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- allow use of 'None' with 'Z' - bumped version to 1.4 (be in sync current dyncall version)
author Tassilo Philipp
date Mon, 03 Apr 2023 19:06:07 +0200
parents 8e905c0798c7
children
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1 dyncall python bindings
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2 Copyright 2007-2016 Daniel Adler
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3 2018-2023 Tassilo Philipp
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4
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5 Dec 4, 2007: initial
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6 Mar 22, 2016: update to dyncall 0.9, includes breaking sig char changes
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7 Apr 19, 2018: update to dyncall 1.0
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8 Apr 7, 2020: update to dyncall 1.1, Python 3 support, using the Capsule
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9 API, as well as support for python unicode strings
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10 Apr 11, 2020: support for getting loaded library path
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11 Apr 12, 2020: breaking change: restrict 'Z' conversions to immutable types
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12 and 'p' to mutable types (and handles)
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13 Apr 13, 2020: added signature char support to specify calling conventions
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14 Oct 27, 2020: allowing 'None' for 'p' params, always passing NULL
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15 Nov 13, 2020: removed pydc.py wrapper overhead (which only called pydcext.so
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16 functions; implies renaming pydcext.* to pydc.*), added type stub
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17 as package_data
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18 Jan 23, 2021: update to dyncall 1.2 (only version bump)
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19 Feb 2, 2021: added callback support (comes with some bigger refactoring);
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20 allow CPython's Py{CObject,Capsule} to be used as 'p'ointers
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21 Aug 3, 2022: added p2Z() helper function (e.g. helpful when working with
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22 string 'p'ointers that eventually need to be free()'d, as no
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23 implicit 'Z' conversion is taking place)
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24 Apr 3, 2023: allowing 'None' for 'Z' params
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29 BUILD/INSTALLATION
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30 ==================
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32 1) make sure dyncall is built and libraries/headers are in include paths or
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33 CFLAGS points to them, etc.
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35 2) Build and install this extension with:
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37 python setup.py install
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38
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39 Building a wheel package isn't supported, currently.
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42 API
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43 ===
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44
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45 In a nutshell for all calls:
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46
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47 libhandle = load(libpath) # if path == None => handle to running process
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48 libpath = get_path(libhandle) # if handle == None => path to executable
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49 funcptr = find(libhandle, symbolname) # lookup symbol by name
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50 call(funcptr, signature, ...) # call C func w/ signature and corresponding args
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51 free(libhandle) # free library
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52
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53 For callback objects to be passed as 'p'ointer args:
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54
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55 cbhandle = new_callback(signature, pyfunc) # signature reflecting C func ptr
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56 free_callback(cbhandle) # release callback object
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58 Notes:
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59 - a pydc.pyi stub file with the precise interface description is available
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60 - there are no functions to set the calling convention mode, however, it can be
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61 set using the signature
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62 - not specifying any calling convention in the signature string will use the
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63 platform's default one
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65
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66 SIGNATURE FORMAT
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67 ================
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68
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69 ignoring calling convention mode switching for simplicity, the signature is
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70 a string with the following format (using * as regex-like repetition):
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71
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72 "x*)y"
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73
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74 where x is positional parameter-type charcode (per argument), y is result-type charcode
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77 SIG | FROM PYTHON 2 | FROM PYTHON 3 | C/C++ | TO PYTHON 2 | TO PYTHON 3
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78 ----+---------------------------------+---------------------------------+---------------------------------+--------------------------------------+---------------------------------------
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79 'v' | | | void | None (Py_None) (e.g. ret of "...)v") | None (Py_None) (e.g. ret of "...)v")
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80 'B' | bool (PyBool) | bool (PyBool) # | int/bool | bool (PyBool) | bool (PyBool) @
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81 'c' | int (PyInt) % | int (PyLong) % | char | int (PyInt) | int (PyLong)
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82 | str (with only a single char) % | str (with only a single char) % | char | int (PyInt) | int (PyLong)
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83 'C' | int (PyInt) % | int (PyLong) % | unsigned char | int (PyInt) | int (PyLong)
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84 | str (with only a single char) % | str (with only a single char) % | unsigned char | int (PyInt) | int (PyLong)
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85 's' | int (PyInt) % | int (PyLong) % | short | int (PyInt) | int (PyLong)
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86 'S' | int (PyInt) % | int (PyLong) % | unsigned short | int (PyInt) | int (PyLong)
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87 'i' | int (PyInt) | int (PyLong) | int | int (PyInt) | int (PyLong)
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88 'I' | int (PyInt) | int (PyLong) | unsigned int | int (PyInt) | int (PyLong)
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89 'j' | int (PyInt) | int (PyLong) | long | int (PyInt) | int (PyLong)
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90 'J' | int (PyInt) | int (PyLong) | unsigned long | int (PyInt) | int (PyLong)
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91 'l' | int (PyInt) | int (PyLongLong) | long long | long (PyLong) | int (PyLong)
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92 | long (PyLong) | - | long long | long (PyLong) | int (PyLong)
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93 'L' | int (PyInt) | int (PyLongLong) | unsigned long long | long (PyLong) | int (PyLong)
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94 | long (PyLong) | - | unsigned long long | long (PyLong) | int (PyLong)
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95 'f' | float (PyFloat) $ | float (PyFloat) $ | float | float (PyFloat) ^ | float (PyFloat) ^
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96 'd' | float (PyFloat) | float (PyFloat) | double | float (PyFloat) | float (PyFloat)
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97 'p' | bytearray (PyByteArray) & | bytearray (PyByteArray) & | void* | int,long (Py_ssize_t) | int (Py_ssize_t)
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98 | int (PyInt) | int (PyLong) | void* | int,long (Py_ssize_t) | int (Py_ssize_t)
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99 | long (PyLong) | - | void* | int,long (Py_ssize_t) | int (Py_ssize_t)
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100 | None (Py_None) | None (Py_None) | void* (always NULL) | int,long (Py_ssize_t) | int (Py_ssize_t)
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101 | (PyCObject,PyCapsule) | (PyCObject,PyCapsule) | void* | int,long (Py_ssize_t) | int (Py_ssize_t) @@@ test
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102 'Z' | str (PyString) ! | str (PyUnicode) ! | const char* (UTF-8 for unicode) | str (PyString) | str (PyUnicode)
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103 | unicode (PyUnicode) ! | - | const char* (UTF-8 for unicode) | str (PyString) | str (PyUnicode)
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104 | - | bytes (PyBytes) ! | const char* (UTF-8 for unicode) | str (PyString) | str (PyUnicode)
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105 | bytearray (PyByteArray) ! | bytearray (PyByteArray) ! | const char* (UTF-8 for unicode) | str (PyString) | str (PyUnicode)
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106 | None (Py_None) | None (Py_None) | const char* (always NULL) | None (Py_None) | None (Py_None)
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107
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108 Annotations:
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109 # converted to 1 if True and 0 otherwise
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110 @ converted to False if 0 and True otherwise
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111 % range/length checked
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112 $ cast to single precision
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113 ^ cast to double precision
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114 & mutable buffer when passed to C
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115 ! immutable buffer when passed to C, as strings (in any form) are considered objects, not buffers; also, not allowed as return type in callback signatures
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116
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117
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118 Also supported are specifying calling convention switches using '_'-prefixed
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119 signature characters:
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120
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121 SIG | DESCRIPTION
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122 ----+-----------------------------------------------------------------------------------------------------------
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123 '_' | prefix indicating that next signature character specifies calling convention; char is one of the following
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124 ':' | platform's default calling convention
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125 '*' | platform's default thiscall (C++ methods) calling convention, first argument of a call is the this pointer
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126 'e' | vararg function
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127 '.' | vararg function's variadic/ellipsis part (...), to be specified before first vararg
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128 'c' | only on x86: cdecl
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129 's' | only on x86: stdcall
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130 'F' | only on x86: fastcall (MS)
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131 'f' | only on x86: fastcall (GNU)
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132 '+' | only on x86: thiscall (MS)
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133 '#' | only on x86: thiscall (GNU)
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134 'A' | only on ARM: ARM mode
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135 'a' | only on ARM: THUMB mode
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136 '$' | syscall
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137
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139 TODO
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140 ====
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141
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142 - calling convention mode handling for callbacks (not sure if ever needed?)
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143 - pydoc "man page"
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144 - stub location: the pydc-stubs folder isn't picked up by mypy, so I question why this is the suggested way
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145 - get into freebsd ports
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146 - releasing GIL when calling into C code (*only* when none of the arguments is a mutable buffer, though)
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147 - support for new dyncall aggregate-by-value interface
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150 BUGS
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151 ====
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152
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153 - when using Python 2, the dyncall call vm object is never dcFree'd, as there
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154 is no way to call a "freefunc" as introduced with Python 3 module definitions
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155 (see PEP 3121 for details)
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156