llvm-project

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# Checks handling of undefined weak external functions.  When the
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# static linker decides they are undefined, check GOT relocations
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# resolve to zero (i.e. a global that contains zero.).
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#
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# RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t.o %s
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# RUN: wasm-ld %t.o -o %t1.wasm
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# RUN: obj2yaml %t1.wasm | FileCheck %s
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#
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# With `--unresolved-symbols=ignore-all` the behaviour should be the same
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# as the default.>
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#
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# RUN: wasm-ld --unresolved-symbols=ignore-all %t.o -o %t2.wasm
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# RUN: obj2yaml %t2.wasm | FileCheck %s
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.functype foo () -> (i32)
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.globl get_foo_addr
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get_foo_addr:
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  .functype get_foo_addr () -> (i32)
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  global.get foo@GOT
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  end_function
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.globl _start
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_start:
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  .functype _start () -> (i32)
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  call get_foo_addr
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  call foo
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  drop
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  end_function
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.weak foo
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# Verify that we do not generate dynamic relocations for the GOT entry.
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# CHECK-NOT: __wasm_apply_global_relocs
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# Verify that we do not generate an import for foo
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# CHECK-NOT:  - Type:            IMPORT
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#      CHECK:   - Type:            GLOBAL
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# CHECK-NEXT:     Globals:
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# CHECK-NEXT:       - Index:           0
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# CHECK-NEXT:         Type:            I32
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# CHECK-NEXT:         Mutable:         true
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# CHECK-NEXT:         InitExpr:
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# CHECK-NEXT:           Opcode:          I32_CONST
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# CHECK-NEXT:           Value:           66560
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# Global 'undefined_weak:foo' representing the GOT entry for foo
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# Unlike other internal GOT entries that need to be mutable this one
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# is immutable and not updated by `__wasm_apply_global_relocs`
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# CHECK-NEXT:       - Index:           1
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# CHECK-NEXT:         Type:            I32
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# CHECK-NEXT:         Mutable:         false
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# CHECK-NEXT:         InitExpr:
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# CHECK-NEXT:           Opcode:          I32_CONST
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# CHECK-NEXT:           Value:           0
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#      CHECK:  - Type:            CUSTOM
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# CHECK-NEXT:    Name:            name
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# CHECK-NEXT:    FunctionNames:
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# CHECK-NEXT:      - Index:           0
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# CHECK-NEXT:        Name:            'undefined_weak:foo'
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# CHECK-NEXT:      - Index:           1
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# CHECK-NEXT:        Name:            get_foo_addr
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# CHECK-NEXT:      - Index:           2
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# CHECK-NEXT:        Name:            _start
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# CHECK-NEXT:    GlobalNames:
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# CHECK-NEXT:      - Index:           0
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# CHECK-NEXT:        Name:            __stack_pointer
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# CHECK-NEXT:      - Index:           1
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# CHECK-NEXT:        Name:            'GOT.func.internal.undefined_weak:foo'
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# With `-pie` or `-shared` the resolution should be deferred to the dynamic
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# linker and the function address should be imported as GOT.func.foo.
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#
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# RUN: wasm-ld --experimental-pic -pie %t.o -o %t3.wasm
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# RUN: obj2yaml %t3.wasm | FileCheck %s --check-prefix=IMPORT
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#      IMPORT:  - Type:            IMPORT
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#      IMPORT:        Field:           foo
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# IMPORT-NEXT:        Kind:            FUNCTION
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# IMPORT-NEXT:        SigIndex:        0
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# IMPORT-NEXT:      - Module:          GOT.func
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# IMPORT-NEXT:        Field:           foo
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# IMPORT-NEXT:        Kind:            GLOBAL
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# IMPORT-NEXT:        GlobalType:      I32
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# IMPORT-NEXT:        GlobalMutable:   true
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#      IMPORT:     GlobalNames:
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# IMPORT-NEXT:       - Index:           0
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# IMPORT-NEXT:         Name:            __memory_base
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# IMPORT-NEXT:       - Index:           1
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# IMPORT-NEXT:         Name:            __table_base
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# IMPORT-NEXT:       - Index:           2
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# IMPORT-NEXT:         Name:            foo
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