Merge remote-tracking branch 'remotes/berrange/tags/docs-pull-request' into staging

docs: add docs about use of automatic cleanup functions

This is ostensibly about adding docs for the g_autofree/g_autoptr
macros. As part of doing that, however, the existing HACKING doc
is merged into the CODING_STYLE doc and the text is converted to
rst with a table of contents.

# gpg: Signature made Thu 05 Sep 2019 14:43:44 BST
# gpg:                using RSA key DAF3A6FDB26B62912D0E8E3FBE86EBB415104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>" [full]
# gpg:                 aka "Daniel P. Berrange <berrange@redhat.com>" [full]
# Primary key fingerprint: DAF3 A6FD B26B 6291 2D0E  8E3F BE86 EBB4 1510 4FDF

* remotes/berrange/tags/docs-pull-request:
  docs: split the CODING_STYLE doc into distinct groups
  docs: document use of automatic cleanup functions in glib
  docs: merge HACKING.rst contents into CODING_STYLE.rst
  docs: convert README, CODING_STYLE and HACKING to RST syntax
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

CODING_STYLE

-QEMU Coding Style
-=================
-
-Please use the script checkpatch.pl in the scripts directory to check
-patches before submitting.
-
-1. Whitespace
-
-Of course, the most important aspect in any coding style is whitespace.
-Crusty old coders who have trouble spotting the glasses on their noses
-can tell the difference between a tab and eight spaces from a distance
-of approximately fifteen parsecs.  Many a flamewar has been fought and
-lost on this issue.
-
-QEMU indents are four spaces.  Tabs are never used, except in Makefiles
-where they have been irreversibly coded into the syntax.
-Spaces of course are superior to tabs because:
-
- - You have just one way to specify whitespace, not two.  Ambiguity breeds
-   mistakes.
- - The confusion surrounding 'use tabs to indent, spaces to justify' is gone.
- - Tab indents push your code to the right, making your screen seriously
-   unbalanced.
- - Tabs will be rendered incorrectly on editors who are misconfigured not
-   to use tab stops of eight positions.
- - Tabs are rendered badly in patches, causing off-by-one errors in almost
-   every line.
- - It is the QEMU coding style.
-
-Do not leave whitespace dangling off the ends of lines.
-
-1.1 Multiline Indent
-
-There are several places where indent is necessary:
-
- - if/else
- - while/for
- - function definition & call
-
-When breaking up a long line to fit within line width, we need a proper indent
-for the following lines.
-
-In case of if/else, while/for, align the secondary lines just after the
-opening parenthesis of the first.
-
-For example:
-
-    if (a == 1 &&
-        b == 2) {
-
-    while (a == 1 &&
-           b == 2) {
-
-In case of function, there are several variants:
-
-    * 4 spaces indent from the beginning
-    * align the secondary lines just after the opening parenthesis of the
-      first
-
-For example:
-
-    do_something(x, y,
-        z);
-
-    do_something(x, y,
-                 z);
-
-    do_something(x, do_another(y,
-                               z));
-
-2. Line width
-
-Lines should be 80 characters; try not to make them longer.
-
-Sometimes it is hard to do, especially when dealing with QEMU subsystems
-that use long function or symbol names.  Even in that case, do not make
-lines much longer than 80 characters.
-
-Rationale:
- - Some people like to tile their 24" screens with a 6x4 matrix of 80x24
-   xterms and use vi in all of them.  The best way to punish them is to
-   let them keep doing it.
- - Code and especially patches is much more readable if limited to a sane
-   line length.  Eighty is traditional.
- - The four-space indentation makes the most common excuse ("But look
-   at all that white space on the left!") moot.
- - It is the QEMU coding style.
-
-3. Naming
-
-Variables are lower_case_with_underscores; easy to type and read.  Structured
-type names are in CamelCase; harder to type but standing out.  Enum type
-names and function type names should also be in CamelCase.  Scalar type
-names are lower_case_with_underscores_ending_with_a_t, like the POSIX
-uint64_t and family.  Note that this last convention contradicts POSIX
-and is therefore likely to be changed.
-
-When wrapping standard library functions, use the prefix qemu_ to alert
-readers that they are seeing a wrapped version; otherwise avoid this prefix.
-
-4. Block structure
-
-Every indented statement is braced; even if the block contains just one
-statement.  The opening brace is on the line that contains the control
-flow statement that introduces the new block; the closing brace is on the
-same line as the else keyword, or on a line by itself if there is no else
-keyword.  Example:
-
-    if (a == 5) {
-        printf("a was 5.\n");
-    } else if (a == 6) {
-        printf("a was 6.\n");
-    } else {
-        printf("a was something else entirely.\n");
-    }
-
-Note that 'else if' is considered a single statement; otherwise a long if/
-else if/else if/.../else sequence would need an indent for every else
-statement.
-
-An exception is the opening brace for a function; for reasons of tradition
-and clarity it comes on a line by itself:
-
-    void a_function(void)
-    {
-        do_something();
-    }
-
-Rationale: a consistent (except for functions...) bracing style reduces
-ambiguity and avoids needless churn when lines are added or removed.
-Furthermore, it is the QEMU coding style.
-
-5. Declarations
-
-Mixed declarations (interleaving statements and declarations within
-blocks) are generally not allowed; declarations should be at the beginning
-of blocks.
-
-Every now and then, an exception is made for declarations inside a
-#ifdef or #ifndef block: if the code looks nicer, such declarations can
-be placed at the top of the block even if there are statements above.
-On the other hand, however, it's often best to move that #ifdef/#ifndef
-block to a separate function altogether.
-
-6. Conditional statements
-
-When comparing a variable for (in)equality with a constant, list the
-constant on the right, as in:
-
-    if (a == 1) {
-        /* Reads like: "If a equals 1" */
-        do_something();
-    }
-
-Rationale: Yoda conditions (as in 'if (1 == a)') are awkward to read.
-Besides, good compilers already warn users when '==' is mis-typed as '=',
-even when the constant is on the right.
-
-7. Comment style
-
-We use traditional C-style /* */ comments and avoid // comments.
-
-Rationale: The // form is valid in C99, so this is purely a matter of
-consistency of style. The checkpatch script will warn you about this.
-
-Multiline comment blocks should have a row of stars on the left,
-and the initial /* and terminating */ both on their own lines:
-    /*
-     * like
-     * this
-     */
-This is the same format required by the Linux kernel coding style.
-
-(Some of the existing comments in the codebase use the GNU Coding
-Standards form which does not have stars on the left, or other
-variations; avoid these when writing new comments, but don't worry
-about converting to the preferred form unless you're editing that
-comment anyway.)
-
-Rationale: Consistency, and ease of visually picking out a multiline
-comment from the surrounding code.
-
-8. trace-events style
-
-8.1 0x prefix
-
-In trace-events files, use a '0x' prefix to specify hex numbers, as in:
-
-some_trace(unsigned x, uint64_t y) "x 0x%x y 0x" PRIx64
-
-An exception is made for groups of numbers that are hexadecimal by
-convention and separated by the symbols '.', '/', ':', or ' ' (such as
-PCI bus id):
-
-another_trace(int cssid, int ssid, int dev_num) "bus id: %x.%x.%04x"
-
-However, you can use '0x' for such groups if you want. Anyway, be sure that
-it is obvious that numbers are in hex, ex.:
-
-data_dump(uint8_t c1, uint8_t c2, uint8_t c3) "bytes (in hex): %02x %02x %02x"
-
-Rationale: hex numbers are hard to read in logs when there is no 0x prefix,
-especially when (occasionally) the representation doesn't contain any letters
-and especially in one line with other decimal numbers. Number groups are allowed
-to not use '0x' because for some things notations like %x.%x.%x are used not
-only in Qemu. Also dumping raw data bytes with '0x' is less readable.
-
-8.2 '#' printf flag
-
-Do not use printf flag '#', like '%#x'.
-
-Rationale: there are two ways to add a '0x' prefix to printed number: '0x%...'
-and '%#...'. For consistency the only one way should be used. Arguments for
-'0x%' are:
- - it is more popular
- - '%#' omits the 0x for the value 0 which makes output inconsistent

README → README.rst

-         QEMU README
-         ===========
+===========
+QEMU README
+===========
 
 QEMU is a generic and open source machine & userspace emulator and
 virtualizer.
@@ -37,6 +38,9 @@ QEMU is multi-platform software intended to be buildable on all modern
 Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety
 of other UNIX targets. The simple steps to build QEMU are:
 
+
+.. code-block:: shell
+
   mkdir build
   cd build
   ../configure
@@ -44,9 +48,9 @@ of other UNIX targets. The simple steps to build QEMU are:
 
 Additional information can also be found online via the QEMU website:
 
-  https://qemu.org/Hosts/Linux
-  https://qemu.org/Hosts/Mac
-  https://qemu.org/Hosts/W32
+* `<https://qemu.org/Hosts/Linux>`_
+* `<https://qemu.org/Hosts/Mac>`_
+* `<https://qemu.org/Hosts/W32>`_
 
 
 Submitting patches
@@ -54,24 +58,29 @@ Submitting patches
 
 The QEMU source code is maintained under the GIT version control system.
 
+.. code-block:: shell
+
    git clone https://git.qemu.org/git/qemu.git
 
 When submitting patches, one common approach is to use 'git
 format-patch' and/or 'git send-email' to format & send the mail to the
 qemu-devel@nongnu.org mailing list. All patches submitted must contain
 a 'Signed-off-by' line from the author. Patches should follow the
-guidelines set out in the HACKING and CODING_STYLE files.
+guidelines set out in the CODING_STYLE.rst file.
 
 Additional information on submitting patches can be found online via
 the QEMU website
 
-  https://qemu.org/Contribute/SubmitAPatch
-  https://qemu.org/Contribute/TrivialPatches
+* `<https://qemu.org/Contribute/SubmitAPatch>`_
+* `<https://qemu.org/Contribute/TrivialPatches>`_
 
 The QEMU website is also maintained under source control.
 
+.. code-block:: shell
+
   git clone https://git.qemu.org/git/qemu-web.git
-  https://www.qemu.org/2017/02/04/the-new-qemu-website-is-up/
+
+* `<https://www.qemu.org/2017/02/04/the-new-qemu-website-is-up/>`_
 
 A 'git-publish' utility was created to make above process less
 cumbersome, and is highly recommended for making regular contributions,
@@ -82,10 +91,12 @@ manually for once.
 
 For installation instructions, please go to
 
-  https://github.com/stefanha/git-publish
+*  `<https://github.com/stefanha/git-publish>`_
 
 The workflow with 'git-publish' is:
 
+.. code-block:: shell
+
   $ git checkout master -b my-feature
   $ # work on new commits, add your 'Signed-off-by' lines to each
   $ git publish
@@ -95,6 +106,8 @@ back to it in the future.
 
 Sending v2:
 
+.. code-block:: shell
+
   $ git checkout my-feature # same topic branch
   $ # making changes to the commits (using 'git rebase', for example)
   $ git publish
@@ -109,7 +122,7 @@ The QEMU project uses Launchpad as its primary upstream bug tracker. Bugs
 found when running code built from QEMU git or upstream released sources
 should be reported via:
 
-  https://bugs.launchpad.net/qemu/
+* `<https://bugs.launchpad.net/qemu/>`_
 
 If using QEMU via an operating system vendor pre-built binary package, it
 is preferable to report bugs to the vendor's own bug tracker first. If
@@ -118,7 +131,7 @@ reported via launchpad.
 
 For additional information on bug reporting consult:
 
-  https://qemu.org/Contribute/ReportABug
+* `<https://qemu.org/Contribute/ReportABug>`_
 
 
 Contact
@@ -127,13 +140,11 @@ Contact
 The QEMU community can be contacted in a number of ways, with the two
 main methods being email and IRC
 
- - qemu-devel@nongnu.org
-   https://lists.nongnu.org/mailman/listinfo/qemu-devel
- - #qemu on irc.oftc.net
+* `<mailto:qemu-devel@nongnu.org>`_
+* `<https://lists.nongnu.org/mailman/listinfo/qemu-devel>`_
+* #qemu on irc.oftc.net
 
 Information on additional methods of contacting the community can be
 found online via the QEMU website:
 
-  https://qemu.org/Contribute/StartHere
-
--- End
+* `<https://qemu.org/Contribute/StartHere>`_

scripts/checkpatch.pl

@@ -461,7 +461,7 @@ sub top_of_kernel_tree {
 
 	my @tree_check = (
 		"COPYING", "MAINTAINERS", "Makefile",
-		"README", "docs", "VERSION",
+		"README.rst", "docs", "VERSION",
 		"vl.c"
 	);