1 # 2 # Copyright (C) 2017 The Android Open Source Project 3 # 4 # Licensed under the Apache License, Version 2.0 (the "License"); 5 # you may not use this file except in compliance with the License. 6 # You may obtain a copy of the License at 7 # 8 # http://www.apache.org/licenses/LICENSE-2.0 9 # 10 # Unless required by applicable law or agreed to in writing, software 11 # distributed under the License is distributed on an "AS IS" BASIS, 12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 # See the License for the specific language governing permissions and 14 # limitations under the License. 15 # 16 17 ########################################################### 18 # Basic math functions for positive integers <= 100 19 # 20 # (SDK versions for example) 21 ########################################################### 22 __MATH_NUMBERS := 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 \ 23 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 \ 24 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 \ 25 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 \ 26 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 27 28 # Returns true if $(1) is a positive integer <= 100, otherwise returns nothing. 29 define math_is_number 30 $(strip \ 31 $(if $(1),,$(error Argument missing)) \ 32 $(if $(word 2,$(1)),$(error Multiple words in a single argument: $(1))) \ 33 $(if $(filter $(1),$(__MATH_NUMBERS)),true)) 34 endef 35 36 #$(warning true == $(call math_is_number,2)) 37 #$(warning == $(call math_is_number,foo)) 38 #$(call math_is_number,1 2) 39 #$(call math_is_number,no 2) 40 41 define _math_check_valid 42 $(if $(call math_is_number,$(1)),,$(error Only positive integers <= 100 are supported (not $(1)))) 43 endef 44 45 # return a list containing integers ranging from [$(1),$(2)] 46 define int_range_list 47 $(call _math_check_valid,$(1))$(call _math_check_valid,$(2))$(wordlist $(1),$(2),$(__MATH_NUMBERS)) 48 endef 49 50 #$(call _math_check_valid,0) 51 #$(call _math_check_valid,1) 52 #$(call _math_check_valid,100) 53 #$(call _math_check_valid,101) 54 #$(call _math_check_valid,) 55 #$(call _math_check_valid,1 2) 56 57 # Returns the greater of $1 or $2. 58 # If $1 or $2 is not a positive integer <= 100, then an error is generated. 59 define math_max 60 $(strip $(call _math_check_valid,$(1)) $(call _math_check_valid,$(2)) \ 61 $(lastword $(filter $(1) $(2),$(__MATH_NUMBERS)))) 62 endef 63 64 #$(call math_max) 65 #$(call math_max,1) 66 #$(call math_max,1 2,3) 67 #$(warning 1 == $(call math_max,1,1)) 68 #$(warning 42 == $(call math_max,5,42)) 69 #$(warning 42 == $(call math_max,42,5)) 70 71 define math_gt_or_eq 72 $(if $(filter $(1),$(call math_max,$(1),$(2))),true) 73 endef 74 75 define math_lt 76 $(if $(call math_gt_or_eq,$(1),$(2)),,true) 77 endef 78 79 #$(warning $(call math_gt_or_eq, 2, 1)) 80 #$(warning $(call math_gt_or_eq, 1, 1)) 81 #$(warning $(if $(call math_gt_or_eq, 1, 2),false,true)) 82 83 # $1 is the variable name to increment 84 define inc_and_print 85 $(strip $(eval $(1) := $($(1)) .)$(words $($(1)))) 86 endef 87 88 # Returns the words in $2 that are numbers and are less than $1 89 define numbers_less_than 90 $(strip \ 91 $(foreach n,$2, \ 92 $(if $(call math_is_number,$(n)), \ 93 $(if $(call math_lt,$(n),$(1)), \ 94 $(n))))) 95 endef 96 97 _INT_LIMIT_WORDS := $(foreach a,x x,$(foreach b,x x x x x x x x x x x x x x x x,\ 98 $(foreach c,x x x x x x x x x x x x x x x x,x x x x x x x x x x x x x x x x))) 99 100 define _int_encode 101 $(if $(filter $(words x $(_INT_LIMIT_WORDS)),$(words $(wordlist 1,$(1),x $(_INT_LIMIT_WORDS)))),\ 102 $(call pretty-error,integer greater than $(words $(_INT_LIMIT_WORDS)) is not supported!),\ 103 $(wordlist 1,$(1),$(_INT_LIMIT_WORDS))) 104 endef 105 106 # _int_max returns the maximum of the two arguments 107 # input: two (x) lists; output: one (x) list 108 # integer cannot be passed in directly. It has to be converted using _int_encode. 109 define _int_max 110 $(subst xx,x,$(join $(1),$(2))) 111 endef 112 113 # first argument is greater than second argument 114 # output: non-empty if true 115 # integer cannot be passed in directly. It has to be converted using _int_encode. 116 define _int_greater-than 117 $(filter-out $(words $(2)),$(words $(call _int_max,$(1),$(2)))) 118 endef 119 120 # first argument equals to second argument 121 # output: non-empty if true 122 # integer cannot be passed in directly. It has to be converted using _int_encode. 123 define _int_equal 124 $(filter $(words $(1)),$(words $(2))) 125 endef 126 127 # first argument is greater than or equal to second argument 128 # output: non-empty if true 129 # integer cannot be passed in directly. It has to be converted using _int_encode. 130 define _int_greater-or-equal 131 $(call _int_greater-than,$(1),$(2))$(call _int_equal,$(1),$(2)) 132 endef 133 134 define int_plus 135 $(words $(call _int_encode,$(1)) $(call _int_encode,$(2))) 136 endef 137 138 define int_subtract 139 $(if $(call _int_greater-or-equal,$(call _int_encode,$(1)),$(call _int_encode,$(2))),\ 140 $(words $(filter-out xx,$(join $(call _int_encode,$(1)),$(call _int_encode,$(2))))),\ 141 $(call pretty-error,$(1) subtract underflow $(2))) 142 endef 143 144 define int_multiply 145 $(words $(foreach a,$(call _int_encode,$(1)),$(call _int_encode,$(2)))) 146 endef 147 148 define int_divide 149 $(if $(filter 0,$(2)),$(call pretty-error,division by zero is not allowed!),$(strip \ 150 $(if $(call _int_greater-or-equal,$(call _int_encode,$(1)),$(call _int_encode,$(2))), \ 151 $(call int_plus,$(call int_divide,$(call int_subtract,$(1),$(2)),$(2)),1),0))) 152 endef 153