Add Outlining Support for strcat

What is the feature you'd like to have?

Currently, in the binary I am looking at, there are a number of string operations that are treated as raw hex numbers applied to variable offsets. It would be nice if these showed in a more 'as it would appear in the code' way, of just general string operations.

Is your feature request related to a problem?

There are other similar examples in the binary (macOS, x86_64) I'm looking at, but this is the most self contained one:

  005851a0  int64_t SerumGUI::getPath_AppDataBase(int64_t arg1, int64_t* arg2)
  005851b5      int64_t rax = *___stack_chk_guard
  005851d4      void var_70
  005851d4      if (_FSFindFolder(0xffff8005, 0x61737570, 0, &var_70) == 0)
  005851dc          int64_t rax_2 = _CFURLCreateFromFSRef(0, &var_70)
  005851f1          _CFURLGetFileSystemRepresentation(rax_2, 0, arg2, 0x200)
  005851f9          _CFRelease(rax_2)
  00585201          int64_t rax_3 = _strlen(arg2)
🐛00585210          *(arg2 + rax_3) = 0x6566782e6d6f632f
🐛0058521e          *(arg2 + rax_3 + 8) = 0x7364726f63657272
🐛0058522d          *(arg2 + rax_3 + 0x10) = 0x2f6d757265732e
  00585239      int64_t rax_4 = *___stack_chk_guard
  00585240      if (rax_4 != rax)
  0058524b          ___stack_chk_fail()
  0058524b          noreturn
  0058524a      return rax_4

If I right click -> Display As -> Character Constant on those hex constants, it looks a bit more readable:

    005851a0  int64_t SerumGUI::getPath_AppDataBase(int64_t arg1, int64_t* arg2)
    005851b5      int64_t rax = *___stack_chk_guard
    005851d4      void var_70
    005851d4      if (_FSFindFolder(0xffff8005, 0x61737570, 0, &var_70) == 0)
    005851dc          int64_t rax_2 = _CFURLCreateFromFSRef(0, &var_70)
    005851f1          _CFURLGetFileSystemRepresentation(rax_2, 0, arg2, 0x200)
    005851f9          _CFRelease(rax_2)
    00585201          int64_t rax_3 = _strlen(arg2)
- 🐛00585210          *(arg2 + rax_3) = 0x6566782e6d6f632f
- 🐛0058521e          *(arg2 + rax_3 + 8) = 0x7364726f63657272
- 🐛0058522d          *(arg2 + rax_3 + 0x10) = 0x2f6d757265732e
+ 🐛00585210          *(arg2 + rax_3) = '/com.xfe'
+ 🐛0058521e          *(arg2 + rax_3 + 8) = 'rrecords'
+ 🐛0058522d          *(arg2 + rax_3 + 0x10) = '.serum/'
    00585239      int64_t rax_4 = *___stack_chk_guard
    00585240      if (rax_4 != rax)
    0058524b          ___stack_chk_fail()
    0058524b          noreturn
    0058524a      return rax_4

But it would be nicer if it was automatically something more like this (or similar):

    005851a0  int64_t SerumGUI::getPath_AppDataBase(int64_t arg1, int64_t* arg2)
    005851b5      int64_t rax = *___stack_chk_guard
    005851d4      void var_70
    005851d4      if (_FSFindFolder(0xffff8005, 0x61737570, 0, &var_70) == 0)
    005851dc          int64_t rax_2 = _CFURLCreateFromFSRef(0, &var_70)
    005851f1          _CFURLGetFileSystemRepresentation(rax_2, 0, arg2, 0x200)
    005851f9          _CFRelease(rax_2)
    00585201          int64_t rax_3 = _strlen(arg2)
- 🐛00585210          *(arg2 + rax_3) = 0x6566782e6d6f632f
- 🐛0058521e          *(arg2 + rax_3 + 8) = 0x7364726f63657272
- 🐛0058522d          *(arg2 + rax_3 + 0x10) = 0x2f6d757265732e
+ 🐛00585210          *(arg2 + rax_3) = '/com.xferrecords.serum/'
    00585239      int64_t rax_4 = *___stack_chk_guard
    00585240      if (rax_4 != rax)
    0058524b          ___stack_chk_fail()
    0058524b          noreturn
    0058524a      return rax_4

Or even better would be:

    005851a0  int64_t SerumGUI::getPath_AppDataBase(int64_t arg1, int64_t* arg2)
    005851b5      int64_t rax = *___stack_chk_guard
    005851d4      void var_70
    005851d4      if (_FSFindFolder(0xffff8005, 0x61737570, 0, &var_70) == 0)
    005851dc          int64_t rax_2 = _CFURLCreateFromFSRef(0, &var_70)
    005851f1          _CFURLGetFileSystemRepresentation(rax_2, 0, arg2, 0x200)
    005851f9          _CFRelease(rax_2)
-   00585201          int64_t rax_3 = _strlen(arg2)
- 🐛00585210          *(arg2 + rax_3) = 0x6566782e6d6f632f
- 🐛0058521e          *(arg2 + rax_3 + 8) = 0x7364726f63657272
- 🐛0058522d          *(arg2 + rax_3 + 0x10) = 0x2f6d757265732e
+ 🐛00585210          _strcat(arg2, "/com.xferrecords.serum/")
    00585239      int64_t rax_4 = *___stack_chk_guard
    00585240      if (rax_4 != rax)
    0058524b          ___stack_chk_fail()
    0058524b          noreturn
    0058524a      return rax_4

• https://www.geeksforgeeks.org/strcat-in-c/

  • char *strcat(char *dest, const char *src);

Are any alternative solutions acceptable?

Unsure.

Additional Information:

• This last screenshot shows another thing that would be nice to improve (which maybe is worth opening as a separate issue), where 32 bit shifts are also being used within the string operations