https://github.com/tpoechtrager/osxcross

Mac OS X cross toolchain for Linux, FreeBSD, OpenBSD and Android (Termux)
https://github.com/tpoechtrager/osxcross

Last synced: about 2 months ago
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Mac OS X cross toolchain for Linux, FreeBSD, OpenBSD and Android (Termux)

• Host: GitHub
• URL: https://github.com/tpoechtrager/osxcross
• Owner: tpoechtrager
• License: gpl-2.0
• Created: 2013-11-10T13:51:50.000Z (about 11 years ago)
• Default Branch: master
• Last Pushed: 2024-08-19T19:48:20.000Z (4 months ago)
• Last Synced: 2024-08-19T23:15:32.259Z (4 months ago)
• Language: C++
• Homepage:
• Size: 28.2 MB
• Stars: 2,838
• Watchers: 82
• Forks: 319
• Open Issues: 115
• Metadata Files:
  • Readme: README.COMPILER-RT.md
  • Changelog: CHANGELOG
  • License: COPYING
  • Authors: AUTHORS

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README

        
## COMPILER-RT ##

### WHAT IS COMPILER-RT? ###

Please see http://compiler-rt.llvm.org.

### INSTALLATION: ###

Ensure you have finished `build.sh`,

then run: `./build_compiler_rt.sh`.

By default, installation steps for compiler-rt will be printed to the terminal

to run manually, but you can automate the installation process by defining

`ENABLE_COMPILER_RT_INSTALL`.

You can verify compiler-rt is working by invoking the following command:

    echo "int main(void){return 0;}" | xcrun clang -xc -o/dev/null -v - 2>&1 | \

      grep "libclang_rt" 1>/dev/null && echo "Success"

If you see "Success", then everything went well.

### USAGE: ###

You do not need to do anything, clang's doing the job for you.

However, `-fsanitize=address` is a bit annoying because the address sanitizer library is linked  

dynamically, and thus requires you to copy the ASAN runtime library onto the target system. 

\[See [README.DEBUGGING](README.DEBUGGING.md) in how to get a backtrace with line numbers and symbol names]

The following example illustrates how to achieve this:

    # Example source code.

    $ cat test.c

    #include 

    #include 

    #include 

    int main(void) {

      char buf[2];

      strcpy(buf, "Hello World"); /* Buffer overflow. */

      puts(buf);

      return 0;

    }

    # Compile the source file.

    $ o64-clang test.c -fsanitize=address -o test

    # Ensure the ASAN library is linked in.

    $ xcrun otool -L test

    test:

            /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 104.1.0) # ASAN dep.

            @rpath/libclang_rt.asan_osx_dynamic.dylib (compatibility version 0.0.0, current version 0.0.0)

            /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1213.0.0)

    # Copy 'test' and 'libclang_rt.asan_osx_dynamic.dylib' onto the target system.

    # You can find the ASAN library path easily with this one-liner:

    $ echo "int main(void){return 0;}" | xcrun clang -fsanitize=address -xc -o/dev/null -v - 2>&1 | \

      tr ' ' '\n' | grep libclang_rt.asan_osx_dynamic.dylib

    [...]/bin/../lib/clang/3.6.2/lib/darwin/libclang_rt.asan_osx_dynamic.dylib

    # Run ./test on the target system:

    $ DYLD_LIBRARY_PATH=. ./test

    =================================================================

    ==410==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fff58c3ec72 at pc [...]

    WRITE of size 12 at 0x7fff58c3ec72 thread T0

        #0 0x1070029ac  ([...]/tmp/libclang_rt.asan_osx_dynamic.dylib+0x3a9ac)

        #1 0x106fc1d3a  ([...]/tmp/./test+0x100000d3a)

        #2 0x106fc1bd3  ([...]/tmp/./test+0x100000bd3)

        #3 0x0  ()

    Address 0x7fff58c3ec72 is located in stack of thread T0 at offset 50 in frame

        #0 0x106fc1bef  ([...]/tmp/./test+0x100000bef)

      This frame has 2 object(s):

        [32, 36) ''

        [48, 50) 'buf' <== Memory access at offset 50 overflows this variable

    HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext

          (longjmp and C++ exceptions *are* supported)

    Shadow bytes around the buggy address:

      0x1fffeb187d30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      0x1fffeb187d40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      0x1fffeb187d50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      0x1fffeb187d60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      0x1fffeb187d70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

    =>0x1fffeb187d80: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f2[02]f3

      0x1fffeb187d90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      0x1fffeb187da0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      0x1fffeb187db0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      0x1fffeb187dc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

      0x1fffeb187dd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

    Shadow byte legend (one shadow byte represents 8 application bytes):

      Addressable:           00

      Partially addressable: 01 02 03 04 05 06 07 

      Heap left redzone:       fa

      Heap right redzone:      fb

      Freed heap region:       fd

      Stack left redzone:      f1

      Stack mid redzone:       f2

      Stack right redzone:     f3

      Stack partial redzone:   f4

      Stack after return:      f5

      Stack use after scope:   f8

      Global redzone:          f9

      Global init order:       f6

      Poisoned by user:        f7

      Container overflow:      fc

      Array cookie:            ac

      Intra object redzone:    bb

      ASan internal:           fe

      Left alloca redzone:     ca

      Right alloca redzone:    cb

    ==410==ABORTING