defsym=foo2=etext+2
> +# RUN: llvm-readobj -t -s %t | FileCheck %s --check-prefix=EXPR
> +# EXPR:     Symbol {
> +# EXPR:      Name: foo2
> +# EXPR-NEXT:  Value: 0x201007
> +# EXPR:     Symbol {
> +# EXPR:      Name: etext
> +# EXPR-NEXT:  Value: 0x201005
> +
> +.globl foo1
> + foo1 = 0x123
> +
> +.global _start
> +_start:
> +  movl $foo2, %edx
> Index: ELF/LinkerScript.cpp
> ===================================================================
> --- ELF/LinkerScript.cpp
> +++ ELF/LinkerScript.cpp
> @@ -74,7 +74,7 @@
>    // If the alignment is trivial, we don't have to compute the full
>    // value to know the offset. This allows this function to succeed in
>    // cases where the output section is not yet known.
> -  if (Alignment == 1)
> +  if (Alignment == 1 && (!Sec || !Sec->getOutputSection()))
>      return Val;
>    return getValue() - getSecAddr();
>  }