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diff --git a/www/SB-api-coding-rules.html b/www/SB-api-coding-rules.html new file mode 100644 index 0000000000000..0f7ef0e1eb5b0 --- /dev/null +++ b/www/SB-api-coding-rules.html @@ -0,0 +1,69 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> +<link href="style.css" rel="stylesheet" type="text/css" /> +<title>LLDB Tutorial</title> +</head> + +<body> + <div class="www_title"> + The SB API Coding Rules + </div> + +<div id="container"> + <div id="content"> + <!--#include virtual="sidebar.incl"--> + <div id="middle"> + <div class="post"> + <h1 class ="postheader">SB API Coding Rules</h1> + <div class="postcontent"> + + + <p>The SB APIs constitute the stable C++ API that lldb presents to external clients, + and which get processed by SWIG to produce the Python bindings to lldb. As such + it is important that they not suffer from the binary incompatibilities that C++ is + so susceptible to. We've established a few rules to ensure that this happens. + + <p>The classes in the SB API's are all called SB<SomeName>, where SomeName is in CamelCase + starting with an upper case letter. The method names are all CamelCase with initial + capital letter as well. + + <p>All the SB API classes are non-virtual, single inheritance classes. They should only include + SBDefines.h or other SB headers as needed. There should be no inlined method implementations + in the header files, they should all be in the implementation files. And there should be no + direct ivar access. + + <p>You also need to choose the ivars for the class with care, since you can't add or remove ivars + without breaking binary compatibility. In some cases, the SB class is a thin wrapper around + an interal lldb_private object. In that case, the class can have a single ivar, which is + either a pointer, shared_ptr or unique_ptr to the object in the lldb_private API. All the + lldb_private classes that get used this way are declared as opaque classes in lldb_forward.h, + which is included in SBDefines.h. So if you need an SB class to wrap an lldb_private class + that isn't in lldb_forward.h, add it there rather than making a direct opaque declaration in + the SB classes .h file. + + <p>If the SB Class needs some state of its own, as well as the backing object, don't include that + as a direct ivar in the SB Class. Instead, make an Impl class in the SB's .cpp file, and then + make the SB object hold a shared or unique pointer to the Impl object. The theory behind this is + that if you need more state in the SB object, those needs are likely to change over time, + and this way the impl class can pick up members without changing the size of the object. + An example of this is the SBValue class. + + <p>In order to fit into the Python API's, we need to be able to default construct all the SB objects. + Since the ivars of the classes are all pointers of one sort or other, this can easily be done, but + it means all the methods must be prepared to handle their opaque implementation pointer being + empty, and doing something reasonable. We also always have an "IsValid" method on all the SB + classes to report whether the object is empty or not. + + <p>Another piece of the SB API infrastructure is the Python (or other script interpreter) customization. + SWIG allows you to add property access, iterators and documentation to classes, but to do that you have to use + a Swig interface file in place of the .h file. Those files have a different format than a straight C++ header file. These + files are called SB<ClassName>.i, and live in "scripts/interface". They are constructed by + starting with the associated .h file, and adding documentation and the Python decorations, etc. We + do this in a decidedly low-tech way, by maintaining the two files in parallel. That simplifies the + build process, but it does mean that if you add a method to the C++ API's for an SB class, you have + to copy the interface to the .i file. +</div> +</body> +</html> |