Detect and fix parsing errors

To get meaningful results there should be no syntax errors in your code. This page contains a step-by-step instruction how to find and fix these kind of problems.

In case the plugin is not able to parse the code this will result in a syntax error like the following:

10: int Bar::foo(){
11:
12:     int
13:         x;
14:
15:     return 111;
16: }
17:
-->  this is a syntax error
23:
24: void Bar::do_valgrind_errors(){
25:
26:     new float();
27:
28:     int a;
29:     if(a) std::cout << "fired!!!" <<

Failed at rules:
        /-alignmentSpecifier
      /-attributeSpecifier
    /-attributeSpecifierSeq
...

Second message you should watch for is:

15:54:46.567 WARN  - [example.cpp:1]: cannot find the sources for '#include <...>'

In both cases you should try to remove them with the hints on this page:

Provide syntactically correct code

The plugin expects to be fed with syntactically correct code. This is a conscious design decision: we do not want to re-implement a compiler and try to follow the KISS principle. Therefore the first step should be always to verify your code base on your target system with your build environment for correctness. Your build environment will give you more guidance as the C++ community plugin will do. Typical problems during this step are:

• libraries from build environment are missing
• not all sources are available, especially 3rd party libraries are often missing
• source code checked out in different folders: includes can't be resolved

Missing preprocessor definitions

To parse the code in the same way as in your build environment you have to set the same macros as in your build environment. Copy your project specific macros to sonar.cxx.defines. For system specific macros it is in most cases easier to write once a header file for the target build environment and reuse this header file with Force Include in all projects. For more help see:

• Predefined Macros
• Dealing with compiler specific code pieces

Visual Studio:

• Project settings: Property Page / Configuration properties / C/C++ / Preprocessor / Preprocessor Definitions
• Visual Studio Predefined Macros

Missing include paths

In most cases you also have to provide include paths. The plugin doesn't know any standard include paths and also no project specific paths. Copy the paths from your build environment and project to sonar.cxx.includeDirectories.

Visual Studio:

• Property Page / Configuration properties / VC++ Directories / Include Directories
• Property Page / Configuration properties / C/C++ / General / Additional Include Directories

Missing support of compiler specific extensions

C++ community plugin implements a C++03 and C++11 compatible grammar but most compilers support additional compiler specific extensions. To get no syntax errors and meaningful results you have to find workarounds for these extensions. To keep the compiler grammar as simple as possible it was a conscious design decision to support such extensions mainly with macro definitions and not by an extension of the grammar. There are only some exceptions to this, where preprocessor directives won't work, see Supported compiler specific extensions. Dealing with compiler specific code peaces gives you an introduction how to do this.

• Microsoft-Specific Modifiers
• GNU compiler extensions to the C++ Language

Incomplete support of C++ specification

In case there are still problems check if your code fits to the latest C++ specification. In case the plugin does not support the code you can try to mock it away, but in most cases you can only raise an issue in this forum to ask for an extension of the grammar.

Parse Error Recovery

An alternative way of dealing with parse errors is using the experimental feature Error Recovery, which swallows most of the parse errors at cost of some accuracy loss. Activate it by setting the according configuration property: sonar.cxx.errorRecoveryEnabled=True. Now the plugin will try to recover from parse errors and output messages like the following into the analysis log:

15:54:45.567 WARN  - [example.cpp:3]: syntax error, skip 'func1'