build for macOS high sierra.

[yoya]

fixing to build error on macOS high sierra.

• bool & boolean confusion on calling jpeglib functions
• errno variables need errno.h

---

% gcc -v
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 9.0.0 (clang-900.0.38)
Target: x86_64-apple-darwin17.5.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

[DomT4]

Semi-related in terms of being macOS/Clang specific, there's an issue with 10.11/Xcode 8 as well that doesn't reproduce with newer versions of macOS/Xcode/Clang/etc:

Making install in examples
clang++ -DHAVE_CONFIG_H -I. -I..    -I../src  -I/usr/local/Cellar/libpng/1.6.34/include/libpng16 -g -O2 -std=gnu++11 -Wall -Werror -Wsign-compare -Wconversion -Wno-sign-conversion -Wno-error=conversion -c -o heif_convert-encoder.o `test -f 'encoder.cc' || echo './'`encoder.cc
clang++ -DHAVE_CONFIG_H -I. -I..    -I../src  -I/usr/local/Cellar/libpng/1.6.34/include/libpng16 -g -O2 -std=gnu++11 -Wall -Werror -Wsign-compare -Wconversion -Wno-sign-conversion -Wno-error=conversion -c -o heif_convert-heif_convert.o `test -f 'heif_convert.cc' || echo './'`heif_convert.cc
clang++ -DHAVE_CONFIG_H -I. -I..    -I../src  -I/usr/local/Cellar/libpng/1.6.34/include/libpng16 -g -O2 -std=gnu++11 -Wall -Werror -Wsign-compare -Wconversion -Wno-sign-conversion -Wno-error=conversion -c -o heif_convert-encoder_jpeg.o `test -f 'encoder_jpeg.cc' || echo './'`encoder_jpeg.cc
clang++ -DHAVE_CONFIG_H -I. -I..    -I../src  -I/usr/local/Cellar/libpng/1.6.34/include/libpng16 -g -O2 -std=gnu++11 -Wall -Werror -Wsign-compare -Wconversion -Wno-sign-conversion -Wno-error=conversion -c -o heif_convert-encoder_png.o `test -f 'encoder_png.cc' || echo './'`encoder_png.cc
encoder.cc:53:43: error: use of undeclared identifier 'malloc'
    uint8_t* data = static_cast<uint8_t*>(malloc(datasize));
                                          ^
encoder.cc:60:7: error: use of undeclared identifier 'free'
      free(data);
      ^
2 errors generated.
make[1]: *** [heif_convert-encoder.o] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [install-recursive] Error 1

[fancycode]

Thanks!