32-bit toolchain warnings

[abelbeck]

First, Thanks much for ne, a real gem! We are cross-compiling under Buildroot with both 32-bit and 64-bit toolchains.

For the 32-bit toolchain case, I get a handful of warnings because sizeof(char *) and sizeof(int64_t) are different.

As far as I can tell, in this use, these warnings can be safely ignored ... please close this issue if you agree. All occurrences of the warnings are here:

/home/dev/astlinux/trunk/output/host/usr/bin/i586-unknown-linux-gnu-gcc  -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -Os  -std=c99 -Wall -Wno-parentheses -D_REGEX_LARGE_OFFSETS -D_GNU_SOURCE -DSTDC_HEADERS -Dinline=__inline__   -O3 -DNDEBUG     -c -o buffer.o buffer.c
buffer.c: In function 'create_mmap_files':
buffer.c:1197:36: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
     ld_buffer_syn[ld_count].line = (char *)start_of_line;
                                    ^
buffer.c:1201:39: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
     ld_buffer_no_syn[ld_count].line = (char *)start_of_line;
                                       ^
buffer.c:1231:34: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   ld_buffer_syn[ld_count].line = (char *)start_of_line;
                                  ^
buffer.c:1235:37: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   ld_buffer_no_syn[ld_count].line = (char *)start_of_line;
                                     ^
buffer.c: In function 'load_fd_mmap':
buffer.c:1275:41: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
      ld->line = ld->line_len ? char_p + (int64_t)ld->line : NULL;
                                         ^
buffer.c:1281:41: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
      ld->line = ld->line_len ? char_p + (int64_t)ld->line : NULL;
                                         ^

[vigna]

You're right. Those line of code temporarily store the pointers in line descriptors as integer offsets. Initially the pointers are syntactically too small (32 bit), but the offsets are in a memory-mapped file, so semantically they are 32-bit, too. The last two warnings are actually widening conversions, so there's no problem there.

The real issue is that it doesn't make any sense to have a 32-bit editor with 64-bit line lengths, line numbers and so on, but making this configurable would be a lot of work.