first detected when the code is executed. Furthermore, \texttt{@} should
not be use in this code. Spatch scans the script code for the next
\texttt{@} and considers that to be the beginning of the next rule, even if
-\texttt{@} occurs within e.g., a string or a comment.
+\texttt{@} occurs within e.g., a comment.
\texttt{virtual} keyword is used to declare virtual rules. Virtual
rules may be subsequently used as a dependency for the rules in the
isomorphisms defined in standard.iso or whatever isomorphism file has been
included. There are, however, some other isomorphisms that are built into
the implementation of Coccinelle and that can be disabled as well. Their
-names are given below. In each case, the text descibes the standard
+names are given below. In each case, the text describes the standard
behavior. Using \NT{disable-iso} with the given name disables this behavior.
\begin{itemize}
The possible types of metavariable declarations are defined by the grammar
rule below. Metavariables should occur at least once in the transformation
-immediately following their declaration. Fresh metavariables must only be
-used in {\tt +} code. These properties are not expressed in the grammar,
-but are checked by a subsequent analysis. The metavariables are designated
-according to the kind of terms they can match, such as a statement, an
-identifier, or an expression. An expression metavariable can be further
-constrained by its type.
+immediately following their declaration. Fresh identifier metavariables
+must only be used in {\tt +} code. These properties are not expressed in
+the grammar, but are checked by a subsequent analysis. The metavariables
+are designated according to the kind of terms they can match, such as a
+statement, an identifier, or an expression. An expression metavariable can
+be further constrained by its type. A declaration metavariable matches the
+declaration of one or more variables, all sharing the same type
+specification ({\em e.g.}, {\tt int a,b,c=3;}). A field metavariable does
+the same, but for structure fields.
\begin{grammar}
\RULE{\rt{metadecl}}
+ \CASE{metavariable \NT{ids} ;}
\CASE{fresh identifier \NT{ids} ;}
\CASE{identifier \NT{COMMA\_LIST}\mth{(}\NT{pmid\_with\_regexp}\mth{)} ;}
\CASE{identifier \NT{COMMA\_LIST}\mth{(}\NT{pmid\_with\_virt\_or\_not\_eq}\mth{)} ;}
\CASE{parameter list [ \NT{const} ] \NT{ids} ;}
\CASE{type \NT{ids} ;}
\CASE{statement \opt{list} \NT{ids} ;}
+ \CASE{declaration \NT{ids} ;}
+ \CASE{field \opt{list} \NT{ids} ;}
\CASE{typedef \NT{ids} ;}
\CASE{declarer name \NT{ids} ;}
% \CASE{\opt{local} function \NT{pmid\_with\_not\_eq\_list} ;}
\CASE{\opt{local} idexpression \some{*} \NT{COMMA\_LIST}\mth{(}\NT{pmid\_with\_not\_eq}\mth{)} ;}
\CASE{expression list \NT{ids} ;}
\CASE{expression \some{*} \NT{COMMA\_LIST}\mth{(}\NT{pmid\_with\_not\_eq}\mth{)} ;}
+ \CASE{expression enum \any{*} \NT{COMMA\_LIST}\mth{(}\NT{pmid\_with\_not\_eq}\mth{)} ;}
+ \CASE{expression struct \any{*} \NT{COMMA\_LIST}\mth{(}\NT{pmid\_with\_not\_eq}\mth{)} ;}
+ \CASE{expression union \any{*} \NT{COMMA\_LIST}\mth{(}\NT{pmid\_with\_not\_eq}\mth{)} ;}
\CASE{expression \NT{COMMA\_LIST}\mth{(}\NT{pmid\_with\_not\_ceq}\mth{)} ;}
\CASE{expression list [ \NT{id} ] \NT{ids} ;}
\CASE{expression list [ \NT{const} ] \NT{ids} ;}
\CASE{position \opt{any} \NT{COMMA\_LIST}\mth{(}\NT{pmid\_with\_not\_eq\_mid}\mth{)} ;}
\end{grammar}
+A metavariable declaration local idexpression v means that v is restricted
+to be a local variable. If it should just be a variable, but not
+necessarily a local one, then drop local. A more complex description of a
+location, such as a->b is considered to be an expression, not an
+ideexpression.
+
+Constant is for constants, such as 27. But it also considers an identifier
+that is all capital letters (possibly containing numbers) as a constant as
+well, because the names gives to macros in Linux usually have this form.
+
+An identifier is the name of a structure field, a macro, a function, or a
+variable. Is is the name of something rather than an expression that has a
+value. But an identifier can be used in the position of an expression as
+well, where it represents a variable.
+
It is possible to specify that an expression list or a parameter list
metavariable should match a specific number of expressions or parameters.
+It is possible to specify some information about the definition of a fresh
+identifier. See the wiki.
+
+
\begin{grammar}
\RULE{\rt{ids}}
\CASE{\NT{COMMA\_LIST}\mth{(}\NT{pmid}\mth{)}}
\RULE{\rt{pmid\_with\_regexp}}
\CASE{\NT{pmid} \~{}= \NT{regexp}}
+ \CASE{\NT{pmid} !\~{}= \NT{regexp}}
\RULE{\rt{pmid\_with\_not\_eq}}
\CASE{\NT{pmid} \OPT{!= \NT{id\_or\_meta}}}
For example, \mth{\msf{metaid}^{\ssf{Type}}} refers to a metavariable
that was declared using \texttt{type} and stands for any type.
+{\tt metavariable} declares a metavariable for which the parser tried to
+figure out the metavariable type based on the usage context. Such a
+metavariable must be used consistently. These metavariables cannot be used
+in all contexts; specifically, they cannot be used in context that would
+make the parsing ambiguous. Some examples are the leftmost term of an
+expression, such as the left-hand side of an assignment, or the type in a
+variable declaration. These restrictions may seems somewhat arbitrary from
+the user's point of view. Thus, it is better to use metavariables with
+metavariable types. If Coccinelle is given the argument {\tt
+ -parse\_cocci}, it will print information about the type that is inferred
+for each metavariable.
+
The \NT{ctype} and \NT{ctypes} nonterminals are used by both the grammar of
metavariable declarations and the grammar of transformations, and are
defined on page~\pageref{types}.
alloc=kmalloc}. There should not be space around the {\tt =}. An
example is in {\tt demos/vm.cocci} and {\tt demos/vm.c}.
+
+\paragraph*{Warning:} Each metavariable declaration causes the declared
+metavariables to be immediately usable, without any inheritance
+indication. Thus the following are correct:
+
+\begin{quote}
+\begin{verbatim}
+@@
+type r.T;
+T x;
+@@
+
+[...] // some semantic patch code
+\end{verbatim}
+\end{quote}
+
+\begin{quote}
+\begin{verbatim}
+@@
+r.T x;
+type r.T;
+@@
+
+[...] // some semantic patch code
+\end{verbatim}
+\end{quote}
+
+\noindent
+But the following is not correct:
+
+\begin{quote}
+\begin{verbatim}
+@@
+type r.T;
+r.T x;
+@@
+
+[...] // some semantic patch code
+\end{verbatim}
+\end{quote}
+
+This applies to position variables, type metavariables, identifier
+metavariables that may be used in specifying a structure type, and
+metavariables used in the initialization of a fresh identifier. In the
+case of a structure type, any identifier metavariable indeed has to be
+declared as an identifier metavariable in advance. The syntax does not
+permit {\tt r.n} as the name of a structure or union type in such a
+declaration.
+
\section{Metavariables for scripts}
Metavariables for scripts can only be inherited from transformation rules.
\begin{grammar}
\RULE{\rt{script\_metavariables}}
- \CASE{@ script:\NT{language} \OPT{depends on \NT{dep}} @
+ \CASE{@ script:\NT{language} \OPT{\NT{rulename}} \OPT{depends on \NT{dep}} @
\any{\NT{script\_metadecl}} @@}
\CASE{@ initialize:\NT{language} \OPT{depends on \NT{dep}} @}
\CASE{@ finalize:\NT{language} \OPT{depends on \NT{dep}} @}
- \RULE{\rt{language}} \CASE{python}
+ \RULE{\rt{language}} \CASE{python} \CASE{ocaml}
- \RULE{\rt{script\_metadecl}} \CASE{\T{id} <{}< \T{rulename\_id}.\T{id} ;}
+ \RULE{\rt{script\_metadecl}}
+ \CASE{\T{id} <{}< \T{rulename\_id}.\T{id} ;}
+ \CASE{\T{id} ;}
\end{grammar}
Currently, the only scripting languages that are supported are Python and
variables initialized by the other script rules, allowing information to be
transmitted from the matching process to the finalize rule.
+A script metavariable that does not specify an origin, using \texttt{<<},
+is newly declared by the script. This metavariable should be assigned to a
+string and can be inherited by subsequent rules as an identifier. In
+Python, the assignment of such a metavariable $x$ should refer to the
+metavariable as {\tt coccinelle.\(x\)}. Examples are in the files
+\texttt{demos/pythontococci.cocci} and \texttt{demos/camltococci.cocci}.
+
+In an ocaml script, the following extended form of \textit{script\_metadecl}
+may be used:
+
+\begin{grammar}
+ \RULE{\rt{script\_metadecl}}
+ \CASE{(\T{id},\T{id}) <{}< \T{rulename\_id}.\T{id} ;}
+ \CASE{\T{id} <{}< \T{rulename\_id}.\T{id} ;}
+ \CASE{\T{id} ;}
+\end{grammar}
+
+\noindent
+In a declaration of the form \texttt{(\T{id},\T{id}) <{}<
+ \T{rulename\_id}.\T{id} ;}, the left component of \texttt{(\T{id},\T{id})}
+receives a string representation of the value of the inherited metavariable
+while the right component receives its abstract syntax tree. The file
+\texttt{parsing\_c/ast\_c.ml} in the Coccinelle implementation gives some
+information about the structure of the abstract syntax tree. Either the
+left or right component may be replaced by \verb+_+, indicating that the
+string representation or abstract syntax trees representation is not
+wanted, respectively.
+
+The abstract syntax tree of a metavariable declared using {\tt
+ metavariable} is not available.
+
\section{Transformation}
The transformation specification essentially has the form of C code,
Each element of a disjunction must be a proper term like an
expression, a statement, an identifier or a declaration. Thus, the
-rule on the left below is not a syntaxically correct SmPL rule. One may
+rule on the left below is not a syntactically correct SmPL rule. One may
use the rule on the right instead.
\begin{center}
(
writeb(...,
|
- readb(
+ readb(...,
)
@--(T)
b)
\end{tabular}
\end{center}
+Some kinds of terms can only appear in + code. These include comments,
+ifdefs, and attributes (\texttt{\_\_attribute\_\_((...))}).
+
\section{Types}
\label{types}
\CASE{\opt{\NT{ctype\_qualif}} long long}
\CASE{double}
\CASE{float}
+ \CASE{size\_t} \CASE{ssize\_t} \CASE{ptrdiff\_t}
+ \CASE{enum \NT{id} \{ \NT{PARAMSEQ}\mth{(}\NT{dot\_expr}, \NT{exp\_whencode}\mth{)} \OPT{,} \}}
\CASE{\OPT{struct\OR union} \T{id} \OPT{\{ \any{\NT{struct\_decl\_list}} \}}}
\RULE{\rt{ctype\_qualif}}
\CASE{\opt{\NT{const\_vol}} \T{id} \NT{d\_ident};}
\RULE{\rt{d\_ident}}
- \CASE{\NT{id} \any{[\opt{\NT{expr}}]}}
+ \CASE{\T{id} \any{[\opt{\NT{expr}}]}}
\RULE{\rt{fn\_ctype}}
\CASE{\NT{generic\_ctype} \any{*}}
\RULE{\rt{funid}}
\CASE{\T{id}}
\CASE{\mth{\T{metaid}^{\ssf{Id}}}}
+ \CASE{\NT{OR}\mth{(}\NT{stmt}\mth{)}}
% \CASE{\mth{\T{metaid}^{\ssf{Func}}}}
% \CASE{\mth{\T{metaid}^{\ssf{LocalFunc}}}}
\end{lstlisting}
\noindent
-It may be nencessary to consider several cases to ensure that the added ode
+It may be necessary to consider several cases to ensure that the added ode
is placed in the right position. For example, one may need one pattern
that considers that the function is declared {\tt inline} and another that
considers that it is not.
\RULE{\rt{initialize}}
\CASE{\NT{dot\_expr}}
- \CASE{\ttlb~\opt{\NT{COMMA\_LIST}\mth{(}\NT{dot\_expr}\mth{)}}~\ttrb}
+ \CASE{\mth{\T{metaid}^{\ssf{Initialiser}}}}
+ \CASE{\ttlb~\opt{\NT{COMMA\_LIST}\mth{(}\NT{init\_list\_elem}\mth{)}}~\ttrb}
+
+ \RULE{\rt{init\_list\_elem}}
+ \CASE{\NT{dot\_expr}}
+ \CASE{\NT{designator} = \NT{dot\_expr}}
+ \CASE{\mth{\T{metaid}^{\ssf{Initialiser}}}}
+ \CASE{\mth{\T{metaid}^{\ssf{InitialiserList}}}}
+ \CASE{\NT{id} : \NT{dot\_expr}}
+
+ \RULE{\rt{designator}}
+ \CASE{. \NT{id}}
+ \CASE{[ \NT{dot\_expr} ]}
+ \CASE{[ \NT{dot\_expr} ... \NT{dot\_expr} ]}
\RULE{\rt{decl\_ident}}
\CASE{\T{DeclarerId}}
\CASE{\mth{\T{metaid}^{\ssf{Declarer}}}}
\end{grammar}
+An initializer for a structure can be ordered or unordered. It is
+considered to be unordered if there is at least one key-value pair
+initializer, e.g., \texttt{.x = e}.
+
\section{Statements}
The first rule {\em statement} describes the various forms of a statement.
\end{grammar}
-\section{Constant, Identifiers and Types for Transformations}
+\section{Constants, Identifiers and Types for Transformations}
\begin{grammar}
\RULE{\rt{const}}
\CASE{"\any{[\^{}"]}"}
\RULE{\rt{id}}
- \CASE{\T{id} \OR \mth{\T{metaid}^{\ssf{Id}}}}
+ \CASE{\T{id} \OR \mth{\T{metaid}^{\ssf{Id}}}
+ \OR {\NT{OR}\mth{(}\NT{stmt}\mth{)}}}
\RULE{\rt{typedef\_ident}}
\CASE{\T{id} \OR \mth{\T{metaid}^{\ssf{Type}}}}
\CASE{"\any{[\^{}"]}"}
\end{grammar}
+\section{Comments}
+
+A \verb+//+ or \verb+/* */+ comment that is annotated with + in the
+leftmost column is considered to be added code. A \verb+//+ or
+\verb+/* */+ comment wthout such an annotation is considered to be a
+comment about the SmPL code, and thus is not matched in the C code.
%%% Local Variables:
%%% mode: LaTeX
HCoop / bpt / coccinelle.git / blobdiff