0af07c0787
... using the temporary section type code 0x40000020 (`clang -c -Wa,--crel,--allow-experimental-crel`). LLVM will change the code and break compatibility (Clang and lld of different versions are not guaranteed to cooperate, unlike other features). CREL with implicit addends are not supported. --- Introduce `RelsOrRelas::crels` to iterate over SHT_CREL sections and update users to check `crels`. (The decoding performance is critical and error checking is difficult. Follow `skipLeb` and `R_*LEB128` handling, do not use `llvm::decodeULEB128`, whichs compiles to a lot of code.) A few users (e.g. .eh_frame, LLDDwarfObj, s390x) require random access. Pass `/*supportsCrel=*/false` to `relsOrRelas` to allocate a buffer and convert CREL to RELA (`relas` instead of `crels` will be used). Since allocating a buffer increases, the conversion is only performed when absolutely necessary. --- Non-alloc SHT_CREL sections may be created in -r and --emit-relocs links. SHT_CREL and SHT_RELA components need reencoding since r_offset/r_symidx/r_type/r_addend may change. (r_type may change because relocations referencing a symbol in a discarded section are converted to `R_*_NONE`). * SHT_CREL components: decode with `RelsOrRelas` and re-encode (`OutputSection::finalizeNonAllocCrel`) * SHT_RELA components: convert to CREL (`relToCrel`). An output section can only have one relocation section. * SHT_REL components: print an error for now. SHT_REL to SHT_CREL conversion for -r/--emit-relocs is complex and unsupported yet. Link: https://discourse.llvm.org/t/rfc-crel-a-compact-relocation-format-for-elf/77600 Pull Request: https://github.com/llvm/llvm-project/pull/98115
102 lines
3.4 KiB
Plaintext
102 lines
3.4 KiB
Plaintext
# REQUIRES: x86
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# RUN: rm -rf %t && split-file %s %t && cd %t
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# RUN: llvm-mc --triple=x86_64 -filetype=obj a.s -o a.o
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# RUN: llvm-mc --triple=x86_64 -filetype=obj -crel a.s -o ac.o
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# RUN: llvm-mc --triple=x86_64 -filetype=obj data.s -o data.o
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# RUN: ld.lld a.o data.o -T 0.t 2>&1 | FileCheck %s --check-prefix=CHECK0 --implicit-check-not=warning:
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# CHECK0: warning: 0.t:3: ignored with fewer than 2 output sections
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# CHECK0-NEXT: warning: 0.t:4: ignored with fewer than 2 output sections
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# RUN: not ld.lld a.o data.o -T 1.t 2>&1 | FileCheck %s --check-prefix=CHECK1 --implicit-check-not=error:
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# RUN: not ld.lld ac.o data.o -T 1.t 2>&1 | FileCheck %s --check-prefix=CHECK1 --implicit-check-not=error:
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# CHECK1: error: a{{.?}}.o:(.text.start+0x11): prohibited cross reference from '.text' to 'data' in '.data'
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## .text and .text1 are in two NOCROSSREFS commands. Violations are reported twice.
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# RUN: not ld.lld --threads=1 a.o data.o -T 2.t 2>&1 | FileCheck %s --check-prefix=CHECK2 --implicit-check-not=error:
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# CHECK2: error: a.o:(.text.start+0x6): prohibited cross reference from '.text' to '.text1' in '.text1'
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# CHECK2-NEXT: error: a.o:(.text.start+0x6): prohibited cross reference from '.text' to '.text1' in '.text1'
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# CHECK2-NEXT: error: a.o:(.text.start+0xb): prohibited cross reference from '.text' to 'foo2' in '.text2'
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# CHECK2-NEXT: error: a.o:(.text.start+0x11): prohibited cross reference from '.text' to 'data' in '.data'
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# CHECK2-NEXT: error: a.o:(.text.start+0x17): prohibited cross reference from '.text' to 'str1' in '.rodata'
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## .data occurs twice in the command, but the violation is only reported once.
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# CHECK2-NEXT: error: a.o:(.text1+0x1): prohibited cross reference from '.text1' to '_edata' in '.data'
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# CHECK2-NEXT: error: a.o:(.nonalloc+0x0): prohibited cross reference from '.nonalloc' to '.text' in '.text'
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# CHECK2-NEXT: error: a.o:(.nonalloc+0x10): prohibited cross reference from '.nonalloc' to 'data' in '.data'
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# RUN: not ld.lld a.o data.o -T 3.t 2>&1 | FileCheck %s --check-prefix=CHECK3 --implicit-check-not=error:
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# CHECK3: error: a.o:(.nonalloc+0x0): prohibited cross reference from '.nonalloc' to '.text' in '.text'
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#--- 0.t
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## Some cases that do not cause errors.
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abs = 42;
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NOCROSSREFS()
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NOCROSSREFS (.text)
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NOCROSSREFS( .text .text3 ); ## ; is ignored
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NOCROSSREFS_TO(.text .text2 .text3 .data );
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NOCROSSREFS_TO (.data .text2 .text3)
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#--- 1.t
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abs = 42;
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NOCROSSREFS(.text ".data")
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#--- 2.t
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abs = 42;
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NOCROSSREFS(.text ".text1" .text ".text1" )
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NOCROSSREFS(.text .text1 .text2 .data .rodata .data .nonalloc)
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#--- 3.t
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abs = 42;
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NOCROSSREFS_TO(.text .text .text1 .text2 .data .nonalloc)
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#--- err1.t
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NOCROSSREFS )
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# RUN: not ld.lld a.o data.o -T err1.t 2>&1 | FileCheck %s --check-prefix=ERR1 --implicit-check-not=error:
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# ERR1: error: err1.t:1: ( expected, but got )
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#--- err2.t
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NOCROSSREFS(.text
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# RUN: not ld.lld a.o data.o -T err2.t 2>&1 | FileCheck %s --check-prefix=ERR2 --implicit-check-not=error:
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# ERR2: error: err2.t:1: unexpected EOF
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#--- a.s
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.global _start, foo1, foo2, foo3
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.section .text.start,"ax"
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_start:
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call _start
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call .text1
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call foo2
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movl data(%rip), %eax
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movl str1(%rip), %eax
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.section .text1,"ax"
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foo1:
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call _edata
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.section .text2,"ax"
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foo2:
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call foo3
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.section .text3,"ax"
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foo3:
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call foo2
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.section .rodata.str1.1,"aMS",@progbits,1
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str1:
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.asciz "abc"
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.section .nonalloc,""
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.quad .text
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.quad .text3
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.quad data
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#--- data.s
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.section .data,"aw"
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.globl data
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data:
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.byte 0
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.quad abs
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