docs/devel/style.rst

94 that use long function or symbol names. If wrapping the line at 80 columns
98 Even in that case, try not to make lines much longer than 80 characters.
110   at all that white space on the left!") moot.
120 uint64_t and family.  Note that this last convention contradicts POSIX
126 A number of short naming conventions exist for variables that use
138 prefix to alert readers that they are seeing a wrapped version, for
140 that are widely called from across the codebase should not have any
144 The ``qemu_`` prefix is also used for functions that modify global
155 lock held, the function that expects the lock to be already held
162 concrete implementation of a function that will not be called
169 statement.  The opening brace is on the line that contains the control
170 flow statement that introduces the new block; the closing brace is on the
184 Note that 'else if' is considered a single statement; otherwise a long if/
219 On the other hand, however, it's often best to move that #ifdef/#ifndef
262 about converting to the preferred form unless you're editing that
295 The "qemu/osdep.h" header contains preprocessor macros that affect the behavior
296 of core system headers like <stdint.h>.  It must be the first include so that
298 that QEMU depends on.
305 the header.  If all that's needed from a header is typedefs, consider
333 If you're using "int" or "long", odds are good that there's a better type.
344 (on all but oddball embedded systems, you can assume that that
347 In the event that you require a specific width, use a standard type
355 space that maps guest RAM physical addresses into an intermediate
356 address space that can map to host virtual address spaces.  Generally
372 'void ``*``' in that target's ABI. (This may not be the same as the size of a
374 on 64 bit CPUs, like sparc32plus.) Definitions of structures that must match
375 the target's ABI must use this type for anything that on the target is defined
380 to use some system interface that requires a type like size_t, pid_t or
383 Also, if you try to use e.g., "unsigned int" as a type, and that
395 Ensure that all of your pointers are "const-correct".
397 give it the "const" attribute.  That way, the reader knows
398 up-front that this is a read-only pointer.  Perhaps more
400 pointer, you're guaranteed that it is used to modify the storage
401 it points to, or it is aliased to another pointer that is.
433 layout does not matter, unless you can show that they provide a significant
454 Please note that ``g_malloc`` will exit on allocation failure, so
560 * you may assume that integers are 2s complement representation
561 * you may assume that right shift of a signed integer duplicates
564 In addition, QEMU assumes that the compiler does not use the latitude
638   live beyond the life of the function, that value must be saved
667 that declaration and the new code. It is also useful to separate
694 Note that there is no need to provide typedefs for QOM structures
774 but often needs to be propagated up the call chain to a place that can
793 for somebody else to handle.  Leave the reporting to the place that
803 Do not call exit() or abort() to handle an error that can be triggered
808 Note that &error_fatal is just another way to exit(1), and &error_abort
824 An exception is made for groups of numbers that are hexadecimal by
832 However, you can use '0x' for such groups if you want. Anyway, be sure that
833 it is obvious that numbers are in hex, ex.: