NAME¶
vera++ - Programmable verification and analysis tool for C++
SYNOPSIS¶
vera++
[options] [file ...]
Introduction¶
Vera++ is a programmable tool for verification, analysis and transformation of
C++ source code.
The main usage scenarios that are foreseen for Vera++ are:
- •
- Ensure that the source code complies with the given coding
standards and conventions.
- •
- Provide source code metrics and statistics.
- •
- Perform automated transformations of the source code, which can
range from pretty-printing to diagnostics to fault
injection and advanced testing.
The main design idea of Vera++ is to create a generic engine that will be able
to parse the C++ code and present it in the form of collections of various
objects to user provided
scripts that will define the concrete actions
to be executed.
Currently the following object collections are provided:
- •
- Collection of source file names.
- •
- Collection of source lines for each file.
- •
- Collection of identified tokens in each file.
Note: It is foreseen that future versions of Vera++ will provide also the
semantic view on the code.
The most important feature of Vera++ is that all activities other than code
parsing are defined by scripts. This means that Vera++ is
flexible and
extensible.
For example, compliance with coding standards can be expressed in terms of
rules, each being defined by a separate script. The scripts can access
all collections listed above and perform actions related to the given rule.
The user can ask to run any given script or some defined set of scripts in a
single program execution.
As a simple example, a coding convention that limits the length of the source
line can be implemented as a script that traverses the collection of files and
the collection of source lines and checks whether each source line fits within
the given limits. A report can be generated for each non-conforming line of
code so that the user gets a clear information about where the problem is
located.
All existing rules present their reports in the format that is compatible with
regular compiler's output, so that it is easy to integrate Vera++ with the
existing build framework.
Similarly, automated transformation procedures are implemented as separate
scripts that scan the above collections and produce another source files
according to their algorithms. A simple example of such transformation might
be a script that removes empty lines from source code.
The Tcl programming language is currently supported for scripts that run within
Vera++.
Running Vera++¶
Vera++ needs to know where the rules and transformation scripts are located. The
following rules are applied:
- •
- If the --root option is used, its argument is used as the name of the
directory where the scripts subdirectory with scripts should be located,
otherwise
- •
- If the VERA_ROOT environment variable is defined, it is used as the name
of the directory where the scripts subdirectory with scripts should be
located, otherwise
- •
- If the HOME environment variable is defined, then the ~/.vera++ directory
is used (and it should contain the scripts subdirectory with scripts),
otherwise
- •
- The current directory should contain the scripts subdirectory.
Options¶
Vera++ recognizes the following parameters:
- -
- (a single minus) indicates that the source code to check will be provided
on the stdin.
- -p --profile profilename
- instructs the program to execute all rules defined in the given profile;
the profile name is just a name of the file that will be found under the
profiles directory, the content of this file is a Tcl script that must set
a rules variable to be the list of all rules that are part of the profile.
An example profile definition that groups three rules (L001, L002 and
L003) might look like:
-
set rules {
L001
L002
L003
}
There is always a default profile that lists all existing rules - it is used
when no profile is named explicitly.
- -R --rule rulename
- instructs the program to execute the given rule; note that the name of the
rule should not contain the file extension of the script implementing the
rule - this is added automatically, so that for example
--rule my_rule means that Vera++ will find the my_rule.tcl script
and will run it.
- --transform transformationname
- instructs the program to execute a single named transformation; the naming
scheme is the same as for the --rule option.
- -o --std-report filename
- writes the standard (gcc-like) report to this file. A single dash - means
that the standard output or the error output will be used, depending on
the usage of the --warning or --error option. This option may be used
several times in order to produce the reports in several locations - for
example on the standard output and in a file. Default value is -.
- -v --vc-report filename
- writes the Visual C report to this file. A single dash - means that the
standard output or the error output will be used, depending on the usage
of the --warning or --error option. This option may be used several times
in order to produce the reports in several locations - for example on the
standard output and in a file. This report is not produced by
default.
- -x --xml-report filename
- writes the XML report to this file. Not used by default. A single dash -
means that the standard output or the error output will be used, depending
on the usage of the --warning or --error option. This option may be used
several times in order to produce the reports in several locations - for
example on the standard output and in a file. This report is not produced
by default.
- -c --checkstyle-report filename
- writes the checkstyle report to this file. Not used by default. A single
dash - means that the standard output or the error output will be used,
depending on the usage of the --warning or --error option. This option may
be used several times in order to produce the reports in several locations
- for example on the standard output and in a file. This report is not
produced by default.
- -s --show-rule
- includes the name of the rule in each report line.
- -d --no-duplicate
- instructs the program to omit duplicated messages in the final report (the
duplicates can be a result of violating the same rule many times in the
same line of source code).
- -w --warning
- reports are marked as warning and generated on the error output.
- -e --error
- reports are marked as error and generated on the error output. An non zero
exit code is used when one or more reports are generated.
- -q --quiet
- don't display the reports. This option is best used with --summary and/or
with --error.
- -S --summary
- displays the number of reports and the number of processed files.
- --parameters filename
- instructs the program to read parameter values from the given file; each
parameter association should be placed in a separate line of this file.
This option may be used several times.
- -P --parameter parameterassociation
- provides the value of the named parameter to the scripts (see the
documentation of each script to see whether it recognizes any parameters);
the parameter association has the form name=value.
- --exclusions exclusionsfilename
- instructs the program to exclude some source files from rule checks, as
described in the given file; the content of this file is a Tcl script that
must set a ruleExclusions array, where keys are rule names and values are
lists of files to omit for the given rule. For example:
-
set ruleExclusions(L002) {
some_file.cpp
}
set ruleExclusions(T005) {
some_file.cpp
some_other_file.cpp
}
Note that the given file names are compared for exact match with the source file
names that are provided as parameters to Vera++. This means that links in
paths are not resolved for comparison purposes. This option may be used
several times.
- -i --inputs filename
- the inputs are read from that file. A single dash - means that the files
to check will be read from the standard input. This option may be used
several times.
- -r --root path
- uses the given path as the vera++ root directory
- --version
- prints the program version information and exits.
- -h --help
- prints the list of recognized options and exits.
- --
- (a double dash) do not interpret any more arguments as options.
Arguments that are not starting with a dash - are treated as source files to
check. Files starting with a dash can be checked by prefixing them with the
current directory shortcut ./.
When no input file is provided either as an argument or with the --input option,
the list of source file names is read from the standard input.
Examples of executing Vera++ with rules¶
To execute all default verification rules against the file file.cpp, run:
-
vera++ file.cpp
To execute only rule L001 (this rule ensures that there is no trailing
whitespace in each source line) against the same file, run:
-
vera++ -R L001 file.cpp
To execute rule L004 (this rule checks for too long source lines) with the
parameter value providing 78 as the maximum line length, run:
-
vera++ -R L004 -P max-line-length=78 file.cpp
To execute all rules from your favorite profile (assuming that the my_favorite
profile definition is stored in the profiles directory) against all header
files in the current filesystem subtree, run:
-
find . -name '*.h' | vera++ --profile my_favorite
Note: Vera++ collects the reports generated by each rule and prints them
out sorted and after all rules were executed. If there were no problem
reports, the output of the program is empty.
Note: Vera++ reports are generated on the standard output by default,
making them easy to use with a pipe. The --warning and --error options are
changing the output to the standard error. The options --std-report,
--vc-report, --xml-report and --quiet may be used to disable the output to the
standard or error output.
To execute the trim_right source code transformation (it removes the trailing
whitespace that the rule L001 above complained about) on all .cpp files in the
current directory run:
-
vera++ --transform trim_right *.cpp
As a result, each .cpp file will be backed up with the additional extension .bak
and the files will be trimmed by removing trailing whitespace. The exact
behavior is defined by the script named trim_right.tcl in the
scripts/transformations directory.
Running Vera++ as a test with CMake¶
CMake offers the possibility to run tests that are considered to pass when they
return a 0 value and to fail otherwise. Fortunately, vera++, when used with
the --error option, has exactly this behavior. Creating the test is just a
matter of listing the sources to check:
-
file(GLOB_RECURSE srcs
${CMAKE_SOURCE_DIR}/src/*.cpp
${CMAKE_SOURCE_DIR}/src/*.h)
add_test(NAME VeraStyle
COMMAND vera++
--error
${srcs})
Running Vera++ during the build with CMake¶
Running vera++ in a test integrates quite badly with the IDEs or with CDash
(
http://cdash.org): the reports are hidden in the test log, and it is not easy
to look at the problematic code. Moreover, a failure in the coding style is
not the same as a failure in a unit or functional test, and shouldn't appear
in the same way. Another option is to run vera++ during the build and make it
generate warnings that are well interpreted by the IDEs and CDash. In
QtCreator for instance, it is then possible to click on the warning to go to
the problematic code.
Running vera++ during the build can be done in a similar way to the previous
section, by replacing the add_test() call with a add_custom_target() that will
run the style check every time the custom target is built.
-
file(GLOB_RECURSE srcs
${CMAKE_SOURCE_DIR}/src/*.cpp
${CMAKE_SOURCE_DIR}/src/*.h)
add_custom_target(VeraStyle ALL
vera++
--warning
${srcs})
For large projects, running the style check every time can be quite time
consuming and uncomfortable for the developer. It is then more convenient to
split the style check in several parts that can be run in parallel, and to
avoid rerunning the check if the files to check have not been modified. A
vera++ macro is available to do that very easily:
-
find_package(vera++)
include(${VERA++_USE_FILE})
add_vera_targets(*.h *.cpp
RECURSE
ROOT "${CMAKE_SOURCE_DIR}")
This macro adds a new style_reports target that is run every time a source file
is modified. A style target is still available to force the style check. The
target names can be configured with the parameters NAME and NAME_ALL. This
macro is the recommended way to use vera++ with CMake.
Backward compatibility with vera++ 1.1¶
Vera++ is still mostly compatible with the vera++ 1.1 command line interface,
but this feature is planned for removal and its usage is not recommended.
Vera++ tries to detect if the old command line style is used by searching for
the old options in the arguments. If no old style option is found, vera++ uses
the new command line parser.
The command line style can be forced to the old style by setting the environment
variable VERA_LEGACY to on, true or 1. Any other value will force vera++ to
use the new command line style.
Note: the behavior of vera++ is not backward compatible with vera++ 1.1 when no
option is passed to vera++ and VERA_LEGACY is not set:
- •
- the reports are generated on the standard output instead of the error
output;
- •
- a single dash - means that the source code to check is read from the
standard input instead of reading the list of files to check;
- •
- the lack of input files makes vera++ read the standard input instead of
generating an error.
Rules¶
F001 Source files should not use the 'r' (CR) character¶
As a commonly accepted practice, line breaks are denoted by a single '\n' (LF)
character or by two characters "\r\n" (CRLF). A single appearance of
'\r' (CR) is discouraged.
Compliance: Boost
The source file names should be well-formed in the sense of their allowed
maximum length and directory depth. Directory and file names should start with
alphabetic character or underscore. In addition, directory names should not
contain dots and file names can have only one dot.
Recognized parameters:
-
Name Default Description
----------------------- --------- -------------------------------------------------
max-directory-depth 8 Maximum depth of the directory structure.
max-dirname-length 31 Maximum length of the directory path component.
max-filename-length 31 Maximum length of the leaf file name.
max-path-length 100 Maximum length of the full path.
Compliance: Boost
L001 No trailing whitespace¶
Trailing whitespace is any whitespace character (space or tab) that is
placed at the end of the source line, after other characters or alone.
The presence of
trailing whitespace artificially influences some source
code metrics and is therefore discouraged.
As a special case, the trailing whitespace in the otherwise empty lines is
allowed provided that the amount of whitespace is identical to the indent in
the previous line - this exception is more friendly with less smart editors,
but can be switched off by setting non-zero value for the
strict-trailing-space parameter.
Recognized parameters:
-
Name Default Description
------------------------- --------- --------------------------------------
strict-trailing-space 0 Strict mode for trailing whitespace.
Compliance: Inspirel
L002 Don't use tab characters¶
Horizontal tabs are not consistently handled by editors and tools.
Avoiding them ensures that the intended formatting of the code is preserved.
Compliance: HICPP, JSF
L003 No leading and no trailing empty lines¶
Leading and trailing empty lines confuse users of various tools (like
head and tail) and artificially influence some source code metrics.
Compliance: Inspirel
L004 Line cannot be too long¶
The source code line should not exceed some
reasonable length.
Recognized parameters:
-
Name Default Description
------------------- --------- -------------------------------------
max-line-length 100 Maximum length of source code line.
Compliance: Inspirel
L005 There should not be too many consecutive empty lines¶
The empty lines (if any) help to introduce more "light" in the source
code, but they should not be overdosed in the sense that too many consecutive
empty lines make the code harder to follow.
Lines containing only whitespace are considered to be empty in this context.
Recognized parameters:
-
Name Default Description
------------------------------- --------- --------------------------------------------
max-consecutive-empty-lines 2 Maximum number of consecutive empty lines.
Compliance: Inspirel
L006 Source file should not be too long¶
The source file should not exceed a
reasonable length.
Long source files can indicate an opportunity for refactoring.
Recognized parameters:
-
Name Default Description
------------------- --------- ------------------------------------
max-file-length 2000 Maximum number of lines in a file.
Compliance: Inspirel
The one-line comment is a comment that starts with //.
The usual intent is to let the comment continue till the end of the line, but
the preprocessing rules of the language allow to actually continue the comment
in the next line if
line-splicing is forced with the backslash at the
end of the line:
-
void foo()
{
// this comment is continued in the next line \
exit(0);
}
It is not immediately obvious what happens in this example. Moreover, the
line-splicing works only if the backslash is really the last character in the
line - which is error prone because any white characters that might appear
after the backslash will change the meaning of the program without being
visible in the code.
Compliance: Inspirel
T002 Reserved names should not be used for preprocessor macros¶
The C++ Standard reserves some forms of names for language implementations. One
of the most frequent violations is a definition of preprocessor macro that
begins with underscore followed by a capital letter or containing two
consecutive underscores:
-
#define _MY_MACRO something
#define MY__MACRO something
Even though the majority of known compilers use more obscure names for internal
purposes and the above code is not likely to cause any significant problems,
all such names are
formally reserved and therefore should not be used.
Apart from the use of underscore in macro names, preprocessor macros should not
be used to redefine language keywords:
-
#define private public
#define const
Compliance: ISO
T003 Some keywords should be followed by a single space¶
Keywords from the following list:
- •
- case
- •
- class
- •
- delete
- •
- enum
- •
- explicit
- •
- extern
- •
- goto
- •
- new
- •
- struct
- •
- union
- •
- using
should be followed by a single space for better readability.
Compliance: Inspirel
Keywords from the following list:
- •
- default
- •
- private
- •
- protected
- •
- public
should be immediately followed by a colon, unless used in the list of base
classes:
-
class A : public B, private C
{
public:
A();
~A();
protected:
// ...
private:
// ...
};
void fun(int a)
{
switch (a)
{
// ...
default:
exit(0);
}
}
Compliance: Inspirel
semicolon
The break and continue keywords should be immediately followed by a semicolon,
with no other tokens in between:
-
while (...)
{
if (...)
{
break;
}
if (...)
{
continue;
}
// ...
}
Compliance: Inspirel
semicolon or a single space
The return and throw keywords should be immediately followed by a semicolon or a
single space:
-
void fun()
{
if (...)
{
return;
}
// ...
}
int add(int a, int b)
{
return a + b;
}
An exception to this rule is allowed for exeption specifications:
-
void fun() throw();
Compliance: Inspirel
the rest of the code
The semicolon should not stand isolated by whitespace or comments from the rest
of the code.
-
int a ; // bad
int b
; // bad
int c; // OK
As an exception from this rule, semicolons surrounded by spaces are allowed in
for loops:
-
for ( ; ; ) // OK as an exception
{
// ...
}
Compliance: Inspirel
T008 Keywords catch, for, if, switch and while should be followed by¶
a single space
Keywords catch, for, if, switch and while should be followed by a single space
and then an opening left parenthesis:
-
catch (...)
{
for (int i = 0; i != 10; ++i)
{
if (foo(i))
{
while (getline(cin, line))
{
switch (i % 3)
{
case 0:
bar(line);
break;
// ...
}
}
}
}
}
Compliance: Inspirel
T009 Comma should not be preceded by whitespace, but should be¶
followed by one
A comma, whether used as operator or in various lists, should not be preceded by
whitespace on its left side, but should be followed by whitespace on its right
side:
-
void fun(int x, int y, int z);
int a[] = {5, 6, 7};
class A : public B,
public C
{
// ...
};
An exception to this rule is allowed for operator,:
-
struct A {};
void operator,(const A &left, const A &right);
Compliance: Inspirel
T010 Identifiers should not be composed of 'l' and¶
'O' characters only
The characters 'l' (which is lowercase 'L') and 'O' (which is uppercase 'o')
should not be the only characters used in the identifier, because this would
make them visually similar to numeric literals.
Compliance: Inspirel
T011 Curly brackets from the same pair should be either in the same¶
line or in the same column
Corresponding curly brackets should be either in the same line or in the same
column. This promotes clarity by emphasising scopes, but allows concise style
of one-line definitions and empty blocks:
-
class MyException {};
struct MyPair
{
int a;
int b;
};
enum state { close, open };
enum colors
{
black,
red,
green,
blue,
white
};
Compliance: Inspirel
The negation operator (exclamation mark) reduces readability of the code due to
its terseness. Prefer explicit logical comparisons or alternative tokens for
increased readability:
-
if (!cond) // error-prone
if (cond == false) // better
if (not cond) // better (alternative keyword)
Compliance: Inspirel
T013 Source files should contain the copyright notice¶
The copyright notice is required by man coding standards and guidelines. In some
countries every written artwork has some copyright, even if implicit. Prefer
explicit notice to avoid any later confusion.
This rule verifies that at least one comment in the source file contains the
"copyright" word.
Compliance: Boost
T014 Source files should refer the Boost Software License¶
The Boost Software License should be referenced in the source code.
This rule verifies that at least one comment in the source file contains the
"Boost Software License" phrase.
Note that this rule is very specific to the Boost libraries and those project
that choose to use the Boost license. It is therefore not part of the default
profile.
Compliance: Boost
The links embedded in comments and string literals should have correct form and
should reference existing files.
Compliance: Boost
T016 Calls to min/max should be protected against accidental macro¶
substitution
The calls to min and max functions should be protected against accidental macro
substitution.
-
x = max(y, z); // wrong, vulnerable to accidental macro substitution
x = (max)(y, z); // OK
x = max BOOST_PREVENT_MACRO_SUBSTITUTION (y, z); // OK
Compliance: Boost
Unnamed namespaces are not allowed in header files.
The typical use of unnamed namespace is to hide module-internal names from the
outside world. Header files are physically concatenated in a single
translation unit, which logically merges all namespaces with the same name.
Unnamed namespaces are also merged in this process, which effectively
undermines their initial purpose.
Use named namespaces in header files. Unnamed namespaces are allowed in
implementation files only.
Compliance: Boost
Using namespace directives are not allowed in header files.
The using namespace directive imports names from the given namespace and when
used in a header file influences the global namespace of all the files that
directly or indirectly include this header file.
It is imaginable to use the using namespace directive in a limited scope in a
header file (for example in a template or inline function definition), but for
the sake of consistency this is also discouraged.
Compliance: C++ Coding Standards
T019 Control structures should have complete curly-braced block of¶
code
Control structures managed by for, if and while constructs can be associated
with a single instruction or with a complex block of code. Standardizing on
the curly-braced blocks in all cases allows one to avoid common pitfalls and
makes the code visually more uniform.
-
if (x) foo(); // bad style
if (x) { foo(); } // OK
if (x)
foo(); // again bad style
if (x)
{ // OK
foo();
}
if (x)
while (y) // bad style
foo(); // bad style
if (x)
{ // OK
while (y)
{ // OK
foo();
}
}
for (int i = 0; i = 10; ++i); // oops!
cout << "Hello\n";
for (int i = 0; i = 10; ++i) // OK
{
cout << "Hello\n";
}
Compliance: Inspirel
move_includes Change prefix of #include paths¶
This transformation allows one to modify the prefix of file paths in #include
directives.
The motivation for this transformation is to help move whole libraries from one
file tree to another.
Please use this transformation as a boilerplate for your own customized version.
For example, the following file:
-
#include "boost/shared_ptr.hpp"
#include "boost/bind.hpp"
will be transformed into:
-
#include "boom/shared_ptr.hpp"
#include "boom/bind.hpp"
Note: The transformation is performed in place, which means that the source
files are modified.
move_macros Change prefix in macros¶
This transformation allows one to modify the prefix of macros.
The motivation for this transformation is to help move whole libraries or source
sets from one naming conventioin to another.
Please use this transformation as a boilerplate for your own customized version.
For example, the following file:
-
#define BOOST_SOME_MACRO 1
// ...
#ifdef BOOST_SOME_MACRO
// ...
#endif
will be transformed into:
-
#define BOOM_SOME_MACRO 1
// ...
#ifdef BOOM_SOME_MACRO
// ...
#endif
Note: This transformation actually does not check whether the given identifier
is indeed a macro name and the prefix replacement is performed systematically
on all identifiers that match.
Note: The transformation is performed in place, which means that the source
files are modified.
move_namespace Change namespace name¶
This transformation allows one to consistently change the namespace name.
The motivation for this transformation is to help move whole libraries or source
sets from one namespace to another, for example to allow the coexistence of
two different version of the same library.
Please use this transformation as a boilerplate for your own customized version.
For example, the following file:
-
namespace boost
{
void foo();
}
void boost::foo() {/* ... */}
will be transformed into:
-
namespace boom
{
void foo();
}
void boom::foo() {/* ... */}
Note: This transformation actually does not check whether the given identifier
is indeed a namespace name and the replacement is performed systematically on
all identifiers that match. Do not use it on code that overloads namespace
names for other purposes.
Note: The transformation is performed in place, which means that the source
files are modified.
to_lower Change identifier naming convention from CamelCase to¶
standard_lowercase
This transformation allows one to modify the naming convention of all
identifiers from CamelCase to standard_lowercase, as used by the standard
library or Boost.
For example, the following code:
-
namespace MyTools
{
class MyClass
{
public:
void myFunction();
};
}
will be transformed into this:
-
namespace my_tools
{
class my_class
{
public:
void my_function();
};
}
Note: The transformation is performed in place, which means that the source
files are modified.
Note: This transformation does not modify comments and string literals.
This transformation generates a XML tree where nodes relate to C++ source code
tokens.
For example, the following file (file.cpp):
-
#include <iostream>
int main()
{
std::cout << "Hello World\n";
}
will be transformed into new file named file.cpp.xml:
-
<?xml version="1.0" encoding="ISO-8859-1"?>
<cpp-source file-name="test.cpp">
<token name="pp_hheader" line="1" column="0">#include <iostream></token>
<token name="newline" line="1" column="19">![CDATA[
]]</token>
<token name="newline" line="2" column="0">![CDATA[
]]</token>
<token name="int" line="3" column="0">int</token>
<token name="space" line="3" column="3"> </token>
<token name="identifier" line="3" column="4">main</token>
<token name="leftparen" line="3" column="8">(</token>
<token name="rightparen" line="3" column="9">)</token>
<token name="newline" line="3" column="10">![CDATA[
]]</token>
<token name="leftbrace" line="4" column="0">{</token>
<token name="newline" line="4" column="1">![CDATA[
]]</token>
<token name="space" line="5" column="0"> </token>
<token name="identifier" line="5" column="4">std</token>
<token name="colon_colon" line="5" column="7">::</token>
<token name="identifier" line="5" column="9">cout</token>
<token name="space" line="5" column="13"> </token>
<token name="shiftleft" line="5" column="14"><<</token>
<token name="space" line="5" column="16"> </token>
<token name="stringlit" line="5" column="17">"Hello World\n"</token>
<token name="semicolon" line="5" column="32">;</token>
<token name="newline" line="5" column="33">![CDATA[
]]</token>
<token name="rightbrace" line="6" column="0">}</token>
<token name="newline" line="6" column="1">![CDATA[
]]</token>
<token name="eof" line="7" column="0"></token>
</cpp-source>
Note: If the source code does not use line splicing, then concatenation of all
XML node values is equivalent to the original C++ code.
This transformation generates a XML tree where nodes relate to C++ source code
tokens.
The difference between this version and the one named to_xml is that here nodes
have names related to token types, which can make it easier for some further
XML transformations.
For example, the following file (file.cpp):
-
#include <iostream>
int main()
{
std::cout << "Hello World\n";
}
will be transformed into new file named file.cpp.xml:
-
<?xml version="1.0" encoding="ISO-8859-1"?>
<cpp-source file-name="test.cpp">
<pp_hheader line="1" column="0">#include <iostream></pp_hheader>
<newline line="1" column="19">![CDATA[
]]</newline>
<newline line="2" column="0">![CDATA[
]]</newline>
<int line="3" column="0">int</int>
<space line="3" column="3"> </space>
<identifier line="3" column="4">main</identifier>
<leftparen line="3" column="8">(</leftparen>
<rightparen line="3" column="9">)</rightparen>
<newline line="3" column="10">![CDATA[
]]</newline>
<leftbrace line="4" column="0">{</leftbrace>
<newline line="4" column="1">![CDATA[
]]</newline>
<space line="5" column="0"> </space>
<identifier line="5" column="4">std</identifier>
<colon_colon line="5" column="7">::</colon_colon>
<identifier line="5" column="9">cout</identifier>
<space line="5" column="13"> </space>
<shiftleft line="5" column="14"><<</shiftleft>
<space line="5" column="16"> </space>
<stringlit line="5" column="17">"Hello World\n"</stringlit>
<semicolon line="5" column="32">;</semicolon>
<newline line="5" column="33">![CDATA[
]]</newline>
<rightbrace line="6" column="0">}</rightbrace>
<newline line="6" column="1">![CDATA[
]]</newline>
<eof line="7" column="0"></eof>
</cpp-source>
Note: If the source code does not use line splicing, then concatenation of all
XML node values is equivalent to the original C++ code.
trim_right Remove trailing white space¶
This transformation removes the trailing whitespace from each line of code.
It can be treated as a quick remedy for problems reported by rule L001.
Note: The transformation is performed in place, which means that the source
files are modified.
Script API¶
The scripts (rules and transformations) are written in Tcl and are executed by
the embedded interpreter that has access to relevant state of the program. A
set of commands is provided to enable easy read-only operation on the
information that was gathered by parsing given source files.
The following Tcl commands are provided:
- •
- getSourceFileNames - returns the list of file names that were
provided to Vera++ as program parameters.
- •
- getLineCount fileName - returns the number of lines in the
given source file.
- •
- getAllLines fileName - returns the list of lines, in their
natural order, that form a give source file.
- •
- getLine fileName lineNumber - returns the selected
line; line numbers are counted from 1.
- •
- getTokens fileName fromLine fromColumn toLine toColumn filter
- returns the list of tokens, in their natural order, from the given
source file and that match the given selection criteria.
The meaning of arguments for selecting tokens is:
- •
- fromLine - the lowest line number (counted from 1), inclusive
- •
- fromColumn - the lowest column number (counted from 0),
inclusive
- •
- toLine - the highest line number, inclusive; -1 means that the
selected range spans to the end of the file
- •
- toColumn - the highest column number, exclusive; -1 means that the
selected range spans to the end of the line defined by toLine.
- •
- filter - the list of selected token types, the recognized token
types are listed below; if this list is empty, then all token types are
allowed.
The getTokens command returns a list of lists - the nested lists have the
following elements:
- •
- value - the literal text of the token
- •
- lineNumber - the line number (from 1) where the token appears
- •
- columnNumber - the column number (from 0) where the token
appears
- •
- name - the name or type of the token; see below for the list of
recognized token types
- •
- getParameter name defaultValue - returns the value of
the given parameter or the provided default value if no such parameter is
defined.
- •
- report fileName lineNumber message - registers
a report for the given file and line; this report is printed at the end of
the program execution, sorted by file and line number. Use this command to
generate output that is compatible with the warning/error output format of
popular compilers.
Examples:¶
To process all lines from all source files, use the following code pattern:
-
foreach fileName [getSourceFileNames] {
foreach line [getAllLines $fileName] {
# ...
}
}
To process all tokens from all source files, use:
-
foreach fileName [getSourceFileNames] {
foreach token [getTokens $fileName 1 0 -1 -1 {}] {
set tokenValue [lindex $token 0]
set lineNumber [lindex $token 1]
set columnNumber [lindex $token 2]
set tokenType [lindex $token 3]
# ...
}
}
To process only curly braces from the given source file, use:
-
foreach token [getTokens $fileName 1 0 -1 -1 {leftbrace rightbrace}] {
# ...
}
The complete rule script for verifying that the lines are no longer than some
limit (the limit can be provided as a parameter, but the default value is
defined in by the script itself):
-
# Line cannot be too long
set maxLength [getParameter "max-line-length" 100]
foreach f [getSourceFileNames] {
set lineNumber 1
foreach line [getAllLines $f] {
if {[string length $line] > $maxLength} {
report $f $lineNumber "line is longer than ${maxLength} characters"
}
incr lineNumber
}
}
The above script is actually the implementation of rule L004.
Notes about line splicing¶
As required by the C++ ISO standard, the line splicing (with the backslash at
the end of the line) is performed before tokenizing. This means that the lists
of tokens might not strictly fit the list of lines.
Due to the internal mechanisms of the parser, the line splicing freezes the line
counter and forces the column counter to continue until the last line in the
spliced block. This means that there might be physical non-empty lines that
apparently don't have any tokens, as well as tokens that have column numbers
not matching the physical source line lengths.
Recognized token types¶
The following token types are recognized by the parser and can be used for
filter selection in the getTokens command (some of these token types are
related to compiler extensions):
-
and
andand
andassign
any
arrow
arrowstar
asm
assign
auto
bool
break
case
catch
ccomment
char
charlit
class
colon
colon_colon
comma
compl
const
constcast
continue
contline
cppcomment
decimalint
default
delete
divide
divideassign
do
dot
dotstar
double
dynamiccast
ellipsis
else
enum
eof
eoi
equal
explicit
export
extern
false
float
floatlit
for
friend
goto
greater
greaterequal
hexaint
identifier
if
inline
int
intlit
leftbrace
leftbracket
leftparen
less
lessequal
long
longintlit
minus
minusassign
minusminus
msext_asm
msext_based
msext_cdecl
msext_declspec
msext_endregion
msext_except
msext_fastcall
msext_finally
msext_inline
msext_int16
msext_int32
msext_int64
msext_int8
msext_leave
msext_region
msext_stdcall
msext_try
mutable
namespace
new
newline
not
notequal
octalint
operator
or
orassign
oror
percent
percentassign
plus
plusassign
plusplus
pound
pound_pound
pp_define
pp_elif
pp_else
pp_endif
pp_error
pp_hheader
pp_if
pp_ifdef
pp_ifndef
pp_include
pp_line
pp_number
pp_pragma
pp_qheader
pp_undef
pp_warning
private
protected
public
question_mark
register
reinterpretcast
return
rightbrace
rightbracket
rightparen
semicolon
shiftleft
shiftleftassign
shiftright
shiftrightassign
short
signed
sizeof
space
space2
star
starassign
static
staticcast
stringlit
struct
switch
template
this
throw
true
try
typedef
typeid
typename
union
unsigned
using
virtual
void
volatile
wchart
while
xor
xorassign
Note¶
There is a predefined rule named DUMP that prints on the screen all tokens with
their types and position. This rule can be helpful as a guideline for creating
custom filtering criteria:
-
vera++ --rule DUMP myfile.cpp
Changes¶
Vera++ 1.2.1¶
Vera++ 1.2.1 differs from 1.2.0 in the following ways:
- •
- BUGFIX: fix --inputs in order to be able to read the inputs from a
file
Vera++ 1.2.0¶
Vera++ 1.2.0 differs from 1.1.2 in the following ways:
- •
- Full Tcl stack printed when a rule fail.
- •
- New command line interface that support long and short options. The old
style command line is still usable for backward compatibility.
- •
- Produce output to standard output by default so the output can easily be
piped to another program. The options --warning and --error make vera++
produce its output on the error output.
- •
- CMake macros to easily run vera++ in any CMake project.
- •
- Easier integration in a test chain by return an error code when at least
one report is produced and the --error option is used. --quiet and
--summary can also help to better integrate vera++ in the test chain.
- •
- The standard output format match gcc's output format for a better
integration in a build chain.
- •
- Can read the list of files to check from one or more files.
- •
- Can read the source code to check from the standard input.
- •
- Can write the several reports in differents formats and in different
places.
- •
- Added --root option to point the the vera root directory from the command
line and ease the usage of custom rules.
- •
- Reports can be produced in checkstyle (http://checkstyle.sourceforge.net/)
XML format.
- •
- Vera++ no more impose the extension of the source files to check.
- •
- Several exclusion files can be used.
- •
- Several parameter files can be used.
- •
- Build system now uses CMake.
- •
- Builds with TCL 8.6.
- •
- Don't require Boost sources to build.
- •
- New documentation generation process to unify the wiki, the html doc and
the manpage.
- •
- Binary packages for MS Windows and Mac OS X (and others).
- •
- Nightly tests to avoid regressions.
- •
- New website.
- •
- BUGFIX: the rule T019 now works properly with do ... while
blocks.
Vera++ 1.1.2¶
Vera++ 1.1.2 differs from 1.1.1 in the following ways:
- •
- Added -xmlreport option.
Vera++ 1.1.1¶
Vera++ 1.1.1 differs from 1.1.0 in the following ways:
- •
- Added -help option.
- •
- Updated code for compatibility with newer versions of Boost. The reference
version of the Boost library is now 1.35 or 1.36.
- •
- BUGFIX: Corrected handling of current directory when neither HOME nor
VERA_ROOT is specified (this affects Windows users only).
Vera++ 1.1.0¶
Vera++ 1.1.0 differs from 1.0.0 in the following ways:
- •
- Updated rules:
- •
- T002: additionally recognizes redefinition (#define) of keywords
- •
- T009: recognizes comment adjacent to colon as an exception to the
rule
- •
- Added rules:
- •
- F001: Source files should not use the \r (CR) character
- •
- F002: File names should be well-formed Note: F002 is not part of the
default profile.
- •
- T012: Negation operator should not be used in its short form
- •
- T013: Source files should contain the copyright notice
- •
- T014: Source files should refer the Boost Software License Note: T014 is
not part of the default profile.
- •
- T015: HTML links in comments and string literals should be correct
- •
- T016: Calls to min/max should be protected against accidental macro
substitution
- •
- T017: Unnamed namespaces are not allowed in header files
- •
- T018: Using namespace is not allowed in header files
- •
- T019: Control structures should have complete curly-braced block of
code
- •
- Added predefined boost profile to emulate the original Boost inspect
tool.
- •
- Added transformations:
- •
- move_namespace: Changes the given identifier, useful for moving the whole
project from one namespace to another.
- •
- move_macros: Changes the given prefix in all identifiers, useful for
moving the whole set of macros that have common prefix.
- •
- move_includes: Changes the given part of #include "..."
directives, useful for moving libraries and whole sets of header
files.
- •
- Added documentation for all available transformations.
- •
- Makefiles modified to better support Windows make users.
- •
- Extension .ipp added to the list of recognized source file
extensions.
- •
- New option -showrules includes name of rules in each report line.
- •
- Changed the profile definition to be an active Tcl script instead of
passive text file.
- •
- Added the possibility to define exclusions to rule checks.
- •
- BUGFIX: Corrected handling of newline tokens.
AUTHORS¶
Maciej Sobczak; Vincent Hobeïka; Gaëtan Lehmann.