8sa1-binutils-gdb/ld/testsuite/ld-msp430-elf/uleb128.s

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MSP430: Support relocations for subtract expressions in .uleb128 directives 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.
2020-09-08 11:13:48 -04:00
.data
.global bar
.balign 2
bar:
.short 42
.short 43
.global foo
foo:
.skip 0xff
.global foo2
.balign 2
foo2:
.short 4
.text
.balign 2
.global byte
byte:
.word foo-bar
.word foo2-bar
.global uleb
.balign 2
uleb:
.uleb128 foo-bar ; this value can be stored in one byte
.uleb128 foo2-bar ; this value requires 2 bytes
.balign 2
.global _start
_start:
nop