differ, you shouldn't use numeric (decimal, octal, nor hex) constants
to refer to characters. You can safely say 'A', but not 0x41. You can
safely say '\n', but not \012. If a character doesn't have a trivial
-input form, you can create a #define for it in both C<utfebcdic.h> and
-C<utf8.h>, so that it resolves to different values depending on the
-character set being used. (There are three different EBCDIC character
-sets defined in C<utfebcdic.h>, so it might be best to insert the
-#define three times in that file.)
+input form, you should add it to the list in
+F<regen/unicode_constants.pl>, and have Perl create #defines for you,
+based on the current platform.
Also, the range 'A' - 'Z' in ASCII is an unbroken sequence of 26 upper
case alphabetic characters. That is not true in EBCDIC. Nor for 'a' to
Download the pmd-bin-X.Y.zip () from the SourceForge site, extract the
pmd-X.Y.jar from it, and then run that on source code thusly:
- java -cp pmd-X.Y.jar net.sourceforge.pmd.cpd.CPD --minimum-tokens 100 --files /some/where/src --language c > cpd.txt
+ java -cp pmd-X.Y.jar net.sourceforge.pmd.cpd.CPD \
+ --minimum-tokens 100 --files /some/where/src --language c > cpd.txt
You may run into memory limits, in which case you should use the -Xmx
option:
=head1 MEMORY DEBUGGERS
-B<NOTE 1>: Running under older memory debuggers such as Purify, valgrind
-or Third Degree greatly slows down the execution: seconds become minutes,
-minutes become hours. For example as of Perl 5.8.1, the
+B<NOTE 1>: Running under older memory debuggers such as Purify,
+valgrind or Third Degree greatly slows down the execution: seconds
+become minutes, minutes become hours. For example as of Perl 5.8.1, the
ext/Encode/t/Unicode.t takes extraordinarily long to complete under
e.g. Purify, Third Degree, and valgrind. Under valgrind it takes more
than six hours, even on a snappy computer. The said test must be doing
something that is quite unfriendly for memory debuggers. If you don't
feel like waiting, that you can simply kill away the perl process.
-Roughly valgrind slows down execution by factor 10, AddressSanitizer
-by factor 2.
+Roughly valgrind slows down execution by factor 10, AddressSanitizer by
+factor 2.
B<NOTE 2>: To minimize the number of memory leak false alarms (see
L</PERL_DESTRUCT_LEVEL> for more information), you have to set the
-environment variable PERL_DESTRUCT_LEVEL to 2.
-
-For csh-like shells:
-
- setenv PERL_DESTRUCT_LEVEL 2
-
-For Bourne-type shells:
-
- PERL_DESTRUCT_LEVEL=2
- export PERL_DESTRUCT_LEVEL
-
-In Unixy environments you can also use the C<env> command:
+environment variable PERL_DESTRUCT_LEVEL to 2. For example, like this:
env PERL_DESTRUCT_LEVEL=2 valgrind ./perl -Ilib ...
unless Perl is built with the Configure option
C<-Accflags=-DDL_UNLOAD_ALL_AT_EXIT>.
-=head2 Rational Software's Purify
-
-Purify is a commercial tool that is helpful in identifying memory
-overruns, wild pointers, memory leaks and other such badness. Perl must
-be compiled in a specific way for optimal testing with Purify. Purify
-is available under Windows NT, Solaris, HP-UX, SGI, and Siemens Unix.
-
-=head3 Purify on Unix
-
-On Unix, Purify creates a new Perl binary. To get the most benefit out
-of Purify, you should create the perl to Purify using:
-
- sh Configure -Accflags=-DPURIFY -Doptimize='-g' \
- -Uusemymalloc -Dusemultiplicity
-
-where these arguments mean:
-
-=over 4
-
-=item * -Accflags=-DPURIFY
-
-Disables Perl's arena memory allocation functions, as well as forcing
-use of memory allocation functions derived from the system malloc.
-
-=item * -Doptimize='-g'
-
-Adds debugging information so that you see the exact source statements
-where the problem occurs. Without this flag, all you will see is the
-source filename of where the error occurred.
-
-=item * -Uusemymalloc
-
-Disable Perl's malloc so that Purify can more closely monitor
-allocations and leaks. Using Perl's malloc will make Purify report most
-leaks in the "potential" leaks category.
-
-=item * -Dusemultiplicity
-
-Enabling the multiplicity option allows perl to clean up thoroughly
-when the interpreter shuts down, which reduces the number of bogus leak
-reports from Purify.
-
-=back
-
-Once you've compiled a perl suitable for Purify'ing, then you can just:
-
- make pureperl
-
-which creates a binary named 'pureperl' that has been Purify'ed. This
-binary is used in place of the standard 'perl' binary when you want to
-debug Perl memory problems.
-
-As an example, to show any memory leaks produced during the standard
-Perl testset you would create and run the Purify'ed perl as:
-
- make pureperl
- cd t
- ../pureperl -I../lib harness
-
-which would run Perl on test.pl and report any memory problems.
-
-Purify outputs messages in "Viewer" windows by default. If you don't
-have a windowing environment or if you simply want the Purify output to
-unobtrusively go to a log file instead of to the interactive window,
-use these following options to output to the log file "perl.log":
-
- setenv PURIFYOPTIONS "-chain-length=25 -windows=no \
- -log-file=perl.log -append-logfile=yes"
-
-If you plan to use the "Viewer" windows, then you only need this
-option:
-
- setenv PURIFYOPTIONS "-chain-length=25"
-
-In Bourne-type shells:
-
- PURIFYOPTIONS="..."
- export PURIFYOPTIONS
-
-or if you have the "env" utility:
-
- env PURIFYOPTIONS="..." ../pureperl ...
-
-=head3 Purify on NT
-
-Purify on Windows NT instruments the Perl binary 'perl.exe' on the fly.
- There are several options in the makefile you should change to get the
-most use out of Purify:
-
-=over 4
-
-=item * DEFINES
-
-You should add -DPURIFY to the DEFINES line so the DEFINES line looks
-something like:
-
- DEFINES = -DWIN32 -D_CONSOLE -DNO_STRICT $(CRYPT_FLAG) -DPURIFY=1
-
-to disable Perl's arena memory allocation functions, as well as to
-force use of memory allocation functions derived from the system
-malloc.
-
-=item * USE_MULTI = define
-
-Enabling the multiplicity option allows perl to clean up thoroughly
-when the interpreter shuts down, which reduces the number of bogus leak
-reports from Purify.
-
-=item * #PERL_MALLOC = define
-
-Disable Perl's malloc so that Purify can more closely monitor
-allocations and leaks. Using Perl's malloc will make Purify report most
-leaks in the "potential" leaks category.
-
-=item * CFG = Debug
-
-Adds debugging information so that you see the exact source statements
-where the problem occurs. Without this flag, all you will see is the
-source filename of where the error occurred.
-
-=back
-
-As an example, to show any memory leaks produced during the standard
-Perl testset you would create and run Purify as:
-
- cd win32
- make
- cd ../t
- purify ../perl -I../lib harness
-
-which would instrument Perl in memory, run Perl on test.pl, then
-finally report any memory problems.
-
=head2 valgrind
-The valgrind tool can be used to find out both memory leaks
-and illegal heap memory accesses. As of version 3.3.0, Valgrind only
-supports Linux on x86, x86-64 and PowerPC and Darwin (OS X) on x86 and
-x86-64). The special "test.valgrind" target can be used to run the
-tests under valgrind. Found errors and memory leaks are logged in
-files named F<testfile.valgrind>.
+The valgrind tool can be used to find out both memory leaks and illegal
+heap memory accesses. As of version 3.3.0, Valgrind only supports Linux
+on x86, x86-64 and PowerPC and Darwin (OS X) on x86 and x86-64). The
+special "test.valgrind" target can be used to run the tests under
+valgrind. Found errors and memory leaks are logged in files named
+F<testfile.valgrind>.
Valgrind also provides a cachegrind tool, invoked on perl as:
=head2 AddressSanitizer
-AddressSanitizer is a clang extension, included in clang since v3.1.
-It checks illegal heap pointers, global pointers, stack pointers and use
-after free, and is so fast that you can easily compile your debugging
-or optimized perl with it. It does not check memory leaks though.
-AddressSanitizer is available for linux, Mac OS X and soon on Windows.
+AddressSanitizer is a clang and gcc extension, included in clang since
+v3.1 and gcc since v4.8. It checks illegal heap pointers, global
+pointers, stack pointers and use after free errors, and is fast enough
+that you can easily compile your debugging or optimized perl with it.
+It does not check memory leaks though. AddressSanitizer is available
+for Linux, Mac OS X and soon on Windows.
-You should create the perl with AddressSanitizer using:
+To build perl with AddressSanitizer, your Configure invocation should
+look like:
- sh Configure -Dcc=clang -Accflags=-faddress-sanitizer \
- -Aldflags=-faddress-sanitizer -Alddlflags=-shared\ -faddress-sanitizer
+ sh Configure -des -Dcc=clang \
+ -Accflags=-faddress-sanitizer -Aldflags=-faddress-sanitizer \
+ -Alddlflags=-shared\ -faddress-sanitizer
where these arguments mean:
=item * -Dcc=clang
-If clang is in your path, otherwise point to the path of the installed or temp.
-clang with AddressSanitizer enabled.
+This should be replaced by the full path to your clang executable if it
+is not in your path.
=item * -Accflags=-faddress-sanitizer
-Instrument pointer accesses with AddressSanitizer.
+Compile perl and extensions sources with AddressSanitizer.
=item * -Aldflags=-faddress-sanitizer
-Link with AddressSanitizer.
+Link the perl executable with AddressSanitizer.
=item * -Alddlflags=-shared\ -faddress-sanitizer
-With a shared libperl.so, i.e. C<-Duseshrplib> is used, you must manually add
-C<-shared>.
+Link dynamic extensions with AddressSanitizer. You must manually
+specify C<-shared> because using C<-Alddlflags=-shared> will prevent
+Configure from setting a default value for C<lddlflags>, which usually
+contains C<-shared> (at least on Linux).
=back
-See L<http://code.google.com/p/address-sanitizer/wiki/AddressSanitizer>
+See also
+L<http://code.google.com/p/address-sanitizer/wiki/AddressSanitizer>.
=head1 PROFILING
=head2 Gprof Profiling
-gprof is a profiling tool available in many Unix platforms, it uses
-F<statistical time-sampling>.
+I<gprof> is a profiling tool available in many Unix platforms which
+uses I<statistical time-sampling>. You can build a profiled version of
+F<perl> by compiling using gcc with the flag C<-pg>. Either edit
+F<config.sh> or re-run F<Configure>. Running the profiled version of
+Perl will create an output file called F<gmon.out> which contains the
+profiling data collected during the execution.
+
+quick hint:
+
+ $ sh Configure -des -Dusedevel -Accflags='-pg' \
+ -Aldflags='-pg' -Alddlflags='-pg -shared' \
+ && make perl
+ $ ./perl ... # creates gmon.out in current directory
+ $ gprof ./perl > out
+ $ less out
-You can build a profiled version of perl called "perl.gprof" by
-invoking the make target "perl.gprof" (What is required is that Perl
-must be compiled using the C<-pg> flag, you may need to re-Configure).
-Running the profiled version of Perl will create an output file called
-F<gmon.out> is created which contains the profiling data collected
-during the execution.
+(you probably need to add C<-shared> to the <-Alddlflags> line until RT
+#118199 is resolved)
-The gprof tool can then display the collected data in various ways.
-Usually gprof understands the following options:
+The F<gprof> tool can then display the collected data in various ways.
+Usually F<gprof> understands the following options:
=over 4
=back
For more detailed explanation of the available commands and output
-formats, see your own local documentation of gprof.
+formats, see your own local documentation of F<gprof>.
-quick hint:
+=head2 GCC gcov Profiling
- $ sh Configure -des -Dusedevel -Doptimize='-pg' && make perl.gprof
- $ ./perl.gprof someprog # creates gmon.out in current directory
- $ gprof ./perl.gprof > out
- $ view out
+I<basic block profiling> is officially available in gcc 3.0 and later.
+You can build a profiled version of F<perl> by compiling using gcc with
+the flags C<-fprofile-arcs -ftest-coverage>. Either edit F<config.sh>
+or re-run F<Configure>.
-=head2 GCC gcov Profiling
+quick hint:
-Starting from GCC 3.0 I<basic block profiling> is officially available
-for the GNU CC.
+ $ sh Configure -des -Dusedevel -Doptimize='-g' \
+ -Accflags='-fprofile-arcs -ftest-coverage' \
+ -Aldflags='-fprofile-arcs -ftest-coverage' \
+ -Alddlflags='-fprofile-arcs -ftest-coverage -shared' \
+ && make perl
+ $ rm -f regexec.c.gcov regexec.gcda
+ $ ./perl ...
+ $ gcov regexec.c
+ $ less regexec.c.gcov
-You can build a profiled version of perl called F<perl.gcov> by
-invoking the make target "perl.gcov" (what is required that Perl must
-be compiled using gcc with the flags C<-fprofile-arcs -ftest-coverage>,
-you may need to re-Configure).
+(you probably need to add C<-shared> to the <-Alddlflags> line until RT
+#118199 is resolved)
Running the profiled version of Perl will cause profile output to be
-generated. For each source file an accompanying ".da" file will be
+generated. For each source file an accompanying F<.gcda> file will be
created.
-To display the results you use the "gcov" utility (which should be
+To display the results you use the I<gcov> utility (which should be
installed if you have gcc 3.0 or newer installed). F<gcov> is run on
source code files, like this
which will cause F<sv.c.gcov> to be created. The F<.gcov> files contain
the source code annotated with relative frequencies of execution
-indicated by "#" markers.
+indicated by "#" markers. If you want to generate F<.gcov> files for
+all profiled object files, you can run something like this:
+
+ for file in `find . -name \*.gcno`
+ do sh -c "cd `dirname $file` && gcov `basename $file .gcno`"
+ done
Useful options of F<gcov> include C<-b> which will summarise the basic
block, branch, and function call coverage, and C<-c> which instead of
relative frequencies will use the actual counts. For more information
on the use of F<gcov> and basic block profiling with gcc, see the
-latest GNU CC manual, as of GCC 3.0 see
-
- http://gcc.gnu.org/onlinedocs/gcc-3.0/gcc.html
-
-and its section titled "8. gcov: a Test Coverage Program"
-
- http://gcc.gnu.org/onlinedocs/gcc-3.0/gcc_8.html#SEC132
-
-quick hint:
-
- $ sh Configure -des -Dusedevel -Doptimize='-g' \
- -Accflags='-fprofile-arcs -ftest-coverage' \
- -Aldflags='-fprofile-arcs -ftest-coverage' && make perl.gcov
- $ rm -f regexec.c.gcov regexec.gcda
- $ ./perl.gcov
- $ gcov regexec.c
- $ view regexec.c.gcov
+latest GNU CC manual. As of gcc 4.8, this is at
+L<http://gcc.gnu.org/onlinedocs/gcc/Gcov-Intro.html#Gcov-Intro>
=head1 MISCELLANEOUS TRICKS
=head2 PERL_DESTRUCT_LEVEL
If you want to run any of the tests yourself manually using e.g.
-valgrind, or the pureperl or perl.third executables, please note that
-by default perl B<does not> explicitly cleanup all the memory it has
-allocated (such as global memory arenas) but instead lets the exit() of
-the whole program "take care" of such allocations, also known as
-"global destruction of objects".
+valgrind, please note that by default perl B<does not> explicitly
+cleanup all the memory it has allocated (such as global memory arenas)
+but instead lets the exit() of the whole program "take care" of such
+allocations, also known as "global destruction of objects".
There is a way to tell perl to do complete cleanup: set the environment
variable PERL_DESTRUCT_LEVEL to a non-zero value. The t/TEST wrapper
does set this to 2, and this is what you need to do too, if you don't
-want to see the "global leaks": For example, for "third-degreed" Perl:
+want to see the "global leaks": For example, for running under valgrind
- env PERL_DESTRUCT_LEVEL=2 ./perl.third -Ilib t/foo/bar.t
+ env PERL_DESTRUCT_LEVEL=2 valgrind ./perl -Ilib t/foo/bar.t
(Note: the mod_perl apache module uses also this environment variable
for its own purposes and extended its semantics. Refer to the mod_perl
Under ithreads the optree is read only. If you want to enforce this, to
check for write accesses from buggy code, compile with
-C<-DPL_OP_SLAB_ALLOC> to enable the OP slab allocator and
C<-DPERL_DEBUG_READONLY_OPS> to enable code that allocates op memory
-via C<mmap>, and sets it read-only at run time. Any write access to an
-op results in a C<SIGBUS> and abort.
+via C<mmap>, and sets it read-only when it is attached to a subroutine.
+Any write access to an op results in a C<SIGBUS> and abort.
This code is intended for development only, and may not be portable
even to all Unix variants. Also, it is an 80% solution, in that it
-isn't able to make all ops read only. Specifically it
+isn't able to make all ops read only. Specifically it does not apply to
+op slabs belonging to C<BEGIN> blocks.
-=over
-
-=item * 1
-
-Only sets read-only on all slabs of ops at C<CHECK> time, hence ops
-allocated later via C<require> or C<eval> will be re-write
-
-=item * 2
-
-Turns an entire slab of ops read-write if the refcount of any op in the
-slab needs to be decreased.
-
-=item * 3
-
-Turns an entire slab of ops read-write if any op from the slab is
-freed.
-
-=back
-
-It's not possible to turn the slabs to read-only after an action
-requiring read-write access, as either can happen during op tree
-building time, so there may still be legitimate write access.
-
-However, as an 80% solution it is still effective, as currently it
-catches a write access during the generation of F<Config.pm>, which
-means that we can't yet build F<perl> with this enabled.
+However, as an 80% solution it is still effective, as it has caught
+bugs in the past.
=head2 The .i Targets
make foo.i
-which will expand the macros using cpp. Don't be scared by the results.
+which will expand the macros using cpp. Don't be scared by the
+results.
=head1 AUTHOR
https://perl5.git.perl.org / perl5.git / blobdiff