When building 21.5.9 on AIX 4.3.3 using either the IBM VisualAge C/C++ Compiler (VAC) or the older IBMCXX Compiler, the process stops at the compilation of src/keymap.c with the following error: "keymap.c", line 4015.1: 1506-191 (E) The character # is not a valid C source character. "keymap.c", line 4015.8: 1506-276 (S) Syntax error: possible missing ')'? "keymap.c", line 4015.2: 1506-045 (S) Undeclared identifier ifdef. "keymap.c", line 4017.2: 1506-201 (S) #else can only appear within a #if, #elif, #ifdef or #ifndef block. "keymap.c", line 4018.75: 1506-275 (S) Unexpected text ')' encountered. "keymap.c", line 4019.2: 1506-202 (S) #endif can only appear at the end of a #if, #elif, #ifdef or #ifndef block. Obviously, the IBM compilers can't handle the "#ifdef" statement within the memcpy function call at line 4015 ff. in src/keymap.c: memcpy ((void *)new, (const void *)c->keys_so_far, #ifdef USE_KKCC c->keys_so_far_total_size * sizeof (Lisp_Key_Data)); #else /* not USE_KKCC */ c->keys_so_far_total_size * sizeof (struct key_data)); #endif /* not USE_KKCC */ Compiling with gcc works fine, but I'd like to use one of the IBM compilers as they provide better optimization for the RS/6000 architecture and produce smaller binaries. If anyone has already built successfully with one of these compilers on AIX, I'd be glad to hear which flags/options are required to get along with the code fragment above. Otherwise I'd kindly ask to move the "memcpy" line into the "#ifdef" and "#else" branches. Although it may look less elegant, it will make XEmacs compile on the RS/6000 architecture with the standard AIX compiler (not everybody has gcc available on AIX). Please let me know what you're thinking. Thanks! Regards, Markus -- Markus Alt IBM Lab Boeblingen, Germany altmark(a)de.ibm.com