No entries for mach-O symbol stubs

[mstange]

The profiler has sampled address 0x77d58 in this libmozglue.dylib. Here's the corresponding binary.

According to the .sym file, this address is outside of any known code:

[...]
FUNC m 77c90 ac 0 bool double_conversion::Advance<char*>(char**, unsigned short, int, char*&)
77c94 4 191 95
77c98 44 195 95
77cdc 4 206 95
77ce0 8 192 95
77ce8 c 193 95
77cf4 4 206 95
77cf8 c 201 95
77d04 20 202 95
77d24 4 203 95
77d28 10 205 95
77d38 4 206 95
STACK CFI INIT 64a8 288 .cfa: $x29 16 + $x29: .cfa -16 + ^ .ra: .cfa -8 + ^ $x19: .cfa -24 + ^ $x20: .cfa -32 + ^ $x21: .cfa -40 + ^ $x22: .cfa -48 + ^
STACK CFI INIT 6730 ec .cfa: $x29 16 + $x29: .cfa -16 + ^ .ra: .cfa -8 + ^
[...]

But according to Hopper, it is inside imp___stubs__OSSpinLockLock:

        ; ================ B E G I N N I N G   O F   P R O C E D U R E ================


                     __ZN17double_conversionL7AdvanceIPcEEbPT_tiRS2_:        // bool double_conversion::Advance<char*>(char**, unsigned short, int, char*&)
0000000000077c90         ldr        x10, [x0]                                   ; CODE XREF=__ZNK17double_conversion23StringToDoubleConverter14StringToDoubleEPKciPi+868, __ZNK17double_conversion23StringToDoubleConverter14StringToDoubleEPKciPi+1052, __ZNK17double_conversion23StringToDoubleConverter14StringToDoubleEPKciPi+2124, __ZNK17double_conversion23StringToDoubleConverter14StringToDoubleEPKciPi+2260
0000000000077c94         cbz        w1, loc_77ce0

0000000000077c98         mov        x8, x10
0000000000077c9c         ldrsb      w14, [x8], #0x1
0000000000077ca0         cmp        w14, #0x38
0000000000077ca4         cset       w11, lt
0000000000077ca8         sub        w15, w14, #0x30
0000000000077cac         cmp        w15, #0xa
0000000000077cb0         cset       w12, lo
0000000000077cb4         str        x8, [x0]
0000000000077cb8         ldr        x9, [x2]
0000000000077cbc         cmp        x8, x9
0000000000077cc0         cset       w13, eq
0000000000077cc4         cmp        w14, #0x37
0000000000077cc8         ccmp       w15, #0x9, #0x2
0000000000077ccc         ccmp       x8, x9, #0x4
0000000000077cd0         b.ne       loc_77cf8

0000000000077cd4         and        w8, w11, w12
0000000000077cd8         orr        w0, w13, w8
0000000000077cdc         ret
                        ; endp

                     loc_77ce0:
0000000000077ce0         add        x8, x10, #0x1                               ; CODE XREF=__ZN17double_conversionL7AdvanceIPcEEbPT_tiRS2_+4
0000000000077ce4         str        x8, [x0]
0000000000077ce8         ldr        x9, [x2]

                     loc_77cec:
0000000000077cec         cmp        x8, x9                                      ; CODE XREF=__ZN17double_conversionL7AdvanceIPcEEbPT_tiRS2_+124, __ZN17double_conversionL7AdvanceIPcEEbPT_tiRS2_+144, __ZN17double_conversionL7AdvanceIPcEEbPT_tiRS2_+160
0000000000077cf0         cset       w0, eq
0000000000077cf4         ret
                        ; endp

                     loc_77cf8:
0000000000077cf8         add        x10, x10, #0x2                              ; CODE XREF=__ZN17double_conversionL7AdvanceIPcEEbPT_tiRS2_+64
0000000000077cfc         cmp        x10, x9
0000000000077d00         b.eq       loc_77d34

0000000000077d04         ldrsb      w11, [x8]
0000000000077d08         cmp        w11, w1
0000000000077d0c         b.ne       loc_77cec

0000000000077d10         ldrsb      w11, [x10]
0000000000077d14         sub        w12, w11, #0x30
0000000000077d18         cmp        w11, #0x37
0000000000077d1c         ccmp       w12, #0x9, #0x2
0000000000077d20         b.hi       loc_77cec

0000000000077d24         str        x10, [x0]
0000000000077d28         ldr        x9, [x2]
0000000000077d2c         mov        x8, x10
0000000000077d30         b          loc_77cec

                     loc_77d34:
0000000000077d34         movz       w0, #0x0                                    ; CODE XREF=__ZN17double_conversionL7AdvanceIPcEEbPT_tiRS2_+112
0000000000077d38         ret
                        ; endp


        ; Section __stubs
        ; Range: [0x77d3c; 0x783c0[ (1668 bytes)
        ; File offset : [490812; 492480[ (1668 bytes)
        ; Flags: 0x80000408
        ;   S_SYMBOL_STUBS
        ;   S_ATTR_PURE_INSTRUCTIONS
        ;   S_ATTR_SOME_INSTRUCTIONS



        ; ================ B E G I N N I N G   O F   P R O C E D U R E ================


                     imp___stubs__NXGetArchInfoFromCpuType:        // NXGetArchInfoFromCpuType
0000000000077d3c         nop                                                    ; CODE XREF=__ZN7mozilla12baseprofiler21AppendSharedLibrariesERNS_10JSONWriterE+1268
0000000000077d40         ldr        x16, #_NXGetArchInfoFromCpuType_ptr         ; _NXGetArchInfoFromCpuType
0000000000077d44         br         x16                                         ; _NXGetArchInfoFromCpuType
                        ; endp


        ; ================ B E G I N N I N G   O F   P R O C E D U R E ================


                     imp___stubs__OSSpinLockLock:        // OSSpinLockLock
0000000000077d48         nop                                                    ; CODE XREF=__ZL13chunk_deallocPvm9ChunkType+68, __ZL13chunk_deallocPvm9ChunkType+356, __ZL13chunk_deallocPvm9ChunkType+396, __ZL13chunk_deallocPvm9ChunkType+748, __ZL13chunk_deallocPvm9ChunkType+920, __ZL11chunk_allocmmbPb+96, __ZL11chunk_allocmmbPb+416, __ZL11chunk_allocmmbPb+784, __ZL11chunk_allocmmbPb+1544, __ZN7arena_t11MallocLargeEmb+76, __ZN7arena_t10PallocHugeEmmb+104
0000000000077d4c         ldr        x16, #_OSSpinLockLock_ptr                   ; _OSSpinLockLock
0000000000077d50         br         x16                                         ; _OSSpinLockLock
                        ; endp


        ; ================ B E G I N N I N G   O F   P R O C E D U R E ================


                     imp___stubs__OSSpinLockUnlock:        // OSSpinLockUnlock
0000000000077d54         nop                                                    ; CODE XREF=__ZL13chunk_deallocPvm9ChunkType+264, __ZL13chunk_deallocPvm9ChunkType+380, __ZL13chunk_deallocPvm9ChunkType+676, __ZL13chunk_deallocPvm9ChunkType+768, __ZL13chunk_deallocPvm9ChunkType+912, __ZL13chunk_deallocPvm9ChunkType+1024, __ZL11chunk_allocmmbPb+332, __ZL11chunk_allocmmbPb+608, __ZL11chunk_allocmmbPb+680, __ZL11chunk_allocmmbPb+776, __ZL11chunk_allocmmbPb+1520
0000000000077d58         ldr        x16, #_OSSpinLockUnlock_ptr                 ; _OSSpinLockUnlock
0000000000077d5c         br         x16                                         ; _OSSpinLockUnlock
                        ; endp

It would be great if dump_syms could emit symbols for these stubs.

See also gimli-rs/object#377 where I've asked how to obtain this type of symbol.