[nautilus/wip/oholy/ci-improvements: 2/3] ci: Use lineup-parameters python script

[Ondrej Holy <oholy src gnome org>]

commit 133ebdad1ff5053bf5d09b2f55767d21eb23ea2d
Author: Ondrej Holy <oholy redhat com>
Date:   Fri Oct 8 12:54:41 2021 +0200

    ci: Use lineup-parameters python script
    
    The lineup-parameters.c is hard to use with meson. Let's use the python
    rewrite from
    https://gitlab.gnome.org/GNOME/epiphany/-/blob/master/data/lineup-parameters
    instead.

 .gitlab-ci.yml           |   1 -
 data/.gitignore          |   1 -
 data/lineup-parameters   | 210 +++++++++++++++++++++
 data/lineup-parameters.c | 483 -----------------------------------------------
 data/meson.build         |  10 -
 data/run-uncrustify.sh   |   3 +-
 6 files changed, 211 insertions(+), 497 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3d2fa263c..ef12ec992 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -34,7 +34,6 @@ style check:
             - 'uncrustify.diff'
         expire_in: 14 days
     script:
-        - gcc data/lineup-parameters.c `pkg-config --cflags --libs gio-2.0 gio-unix-2.0` -o 
data/lineup-parameters
         - LANG=C.utf8 data/run-uncrustify.sh
         - git diff --exit-code | tee uncrustify.diff
     except:
diff --git a/data/.gitignore b/data/.gitignore
index 89808d77c..511518769 100644
--- a/data/.gitignore
+++ b/data/.gitignore
@@ -1,4 +1,3 @@
-/lineup-parameters
 /nautilus-autorun-software.desktop
 /org.freedesktop.FileManager1.service
 /org.gnome.Nautilus.appdata.xml
diff --git a/data/lineup-parameters b/data/lineup-parameters
new file mode 100755
index 000000000..aae22de0e
--- /dev/null
+++ b/data/lineup-parameters
@@ -0,0 +1,210 @@
+#!/usr/bin/env python3
+#
+# Copyright © 2019 Michael Catanzaro <mcatanzaro gnome org>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Based on original C lineup-parameters by Sébastien Wilmet <swilmet gnome org>
+# Rewritten in Python to allow simple execution from source directory.
+#
+# Usage: lineup-parameters [file]
+# If the file is not given, stdin is read.
+# The result is printed to stdout.
+#
+# The restrictions:
+# - The function name must be at column 0, followed by a space and an opening
+#   parenthesis;
+# - One parameter per line;
+# - A parameter must follow certain rules (see the regex in the code), but it
+#   doesn't accept all possibilities of the C language.
+# - The opening curly brace ("{") of the function must also be at column 0.
+#
+# If one restriction is missing, the function declaration is not modified.
+#
+# Example:
+#
+# gboolean
+# frobnitz (Frobnitz *frobnitz,
+#           gint magic_number,
+#           GError **error)
+# {
+#   ...
+# }
+#
+# Becomes:
+#
+# gboolean
+# frobnitz (Frobnitz  *frobnitz,
+#           gint       magic_number,
+#           GError   **error)
+# {
+#   ...
+# }
+#
+# TODO: support "..." vararg parameter
+
+import argparse
+import re
+import sys
+
+from typing import NamedTuple
+
+# https://regexr.com/ is your friend.
+functionNameRegex = re.compile(r'^(\w+) ?\(')
+parameterRegex = re.compile(
+    r'^\s*(?P<type>(const\s+)?\w+)'
+    r'\s+(?P<stars>\**)'
+    r'\s*(?P<name>\w+)'
+    r'\s*(?P<end>,|\))'
+    r'\s*$')
+openingCurlyBraceRegex = re.compile(r'^{\s*$')
+
+
+def matchFunctionName(line):
+    match = functionNameRegex.match(line)
+    if match:
+        functionName = match.group(1)
+        firstParamPosition = match.end(0)
+        return (functionName, firstParamPosition)
+    return (None, 0)
+
+
+class ParameterInfo(NamedTuple):
+    paramType: str
+    name: str
+    numStars: int
+    isLastParameter: bool
+
+
+def matchParameter(line):
+    _, firstParamPosition = matchFunctionName(line)
+    match = parameterRegex.match(line[firstParamPosition:])
+    if match is None:
+        return None
+    paramType = match.group('type')
+    assert(paramType is not None)
+    name = match.group('name')
+    assert(name is not None)
+    stars = match.group('stars')
+    numStars = len(stars) if stars is not None else 0
+    end = match.group('end')
+    isLastParameter = True if end is not None and end == ')' else False
+    return ParameterInfo(paramType, name, numStars, isLastParameter)
+
+
+def matchOpeningCurlyBrace(line):
+    return True if openingCurlyBraceRegex.match(line) is not None else False
+
+
+# Length returned is number of lines the declaration takes up
+def getFunctionDeclarationLength(remainingLines):
+    for i in range(len(remainingLines)):
+        currentLine = remainingLines[i]
+        parameterInfo = matchParameter(currentLine)
+        if parameterInfo is None:
+            return 0
+        if parameterInfo.isLastParameter:
+            if i + 1 == len(remainingLines):
+                return 0
+            nextLine = remainingLines[i + 1]
+            if not matchOpeningCurlyBrace(nextLine):
+                return 0
+            return i + 1
+    return 0
+
+
+def getParameterInfos(remainingLines, length):
+    parameterInfos = []
+    for i in range(length):
+        parameterInfos.append(matchParameter(remainingLines[i]))
+    return parameterInfos
+
+
+def computeSpacing(parameterInfos):
+    maxTypeLength = 0
+    maxStarsLength = 0
+    for parameterInfo in parameterInfos:
+        maxTypeLength = max(maxTypeLength, len(parameterInfo.paramType))
+        maxStarsLength = max(maxStarsLength, parameterInfo.numStars)
+    return (maxTypeLength, maxStarsLength)
+
+
+def printParameter(parameterInfo, maxTypeLength, maxStarsLength, outfile):
+    outfile.write(f'{parameterInfo.paramType:<{maxTypeLength + 1}}')
+    paramNamePaddedWithStars = f'{parameterInfo.name:*>{parameterInfo.numStars + len(parameterInfo.name)}}'
+    outfile.write(f'{paramNamePaddedWithStars:>{maxStarsLength + len(parameterInfo.name)}}')
+
+
+def printFunctionDeclaration(remainingLines, length, useTabs, outfile):
+    functionName, _ = matchFunctionName(remainingLines[0])
+    assert(functionName is not None)
+    outfile.write(f'{functionName} (')
+    numSpacesToParenthesis = len(functionName) + 2
+    whitespace = ''
+    if useTabs:
+        tabs = ''.ljust(numSpacesToParenthesis // 8, '\t')
+        spaces = ''.ljust(numSpacesToParenthesis % 8)
+        whitespace = tabs + spaces
+    else:
+        whitespace = ''.ljust(numSpacesToParenthesis)
+    parameterInfos = getParameterInfos(remainingLines, length)
+    maxTypeLength, maxStarsLength = computeSpacing(parameterInfos)
+    numParameters = len(parameterInfos)
+    for i in range(numParameters):
+        parameterInfo = parameterInfos[i]
+        if i != 0:
+            outfile.write(whitespace)
+        printParameter(parameterInfo, maxTypeLength, maxStarsLength, outfile)
+        if i + 1 != numParameters:
+            outfile.write(',\n')
+    outfile.write(')\n')
+
+
+def parseContents(infile, useTabs, outfile):
+    lines = infile.readlines()
+    i = 0
+    while i < len(lines):
+        line = lines[i]
+        functionName, _ = matchFunctionName(line)
+        if functionName is None:
+            outfile.write(line)
+            i += 1
+            continue
+        remainingLines = lines[i:]
+        length = getFunctionDeclarationLength(remainingLines)
+        if length == 0:
+            outfile.write(line)
+            i += 1
+            continue
+        printFunctionDeclaration(remainingLines, length, useTabs, outfile)
+        i += length
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description='Line up parameters of C functions')
+    parser.add_argument('infile', nargs='?',
+                        type=argparse.FileType('r'),
+                        default=sys.stdin,
+                        help='input C source file')
+    parser.add_argument('-o', metavar='outfile', nargs='?',
+                        type=argparse.FileType('w'),
+                        default=sys.stdout,
+                        help='where to output modified file')
+    parser.add_argument('--tabs', action='store_true',
+                        help='whether use tab characters in the output')
+    args = parser.parse_args()
+    parseContents(args.infile, args.tabs, args.o)
+    args.infile.close()
+    args.o.close()
diff --git a/data/meson.build b/data/meson.build
index cc1561d89..f27426a5c 100644
--- a/data/meson.build
+++ b/data/meson.build
@@ -15,16 +15,6 @@ install_data(
 
 po_dir = join_paths(meson.source_root(), 'po')
 
-line_up_parameters = executable(
-  'lineup-parameters',
-  'lineup-parameters.c',
-  build_by_default: false,
-  dependencies: [
-    gio,
-    gio_unix,
-  ]
-)
-
 desktop_conf = configuration_data()
 
 desktop_conf.set('icon', application_id)
diff --git a/data/run-uncrustify.sh b/data/run-uncrustify.sh
index 78ac8d6cd..a50c0d3dd 100755
--- a/data/run-uncrustify.sh
+++ b/data/run-uncrustify.sh
@@ -10,8 +10,7 @@ fi
 
 if [ ! -x "$DATA/lineup-parameters" ];
 then
-    echo "Script lineup-parameters does not exists here in (source directory)/data, probably because 
Nautilus was built in a different directory than the source directory.
-Copy the program in the (build directory)/data/lineup-parameters here in (source directory)/data and run 
again run-uncrustify.sh."
+    echo "Script lineup-parameters does not exists."
     exit 1
 fi