patch-2.2.16 linux/Documentation/kbuild/config-language.txt

• Lines: 310
• Date: Wed Jun 7 14:26:42 2000
• Orig file: v2.2.15/linux/Documentation/kbuild/config-language.txt
• Orig date: Mon Feb 1 12:03:20 1999

diff -urN v2.2.15/linux/Documentation/kbuild/config-language.txt linux/Documentation/kbuild/config-language.txt
@@ -1,5 +1,5 @@
 Config Language Specification
-21 January 1999
+18 October 1999
 Michael Elizabeth Chastain, <mailto:mec@shout.net>
 
 
@@ -82,7 +82,10 @@
     double-quoted string.  If the word is unquoted or double quoted,
     then $-substition will be performed on the word.
 
-    A /symbol/ is a single unquoted word.
+    A /symbol/ is a single unquoted word.  A symbol must have a name of
+    the form CONFIG_*.  scripts/mkdep.c relies on this convention in order
+    to generate dependencies on individual CONFIG_* symbols instead of
+    making one massive dependency on include/linux/autoconf.h.
 
     A /dep/ is a dependency.  Syntactically, it is a /word/.  At run
     time, a /dep/ must evaluate to "y", "m", "n", or "".
@@ -117,6 +120,7 @@
     Dependent statements:
 
         dep_bool        /prompt/ /symbol/ /dep/ ...
+        dep_mbool       /prompt/ /symbol/ /dep/ ...
         dep_hex         /prompt/ /symbol/ /word/ /dep/ ...
         dep_int         /prompt/ /symbol/ /word/ /dep/ ...
         dep_string      /prompt/ /symbol/ /word/ /dep/ ...
@@ -189,7 +193,7 @@
 
 Configure:  implemented
 Menuconfig: implemented
-Xconfig:    does not display, but writes to output files
+Xconfig:    implemented
 mconfig:    implemented
 
 Example:
@@ -355,8 +359,8 @@
 number is a legal value.
 
 Configure:  implemented
-Menuconfig: not implemented
-Xconfig:    not implemented
+Menuconfig: implemented
+Xconfig:    implemented
 mconfig:    implemented
 
 Example:
@@ -377,14 +381,14 @@
 legal value.
 
 Configure:  implemented
-Menuconfig: not implemented
-Xconfig:    not implemented
+Menuconfig: implemented
+Xconfig:    implemented
 mconfig:    implemented
 
 Example:
 
-    # Not from the corpus
-    define_int CONFIG_UID_TORVALDS 2026
+    # drivers/char/ftape/Config.in
+    define_int CONFIG_FT_ALPHA_CLOCK 0
 
 
 
@@ -394,8 +398,8 @@
 are any ASCII string, except for the characters '"' and '\\'.
 
 Configure:  implemented
-Menuconfig: not implemented
-Xconfig:    not implemented
+Menuconfig: implemented
+Xconfig:    implemented
 mconfig:    implemented
 
 Example
@@ -414,17 +418,22 @@
 instead of define_bool to define tristate values.  This aids in static
 type checking.
 
-Configure:  not implemented
-Menuconfig: not implemented
-Xconfig:    not implemented
+Configure:  implemented
+Menuconfig: implemented
+Xconfig:    implemented
 mconfig:    implemented
 
 Example:
 
-    # not from the corpus
-    if [ "$CONFIG_ZFTAPE" != "n" ]; then
-      comment 'The compressor will be built as a module only!'
-      define_tristate CONFIG_ZFT_COMPRESSOR m
+    # drivers/video/Config.in
+    if [ "$CONFIG_FB_AMIGA" = "y" ]; then
+       define_tristate CONFIG_FBCON_AFB y
+       define_tristate CONFIG_FBCON_ILBM y
+    else
+       if [ "$CONFIG_FB_AMIGA" = "m" ]; then
+          define_tristate CONFIG_FBCON_AFB m
+          define_tristate CONFIG_FBCON_ILBM m
+       fi
     fi
 
 
@@ -433,22 +442,62 @@
 
 This verb evaluates all of the dependencies in the dependency list.
 Any dependency which has a value of "y" does not restrict the input
-range.  Any dependency which has a value of "n", or which has some
-other value, restricts the input range to "n".
+range.  Any dependency which has an empty value is ignored.
+Any dependency which has a value of "n", or which has some other value,
+(like "m") restricts the input range to "n".  Quoting dependencies is not
+allowed. Using dependencies with an empty value possible is not
+recommended.  See also dep_mbool below.
 
 If the input range is restricted to the single choice "n", dep_bool
 silently assigns "n" to /symbol/.  If the input range has more than
 one choice, dep_bool displays /prompt/ to the user, accepts a value
 from the user, and assigns that value to /symbol/.
 
-Configure:  not implemented
-Menuconfig: not implemented
-XConfig:    not implemented
+Configure:  implemented
+Menuconfig: implemented
+XConfig:    implemented
 mconfig:    implemented
 
-    # not from the corpus
-    dep_bool 'RZ1000 chipset bugfix/support' CONFIG_BLK_DEV_RZ1000 $CONFIG_PCI
+Example:
+
+    # drivers/net/Config.in
+    dep_bool 'Aironet 4500/4800 PCI support 'CONFIG_AIRONET4500_PCI $CONFIG_PCI
+
+Known bugs:
+- Xconfig does not write "# foo is not set" to .config (as well as
+  "#unset foo" to autoconf.h) if command is disabled by its dependencies.
+
+
+=== dep_mbool /prompt/ /symbol/ /dep/ ...
+
+This verb evaluates all of the dependencies in the dependency list.
+Any dependency which has a value of "y" or "m" does not restrict the
+input range.  Any dependency which has an empty value is ignored.
+Any dependency which has a value of "n", or which has some other value,
+restricts the input range to "n".  Quoting dependencies is not allowed.
+Using dependencies with an empty value possible is not recommended.
 
+If the input range is restricted to the single choice "n", dep_bool
+silently assigns "n" to /symbol/.  If the input range has more than
+one choice, dep_bool displays /prompt/ to the user, accepts a value
+from the user, and assigns that value to /symbol/.
+
+Notice that the only difference between dep_bool and dep_mbool
+is in the way of treating the "m" value as a dependency.
+
+Configure:  implemented
+Menuconfig: implemented
+XConfig:    implemented
+mconfig:    not implemented
+
+Example:
+
+    # Not from the corpus
+    dep_mbool 'Packet socket: mmapped IO' CONFIG_PACKET_MMAP $CONFIG_PACKET
+
+Known bugs:
+- Xconfig does not write "# foo is not set" to .config (as well as
+  "#unset foo" to autoconf.h) if command is disabled by its dependencies.
 
 
 === dep_hex /prompt/ /symbol/ /word/ /dep/ ...
@@ -464,13 +513,15 @@
 
 
 
-=== dep_tristate /prompt/ /symbol /dep/ ...
+=== dep_tristate /prompt/ /symbol/ /dep/ ...
 
 This verb evaluates all of the dependencies in the dependency list.
-Any dependency which as a value of "y" does not restrict the input range.
+Any dependency which has a value of "y" does not restrict the input range.
 Any dependency which has a value of "m" restricts the input range to
-"m" or "n".  Any dependency which has a value of "n", or which has some
-other value, restricts the input range to "n".
+"m" or "n".  Any dependency which has an empty value is ignored.
+Any dependency which has a value of "n", or which has some other value,
+restricts the input range to "n".  Quoting dependencies is not allowed.
+Using dependencies with an empty value possible is not recommended.
 
 If the input range is restricted to the single choice "n", dep_tristate
 silently assigns "n" to /symbol/.  If the input range has more than
@@ -478,10 +529,18 @@
 from the user, and assigns that value to /symbol/.
 
 Configure:  implemented
-Menuconfig: implemented (but silently ignores dependencies after the first)
-Xconfig:    implemented (but silently ignores dependencies after the first)
+Menuconfig: implemented
+Xconfig:    implemented
 mconfig:    implemented
 
+Example:
+
+    # drivers/char/Config.in
+    dep_tristate 'Parallel printer support' CONFIG_PRINTER $CONFIG_PARPORT
+
+Known bugs:
+- Xconfig does not write "# foo is not set" to .config (as well as
+  "#unset foo" to autoconf.h) if command is disabled by its dependencies.
 
 
 === unset /symbol/ ...
@@ -492,9 +551,16 @@
 
 Configure:  implemented
 Menuconfig: implemented
-Xconfig:    not implemented
+Xconfig:    implemented (with bugs)
 mconfig:    implemented
 
+Example:
+
+    # arch/mips/config.in
+    unset CONFIG_PCI
+    unset CONFIG_MIPS_JAZZ
+    unset CONFIG_VIDEO_G364
+
 
 
 === choice /prompt/ /word/ /word/
@@ -525,6 +591,14 @@
 Xconfig:    implemented
 mconfig:    implemented
 
+Example:
+
+    # arch/i386/config.in
+    choice '  PCI access mode' \
+        "BIOS           CONFIG_PCI_GOBIOS       \
+         Direct         CONFIG_PCI_GODIRECT     \
+         Any            CONFIG_PCI_GOANY"       Any
+
 
 
 === nchoice /prompt/ /symbol/ /prompt/ /symbol/ ...
@@ -555,32 +629,40 @@
 /expr/ may contain the following atoms and operators.  Note that, unlike
 shell, you must use double quotes around every atom.
 
-    "..."		a literal
-    "$..."		a variable
-
-    /atom/  = /atom/	true if atoms have identical value
-    /atom/ != /atom/	true if atoms have different value
+    /atom/:
+	"..."			a literal
+	"$..."			a variable
+
+    /expr/:
+	/atom/  = /atom/	true if atoms have identical value
+	/atom/ != /atom/	true if atoms have different value
+
+    /expr/:
+	/expr/ -o /expr/	true if either expression is true
+	/expr/ -a /expr/	true if both expressions are true
+	! /expr/		true if expression is not true
+
+Note that a naked /atom/ is not a valid /expr/.  If you try to use it
+as such:
+
+    # Do not do this.
+    if [ "$CONFIG_EXPERIMENTAL" ]; then
+	bool 'Bogus experimental feature' CONFIG_BOGUS
+    fi
 
-    /expr/ -o /expr/	true if either expression is true
-    /expr/ -a /expr/	true if both expressions are true
-    ! /expr/		true if expression is not true
+... then you will be surprised, because CONFIG_EXPERIMENTAL never has a
+value of the empty string!  It is always "y" or "n", and both of these
+are treated as true (non-empty) by the bash-based interpreters Configure
+and Menuconfig.
 
 Configure:  implemented
 Menuconfig: implemented
 XConfig:    implemented, with bugs
 mconfig:    implemented
 
-Xconfig has several known bugs, and probably some unknown bugs too:
-
-- In a comparison, if the left-hand atom is a variable and that variable
-  is from a choice list, the right-hand atom must be "y".
-
-- In a comparison, if the right-hand atom is a variable and that variable
-  is from a choice list, you lose.  tkparse will throw a segmentation
-  violation, silently generate bizarre TCL code, or something else.
+Xconfig has some known bugs, and probably some unknown bugs too:
 
-- tkparse gives the wrong precedence to -o, -a, and !.  Don't use both
-  -o and -a in an expression.  Don't use ! at all.
+- literals with an empty "" value are not properly handled.