scripts/kernel-doc.py: move output classes to a separate file

In preparation for letting kerneldoc Sphinx extension to import
Python libraries, move kernel-doc output logic to a separate file.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/81087eff25d11c265019a8631f7fc8d3904795d0.1744106242.git.mchehab+huawei@kernel.org

1 files changed, 736 insertions, 0 deletions

diff --git a/scripts/lib/kdoc/kdoc_output.py b/scripts/lib/kdoc/kdoc_output.py
new file mode 100755
index 000000000000..24e40b3e7d1d
--- /dev/null
+++ b/scripts/lib/kdoc/kdoc_output.py
@@ -0,0 +1,736 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+# Copyright(c) 2025: Mauro Carvalho Chehab <mchehab@kernel.org>.
+#
+# pylint: disable=C0301,R0911,R0912,R0913,R0914,R0915,R0917
+
+# TODO: implement warning filtering
+
+"""
+Implement output filters to print kernel-doc documentation.
+
+The implementation uses a virtual base class (OutputFormat) which
+contains a dispatches to virtual methods, and some code to filter
+out output messages.
+
+The actual implementation is done on one separate class per each type
+of output. Currently, there are output classes for ReST and man/troff.
+"""
+
+import os
+import re
+from datetime import datetime
+
+from dateutil import tz
+
+from kdoc_parser import KernelDoc, type_param
+from kdoc_re import Re
+
+
+function_pointer = Re(r"([^\(]*\(\*)\s*\)\s*\(([^\)]*)\)", cache=False)
+
+# match expressions used to find embedded type information
+type_constant = Re(r"\b``([^\`]+)``\b", cache=False)
+type_constant2 = Re(r"\%([-_*\w]+)", cache=False)
+type_func = Re(r"(\w+)\(\)", cache=False)
+type_param_ref = Re(r"([\!~\*]?)\@(\w*((\.\w+)|(->\w+))*(\.\.\.)?)", cache=False)
+
+# Special RST handling for func ptr params
+type_fp_param = Re(r"\@(\w+)\(\)", cache=False)
+
+# Special RST handling for structs with func ptr params
+type_fp_param2 = Re(r"\@(\w+->\S+)\(\)", cache=False)
+
+type_env = Re(r"(\$\w+)", cache=False)
+type_enum = Re(r"\&(enum\s*([_\w]+))", cache=False)
+type_struct = Re(r"\&(struct\s*([_\w]+))", cache=False)
+type_typedef = Re(r"\&(typedef\s*([_\w]+))", cache=False)
+type_union = Re(r"\&(union\s*([_\w]+))", cache=False)
+type_member = Re(r"\&([_\w]+)(\.|->)([_\w]+)", cache=False)
+type_fallback = Re(r"\&([_\w]+)", cache=False)
+type_member_func = type_member + Re(r"\(\)", cache=False)
+
+
+class OutputFormat:
+    # output mode.
+    OUTPUT_ALL          = 0 # output all symbols and doc sections
+    OUTPUT_INCLUDE      = 1 # output only specified symbols
+    OUTPUT_EXPORTED     = 2 # output exported symbols
+    OUTPUT_INTERNAL     = 3 # output non-exported symbols
+
+    # Virtual member to be overriden at the  inherited classes
+    highlights = []
+
+    def __init__(self):
+        """Declare internal vars and set mode to OUTPUT_ALL"""
+
+        self.out_mode = self.OUTPUT_ALL
+        self.enable_lineno = None
+        self.nosymbol = {}
+        self.symbol = None
+        self.function_table = set()
+        self.config = None
+
+    def set_config(self, config):
+        self.config = config
+
+    def set_filter(self, export, internal, symbol, nosymbol, function_table,
+                   enable_lineno):
+        """
+        Initialize filter variables according with the requested mode.
+
+        Only one choice is valid between export, internal and symbol.
+
+        The nosymbol filter can be used on all modes.
+        """
+
+        self.enable_lineno = enable_lineno
+
+        if symbol:
+            self.out_mode = self.OUTPUT_INCLUDE
+            function_table = symbol
+        elif export:
+            self.out_mode = self.OUTPUT_EXPORTED
+        elif internal:
+            self.out_mode = self.OUTPUT_INTERNAL
+        else:
+            self.out_mode = self.OUTPUT_ALL
+
+        if nosymbol:
+            self.nosymbol = set(nosymbol)
+
+        if function_table:
+            self.function_table = function_table
+
+    def highlight_block(self, block):
+        """
+        Apply the RST highlights to a sub-block of text.
+        """
+
+        for r, sub in self.highlights:
+            block = r.sub(sub, block)
+
+        return block
+
+    def check_doc(self, name):
+        """Check if DOC should be output"""
+
+        if self.out_mode == self.OUTPUT_ALL:
+            return True
+
+        if self.out_mode == self.OUTPUT_INCLUDE:
+            if name in self.nosymbol:
+                return False
+
+            if name in self.function_table:
+                return True
+
+        return False
+
+    def check_declaration(self, dtype, name):
+        if name in self.nosymbol:
+            return False
+
+        if self.out_mode == self.OUTPUT_ALL:
+            return True
+
+        if self.out_mode in [self.OUTPUT_INCLUDE, self.OUTPUT_EXPORTED]:
+            if name in self.function_table:
+                return True
+
+        if self.out_mode == self.OUTPUT_INTERNAL:
+            if dtype != "function":
+                return True
+
+            if name not in self.function_table:
+                return True
+
+        return False
+
+    def check_function(self, fname, name, args):
+        return True
+
+    def check_enum(self, fname, name, args):
+        return True
+
+    def check_typedef(self, fname, name, args):
+        return True
+
+    def msg(self, fname, name, args):
+
+        dtype = args.get('type', "")
+
+        if dtype == "doc":
+            self.out_doc(fname, name, args)
+            return False
+
+        if not self.check_declaration(dtype, name):
+            return False
+
+        if dtype == "function":
+            self.out_function(fname, name, args)
+            return False
+
+        if dtype == "enum":
+            self.out_enum(fname, name, args)
+            return False
+
+        if dtype == "typedef":
+            self.out_typedef(fname, name, args)
+            return False
+
+        if dtype in ["struct", "union"]:
+            self.out_struct(fname, name, args)
+            return False
+
+        # Warn if some type requires an output logic
+        self.config.log.warning("doesn't now how to output '%s' block",
+                                dtype)
+
+        return True
+
+    # Virtual methods to be overridden by inherited classes
+    def out_doc(self, fname, name, args):
+        pass
+
+    def out_function(self, fname, name, args):
+        pass
+
+    def out_enum(self, fname, name, args):
+        pass
+
+    def out_typedef(self, fname, name, args):
+        pass
+
+    def out_struct(self, fname, name, args):
+        pass
+
+
+class RestFormat(OutputFormat):
+    # """Consts and functions used by ReST output"""
+
+    highlights = [
+        (type_constant, r"``\1``"),
+        (type_constant2, r"``\1``"),
+
+        # Note: need to escape () to avoid func matching later
+        (type_member_func, r":c:type:`\1\2\3\\(\\) <\1>`"),
+        (type_member, r":c:type:`\1\2\3 <\1>`"),
+        (type_fp_param, r"**\1\\(\\)**"),
+        (type_fp_param2, r"**\1\\(\\)**"),
+        (type_func, r"\1()"),
+        (type_enum, r":c:type:`\1 <\2>`"),
+        (type_struct, r":c:type:`\1 <\2>`"),
+        (type_typedef, r":c:type:`\1 <\2>`"),
+        (type_union, r":c:type:`\1 <\2>`"),
+
+        # in rst this can refer to any type
+        (type_fallback, r":c:type:`\1`"),
+        (type_param_ref, r"**\1\2**")
+    ]
+    blankline = "\n"
+
+    sphinx_literal = Re(r'^[^.].*::$', cache=False)
+    sphinx_cblock = Re(r'^\.\.\ +code-block::', cache=False)
+
+    def __init__(self):
+        """
+        Creates class variables.
+
+        Not really mandatory, but it is a good coding style and makes
+        pylint happy.
+        """
+
+        super().__init__()
+        self.lineprefix = ""
+
+    def print_lineno(self, ln):
+        """Outputs a line number"""
+
+        if self.enable_lineno and ln:
+            print(f".. LINENO {ln}")
+
+    def output_highlight(self, args):
+        input_text = args
+        output = ""
+        in_literal = False
+        litprefix = ""
+        block = ""
+
+        for line in input_text.strip("\n").split("\n"):
+
+            # If we're in a literal block, see if we should drop out of it.
+            # Otherwise, pass the line straight through unmunged.
+            if in_literal:
+                if line.strip():  # If the line is not blank
+                    # If this is the first non-blank line in a literal block,
+                    # figure out the proper indent.
+                    if not litprefix:
+                        r = Re(r'^(\s*)')
+                        if r.match(line):
+                            litprefix = '^' + r.group(1)
+                        else:
+                            litprefix = ""
+
+                        output += line + "\n"
+                    elif not Re(litprefix).match(line):
+                        in_literal = False
+                    else:
+                        output += line + "\n"
+                else:
+                    output += line + "\n"
+
+            # Not in a literal block (or just dropped out)
+            if not in_literal:
+                block += line + "\n"
+                if self.sphinx_literal.match(line) or self.sphinx_cblock.match(line):
+                    in_literal = True
+                    litprefix = ""
+                    output += self.highlight_block(block)
+                    block = ""
+
+        # Handle any remaining block
+        if block:
+            output += self.highlight_block(block)
+
+        # Print the output with the line prefix
+        for line in output.strip("\n").split("\n"):
+            print(self.lineprefix + line)
+
+    def out_section(self, args, out_reference=False):
+        """
+        Outputs a block section.
+
+        This could use some work; it's used to output the DOC: sections, and
+        starts by putting out the name of the doc section itself, but that
+        tends to duplicate a header already in the template file.
+        """
+
+        sectionlist = args.get('sectionlist', [])
+        sections = args.get('sections', {})
+        section_start_lines = args.get('section_start_lines', {})
+
+        for section in sectionlist:
+            # Skip sections that are in the nosymbol_table
+            if section in self.nosymbol:
+                continue
+
+            if not self.out_mode == self.OUTPUT_INCLUDE:
+                if out_reference:
+                    print(f".. _{section}:\n")
+
+                if not self.symbol:
+                    print(f'{self.lineprefix}**{section}**\n')
+
+            self.print_lineno(section_start_lines.get(section, 0))
+            self.output_highlight(sections[section])
+            print()
+        print()
+
+    def out_doc(self, fname, name, args):
+        if not self.check_doc(name):
+            return
+
+        self.out_section(args, out_reference=True)
+
+    def out_function(self, fname, name, args):
+
+        oldprefix = self.lineprefix
+        signature = ""
+
+        func_macro = args.get('func_macro', False)
+        if func_macro:
+            signature = args['function']
+        else:
+            if args.get('functiontype'):
+                signature = args['functiontype'] + " "
+            signature += args['function'] + " ("
+
+        parameterlist = args.get('parameterlist', [])
+        parameterdescs = args.get('parameterdescs', {})
+        parameterdesc_start_lines = args.get('parameterdesc_start_lines', {})
+
+        ln = args.get('ln', 0)
+
+        count = 0
+        for parameter in parameterlist:
+            if count != 0:
+                signature += ", "
+            count += 1
+            dtype = args['parametertypes'].get(parameter, "")
+
+            if function_pointer.search(dtype):
+                signature += function_pointer.group(1) + parameter + function_pointer.group(3)
+            else:
+                signature += dtype
+
+        if not func_macro:
+            signature += ")"
+
+        if args.get('typedef') or not args.get('functiontype'):
+            print(f".. c:macro:: {args['function']}\n")
+
+            if args.get('typedef'):
+                self.print_lineno(ln)
+                print("   **Typedef**: ", end="")
+                self.lineprefix = ""
+                self.output_highlight(args.get('purpose', ""))
+                print("\n\n**Syntax**\n")
+                print(f"  ``{signature}``\n")
+            else:
+                print(f"``{signature}``\n")
+        else:
+            print(f".. c:function:: {signature}\n")
+
+        if not args.get('typedef'):
+            self.print_lineno(ln)
+            self.lineprefix = "   "
+            self.output_highlight(args.get('purpose', ""))
+            print()
+
+        # Put descriptive text into a container (HTML <div>) to help set
+        # function prototypes apart
+        self.lineprefix = "  "
+
+        if parameterlist:
+            print(".. container:: kernelindent\n")
+            print(f"{self.lineprefix}**Parameters**\n")
+
+        for parameter in parameterlist:
+            parameter_name = Re(r'\[.*').sub('', parameter)
+            dtype = args['parametertypes'].get(parameter, "")
+
+            if dtype:
+                print(f"{self.lineprefix}``{dtype}``")
+            else:
+                print(f"{self.lineprefix}``{parameter}``")
+
+            self.print_lineno(parameterdesc_start_lines.get(parameter_name, 0))
+
+            self.lineprefix = "    "
+            if parameter_name in parameterdescs and \
+               parameterdescs[parameter_name] != KernelDoc.undescribed:
+
+                self.output_highlight(parameterdescs[parameter_name])
+                print()
+            else:
+                print(f"{self.lineprefix}*undescribed*\n")
+            self.lineprefix = "  "
+
+        self.out_section(args)
+        self.lineprefix = oldprefix
+
+    def out_enum(self, fname, name, args):
+
+        oldprefix = self.lineprefix
+        name = args.get('enum', '')
+        parameterlist = args.get('parameterlist', [])
+        parameterdescs = args.get('parameterdescs', {})
+        ln = args.get('ln', 0)
+
+        print(f"\n\n.. c:enum:: {name}\n")
+
+        self.print_lineno(ln)
+        self.lineprefix = "  "
+        self.output_highlight(args.get('purpose', ''))
+        print()
+
+        print(".. container:: kernelindent\n")
+        outer = self.lineprefix + "  "
+        self.lineprefix = outer + "  "
+        print(f"{outer}**Constants**\n")
+
+        for parameter in parameterlist:
+            print(f"{outer}``{parameter}``")
+
+            if parameterdescs.get(parameter, '') != KernelDoc.undescribed:
+                self.output_highlight(parameterdescs[parameter])
+            else:
+                print(f"{self.lineprefix}*undescribed*\n")
+            print()
+
+        self.lineprefix = oldprefix
+        self.out_section(args)
+
+    def out_typedef(self, fname, name, args):
+
+        oldprefix = self.lineprefix
+        name = args.get('typedef', '')
+        ln = args.get('ln', 0)
+
+        print(f"\n\n.. c:type:: {name}\n")
+
+        self.print_lineno(ln)
+        self.lineprefix = "   "
+
+        self.output_highlight(args.get('purpose', ''))
+
+        print()
+
+        self.lineprefix = oldprefix
+        self.out_section(args)
+
+    def out_struct(self, fname, name, args):
+
+        name = args.get('struct', "")
+        purpose = args.get('purpose', "")
+        declaration = args.get('definition', "")
+        dtype = args.get('type', "struct")
+        ln = args.get('ln', 0)
+
+        parameterlist = args.get('parameterlist', [])
+        parameterdescs = args.get('parameterdescs', {})
+        parameterdesc_start_lines = args.get('parameterdesc_start_lines', {})
+
+        print(f"\n\n.. c:{dtype}:: {name}\n")
+
+        self.print_lineno(ln)
+
+        oldprefix = self.lineprefix
+        self.lineprefix += "  "
+
+        self.output_highlight(purpose)
+        print()
+
+        print(".. container:: kernelindent\n")
+        print(f"{self.lineprefix}**Definition**::\n")
+
+        self.lineprefix = self.lineprefix + "  "
+
+        declaration = declaration.replace("\t", self.lineprefix)
+
+        print(f"{self.lineprefix}{dtype} {name}" + ' {')
+        print(f"{declaration}{self.lineprefix}" + "};\n")
+
+        self.lineprefix = "  "
+        print(f"{self.lineprefix}**Members**\n")
+        for parameter in parameterlist:
+            if not parameter or parameter.startswith("#"):
+                continue
+
+            parameter_name = parameter.split("[", maxsplit=1)[0]
+
+            if parameterdescs.get(parameter_name) == KernelDoc.undescribed:
+                continue
+
+            self.print_lineno(parameterdesc_start_lines.get(parameter_name, 0))
+
+            print(f"{self.lineprefix}``{parameter}``")
+
+            self.lineprefix = "    "
+            self.output_highlight(parameterdescs[parameter_name])
+            self.lineprefix = "  "
+
+            print()
+
+        print()
+
+        self.lineprefix = oldprefix
+        self.out_section(args)
+
+
+class ManFormat(OutputFormat):
+    """Consts and functions used by man pages output"""
+
+    highlights = (
+        (type_constant, r"\1"),
+        (type_constant2, r"\1"),
+        (type_func, r"\\fB\1\\fP"),
+        (type_enum, r"\\fI\1\\fP"),
+        (type_struct, r"\\fI\1\\fP"),
+        (type_typedef, r"\\fI\1\\fP"),
+        (type_union, r"\\fI\1\\fP"),
+        (type_param, r"\\fI\1\\fP"),
+        (type_param_ref, r"\\fI\1\2\\fP"),
+        (type_member, r"\\fI\1\2\3\\fP"),
+        (type_fallback, r"\\fI\1\\fP")
+    )
+    blankline = ""
+
+    def __init__(self):
+        """
+        Creates class variables.
+
+        Not really mandatory, but it is a good coding style and makes
+        pylint happy.
+        """
+
+        super().__init__()
+
+        dt = datetime.now()
+        if os.environ.get("KBUILD_BUILD_TIMESTAMP", None):
+            # use UTC TZ
+            to_zone = tz.gettz('UTC')
+            dt = dt.astimezone(to_zone)
+
+        self.man_date = dt.strftime("%B %Y")
+
+    def output_highlight(self, block):
+
+        contents = self.highlight_block(block)
+
+        if isinstance(contents, list):
+            contents = "\n".join(contents)
+
+        for line in contents.strip("\n").split("\n"):
+            line = Re(r"^\s*").sub("", line)
+
+            if line and line[0] == ".":
+                print("\\&" + line)
+            else:
+                print(line)
+
+    def out_doc(self, fname, name, args):
+        module = args.get('module')
+        sectionlist = args.get('sectionlist', [])
+        sections = args.get('sections', {})
+
+        print(f'.TH "{module}" 9 "{module}" "{self.man_date}" "API Manual" LINUX')
+
+        for section in sectionlist:
+            print(f'.SH "{section}"')
+            self.output_highlight(sections.get(section))
+
+    def out_function(self, fname, name, args):
+        """output function in man"""
+
+        parameterlist = args.get('parameterlist', [])
+        parameterdescs = args.get('parameterdescs', {})
+        sectionlist = args.get('sectionlist', [])
+        sections = args.get('sections', {})
+
+        print(f'.TH "{args['function']}" 9 "{args['function']}" "{self.man_date}" "Kernel Hacker\'s Manual" LINUX')
+
+        print(".SH NAME")
+        print(f"{args['function']} \\- {args['purpose']}")
+
+        print(".SH SYNOPSIS")
+        if args.get('functiontype', ''):
+            print(f'.B "{args['functiontype']}" {args['function']}')
+        else:
+            print(f'.B "{args['function']}')
+
+        count = 0
+        parenth = "("
+        post = ","
+
+        for parameter in parameterlist:
+            if count == len(parameterlist) - 1:
+                post = ");"
+
+            dtype = args['parametertypes'].get(parameter, "")
+            if function_pointer.match(dtype):
+                # Pointer-to-function
+                print(f'".BI "{parenth}{function_pointer.group(1)}" " ") ({function_pointer.group(2)}){post}"')
+            else:
+                dtype = Re(r'([^\*])$').sub(r'\1 ', dtype)
+
+                print(f'.BI "{parenth}{dtype}"  "{post}"')
+            count += 1
+            parenth = ""
+
+        if parameterlist:
+            print(".SH ARGUMENTS")
+
+        for parameter in parameterlist:
+            parameter_name = re.sub(r'\[.*', '', parameter)
+
+            print(f'.IP "{parameter}" 12')
+            self.output_highlight(parameterdescs.get(parameter_name, ""))
+
+        for section in sectionlist:
+            print(f'.SH "{section.upper()}"')
+            self.output_highlight(sections[section])
+
+    def out_enum(self, fname, name, args):
+
+        name = args.get('enum', '')
+        parameterlist = args.get('parameterlist', [])
+        sectionlist = args.get('sectionlist', [])
+        sections = args.get('sections', {})
+
+        print(f'.TH "{args['module']}" 9 "enum {args['enum']}" "{self.man_date}" "API Manual" LINUX')
+
+        print(".SH NAME")
+        print(f"enum {args['enum']} \\- {args['purpose']}")
+
+        print(".SH SYNOPSIS")
+        print(f"enum {args['enum']}" + " {")
+
+        count = 0
+        for parameter in parameterlist:
+            print(f'.br\n.BI "    {parameter}"')
+            if count == len(parameterlist) - 1:
+                print("\n};")
+            else:
+                print(", \n.br")
+
+            count += 1
+
+        print(".SH Constants")
+
+        for parameter in parameterlist:
+            parameter_name = Re(r'\[.*').sub('', parameter)
+            print(f'.IP "{parameter}" 12')
+            self.output_highlight(args['parameterdescs'].get(parameter_name, ""))
+
+        for section in sectionlist:
+            print(f'.SH "{section}"')
+            self.output_highlight(sections[section])
+
+    def out_typedef(self, fname, name, args):
+        module = args.get('module')
+        typedef = args.get('typedef')
+        purpose = args.get('purpose')
+        sectionlist = args.get('sectionlist', [])
+        sections = args.get('sections', {})
+
+        print(f'.TH "{module}" 9 "{typedef}" "{self.man_date}" "API Manual" LINUX')
+
+        print(".SH NAME")
+        print(f"typedef {typedef} \\- {purpose}")
+
+        for section in sectionlist:
+            print(f'.SH "{section}"')
+            self.output_highlight(sections.get(section))
+
+    def out_struct(self, fname, name, args):
+        module = args.get('module')
+        struct_type = args.get('type')
+        struct_name = args.get('struct')
+        purpose = args.get('purpose')
+        definition = args.get('definition')
+        sectionlist = args.get('sectionlist', [])
+        parameterlist = args.get('parameterlist', [])
+        sections = args.get('sections', {})
+        parameterdescs = args.get('parameterdescs', {})
+
+        print(f'.TH "{module}" 9 "{struct_type} {struct_name}" "{self.man_date}" "API Manual" LINUX')
+
+        print(".SH NAME")
+        print(f"{struct_type} {struct_name} \\- {purpose}")
+
+        # Replace tabs with two spaces and handle newlines
+        declaration = definition.replace("\t", "  ")
+        declaration = Re(r"\n").sub('"\n.br\n.BI "', declaration)
+
+        print(".SH SYNOPSIS")
+        print(f"{struct_type} {struct_name} " + "{" + "\n.br")
+        print(f'.BI "{declaration}\n' + "};\n.br\n")
+
+        print(".SH Members")
+        for parameter in parameterlist:
+            if parameter.startswith("#"):
+                continue
+
+            parameter_name = re.sub(r"\[.*", "", parameter)
+
+            if parameterdescs.get(parameter_name) == KernelDoc.undescribed:
+                continue
+
+            print(f'.IP "{parameter}" 12')
+            self.output_highlight(parameterdescs.get(parameter_name))
+
+        for section in sectionlist:
+            print(f'.SH "{section}"')
+            self.output_highlight(sections.get(section))