Calling clCreateProgramFromSource on a single source with the strings arg set the the address of an #included character array segfaults, but passing the array in as an element of a character pointer array works.

#include "prog_src.h"
const char *cl_srcs[1];
cl_srcs[0] = prog_src_cl;

cl.prog = clCreateProgramWithSource(cl.context, 1, cl_srcs, NULL, &err);
puts("test0");
cl.prog = clCreateProgramWithSource(cl.context, 1, &prog_src_cl, NULL, &err);
puts("test1");

"test0" will print and then the program segfaults, i'm not sure why it doesn't work with the second version, prog_src_cl is an unsigned char * in the file #included.

Any help would be much appreciated as i cant seem to wrap my head around why something so seemingly trivial doesnt work as expected.

CodePudding user response：

The function clCreateProgramWithSource expects the source to be passed via the parameter const char** strings. You say prog_src_cl is a character array. This means that &proc_src_cl is of type const char (*)[N]. (Pointer to N-element array of constant characters, where N is probably the length of the string used to initialise the array, plus 1 for the nul termination character.) This is not the same as const char**, and you cannot safely convert between them!

I recommend you turn on more type checking options in your C compiler, for example by passing -Wextra to clang or gcc. For example, clang catches this programming error in the -Wincompatible-pointer-types warning, which is included in -Wextra.