7c426fb1a6
D43468+D44380 added INSERT [AFTER|BEFORE] for non-orphan sections. This patch
makes INSERT work for orphan sections as well.
`SECTIONS {...} INSERT [AFTER|BEFORE] .foo` does not set `hasSectionCommands`, so the result
will be similar to a regular link without a linker script. The differences when `hasSectionCommands` is set include:
* image base is different
* -z noseparate-code/-z noseparate-loadable-segments are unavailable
* some special symbols such as `_end _etext _edata` are not defined
The behavior is similar to GNU ld:
INSERT is not considered an external linker script.
This feature makes the section layout more flexible. It can be used to:
* Place .nv_fatbin before other readonly SHT_PROGBITS sections to mitigate relocation overflows.
* Disturb the layout to expose address sensitive application bugs.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D74375
43 lines
1.8 KiB
Plaintext
43 lines
1.8 KiB
Plaintext
# REQUIRES: x86
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# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/insert-after.s -o %t1.o
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## Main linker script contains .text and .data sections. Here
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## we check that can use INSERT BEFORE to insert sections .foo.data
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## and .foo.text at the right places.
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# RUN: ld.lld %t1.o -o %t1 --script %p/Inputs/insert-after.script --script %s
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# RUN: llvm-readelf -S -l %t1 | FileCheck %s
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# CHECK: Name Type Address Off
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# CHECK-NEXT: NULL 0000000000000000 000000
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# CHECK-NEXT: .foo.text PROGBITS 0000000000000000 001000
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# CHECK-NEXT: .text PROGBITS 0000000000000008 001008
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# CHECK-NEXT: .foo.data PROGBITS 0000000000000010 001010
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# CHECK-NEXT: .data PROGBITS 0000000000000018 001018
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# CHECK: Type
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# CHECK-NEXT: LOAD {{.*}} R E
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# CHECK-NEXT: LOAD {{.*}} RW
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# CHECK-NEXT: GNU_STACK {{.*}} RW
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## There is no main linker script. INSERT BEFORE just reorders output sections,
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## without making more layout changes. Address/offset assignments are different
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## with a main linker script.
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# RUN: ld.lld --script %s %t1.o -o %t2
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# RUN: llvm-readelf -S -l %t2 | FileCheck --check-prefix=CHECK2 %s
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# CHECK2: Name Type Address Off
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# CHECK2-NEXT: NULL 0000000000000000 000000
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# CHECK2-NEXT: .foo.text PROGBITS 0000000000201158 000158
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# CHECK2-NEXT: .text PROGBITS 0000000000201160 000160
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# CHECK2-NEXT: .foo.data PROGBITS 0000000000202168 000168
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# CHECK2-NEXT: .data PROGBITS 0000000000202170 000170
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# CHECK2: Type
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# CHECK2-NEXT: PHDR {{.*}} R
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# CHECK2-NEXT: LOAD {{.*}} R
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# CHECK2-NEXT: LOAD {{.*}} R E
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# CHECK2-NEXT: LOAD {{.*}} RW
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SECTIONS { .foo.data : { *(.foo.data) } } INSERT BEFORE .data;
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## The input section .foo.text is an orphan. It will be placed in .foo.text
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SECTIONS { .foo.text : {} } INSERT BEFORE .text;
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