Description:
------------
Hi,

NetBSD 7.0 i386 builds are consistently segfaulting generating phar.php
Example build log: http://nyftp.netbsd.org/pub/pkgsrc/packages/reports/2017Q1/NetBSD-7.0-i386/20170430.0103/php-7.1.3nb1/build.log

(Sorry for reporting a bug against 7.1.3, I didn't notice as I was experimenting, and this is in an extremely slow VM - I don't see relevant changes in 7.1.4)

We have some local modifications to the package, you can view them here:
https://github.com/NetBSD/pkgsrc/tree/trunk/lang/php71
(None of them touch deep PHP internals)

A backtrace of such a segfault is:

(gdb) core ./work/php-7.1.3/php.core                                            
[New process 1]                                                                 
Core was generated by `php'.                                                    
Program terminated with signal SIGSEGV, Segmentation fault.                     
#0  0x0857b17b in zval_get_type (pz=0x7ae11780)                                 
    at /pkgsrc/lang/php71/work/php-7.1.3/Zend/zend_types.h:332                  
332             return pz->u1.v.type;                                           
(gdb) bt
#0  0x0857b17b in zval_get_type (pz=0x7ae11780)
    at /pkgsrc/lang/php71/work/php-7.1.3/Zend/zend_types.h:332
#1  ZEND_UNSET_DIM_SPEC_CV_CONST_HANDLER ()
    at /pkgsrc/lang/php71/work/php-7.1.3/Zend/zend_vm_execute.h:39969
#2  0x084f5b20 in execute_ex (ex=0xbb214020)
    at /pkgsrc/lang/php71/work/php-7.1.3/Zend/zend_vm_execute.h:429
#3  0x084f6237 in zend_execute (op_array=0xbb26d080, return_value=0x0)
    at /pkgsrc/lang/php71/work/php-7.1.3/Zend/zend_vm_execute.h:474
#4  0x0847b116 in zend_execute_scripts (type=8, retval=0x0, file_count=3)
    at /pkgsrc/lang/php71/work/php-7.1.3/Zend/zend.c:1476
#5  0x083ec7e0 in php_execute_script (primary_file=0xbfbfdce0)
    at /pkgsrc/lang/php71/work/php-7.1.3/main/main.c:2537
#6  0x085c034c in do_cli (argc=14, argv=0xbfbfded8)
    at /pkgsrc/lang/php71/work/php-7.1.3/sapi/cli/php_cli.c:993
#7  0x085c1228 in main (argc=14, argv=0xbfbfded8)
    at /pkgsrc/lang/php71/work/php-7.1.3/sapi/cli/php_cli.c:1381

I personally attempted to build the package in qemu-system-i386, using GCC 4.8.5.

I've made the following change that made me able to build it:

--- configure.orig      2017-04-11 15:37:37.000000000 +0000
+++ configure
@@ -5737,10 +5737,7 @@ if test "$ZEND_GCC_GLOBAL_REGS" != "no";
 #else
 # define ZEND_GCC_VERSION 0
 #endif
-#if defined(__GNUC__) && ZEND_GCC_VERSION >= 4008 && defined(i386)
-# define ZEND_VM_FP_GLOBAL_REG "%esi"
-# define ZEND_VM_IP_GLOBAL_REG "%edi"
-#elif defined(__GNUC__) && ZEND_GCC_VERSION >= 4008 && defined(__x86_64__)
+#if defined(__GNUC__) && ZEND_GCC_VERSION >= 4008 && defined(__x86_64__)
 # define ZEND_VM_FP_GLOBAL_REG "%r14"
 # define ZEND_VM_IP_GLOBAL_REG "%r15"
 #elif defined(__GNUC__) && ZEND_GCC_VERSION >= 4008 && defined(__powerpc64__)

Disabling the use of a global register for i386 (I think).

I don't have a rationale for it, I just found it unbelievable that such a thing works, and disabling it did the trick.

This may be a GCC bug if you believe it should work.