In the Macintosh Pascal mailing list (<http://pascal-central.com/maillist.html>) Scott Lindhurst wrote:

I just started playing around with gpc, working on getting some old code to work with it, and have found a bug. This is version 3.3.2d1, just downloaded a few days ago with the accompanying GPCInterfacesB2, on OS X 10.2.8.

I get the message "gpc: Internal error: Illegal instruction (program gpc1)" when compiling the following program:

program bug;

uses GPCMacOSAll, GPCStringsAll; {No error if remove GPCStringsAll}

var tix: UInt32; {No error if change to integer or longint} begin tix := 1;

if tix > TickCount then {error while processing this line} tix := 2; end.

My makefile generates this command line (which is going to be wrapped, sorry): gpc --automake --unit-path=./:/Developer/Pascal/GPCPInterfaces/ --object-path=./build/ --unit-destination-path=./build/ --executable-path=./build/ -Wl,-framework,Carbon,-framework,ApplicationServices -o ./bug -Wl,-x -O2 -Wall -Wno-identifier-case --ignore-garbage-after-dot --longjmp-all-nonlocal-labels ./bug.pas

but the internal error can be reproduced with just gpc --unit-path=/Developer/Pascal/GPCPInterfaces/ ./bug.pas

I have the workaround of using integer or longint instead of UInt32.

Peter N. Lewis helped out by noting that "limit stacksize 8096" solves the problem. This is true, but still it is strange that the compiler needs such a huge amount of stack for compilation. So, I wonder if maybe there is indeed a problem in the compiler, solved only "by accident" by a stacklimit of nearly a megabyte. When I set "limit stacksize 4096", the backtrace reads: Date/Time: 2003-11-07 11:36:46 +0100 OS Version: 10.2.8 (Build 6R73) Host: G4.local. Command: gpc1 PID: 437 Exception: EXC_BAD_ACCESS (0x0001) Codes: KERN_INVALID_ADDRESS (0x0001) at 0xbff7fff0 Thread 0 Crashed: #0 0x000a9dc8 in tree_size (tree.c:161) #1 0x000aa024 in make_node (tree.c:237) #2 0x000c6980 in alloc_node (stringpool.c:70) #3 0x0024b4b0 in ht_lookup (hashtable.c:162) #4 0x000c6b1c in get_identifier (stringpool.c:109) #5 0x0001bb04 in get_operator (expressions.c:425) #6 0x0001c7e4 in build_pascal_binary_op (expressions.c:661) #7 0x0001c514 in parser_build_binary_op (expressions.c:583) #8 0x0000dd48 in yyuserAction (parse.c:4580) #9 0x000136c8 in yydoAction (parse.c:8238) #10 0x00013190 in yyglrReduce (parse.c:8290) #11 0x000124d0 in main_yyparse (parse.c:8991) #12 0x000a49c0 in compile_file (toplev.c:2134) #13 0x000a9c38 in do_compile (toplev.c:5402) #14 0x000a9d04 in toplev_main (toplev.c:5432) #15 0x00001fa8 in _start (crt.c:267) #16 0x00001e28 in start PPC Thread State: srr0: 0x000a9dc8 srr1: 0x0200f930 vrsave: 0x00000000 xer: 0x20000000 lr: 0x000a9dc0 ctr: 0x000c6968 mq: 0x00000000 r0: 0x000aa024 r1: 0xbff80040 r2: 0x6c616773 r3: 0xbff80080 r4: 0x0000002a r5: 0x0000002a r6: 0x00000001 r7: 0x00000002 r8: 0x727900e4 r9: 0x002e8a28 r10: 0x02a4f000 r11: 0x00020000 r12: 0x48042447 r13: 0x00000000 r14: 0x00000000 r15: 0x00000000 r16: 0x00000000 r17: 0x00000000 r18: 0x00387e40 r19: 0x002eb814 r20: 0x00000000 r21: 0x00000001 r22: 0xbff80200 r23: 0x0000002a r24: 0x0000b04b r25: 0xe972469b r26: 0x00883890 r27: 0x00000078 r28: 0x00000000 r29: 0x00011a6c r30: 0x00000001 r31: 0x000a9dc0 [G4:~] adriaan% gpc -v Reading specs from /Developer/Pascal/gpc332d1/lib/gcc-lib/powerpc-apple-darwin/3.3.2/specs Configured with: ../gpc-332d1/configure --enable-languages=pascal,c --prefix=/Developer/Pascal/gpc332d1 --enable-threads=posix --target=powerpc-apple-darwin Thread model: posix gpc version 20030830, based on gcc-3.3.2 The same problem also occurs with the previous alpha and gcc-3.3, but the backtrace is different: Date/Time: 2003-11-07 11:34:03 +0100 OS Version: 10.2.8 (Build 6R73) Host: G4.local. Command: gpc1 PID: 404 Exception: EXC_BAD_ACCESS (0x0001) Codes: KERN_INVALID_ADDRESS (0x0001) at 0xbff7ffe0 Thread 0 Crashed: #0 0x000c3b74 in alloc_page (ggc-page.c:660) #1 0x000c2b24 in ggc_alloc (ggc-page.c:1026) #2 0x0009c430 in make_node (tree.c:292) #3 0x000c25ac in alloc_node (stringpool.c:70) #4 0x0023cd30 in ht_lookup (hashtable.c:161) #5 0x000c2748 in get_identifier (stringpool.c:109) #6 0x000097d4 in get_operator (expressions.c:426) #7 0x0000a478 in build_pascal_binary_op (expressions.c:656) #8 0x0000a1ac in parser_build_binary_op (expressions.c:578) #9 0x0002d8d8 in main_yyparse (parse.c:2400) #10 0x00096e88 in compile_file (toplev.c:2134) #11 0x0009c03c in do_compile (toplev.c:5370) #12 0x0009c108 in toplev_main (toplev.c:5400) #13 0x000018a8 in _start (crt.c:267) #14 0x00001728 in start PPC Thread State: srr0: 0x000c3b74 srr1: 0x0000f930 vrsave: 0x00000000 xer: 0x00000000 lr: 0x000c3b6c ctr: 0x0009c3a0 mq: 0x00000000 r0: 0x000c2b24 r1: 0xbff80060 r2: 0x6c616773 r3: 0x00000023 r4: 0xbff80280 r5: 0x00000027 r6: 0x00000000 r7: 0x00000003 r8: 0xbff80100 r9: 0x002db53c r10: 0x00000001 r11: 0x0000002c r12: 0x88048444 r13: 0x00000003 r14: 0x000000c8 r15: 0xbfffec80 r16: 0x00000034 r17: 0x00000000 r18: 0x0036c9a0 r19: 0x002d94e4 r20: 0x00000000 r21: 0x02fa3e70 r22: 0x00000001 r23: 0xbff80280 r24: 0x00302ad0 r25: 0x00302ad0 r26: 0x00824890 r27: 0x0000008c r28: 0x03423e70 r29: 0x0000002c r30: 0x002fc69c r31: 0x000c3b6c The needed units can be found at <www.microbizz.nl/GPCMacOSAll.pas.bz2> and <www.microbizz.nl/GPCStringsAll.pas.bz2>. They were too large to include with this message. Regards, Adriaan van Os