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7d81bc937c
Link-time relaxations of branches are common for MSP430, given that GCC can generate pessimal branch instructions, and the -mcode-region=either/-mdata-region=either options to shuffle sections can further change the type of branch instruction required. These relaxations can result in invalid code when .uleb128 directives, used in the .gcc_except_table section, are used to calculate the distance between two labels. A value for the .uleb128 directive is calculated at assembly-time, and can't be updated at link-time, even if relaxation causes the distance between the labels to change. This patch adds relocations for subtract expressions in .uleb128 directives, to allow the linker to re-calculate the value of these expressions after relaxation has been performed. bfd/ChangeLog: * bfd-in2.h (bfd_reloc_code_real): Add BFD_RELOC_MSP430_{SET,SUB}_ULEB128. * elf32-msp430.c (msp430_elf_ignore_reloc): New. (elf_msp430_howto_table): Add R_MSP430{,X}_GNU_{SET,SUB}_ULEB128. (msp430_reloc_map): Add R_MSP430_GNU_{SET,SUB}_ULEB128. (msp430x_reloc_map): Add R_MSP430X_GNU_{SET,SUB}_ULEB128. (write_uleb128): New. (msp430_final_link_relocate): Handle R_MSP430{,X}_GNU_{SET,SUB}_ULEB128. * libbfd.c (_bfd_write_unsigned_leb128): New. * libbfd.h (_bfd_write_unsigned_leb128): New prototype. Add BFD_RELOC_MSP430_{SET,SUB}_ULEB128. * reloc.c: Document BFD_RELOC_MSP430_{SET,SUB}_ULEB128. binutils/ChangeLog: * readelf.c (target_specific_reloc_handling): Handle R_MSP430{,X}_GNU_{SET,SUB}_ULEB128. gas/ChangeLog: * config/tc-msp430.c (msp430_insert_uleb128_fixes): New. (msp430_md_end): Call msp430_insert_uleb128_fixes. include/ChangeLog: * elf/msp430.h (elf_msp430_reloc_type): Add R_MSP430_GNU_{SET,SUB}_ULEB128. (elf_msp430x_reloc_type): Add R_MSP430X_GNU_{SET,SUB}_ULEB128. ld/ChangeLog: * testsuite/ld-msp430-elf/msp430-elf.exp: Run new tests. * testsuite/ld-msp430-elf/uleb128.s: New test. * testsuite/ld-msp430-elf/uleb128_430.d: New test. * testsuite/ld-msp430-elf/uleb128_430x.d: New test.
35 lines
390 B
ArmAsm
35 lines
390 B
ArmAsm
.data
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.global bar
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.balign 2
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bar:
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.short 42
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.short 43
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.global foo
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foo:
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.skip 0xff
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.global foo2
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.balign 2
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foo2:
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.short 4
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.text
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.balign 2
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.global byte
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byte:
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.word foo-bar
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.word foo2-bar
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.global uleb
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.balign 2
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uleb:
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.uleb128 foo-bar ; this value can be stored in one byte
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.uleb128 foo2-bar ; this value requires 2 bytes
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.balign 2
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.global _start
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_start:
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nop
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