2 If there are any non-option arguments, they are taken to be
3 names of objects to be saved (probably doesn't work properly yet).
4 Without extra arguments, it saves the main program.
5 -ofilename Output to filename instead of STDOUT
6 -v Verbose (currently gives a few compilation statistics)
7 -- Force end of options
8 -uPackname Force apparently unused subs from package Packname to
9 be compiled. This allows programs to use eval "foo()"
10 even when sub foo is never seen to be used at compile
11 time. The down side is that any subs which really are
12 never used also have code generated. This option is
13 necessary, for example, if you have a signal handler
14 foo which you initialise with $SIG{BAR} = "foo".
15 A better fix, though, is just to change it to
16 $SIG{BAR} = \&foo. You can have multiple -u options.
17 -D Debug options (concat or separate flags like perl -D)
18 o OPs, prints each OP as it's processed
19 c COPs, prints COPs as processed (incl. file & line num)
20 A prints AV information on saving
21 C prints CV information on saving
22 M prints MAGIC information on saving
23 -f Force optimisations on or off one at a time.
24 cog Copy-on-grow: PVs declared and initialised statically
25 no-cog No copy-on-grow
26 -On Optimisation level (n = 0, 1, 2, ...). -O means -O1.
27 Currently, -O1 and higher set -fcog.
30 perl -MO=C foo.pl > foo.c
31 perl cc_harness -o foo foo.c
33 perl -MO=C,-v,-DcA bar.pl > /dev/null
36 If there are any non-option arguments, they are taken to be names of
37 subs to be saved. Without extra arguments, it saves the main program.
38 -ofilename Output to filename instead of STDOUT
39 -- Force end of options
40 -uPackname Force apparently unused subs from package Packname to
41 be compiled. This allows programs to use eval "foo()"
42 even when sub foo is never seen to be used at compile
43 time. The down side is that any subs which really are
44 never used also have code generated. This option is
45 necessary, for example, if you have a signal handler
46 foo which you initialise with $SIG{BAR} = "foo".
47 A better fix, though, is just to change it to
48 $SIG{BAR} = \&foo. You can have multiple -u options.
49 -D Debug options (concat or separate flags like perl -D)
50 r Writes debugging output to STDERR just as it's about
51 to write to the program's runtime (otherwise writes
52 debugging info as comments in its C output).
53 O Outputs each OP as it's compiled
54 s Outputs the contents of the shadow stack at each OP
55 p Outputs the contents of the shadow pad of lexicals as
56 it's loaded for each sub or the main program.
57 q Outputs the name of each fake PP function in the queue
58 as it's about to processes.
59 l Output the filename and line number of each original
60 line of Perl code as it's processed (pp_nextstate).
61 t Outputs timing information of compilation stages
62 -f Force optimisations on or off one at a time.
64 cog Copy-on-grow: PVs declared and initialised statically
65 no-cog No copy-on-grow
66 These two not in CC yet.
68 freetmps-each-bblock Delays FREETMPS from the end of each
69 statement to the end of the each basic
71 freetmps-each-loop Delays FREETMPS from the end of each
72 statement to the end of the group of
73 basic blocks forming a loop. At most
74 one of the freetmps-each-* options can
76 omit-taint Omits generating code for handling
77 perl's tainting mechanism.
78 -On Optimisation level (n = 0, 1, 2, ...). -O means -O1.
79 Currently, -O1 sets -ffreetmps-each-bblock and -O2
80 sets -ffreetmps-each-loop.
83 perl -MO=CC,-O2,-ofoo.c foo.pl
84 perl cc_harness -o foo foo.c
87 Bytecode backend invocation
89 If there are any non-option arguments, they are taken to be
90 names of objects to be saved (probably doesn't work properly yet).
91 Without extra arguments, it saves the main program.
92 -ofilename Output to filename instead of STDOUT.
93 -- Force end of options.
94 -f Force optimisations on or off one at a time.
95 Each can be preceded by no- to turn the option off.
97 Only fills in the necessary fields of ops which have
98 been optimised away by perl's internal compiler.
100 Leaves out code to fill in the op_seq field of all ops
101 which is only used by perl's internal compiler.
103 If op->op_next ever points to a NULLOP, replaces the
104 op_next field with the first non-NULLOP in the path
107 Leaves out code to fill in the pointers which link the
108 internal syntax tree together. They're not needed at
109 run-time but leaving them out will make it impossible
110 to recompile or disassemble the resulting program.
111 It will also stop "goto label" statements from working.
112 -On Optimisation level (n = 0, 1, 2, ...). -O means -O1.
113 -O1 sets -fcompress-nullops -fomit-sequence numbers.
114 -O6 adds -fstrip-syntax-tree.
115 -D Debug options (concat or separate flags like perl -D)
116 o OPs, prints each OP as it's processed.
117 a tells the assembler to include source assembler lines
118 in its output as bytecode comments.
119 C prints each CV taken from the final symbol tree walk.
120 -S Output assembler source rather than piping it
121 through the assembler and outputting bytecode.
122 -m Compile as a module rather than a standalone program.
123 Currently this just means that the bytecodes for
124 initialising main_start, main_root and curpad are
128 perl -MO=Bytecode,-O6,-o,foo.plc foo.pl
130 perl -MO=Bytecode,-S foo.pl > foo.S
131 assemble foo.S > foo.plc
134 perl -MO=Bytecode,-m,-oFoo.pmc Foo.pm
136 Backends for debugging
137 perl -MO=Terse,exec foo.pl
138 perl -MO=Debug bar.pl
141 Used with "perl -MO=Backend,foo,bar prog.pl" to invoke the backend
142 B::Backend with options foo and bar. O invokes the sub
143 B::Backend::compile() with arguments foo and bar at BEGIN time.
144 That compile() sub must do any inital argument processing replied.
145 If unsuccessful, it should return a string which O arranges to be
146 printed as an error message followed by a clean error exit. In the
147 normal case where any option processing in compile() is successful,
148 it should return a sub ref (usually a closure) to perform the
149 actual compilation. When O regains control, it ensures that the
150 "-c" option is forced (so that the program being compiled doesn't
151 end up running) and registers an END block to call back the sub ref
152 returned from the backend's compile(). Perl then continues by
153 parsing prog.pl (just as it would with "perl -c prog.pl") and after
154 doing so, assuming there are no parse-time errors, the END block
155 of O gets called and the actual backend compilation happens. Phew.