test/Shell/Breakpoint/wasm-skip-function-header.test

# A WebAssembly function begins with a local variable declaration header that is
# part of the function but is not an executable instruction. A breakpoint set at
# a function's raw start address, such as one added by a scripted resolver, must
# skip the header and resolve to the first instruction, otherwise it can never
# be hit.
#
# The function "helper" starts at file address 0x5 with a 3-byte header, so its
# first instruction is at 0x8.

# RUN: split-file %s %t
# RUN: yaml2obj %t/hdr.yaml -o %t/a.wasm
# RUN: %lldb %t/a.wasm \
# RUN:   -o "command script import %t/resolver.py" \
# RUN:   -o "breakpoint set -P resolver.HelperResolver" \
# RUN:   -o "breakpoint list" \
# RUN:   -o exit 2>&1 | FileCheck %s

# CHECK: Breakpoint 1: where = {{.*}}`helper + 3{{.*}}, address = 0x{{0*}}8

#--- resolver.py
import lldb


class HelperResolver:
    def __init__(self, bkpt, extra_args, internal_dict):
        self.bkpt = bkpt

    def __callback__(self, sym_ctx):
        # Add a location at the raw function start, as a scripted resolver does.
        symbol = sym_ctx.module.FindSymbol("helper")
        if symbol:
            self.bkpt.AddLocation(symbol.GetStartAddress())

    def __get_depth__(self):
        return lldb.eSearchDepthModule

    def get_short_help(self):
        return "Resolve at helper's start"


#--- hdr.yaml
--- !WASM
FileHeader:
  Version:         0x1
Sections:
  - Type:            TYPE
    Signatures:
      - Index:           0
        ParamTypes:      []
        ReturnTypes:     []
      - Index:           1
        ParamTypes:
          - I32
        ReturnTypes:
          - I32
      - Index:           2
        ParamTypes:      []
        ReturnTypes:
          - I32
  - Type:            FUNCTION
    FunctionTypes:   [ 0, 1, 2 ]
  - Type:            MEMORY
    Memories:
      - Minimum:         0x1
  - Type:            GLOBAL
    Globals:
      - Index:           0
        Type:            I32
        Mutable:         true
        InitExpr:
          Opcode:          I32_CONST
          Value:           65536
  - Type:            EXPORT
    Exports:
      - Name:            memory
        Kind:            MEMORY
        Index:           0
  - Type:            CODE
    Functions:
      - Index:           0
        Locals:          []
        Body:            0B
      - Index:           1
        Locals:
          - Type:            I32
            Count:           1
        Body:            23808080800041106B21012001200036020C2001200128020C41016A36020820012802080F0B
      - Index:           2
        Locals:          []
        Body:            41291081808080000F0B
  - Type:            CUSTOM
    Name:            .debug_abbrev
    Payload:         011101250E1305030E10171B0E110155170000022E01110112064018030E3A0B3B0B271949133F1900000305000218030E3A0B3B0B491300000434000218030E3A0B3B0B49130000052E00110112064018030E3A0B3B0B271949133F190000062400030E3E0B0B0B000000
  - Type:            CUSTOM
    HeaderSecSizeEncodingLen: 2
    Name:            .debug_info
    Payload:         7A0000000400000000000401290000001D00230000000000000014000000000000000000000002050000002900000004ED00019F080000000101760000000302910C02000000010176000000040291080000000001027600000000052F0000000B00000007ED03000000009F0F0000000105760000000604000000050400
  - Type:            CUSTOM
    Name:            .debug_ranges
    Payload:         050000002E0000002F0000003A0000000000000000000000
  - Type:            CUSTOM
    Name:            .debug_str
    Payload:         79007800696E740068656C706572006B656570002F746D702F7761736D726570726F006864722E6300636C616E672076657273696F6E2032322E312E302D776173692D73646B202868747470733A2F2F6769746875622E636F6D2F6C6C766D2F6C6C766D2D70726F6A65637420343433346461626236393931363835366238323466363861363462303239633637313735653533322900
  - Type:            CUSTOM
    Name:            .debug_line
    Payload:         5800000004001D000000010101FB0E0D000101010100000001000001006864722E6300000000000005020500000001050B0A084B050D067405073C050A063D05030658020200010105190A0005023000000016051206820202000101
  - Type:            CUSTOM
    Name:            name
    FunctionNames:
      - Index:           0
        Name:            __wasm_call_ctors
      - Index:           1
        Name:            helper
      - Index:           2
        Name:            keep
    GlobalNames:
      - Index:           0
        Name:            __stack_pointer
...