Perl 内部结构详解 -- PerlGuts Illustrated (6 CV)
CV
code value，函数的结构，如下图：
下边示例可以看到几个主要参数：
函数所在的Stash & GV。
函数的参数表和临时变量表PADLIST。
use Devel::Peek;use Data::Dumper;sub test{my ($a,$b) = @_;Dump \&test;test(++$a,--$b) if $b>0;}Dump \&test;test(1,2);输出：SV = RV(0x298f50) at 0x298f44 REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x182a834 SV = PVCV(0x1829024) at 0x182a834 REFCNT = 2 FLAGS = () COMP_STASH = 0x298e34"main" START = 0x18ba94c ===> 0 ROOT = 0x18ba4cc GVGV::GV = 0x184b34c"main" :: "test" FILE = "tmp.pl" DEPTH = 0 FLAGS = 0x0 OUTSIDE_SEQ = 535 PADLIST = 0x182a864 PADNAME = 0x182a934(0x18c7c6c) PAD = 0x182a8c4(0x18c7be4) 1. 0x182a854<1> (535,536) "$a" 2. 0x182a884<1> (535,536) "$b" OUTSIDE = 0x299094 (MAIN)SV = RV(0x298f50) at 0x298f44 REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x182a834 SV = PVCV(0x1829024) at 0x182a834 REFCNT = 4 FLAGS = () COMP_STASH = 0x298e34"main" START = 0x18ba94c ===> 0 ROOT = 0x18ba4cc GVGV::GV = 0x184b34c"main" :: "test" FILE = "tmp.pl" DEPTH = 1 FLAGS = 0x0 OUTSIDE_SEQ = 535 PADLIST = 0x182a864 PADNAME = 0x182a934(0x18c7c6c) PAD = 0x182a8c4(0x18c7be4) 1. 0x182a854<1> (535,536) "$a" 2. 0x182a884<1> (535,536) "$b" OUTSIDE = 0x299094 (MAIN)SV = RV(0x1899240) at 0x1899234 REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x182a834 SV = PVCV(0x1829024) at 0x182a834 REFCNT = 4 FLAGS = () COMP_STASH = 0x298e34"main" START = 0x18ba94c ===> 0 ROOT = 0x18ba4cc GVGV::GV = 0x184b34c"main" :: "test" FILE = "tmp.pl" DEPTH = 2 FLAGS = 0x0 OUTSIDE_SEQ = 535 PADLIST = 0x182a864 PADNAME = 0x182a934(0x18c7c6c) PAD = 0x182a8c4(0x18c7be4) 1. 0x182a854<1> (535,536) "$a" 2. 0x182a884<1> (535,536) "$b" OUTSIDE = 0x299094 (MAIN)SV = RV(0x1863a28) at 0x1863a1c REFCNT = 1 FLAGS = (TEMP,ROK) RV = 0x182a834 SV = PVCV(0x1829024) at 0x182a834 REFCNT = 4 FLAGS = () COMP_STASH = 0x298e34"main" START = 0x18ba94c ===> 0 ROOT = 0x18ba4cc GVGV::GV = 0x184b34c"main" :: "test" FILE = "tmp.pl" DEPTH = 3 FLAGS = 0x0 OUTSIDE_SEQ = 535 PADLIST = 0x182a864 PADNAME = 0x182a934(0x18c7c6c) PAD = 0x182a8c4(0x18c7be4) 1. 0x182a854<1> (535,536) "$a" 2. 0x182a884<1> (535,536) "$b" OUTSIDE = 0x299094 (MAIN)
词法变量(my & our)会设置SVs_PADMY/SVs_PADOUR标记，目标设置SVs_PADTMP标记。
