[Qemu-devel] [PATCH 3/4] HACKING.md : Reformatted to fit the Markdown (.md) format.

[Yoni Bettan]

Signed-off-by: Yoni Bettan <address@hidden>
---
 HACKING => HACKING.md | 186 ++++++++++++++++++++++--------------------
 1 file changed, 97 insertions(+), 89 deletions(-)
 rename HACKING => HACKING.md (53%)

diff --git a/HACKING b/HACKING.md
similarity index 53%
rename from HACKING
rename to HACKING.md
index 0fc3e0fc04..f9d7631e64 100644
--- a/HACKING
+++ b/HACKING.md
@@ -1,86 +1,90 @@
-1. Preprocessor
+## Preprocessor
 
-1.1. Variadic macros
+### Variadic macros
 
 For variadic macros, stick with this C99-like syntax:
 
+```
 #define DPRINTF(fmt, ...)                                       \
     do { printf("IRQ: " fmt, ## __VA_ARGS__); } while (0)
+```
 
-1.2. Include directives
+### Include directives
 
 Order include directives as follows:
 
+```
 #include "qemu/osdep.h"  /* Always first... */
 #include <...>           /* then system headers... */
 #include "..."           /* and finally QEMU headers. */
+```
 
-The "qemu/osdep.h" header contains preprocessor macros that affect the behavior
-of core system headers like <stdint.h>.  It must be the first include so that
+The `qemu/osdep.h` header contains preprocessor macros that affect the behavior
+of core system headers like `<stdint.h>`.  It must be the first include so that
 core system headers included by external libraries get the preprocessor macros
 that QEMU depends on.
 
-Do not include "qemu/osdep.h" from header files since the .c file will have
+Do not include `qemu/osdep.h` from header files since the .c file will have
 already included it.
 
-2. C types
+## C types
 
 It should be common sense to use the right type, but we have collected
 a few useful guidelines here.
 
-2.1. Scalars
+### Scalars
 
-If you're using "int" or "long", odds are good that there's a better type.
-If a variable is counting something, it should be declared with an
-unsigned type.
+If you're using `int` or `long`, odds are good that there's a better type.
+If a variable is counting something, it should be declared with
+`unsigned <type>`.
 
-If it's host memory-size related, size_t should be a good choice (use
-ssize_t only if required). Guest RAM memory offsets must use ram_addr_t,
+If it's host memory-size related, `size_t` should be a good choice (use
+`ssize_t` only if required). Guest RAM memory offsets must use `ram_addr_t`,
 but only for RAM, it may not cover whole guest address space.
 
-If it's file-size related, use off_t.
-If it's file-offset related (i.e., signed), use off_t.
-If it's just counting small numbers use "unsigned int";
+If it's file-size related, use `off_t`.
+If it's file-offset related (i.e., signed), `use off_t`.
+If it's just counting small numbers use `unsigned int`;
 (on all but oddball embedded systems, you can assume that that
 type is at least four bytes wide).
 
 In the event that you require a specific width, use a standard type
-like int32_t, uint32_t, uint64_t, etc.  The specific types are
+like `int32_t`, `uint32_t`, `uint64_t`, etc.  The specific types are
 mandatory for VMState fields.
 
-Don't use Linux kernel internal types like u32, __u32 or __le32.
+Don't use Linux kernel internal types like `u32`, `__u32` or `__le32`.
 
-Use hwaddr for guest physical addresses except pcibus_t
-for PCI addresses.  In addition, ram_addr_t is a QEMU internal address
+Use `hwaddr` for guest physical addresses except `pcibus_t`
+for PCI addresses.  In addition, `ram_addr_t` is a QEMU internal address
 space that maps guest RAM physical addresses into an intermediate
 address space that can map to host virtual address spaces.  Generally
-speaking, the size of guest memory can always fit into ram_addr_t but
+speaking, the size of guest memory can always fit into `ram_addr_t` but
 it would not be correct to store an actual guest physical address in a
-ram_addr_t.
+`ram_addr_t`.
 
 For CPU virtual addresses there are several possible types.
-vaddr is the best type to use to hold a CPU virtual address in
+`vaddr` is the best type to use to hold a CPU virtual address in
 target-independent code. It is guaranteed to be large enough to hold a
 virtual address for any target, and it does not change size from target
 to target. It is always unsigned.
-target_ulong is a type the size of a virtual address on the CPU; this means
+`target_ulong` is a type the size of a virtual address on the CPU; this means
 it may be 32 or 64 bits depending on which target is being built. It should
 therefore be used only in target-specific code, and in some
 performance-critical built-per-target core code such as the TLB code.
-There is also a signed version, target_long.
-abi_ulong is for the *-user targets, and represents a type the size of
-'void *' in that target's ABI. (This may not be the same as the size of a
+There is also a signed version, `target_long`.
+`abi_ulong` is for the `*-user` targets, and represents a type the size of
+`void *` in that target's ABI. (This may not be the same as the size of a
 full CPU virtual address in the case of target ABIs which use 32 bit pointers
-on 64 bit CPUs, like sparc32plus.) Definitions of structures that must match
+on 64 bit CPUs, like `sparc32plus`.) Definitions of structures that must match
 the target's ABI must use this type for anything that on the target is defined
-to be an 'unsigned long' or a pointer type.
-There is also a signed version, abi_long.
+to be an `unsigned long` or a pointer type.
+There is also a signed version, `abi_long`.
 
 Of course, take all of the above with a grain of salt.  If you're about
-to use some system interface that requires a type like size_t, pid_t or
-off_t, use matching types for any corresponding variables.
+to use some system interface that requires a type like `size_t`, `pid_t` or
+`off_t`, use matching types for any corresponding variables.
 
-Also, if you try to use e.g., "unsigned int" as a type, and that
+Also, if you try to use e.g., `unsigned int` as a type, and that
 conflicts with the signedness of a related variable, sometimes
 it's best just to use the *wrong* type, if "pulling the thread"
 and fixing all related variables would be too invasive.
@@ -89,83 +93,86 @@ Finally, while using descriptive types is important, be 
careful not to
 go overboard.  If whatever you're doing causes warnings, or requires
 casts, then reconsider or ask for help.
 
-2.2. Pointers
+### Pointers
 
 Ensure that all of your pointers are "const-correct".
 Unless a pointer is used to modify the pointed-to storage,
-give it the "const" attribute.  That way, the reader knows
+give it the `const` attribute.  That way, the reader knows
 up-front that this is a read-only pointer.  Perhaps more
 importantly, if we're diligent about this, when you see a non-const
 pointer, you're guaranteed that it is used to modify the storage
 it points to, or it is aliased to another pointer that is.
 
-2.3. Typedefs
-Typedefs are used to eliminate the redundant 'struct' keyword.
+### Typedefs
+Typedefs are used to eliminate the redundant `struct` keyword.
 
-2.4. Reserved namespaces in C and POSIX
-Underscore capital, double underscore, and underscore 't' suffixes should be
+### Reserved namespaces in C and POSIX
+`_`, `__`, and underscore `*_t` suffixes should be
 avoided.
 
-3. Low level memory management
+## Low level memory management
 
-Use of the malloc/free/realloc/calloc/valloc/memalign/posix_memalign
+Use of the `malloc/free/realloc/calloc/valloc/memalign/posix_memalign`
 APIs is not allowed in the QEMU codebase. Instead of these routines,
-use the GLib memory allocation routines g_malloc/g_malloc0/g_new/
-g_new0/g_realloc/g_free or QEMU's qemu_memalign/qemu_blockalign/qemu_vfree
+use the GLib memory allocation routines `g_malloc/g_malloc0/g_new/
+g_new0/g_realloc/g_free or QEMU's qemu_memalign/qemu_blockalign/qemu_vfree`
 APIs.
 
-Please note that g_malloc will exit on allocation failure, so there
+Please note that `g_malloc` will exit on allocation failure, so there
 is no need to test for failure (as you would have to with malloc).
-Calling g_malloc with a zero size is valid and will return NULL.
+Calling `g_malloc` with a zero size is valid and will return `NULL`.
 
-Prefer g_new(T, n) instead of g_malloc(sizeof(T) * n) for the following
+Prefer `g_new(T, n)` instead of `g_malloc(sizeof(T) * n)` for the following
 reasons:
 
-  a. It catches multiplication overflowing size_t;
-  b. It returns T * instead of void *, letting compiler catch more type
+  a. It catches multiplication overflowing `size_t`;
+  b. It returns `T *` instead of `void *`, letting compiler catch more type
      errors.
 
-Declarations like T *v = g_malloc(sizeof(*v)) are acceptable, though.
+Declarations like `T *v = g_malloc(sizeof(*v))` are acceptable, though.
 
-Memory allocated by qemu_memalign or qemu_blockalign must be freed with
-qemu_vfree, since breaking this will cause problems on Win32.
+Memory allocated by `qemu_memalign` or `qemu_blockalign` must be freed with
+`qemu_vfree`, since breaking this will cause problems on Win32.
 
-4. String manipulation
+## String manipulation
 
-Do not use the strncpy function.  As mentioned in the man page, it does *not*
+Do not use the `strncpy` function.  As mentioned in the man page, it does *not*
 guarantee a NULL-terminated buffer, which makes it extremely dangerous to use.
 It also zeros trailing destination bytes out to the specified length.  Instead,
 use this similar function when possible, but note its different signature:
-void pstrcpy(char *dest, int dest_buf_size, const char *src)
+`void pstrcpy(char *dest, int dest_buf_size, const char *src)`
 
-Don't use strcat because it can't check for buffer overflows, but:
-char *pstrcat(char *buf, int buf_size, const char *s)
+Don't use `strcat` because it can't check for buffer overflows, but:
+`char *pstrcat(char *buf, int buf_size, const char *s)`
 
-The same limitation exists with sprintf and vsprintf, so use snprintf and
-vsnprintf.
+The same limitation exists with `sprintf` and `vsprintf`, so use `snprintf` and
+`vsnprintf`.
 
 QEMU provides other useful string functions:
+
+```
 int strstart(const char *str, const char *val, const char **ptr)
 int stristart(const char *str, const char *val, const char **ptr)
 int qemu_strnlen(const char *s, int max_len)
+```
 
-There are also replacement character processing macros for isxyz and toxyz,
-so instead of e.g. isalnum you should use qemu_isalnum.
+There are also replacement character processing macros for `isxyz` and `toxyz`,
+so instead of e.g. `isalnum` you should use `qemu_isalnum`.
 
-Because of the memory management rules, you must use g_strdup/g_strndup
-instead of plain strdup/strndup.
+Because of the memory management rules, you must use `g_strdup/g_strndup`
+instead of plain `strdup/strndup`.
 
-5. Printf-style functions
+## Printf-style functions
 
 Whenever you add a new printf-style function, i.e., one with a format
-string argument and following "..." in its prototype, be sure to use
+string argument and following `...` in its prototype, be sure to use
 gcc's printf attribute directive in the prototype.
 
-This makes it so gcc's -Wformat and -Wformat-security options can do
+This makes it so gcc's `-Wformat` and `-Wformat-security` options can do
 their jobs and cross-check format strings with the number and types
 of arguments.
 
-6. C standard, implementation defined and undefined behaviors
+## C standard, implementation defined and undefined behaviors
 
 C code in QEMU should be written to the C99 language specification. A copy
 of the final version of the C99 standard with corrigenda TC1, TC2, and TC3
@@ -181,37 +188,38 @@ argument...) However there are a few areas where we allow 
ourselves to
 assume certain behaviors because in practice all the platforms we care about
 behave in the same way and writing strictly conformant code would be
 painful. These are:
- * you may assume that integers are 2s complement representation
- * you may assume that right shift of a signed integer duplicates
-   the sign bit (ie it is an arithmetic shift, not a logical shift)
+
+* you may assume that integers are 2s complement representation
+* you may assume that right shift of a signed integer duplicates
+  the sign bit (ie it is an arithmetic shift, not a logical shift)
 
 In addition, QEMU assumes that the compiler does not use the latitude
-given in C99 and C11 to treat aspects of signed '<<' as undefined, as
+given in C99 and C11 to treat aspects of signed `<<` as undefined, as
 documented in the GNU Compiler Collection manual starting at version 4.0.
 
-7. Error handling and reporting
+## Error handling and reporting
 
-7.1 Reporting errors to the human user
+### Reporting errors to the human user
 
-Do not use printf(), fprintf() or monitor_printf().  Instead, use
-error_report() or error_vreport() from error-report.h.  This ensures the
+Do not use `printf()`, `fprintf()` or `monitor_printf()`.  Instead, use
+`error_report()` or `error_vreport()` from `error-report.h`.  This ensures the
 error is reported in the right place (current monitor or stderr), and in
 a uniform format.
 
-Use error_printf() & friends to print additional information.
+Use `error_printf()` & friends to print additional information.
 
-error_report() prints the current location.  In certain common cases
+`error_report()` prints the current location.  In certain common cases
 like command line parsing, the current location is tracked
-automatically.  To manipulate it manually, use the loc_*() from
-error-report.h.
+automatically.  To manipulate it manually, use the `loc_*()` from
+`error-report.h`.
 
-7.2 Propagating errors
+### Propagating errors
 
 An error can't always be reported to the user right where it's detected,
 but often needs to be propagated up the call chain to a place that can
 handle it.  This can be done in various ways.
 
-The most flexible one is Error objects.  See error.h for usage
+The most flexible one is Error objects.  See `error.h` for usage
 information.
 
 Use the simplest suitable method to communicate success / failure to
@@ -220,26 +228,26 @@ error, non-negative / -errno, non-null / null, or Error 
objects.
 
 Example: when a function returns a non-null pointer on success, and it
 can fail only in one way (as far as the caller is concerned), returning
-null on failure is just fine, and certainly simpler and a lot easier on
-the eyes than propagating an Error object through an Error ** parameter.
+`NULL` on failure is just fine, and certainly simpler and a lot easier on
+the eyes than propagating an Error object through an `Error ** parameter`.
 
 Example: when a function's callers need to report details on failure
-only the function really knows, use Error **, and set suitable errors.
+only the function really knows, use `Error **`, and set suitable errors.
 
 Do not report an error to the user when you're also returning an error
 for somebody else to handle.  Leave the reporting to the place that
 consumes the error returned.
 
-7.3 Handling errors
+### Handling errors
 
-Calling exit() is fine when handling configuration errors during
+Calling `exit()` is fine when handling configuration errors during
 startup.  It's problematic during normal operation.  In particular,
-monitor commands should never exit().
+monitor commands should never `exit()`.
 
-Do not call exit() or abort() to handle an error that can be triggered
+Do not call `exit()` or `abort()` to handle an error that can be triggered
 by the guest (e.g., some unimplemented corner case in guest code
 translation or device emulation).  Guests should not be able to
 terminate QEMU.
 
-Note that &error_fatal is just another way to exit(1), and &error_abort
-is just another way to abort().
+Note that `&error_fatal` is just another way to `exit(1)`, and `&error_abort`
+is just another way to `abort()`.
-- 
2.17.1