lld/test/wasm/weak-undefined-pic.s

   1 # Checks handling of undefined weak external functions.  When the
   2 # static linker decides they are undefined, check GOT relocations
   3 # resolve to zero (i.e. a global that contains zero.).
   4 #
   5 # RUN: llvm-mc -filetype=obj -triple=wasm32-unknown-unknown -o %t.o %s
   6 # RUN: wasm-ld %t.o -o %t1.wasm
   7 # RUN: obj2yaml %t1.wasm | FileCheck %s
   8 #
   9 # With `--unresolved-symbols=ignore-all` the behaviour should be the same
  10 # as the default.>
  11 #
  12 # RUN: wasm-ld --unresolved-symbols=ignore-all %t.o -o %t2.wasm
  13 # RUN: obj2yaml %t2.wasm | FileCheck %s
  14
  15 .functype foo () -> (i32)
  16
  17 .globl get_foo_addr
  18 get_foo_addr:
  19   .functype get_foo_addr () -> (i32)
  20   global.get foo@GOT
  21   end_function
  22
  23 .globl _start
  24 _start:
  25   .functype _start () -> (i32)
  26   call get_foo_addr
  27   call foo
  28   drop
  29   end_function
  30
  31 .weak foo
  32
  33 # Verify that we do not generate dynamic relocations for the GOT entry.
  34
  35 # CHECK-NOT: __wasm_apply_global_relocs
  36
  37 # Verify that we do not generate an import for foo
  38
  39 # CHECK-NOT:  - Type:            IMPORT
  40
  41 #      CHECK:   - Type:            GLOBAL
  42 # CHECK-NEXT:     Globals:
  43 # CHECK-NEXT:       - Index:           0
  44 # CHECK-NEXT:         Type:            I32
  45 # CHECK-NEXT:         Mutable:         true
  46 # CHECK-NEXT:         InitExpr:
  47 # CHECK-NEXT:           Opcode:          I32_CONST
  48 # CHECK-NEXT:           Value:           66560
  49 # Global 'undefined_weak:foo' representing the GOT entry for foo
  50 # Unlike other internal GOT entries that need to be mutable this one
  51 # is immutable and not updated by `__wasm_apply_global_relocs`
  52 # CHECK-NEXT:       - Index:           1
  53 # CHECK-NEXT:         Type:            I32
  54 # CHECK-NEXT:         Mutable:         false
  55 # CHECK-NEXT:         InitExpr:
  56 # CHECK-NEXT:           Opcode:          I32_CONST
  57 # CHECK-NEXT:           Value:           0
  58
  59 #      CHECK:  - Type:            CUSTOM
  60 # CHECK-NEXT:    Name:            name
  61 # CHECK-NEXT:    FunctionNames:
  62 # CHECK-NEXT:      - Index:           0
  63 # CHECK-NEXT:        Name:            'undefined_weak:foo'
  64 # CHECK-NEXT:      - Index:           1
  65 # CHECK-NEXT:        Name:            get_foo_addr
  66 # CHECK-NEXT:      - Index:           2
  67 # CHECK-NEXT:        Name:            _start
  68 # CHECK-NEXT:    GlobalNames:
  69 # CHECK-NEXT:      - Index:           0
  70 # CHECK-NEXT:        Name:            __stack_pointer
  71 # CHECK-NEXT:      - Index:           1
  72 # CHECK-NEXT:        Name:            'GOT.func.internal.undefined_weak:foo'
  73
  74 # With `-pie` or `-shared` the resolution should be deferred to the dynamic
  75 # linker and the function address should be imported as GOT.func.foo.
  76 #
  77 # RUN: wasm-ld --experimental-pic -pie %t.o -o %t3.wasm
  78 # RUN: obj2yaml %t3.wasm | FileCheck %s --check-prefix=IMPORT
  79
  80 #      IMPORT:  - Type:            IMPORT
  81 #      IMPORT:        Field:           foo
  82 # IMPORT-NEXT:        Kind:            FUNCTION
  83 # IMPORT-NEXT:        SigIndex:        0
  84 # IMPORT-NEXT:      - Module:          GOT.func
  85 # IMPORT-NEXT:        Field:           foo
  86 # IMPORT-NEXT:        Kind:            GLOBAL
  87 # IMPORT-NEXT:        GlobalType:      I32
  88 # IMPORT-NEXT:        GlobalMutable:   true
  89
  90 #      IMPORT:     GlobalNames:
  91 # IMPORT-NEXT:       - Index:           0
  92 # IMPORT-NEXT:         Name:            __memory_base
  93 # IMPORT-NEXT:       - Index:           1
  94 # IMPORT-NEXT:         Name:            __table_base
  95 # IMPORT-NEXT:       - Index:           2
  96 # IMPORT-NEXT:         Name:            foo