[PATCH v3 12/17] scripts: kernel-doc: parse next structs/unions

From: Mauro Carvalho Chehab
Date: Wed Oct 04 2017 - 08:02:20 EST


There are several places within the Kernel tree with nested
structs/unions, like this one:

struct ingenic_cgu_clk_info {
const char *name;
enum {
CGU_CLK_NONE = 0,
CGU_CLK_EXT = BIT(0),
CGU_CLK_PLL = BIT(1),
CGU_CLK_GATE = BIT(2),
CGU_CLK_MUX = BIT(3),
CGU_CLK_MUX_GLITCHFREE = BIT(4),
CGU_CLK_DIV = BIT(5),
CGU_CLK_FIXDIV = BIT(6),
CGU_CLK_CUSTOM = BIT(7),
} type;
int parents[4];
union {
struct ingenic_cgu_pll_info pll;
struct {
struct ingenic_cgu_gate_info gate;
struct ingenic_cgu_mux_info mux;
struct ingenic_cgu_div_info div;
struct ingenic_cgu_fixdiv_info fixdiv;
};
struct ingenic_cgu_custom_info custom;
};
};

Currently, such struct is documented as:

**Definition**

::
struct ingenic_cgu_clk_info {
const char * name;
};

**Members**

``name``
name of the clock

With is obvioulsy wrong. It also generates an error:
drivers/clk/ingenic/cgu.h:169: warning: No description found for parameter 'enum'

However, there's nothing wrong with this kernel-doc markup: everything
is documented there.

It makes sense to document all fields there. So, add a
way for the core to parse those structs.

With this patch, all documented fields will properly generate
documentation.

Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
---
Documentation/doc-guide/kernel-doc.rst | 46 +++++++++++++
scripts/kernel-doc | 121 ++++++++++++++++++---------------
2 files changed, 114 insertions(+), 53 deletions(-)

diff --git a/Documentation/doc-guide/kernel-doc.rst b/Documentation/doc-guide/kernel-doc.rst
index 96012f9e314d..9e63a18cceea 100644
--- a/Documentation/doc-guide/kernel-doc.rst
+++ b/Documentation/doc-guide/kernel-doc.rst
@@ -281,6 +281,52 @@ comment block.
The kernel-doc data structure comments describe each member of the structure,
in order, with the member descriptions.

+Nested structs/unions
+~~~~~~~~~~~~~~~~~~~~~
+
+It is possible to document nested structs unions, like::
+
+ /**
+ * struct nested_foobar - a struct with nested unions and structs
+ * @arg1: - first argument of anonymous union/anonymous struct
+ * @arg2: - second argument of anonymous union/anonymous struct
+ * @arg3: - third argument of anonymous union/anonymous struct
+ * @arg4: - fourth argument of anonymous union/anonymous struct
+ * @bar.st1.arg1 - first argument of struct st1 on union bar
+ * @bar.st1.arg2 - second argument of struct st1 on union bar
+ * @bar.st2.arg1 - first argument of struct st2 on union bar
+ * @bar.st2.arg2 - second argument of struct st2 on union bar
+ struct nested_foobar {
+ /* Anonymous union/struct*/
+ union {
+ struct {
+ int arg1;
+ int arg2;
+ }
+ struct {
+ void *arg3;
+ int arg4;
+ }
+ }
+ union {
+ struct {
+ int arg1;
+ int arg2;
+ } st1;
+ struct {
+ void *arg1;
+ int arg2;
+ } st2;
+ } bar;
+ };
+
+.. note::
+
+ #) When documenting nested structs or unions, if the struct/union ``foo``
+ is named, the argument ``bar`` inside it should be documented as
+ ``@foo.bar:``
+ #) When the nested struct/union is anonymous, the argument ``bar`` on it
+ should be documented as ``@bar:``

Typedef documentation
---------------------
diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index d8c98e45b1ce..1b4a096a409b 100755
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -210,7 +210,7 @@ my $anon_struct_union = 0;
my $type_constant = '\b``([^\`]+)``\b';
my $type_constant2 = '\%([-_\w]+)';
my $type_func = '(\w+)\(\)';
-my $type_param = '\@(\w+(\.\.\.)?)';
+my $type_param = '\@(\w*(\.\w+)*(\.\.\.)?)';
my $type_fp_param = '\@(\w+)\(\)'; # Special RST handling for func ptr params
my $type_env = '(\$\w+)';
my $type_enum = '\&(enum\s*([_\w]+))';
@@ -667,32 +667,12 @@ sub output_struct_man(%) {
print ".SH NAME\n";
print $args{'type'} . " " . $args{'struct'} . " \\- " . $args{'purpose'} . "\n";

+ my $declaration = $args{'definition'};
+ $declaration =~ s/\t/ /g;
+ $declaration =~ s/\n/"\n.br\n.BI \"/g;
print ".SH SYNOPSIS\n";
print $args{'type'} . " " . $args{'struct'} . " {\n.br\n";
-
- foreach my $parameter (@{$args{'parameterlist'}}) {
- if ($parameter =~ /^#/) {
- print ".BI \"$parameter\"\n.br\n";
- next;
- }
- my $parameter_name = $parameter;
- $parameter_name =~ s/\[.*//;
-
- ($args{'parameterdescs'}{$parameter_name} ne $undescribed) || next;
- $type = $args{'parametertypes'}{$parameter};
- if ($type =~ m/([^\(]*\(\*)\s*\)\s*\(([^\)]*)\)/) {
- # pointer-to-function
- print ".BI \" " . $1 . "\" " . $parameter . " \") (" . $2 . ")" . "\"\n;\n";
- } elsif ($type =~ m/^(.*?)\s*(:.*)/) {
- # bitfield
- print ".BI \" " . $1 . "\ \" " . $parameter . $2 . " \"" . "\"\n;\n";
- } else {
- $type =~ s/([^\*])$/$1 /;
- print ".BI \" " . $type . "\" " . $parameter . " \"" . "\"\n;\n";
- }
- print "\n.br\n";
- }
- print "};\n.br\n";
+ print ".BI \"$declaration\n};\n.br\n\n";

print ".SH Members\n";
foreach $parameter (@{$args{'parameterlist'}}) {
@@ -930,29 +910,9 @@ sub output_struct_rst(%) {

print "**Definition**\n\n";
print "::\n\n";
- print " " . $args{'type'} . " " . $args{'struct'} . " {\n";
- foreach $parameter (@{$args{'parameterlist'}}) {
- if ($parameter =~ /^#/) {
- print " " . "$parameter\n";
- next;
- }
-
- my $parameter_name = $parameter;
- $parameter_name =~ s/\[.*//;
-
- ($args{'parameterdescs'}{$parameter_name} ne $undescribed) || next;
- $type = $args{'parametertypes'}{$parameter};
- if ($type =~ m/([^\(]*\(\*)\s*\)\s*\(([^\)]*)\)/) {
- # pointer-to-function
- print " $1 $parameter) ($2);\n";
- } elsif ($type =~ m/^(.*?)\s*(:.*)/) {
- # bitfield
- print " $1 $parameter$2;\n";
- } else {
- print " " . $type . " " . $parameter . ";\n";
- }
- }
- print " };\n\n";
+ my $declaration = $args{'definition'};
+ $declaration =~ s/\t/ /g;
+ print " " . $args{'type'} . " " . $args{'struct'} . " {\n$declaration };\n\n";

print "**Members**\n\n";
$lineprefix = " ";
@@ -1030,16 +990,11 @@ sub dump_struct($$) {
$declaration_name = $2;
my $members = $3;

- # ignore embedded structs or unions
- $members =~ s/({.*})//g;
- $nested = $1;
-
# ignore members marked private:
$members =~ s/\/\*\s*private:.*?\/\*\s*public:.*?\*\///gosi;
$members =~ s/\/\*\s*private:.*//gosi;
# strip comments:
$members =~ s/\/\*.*?\*\///gos;
- $nested =~ s/\/\*.*?\*\///gos;
# strip kmemcheck_bitfield_{begin,end}.*;
$members =~ s/kmemcheck_bitfield_.*?;//gos;
# strip attributes
@@ -1051,13 +1006,73 @@ sub dump_struct($$) {
# replace DECLARE_HASHTABLE
$members =~ s/DECLARE_HASHTABLE\s*\(([^,)]+), ([^,)]+)\)/unsigned long $1\[1 << (($2) - 1)\]/gos;

+ my $declaration = $members;
+
+ # Split nested struct/union elements as newer ones
+ my $cont = 1;
+ while ($cont) {
+ $cont = 0;
+ while ($members =~ m/(struct|union)([^{};]+){([^{}]*)}([^{}\;]*)\;/) {
+ my $newmember = "$1 $4;";
+ my $id = $4;
+ my $content = $3;
+ $id =~ s/[:\[].*//;
+ $id =~ s/^\*+//;
+ foreach my $arg (split /;/, $content) {
+ next if ($arg =~ m/^\s*$/);
+ my $type = $arg;
+ my $name = $arg;
+ $type =~ s/\s\S+$//;
+ $name =~ s/.*\s//;
+ $name =~ s/[:\[].*//;
+ $name =~ s/^\*+//;
+ next if (($name =~ m/^\s*$/));
+ if ($id =~ m/^\s*$/) {
+ # anonymous struct/union
+ $newmember .= "$type $name;";
+ } else {
+ $newmember .= "$type $id.$name;";
+ }
+ }
+ $members =~ s/(struct|union)([^{};]+){([^{}]*)}([^{}\;]*)\;/$newmember/;
+ $cont = 1;
+ };
+ };
+
+ # Ignore other nested elements, like enums
+ $members =~ s/({[^\{\}]*})//g;
+ $nested = $decl_type;
+ $nested =~ s/\/\*.*?\*\///gos;
+
create_parameterlist($members, ';', $file);
check_sections($file, $declaration_name, $decl_type, $sectcheck, $struct_actual, $nested);

+ # Adjust declaration for better display
+ $declaration =~ s/([{;])/$1\n/g;
+ $declaration =~ s/}\s+;/};/g;
+ # Better handle inlined enums
+ do {} while ($declaration =~ s/(enum\s+{[^}]+),([^\n])/$1,\n$2/);
+
+ my @def_args = split /\n/, $declaration;
+ my $level = 1;
+ $declaration = "";
+ foreach my $clause (@def_args) {
+ $clause =~ s/^\s+//;
+ $clause =~ s/\s+$//;
+ $clause =~ s/\s+/ /;
+ next if (!$clause);
+ $level-- if ($clause =~ m/(})/ && $level > 1);
+ if (!($clause =~ m/^\s*#/)) {
+ $declaration .= "\t" x $level;
+ }
+ $declaration .= "\t" . $clause . "\n";
+ $level++ if ($clause =~ m/({)/ && !($clause =~m/}/));
+ }
output_declaration($declaration_name,
'struct',
{'struct' => $declaration_name,
'module' => $modulename,
+ 'definition' => $declaration,
'parameterlist' => \@parameterlist,
'parameterdescs' => \%parameterdescs,
'parametertypes' => \%parametertypes,
--
2.13.6