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An undefined symbol in a shared object can be versioned, like `f@v1`. We currently insert `f` as an Undefined into the symbol table, but we should insert `f@v1` instead. The string `v1` is inferred from SHT_GNU_versym and SHT_GNU_verneed. This patch implements the functionality. Failing to do this can cause two issues: * If a versioned symbol referenced by a shared object is defined in the executable, we will fail to export it. * If a versioned symbol referenced by a shared object in another object file, --no-allow-shlib-undefined may spuriously report an "undefined reference to " error. See https://bugs.llvm.org/show_bug.cgi?id=44842 (Linking -lfftw3 -lm on Arch Linux can cause `undefined reference to __log_finite`) Reviewed By: grimar Differential Revision: https://reviews.llvm.org/D80059
38 lines
1.3 KiB
ArmAsm
38 lines
1.3 KiB
ArmAsm
# REQUIRES: x86
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# RUN: echo 'v1 { f; }; v2 { g; };' > %t.ver
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# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
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# RUN: ld.lld -shared --version-script %t.ver %t.o -o %t.so
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# RUN: ld.lld --version-script %t.ver %t.o %t.so -o /dev/null -y f@v1 | \
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# RUN: FileCheck --check-prefix=TRACE %s --implicit-check-not=f@v1
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## TRACE: {{.*}}.o: definition of f@v1
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## TRACE-NEXT: {{.*}}.so: shared definition of f@v1
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# RUN: echo '.symver f,f@v1; .symver g,g@v2; call f; call g' | \
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# RUN: llvm-mc -filetype=obj -triple=x86_64 - -o %t1.o
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# RUN: ld.lld -shared %t1.o %t.so -o %t1.so
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## Test that we can parse SHT_GNU_verneed to know that the undefined symbols in
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## %t1.so are called 'f@v1' and 'g@v2', which can be satisfied by the executable.
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## We will thus export the symbols.
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# RUN: ld.lld -pie %t.o %t1.so -o %t
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# RUN: llvm-nm -D %t | FileCheck --check-prefix=NM %s
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# NM: T f
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# NM: T g
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## The default is --no-allow-shlib-undefined.
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## Don't error because undefined symbols in %t1.so are satisfied by %t.so
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# RUN: llvm-mc -filetype=obj -triple=x86_64 /dev/null -o %t2.o
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# RUN: ld.lld %t2.o %t1.so %t.so -y f@v1 -o /dev/null | FileCheck %s
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# CHECK: {{.*}}1.so: reference to f@v1
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# CHECK-NEXT: {{.*}}.so: shared definition of f@v1
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.globl f_v1, g_v2
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.symver f_v1,f@v1
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.symver g_v2,g@v2
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f_v1:
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g_v2:
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