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author | Heinrich Schuchardt <xypron.glpk@gmx.de> | 2020-06-05 06:13:44 +0300 |
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committer | Tom Rini <trini@konsulko.com> | 2020-07-17 15:45:29 +0300 |
commit | aac9f284dbc3ae6a14d6fc8cf06c89aa9431b75b (patch) | |
tree | 942abedcb553e941ee1b8a51895132bd1f39ce52 /doc/README.coccinelle | |
parent | 7c3cc6f106ed1ca13b0ff6eea9f8e1473240aef3 (diff) | |
download | u-boot-aac9f284dbc3ae6a14d6fc8cf06c89aa9431b75b.tar.xz |
doc: Coccinelle: move to HTML doc
Move doc/README.coccinelle to doc/develop/coccinelle.rst using the current
linux-next version of the text.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Diffstat (limited to 'doc/README.coccinelle')
-rw-r--r-- | doc/README.coccinelle | 491 |
1 files changed, 0 insertions, 491 deletions
diff --git a/doc/README.coccinelle b/doc/README.coccinelle deleted file mode 100644 index 4a64b4c69d..0000000000 --- a/doc/README.coccinelle +++ /dev/null @@ -1,491 +0,0 @@ -.. Copyright 2010 Nicolas Palix <npalix@diku.dk> -.. Copyright 2010 Julia Lawall <julia@diku.dk> -.. Copyright 2010 Gilles Muller <Gilles.Muller@lip6.fr> - -.. highlight:: none - -Coccinelle -========== - -Coccinelle is a tool for pattern matching and text transformation that has -many uses in kernel development, including the application of complex, -tree-wide patches and detection of problematic programming patterns. - -Getting Coccinelle -------------------- - -The semantic patches included in the kernel use features and options -which are provided by Coccinelle version 1.0.0-rc11 and above. -Using earlier versions will fail as the option names used by -the Coccinelle files and coccicheck have been updated. - -Coccinelle is available through the package manager -of many distributions, e.g. : - - - Debian - - Fedora - - Ubuntu - - OpenSUSE - - Arch Linux - - NetBSD - - FreeBSD - -You can get the latest version released from the Coccinelle homepage at -http://coccinelle.lip6.fr/ - -Information and tips about Coccinelle are also provided on the wiki -pages at http://cocci.ekstranet.diku.dk/wiki/doku.php - -Once you have it, run the following command:: - - ./configure - make - -as a regular user, and install it with:: - - sudo make install - -Supplemental documentation ---------------------------- - -For supplemental documentation refer to the wiki: - -https://bottest.wiki.kernel.org/coccicheck - -The wiki documentation always refers to the linux-next version of the script. - -Using Coccinelle on the Linux kernel ------------------------------------- - -A Coccinelle-specific target is defined in the top level -Makefile. This target is named ``coccicheck`` and calls the ``coccicheck`` -front-end in the ``scripts`` directory. - -Four basic modes are defined: ``patch``, ``report``, ``context``, and -``org``. The mode to use is specified by setting the MODE variable with -``MODE=<mode>``. - -- ``patch`` proposes a fix, when possible. - -- ``report`` generates a list in the following format: - file:line:column-column: message - -- ``context`` highlights lines of interest and their context in a - diff-like style.Lines of interest are indicated with ``-``. - -- ``org`` generates a report in the Org mode format of Emacs. - -Note that not all semantic patches implement all modes. For easy use -of Coccinelle, the default mode is "report". - -Two other modes provide some common combinations of these modes. - -- ``chain`` tries the previous modes in the order above until one succeeds. - -- ``rep+ctxt`` runs successively the report mode and the context mode. - It should be used with the C option (described later) - which checks the code on a file basis. - -Examples -~~~~~~~~ - -To make a report for every semantic patch, run the following command:: - - make coccicheck MODE=report - -To produce patches, run:: - - make coccicheck MODE=patch - - -The coccicheck target applies every semantic patch available in the -sub-directories of ``scripts/coccinelle`` to the entire Linux kernel. - -For each semantic patch, a commit message is proposed. It gives a -description of the problem being checked by the semantic patch, and -includes a reference to Coccinelle. - -As any static code analyzer, Coccinelle produces false -positives. Thus, reports must be carefully checked, and patches -reviewed. - -To enable verbose messages set the V= variable, for example:: - - make coccicheck MODE=report V=1 - -Coccinelle parallelization ---------------------------- - -By default, coccicheck tries to run as parallel as possible. To change -the parallelism, set the J= variable. For example, to run across 4 CPUs:: - - make coccicheck MODE=report J=4 - -As of Coccinelle 1.0.2 Coccinelle uses Ocaml parmap for parallelization, -if support for this is detected you will benefit from parmap parallelization. - -When parmap is enabled coccicheck will enable dynamic load balancing by using -``--chunksize 1`` argument, this ensures we keep feeding threads with work -one by one, so that we avoid the situation where most work gets done by only -a few threads. With dynamic load balancing, if a thread finishes early we keep -feeding it more work. - -When parmap is enabled, if an error occurs in Coccinelle, this error -value is propagated back, the return value of the ``make coccicheck`` -captures this return value. - -Using Coccinelle with a single semantic patch ---------------------------------------------- - -The optional make variable COCCI can be used to check a single -semantic patch. In that case, the variable must be initialized with -the name of the semantic patch to apply. - -For instance:: - - make coccicheck COCCI=<my_SP.cocci> MODE=patch - -or:: - - make coccicheck COCCI=<my_SP.cocci> MODE=report - - -Controlling Which Files are Processed by Coccinelle ---------------------------------------------------- - -By default the entire kernel source tree is checked. - -To apply Coccinelle to a specific directory, ``M=`` can be used. -For example, to check drivers/net/wireless/ one may write:: - - make coccicheck M=drivers/net/wireless/ - -To apply Coccinelle on a file basis, instead of a directory basis, the -following command may be used:: - - make C=1 CHECK="scripts/coccicheck" - -To check only newly edited code, use the value 2 for the C flag, i.e.:: - - make C=2 CHECK="scripts/coccicheck" - -In these modes, which works on a file basis, there is no information -about semantic patches displayed, and no commit message proposed. - -This runs every semantic patch in scripts/coccinelle by default. The -COCCI variable may additionally be used to only apply a single -semantic patch as shown in the previous section. - -The "report" mode is the default. You can select another one with the -MODE variable explained above. - -Debugging Coccinelle SmPL patches ---------------------------------- - -Using coccicheck is best as it provides in the spatch command line -include options matching the options used when we compile the kernel. -You can learn what these options are by using V=1, you could then -manually run Coccinelle with debug options added. - -Alternatively you can debug running Coccinelle against SmPL patches -by asking for stderr to be redirected to stderr, by default stderr -is redirected to /dev/null, if you'd like to capture stderr you -can specify the ``DEBUG_FILE="file.txt"`` option to coccicheck. For -instance:: - - rm -f cocci.err - make coccicheck COCCI=scripts/coccinelle/free/kfree.cocci MODE=report DEBUG_FILE=cocci.err - cat cocci.err - -You can use SPFLAGS to add debugging flags, for instance you may want to -add both --profile --show-trying to SPFLAGS when debugging. For instance -you may want to use:: - - rm -f err.log - export COCCI=scripts/coccinelle/misc/irqf_oneshot.cocci - make coccicheck DEBUG_FILE="err.log" MODE=report SPFLAGS="--profile --show-trying" M=./drivers/mfd/arizona-irq.c - -err.log will now have the profiling information, while stdout will -provide some progress information as Coccinelle moves forward with -work. - -DEBUG_FILE support is only supported when using coccinelle >= 1.2. - -.cocciconfig support --------------------- - -Coccinelle supports reading .cocciconfig for default Coccinelle options that -should be used every time spatch is spawned, the order of precedence for -variables for .cocciconfig is as follows: - -- Your current user's home directory is processed first -- Your directory from which spatch is called is processed next -- The directory provided with the --dir option is processed last, if used - -Since coccicheck runs through make, it naturally runs from the kernel -proper dir, as such the second rule above would be implied for picking up a -.cocciconfig when using ``make coccicheck``. - -``make coccicheck`` also supports using M= targets.If you do not supply -any M= target, it is assumed you want to target the entire kernel. -The kernel coccicheck script has:: - - if [ "$KBUILD_EXTMOD" = "" ] ; then - OPTIONS="--dir $srctree $COCCIINCLUDE" - else - OPTIONS="--dir $KBUILD_EXTMOD $COCCIINCLUDE" - fi - -KBUILD_EXTMOD is set when an explicit target with M= is used. For both cases -the spatch --dir argument is used, as such third rule applies when whether M= -is used or not, and when M= is used the target directory can have its own -.cocciconfig file. When M= is not passed as an argument to coccicheck the -target directory is the same as the directory from where spatch was called. - -If not using the kernel's coccicheck target, keep the above precedence -order logic of .cocciconfig reading. If using the kernel's coccicheck target, -override any of the kernel's .coccicheck's settings using SPFLAGS. - -We help Coccinelle when used against Linux with a set of sensible defaults -options for Linux with our own Linux .cocciconfig. This hints to coccinelle -git can be used for ``git grep`` queries over coccigrep. A timeout of 200 -seconds should suffice for now. - -The options picked up by coccinelle when reading a .cocciconfig do not appear -as arguments to spatch processes running on your system, to confirm what -options will be used by Coccinelle run:: - - spatch --print-options-only - -You can override with your own preferred index option by using SPFLAGS. Take -note that when there are conflicting options Coccinelle takes precedence for -the last options passed. Using .cocciconfig is possible to use idutils, however -given the order of precedence followed by Coccinelle, since the kernel now -carries its own .cocciconfig, you will need to use SPFLAGS to use idutils if -desired. See below section "Additional flags" for more details on how to use -idutils. - -Additional flags ----------------- - -Additional flags can be passed to spatch through the SPFLAGS -variable. This works as Coccinelle respects the last flags -given to it when options are in conflict. :: - - make SPFLAGS=--use-glimpse coccicheck - -Coccinelle supports idutils as well but requires coccinelle >= 1.0.6. -When no ID file is specified coccinelle assumes your ID database file -is in the file .id-utils.index on the top level of the kernel, coccinelle -carries a script scripts/idutils_index.sh which creates the database with:: - - mkid -i C --output .id-utils.index - -If you have another database filename you can also just symlink with this -name. :: - - make SPFLAGS=--use-idutils coccicheck - -Alternatively you can specify the database filename explicitly, for -instance:: - - make SPFLAGS="--use-idutils /full-path/to/ID" coccicheck - -See ``spatch --help`` to learn more about spatch options. - -Note that the ``--use-glimpse`` and ``--use-idutils`` options -require external tools for indexing the code. None of them is -thus active by default. However, by indexing the code with -one of these tools, and according to the cocci file used, -spatch could proceed the entire code base more quickly. - -SmPL patch specific options ---------------------------- - -SmPL patches can have their own requirements for options passed -to Coccinelle. SmPL patch specific options can be provided by -providing them at the top of the SmPL patch, for instance:: - - // Options: --no-includes --include-headers - -SmPL patch Coccinelle requirements ----------------------------------- - -As Coccinelle features get added some more advanced SmPL patches -may require newer versions of Coccinelle. If an SmPL patch requires -at least a version of Coccinelle, this can be specified as follows, -as an example if requiring at least Coccinelle >= 1.0.5:: - - // Requires: 1.0.5 - -Proposing new semantic patches -------------------------------- - -New semantic patches can be proposed and submitted by kernel -developers. For sake of clarity, they should be organized in the -sub-directories of ``scripts/coccinelle/``. - - -Detailed description of the ``report`` mode -------------------------------------------- - -``report`` generates a list in the following format:: - - file:line:column-column: message - -Example -~~~~~~~ - -Running:: - - make coccicheck MODE=report COCCI=scripts/coccinelle/api/err_cast.cocci - -will execute the following part of the SmPL script:: - - <smpl> - @r depends on !context && !patch && (org || report)@ - expression x; - position p; - @@ - - ERR_PTR@p(PTR_ERR(x)) - - @script:python depends on report@ - p << r.p; - x << r.x; - @@ - - msg="ERR_CAST can be used with %s" % (x) - coccilib.report.print_report(p[0], msg) - </smpl> - -This SmPL excerpt generates entries on the standard output, as -illustrated below:: - - /home/user/linux/crypto/ctr.c:188:9-16: ERR_CAST can be used with alg - /home/user/linux/crypto/authenc.c:619:9-16: ERR_CAST can be used with auth - /home/user/linux/crypto/xts.c:227:9-16: ERR_CAST can be used with alg - - -Detailed description of the ``patch`` mode ------------------------------------------- - -When the ``patch`` mode is available, it proposes a fix for each problem -identified. - -Example -~~~~~~~ - -Running:: - - make coccicheck MODE=patch COCCI=scripts/coccinelle/api/err_cast.cocci - -will execute the following part of the SmPL script:: - - <smpl> - @ depends on !context && patch && !org && !report @ - expression x; - @@ - - - ERR_PTR(PTR_ERR(x)) - + ERR_CAST(x) - </smpl> - -This SmPL excerpt generates patch hunks on the standard output, as -illustrated below:: - - diff -u -p a/crypto/ctr.c b/crypto/ctr.c - --- a/crypto/ctr.c 2010-05-26 10:49:38.000000000 +0200 - +++ b/crypto/ctr.c 2010-06-03 23:44:49.000000000 +0200 - @@ -185,7 +185,7 @@ static struct crypto_instance *crypto_ct - alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER, - CRYPTO_ALG_TYPE_MASK); - if (IS_ERR(alg)) - - return ERR_PTR(PTR_ERR(alg)); - + return ERR_CAST(alg); - - /* Block size must be >= 4 bytes. */ - err = -EINVAL; - -Detailed description of the ``context`` mode --------------------------------------------- - -``context`` highlights lines of interest and their context -in a diff-like style. - - **NOTE**: The diff-like output generated is NOT an applicable patch. The - intent of the ``context`` mode is to highlight the important lines - (annotated with minus, ``-``) and gives some surrounding context - lines around. This output can be used with the diff mode of - Emacs to review the code. - -Example -~~~~~~~ - -Running:: - - make coccicheck MODE=context COCCI=scripts/coccinelle/api/err_cast.cocci - -will execute the following part of the SmPL script:: - - <smpl> - @ depends on context && !patch && !org && !report@ - expression x; - @@ - - * ERR_PTR(PTR_ERR(x)) - </smpl> - -This SmPL excerpt generates diff hunks on the standard output, as -illustrated below:: - - diff -u -p /home/user/linux/crypto/ctr.c /tmp/nothing - --- /home/user/linux/crypto/ctr.c 2010-05-26 10:49:38.000000000 +0200 - +++ /tmp/nothing - @@ -185,7 +185,6 @@ static struct crypto_instance *crypto_ct - alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER, - CRYPTO_ALG_TYPE_MASK); - if (IS_ERR(alg)) - - return ERR_PTR(PTR_ERR(alg)); - - /* Block size must be >= 4 bytes. */ - err = -EINVAL; - -Detailed description of the ``org`` mode ----------------------------------------- - -``org`` generates a report in the Org mode format of Emacs. - -Example -~~~~~~~ - -Running:: - - make coccicheck MODE=org COCCI=scripts/coccinelle/api/err_cast.cocci - -will execute the following part of the SmPL script:: - - <smpl> - @r depends on !context && !patch && (org || report)@ - expression x; - position p; - @@ - - ERR_PTR@p(PTR_ERR(x)) - - @script:python depends on org@ - p << r.p; - x << r.x; - @@ - - msg="ERR_CAST can be used with %s" % (x) - msg_safe=msg.replace("[","@(").replace("]",")") - coccilib.org.print_todo(p[0], msg_safe) - </smpl> - -This SmPL excerpt generates Org entries on the standard output, as -illustrated below:: - - * TODO [[view:/home/user/linux/crypto/ctr.c::face=ovl-face1::linb=188::colb=9::cole=16][ERR_CAST can be used with alg]] - * TODO [[view:/home/user/linux/crypto/authenc.c::face=ovl-face1::linb=619::colb=9::cole=16][ERR_CAST can be used with auth]] - * TODO [[view:/home/user/linux/crypto/xts.c::face=ovl-face1::linb=227::colb=9::cole=16][ERR_CAST can be used with alg]] |