Commit Graph

4805 Commits

Author SHA1 Message Date
Masahiro Yamada 558e78e3ce kconfig: split some C files out of zconf.y
I want to compile each C file independently instead of including all
of them from zconf.y.

Split out confdata.c, expr.c, symbol.c, and preprocess.c .
These are low-hanging fruits.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-28 22:22:38 +09:00
Masahiro Yamada 0c87410010 kconfig: convert to SPDX License Identifier
All files in lxdialog/ are licensed under GPL-2.0+, and the rest are
under GPL-2.0. I added GPL-2.0 tags to test scripts in tests/.

Documentation/process/license-rules.rst does not suggest anything
about the flex/bison files. Because flex does not accept the C++
comment style at the very top of a file, I used the C style for
zconf.l, and so for zconf.y for consistency.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-28 22:22:28 +09:00
Masahiro Yamada 979f2b2f79 kconfig: remove keyword lookup table entirely
Commit 7a88488bbc ("[PATCH] kconfig: use gperf for kconfig keywords")
introduced gperf for the keyword lookup.

Then, commit bb3290d916 ("Remove gperf usage from toolchain") killed
the gperf use. As a result, the linear keyword search was left behind.

If we do not use gperf, there is no reason to have the separate table
of the keywords. Move all keywords back to the lexer.

I also refactored the lexer to remove the COMMAND and PARAM states.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-28 20:44:38 +09:00
Masahiro Yamada 4b31a32caf kconfig: update current_pos in the second lexer
To simplify the generated lexer, let the hand-made lexer update the
file name and line number for the parser.

I tested this with DEBUG_PARSE, and confirmed the same file names
and line numbers were dumped.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:25:56 +09:00
Masahiro Yamada 824fa3b3b5 kconfig: switch to ASSIGN_VAL state in the second lexer
To simplify the generated lexer, switch to the ASSIGN_VAL state in
the hand-made lexer.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:25:55 +09:00
Masahiro Yamada b3d1d9d3c3 kconfig: stop associating kconf_id with yylval
The lexer has conventionally associated kconf_id data with yylval
to carry additional information to the parser.

No token is relying on this any more.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:25:55 +09:00
Masahiro Yamada caaebb3c6d kconfig: refactor end token rules
T_ENDMENU, T_ENDCHOICE, T_ENDIF are the last users of kconf_id
associated with yylval. Refactor them to not use it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:25:54 +09:00
Masahiro Yamada f5451582c4 kconfig: stop supporting '.' and '/' in unquoted words
In my understanding, special characters such as '.' and '/' are
supported in unquoted words to use bare file paths in the "source"
statement.

With the previous commit surrounding all file paths with double
quotes, we can drop this.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:25:54 +09:00
Masahiro Yamada 171a515d08 kconfig: use T_WORD instead of T_VARIABLE for variables
There is no grammatical ambiguity by using T_WORD for variables.
The parser can distinguish variables from symbols from the context.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:25:53 +09:00
Masahiro Yamada c3d228713b kconfig: use specific tokens instead of T_ASSIGN for assignments
Currently, the lexer returns T_ASSIGN for all of =, :=, and +=
associating yylval with the flavor.

I want to make the generated lexer as simple as possible. So, the
lexer should convert keywords to tokens without thinking about the
meaning.

   =  ->  T_EQUAL
  :=  ->  T_COLON_EQUAL
  +=  ->  T_PLUS_EQUAL

Unfortunately, Kconfig uses = instead of == for the equal operator.
So, the same token T_EQUAL is used for assignment and comparison.
The parser can still distinguish them from the context.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:25:52 +09:00
Masahiro Yamada ce2164ab58 kconfig: refactor scanning and parsing "option" properties
For the keywords "modules", "defconfig_list", and "allnoconfig_y",
the lexer should pass specific tokens instead of generic T_WORD.

This simplifies both the lexer and the parser.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:25:52 +09:00
Masahiro Yamada 3c8f317d4c kconfig: use distinct tokens for type and default properties
This commit removes kconf_id::stype to prepare for the entire
removal of kconf_id.c

To simplify the lexer, I want keywords straight-mapped to tokens.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-22 00:25:34 +09:00
Masahiro Yamada a01e5d242d kconfig: remove redundant token defines
These are already defined as %left.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-15 17:45:22 +09:00
Masahiro Yamada 4b5ec81bfe kconfig: rename depends_list to comment_option_list
Now the comment_stmt is the only user of depends_list. Rename it to
comment_option_list

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-15 17:45:22 +09:00
Masahiro Yamada 1f31be9ec0 kconfig: loosen the order of "visible" and "depends on" in menu entry
Currently, "visible" and "depends on", if defined in a menu entry,
must appear in that order.

The real example is in drivers/media/tuners/Kconfig:

  menu "Customize TV tuners"
          visible if <expr1>
          depends on <expr2>

... is fine, but you cannot change the property order like this:

  menu "Customize TV tuners"
          depends on <expr2>
          visible if <expr1>

Kconfig does not require a specific order of properties. In this case,
menu_add_visibility(() and menu_add_dep() are orthogonal.

Loosen this unreasonable restriction.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-15 17:45:21 +09:00
Masahiro Yamada 94d4e1b602 kconfig: remove redundant menu_block rule
The code block surrounded by "menu" ... "endmenu" is stmt_list.

Remove the redundant menu_block symbol entirely.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-15 17:45:21 +09:00
Masahiro Yamada 4891796c6f kconfig: remove redundant if_block rule
The code block surrounded by "if" ... "endif" is stmt_list.

Remove the redundant if_block symbol entirely.

Remove "stmt_list: stmt_list end" rule as well since it would
obviously cause conflicts.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-15 17:45:21 +09:00
Masahiro Yamada 2f60e46e60 kconfig: remove grammatically ambiguous option_error
This commit decreases 6 shift/reduce conflicts, and finally achieves
conflict-free parser.

Since Kconfig has no terminator for a config block, detecting the end
of config_stmt is not easy.

For example, there are two ways for handling the error in the following
code:

  1 config FOO
  2         =

 [A] Print "unknown option" error, assuming the line 2 is a part of
     config_option_list

 [B] Print "invalid statement", assuming the line 1 is reduced into
     a config_stmt by itself

Bison actually chooses [A] because it performs the shift rather than
the reduction where both are possible.

However, there is no reason to choose one over the other.

Let's remove the option_error, and let it fall back to [B].

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-15 17:45:20 +09:00
Masahiro Yamada 6900ae9eee kconfig: remove grammatically ambiguous "unexpected option" diagnostic
This commit decreases 15 shift/reduce conflicts.

The location of this error recovery is ambiguous.

For example, there are two ways to interpret the following code:

  1 config FOO
  2         bool "foo"

 [A] Both lines are reduced together into a config_stmt.

 [B] The only line 1 is reduced into a config_stmt, and the line 2
     matches to "option_name error T_EOL"

Of course, we expect [A], but [B] could be grammatically possible.

Kconfig has no terminator for a config block. So, we cannot detect its
end until we see a non-property keyword. People often insert a blank
line between two config blocks, but it is just a coding convention.
Blank lines are actually allowed anywhere in Kconfig files.

The real error is when a property keyword appears right after "endif",
"endchoice", "endmenu",  "source", "comment", or variable assignment.

Instead of fixing the grammatical ambiguity, I chose to simply remove
this error recovery.

The difference is

  unexpected option "bool"

... is turned into a more generic message:

  invalid statement

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-15 17:45:20 +09:00
Masahiro Yamada 723679339d kconfig: warn no new line at end of file
It would be nice to warn if a new line is missing at end of file.

We could do this by checkpatch.pl for arbitrary files, but new line
is rather essential as a statement terminator in Kconfig.

The warning message looks like this:

  kernel/Kconfig.preempt:60:warning: no new line at end of file

Currently, kernel/Kconfig.preempt is the only file with no new line
at end of file. Fix it.

I know there are some false negative cases. For example, no warning
is displayed when the last line contains some whitespaces/comments,
but no new line. Yet, this commit works well for most cases.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-15 17:44:35 +09:00
Masahiro Yamada 0bcc547ec4 kconfig: clean up EOF handling in the lexer
A new file should always start in the INITIAL state.

When the lexer bumps into EOF, the lexer must get back to the INITIAL
state anyway. Remove the redundant <<EOF>> pattern in the PARAM state.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-13 00:20:09 +09:00
Masahiro Yamada cc66bca775 kconfig: fix ambiguous grammar in terms of new lines
This commit decreases 8 shift/reduce conflicts.

A certain amount of grammatical ambiguity comes from how to reduce
excessive T_EOL tokens.

Let's take a look at the example code below:

  1  config A
  2          bool "a"
  3
  4          depends on B
  5
  6  config B
  7          def_bool y

The line 3 is melt into "config_option_list", but the line 5 can be
either a part of "config_option_list" or "common_stmt" by itself.

Currently, the lexer converts '\n' to T_EOL verbatim. In Kconfig,
a new line works as a statement terminator, but new lines in empty
lines are not critical since empty lines (or lines that contain only
whitespaces/comments) are just no-op.

If the lexer simply discards no-op lines, the parser will not be
bothered by excessive T_EOL tokens.

Of course, this means we are shifting the complexity from the parser
to the lexer, but it is much easier than tackling on shift/reduce
conflicts.

I introduced the second stage lexer to tweak the behavior.

Discard T_EOL if the previous token is T_EOL or T_HELPTEXT.
Two T_EOL tokens in a row is meaningless. T_HELPTEXT is a special
token that is reduced without T_EOL.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-13 00:18:54 +09:00
Masahiro Yamada 21c5ecf604 kconfig: refactor pattern matching in STRING state
Here, similar matching patters are duplicated in order to look ahead
the '\n' character. If the next character is '\n', the lexer returns
T_WORD_QUOTE because it must be prepared to return T_EOL at the next
match.

Use unput('\n') trick to reduce the code duplication.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-13 00:16:24 +09:00
Masahiro Yamada be3c807597 kconfig: remove unneeded pattern matching to whitespaces
Whitespaces are consumed in the COMMAND state anyway.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-13 00:16:23 +09:00
Masahiro Yamada 413cd19d81 kconfig: require T_EOL to reduce visible statement
All line-oriented statements should be reduced when seeing a T_EOL
token. I guess missing T_EOL for the "visible" statement is just a
mistake. This commit decreases one shift/reduce conflict.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-12-13 00:16:22 +09:00