1# $NetBSD: directive-for.mk,v 1.27 2024/07/06 10:14:35 rillig Exp $ 2# 3# Tests for the .for directive. 4# 5# TODO: Describe naming conventions for the loop variables. 6# .for f in values 7# .for file in values 8# .for _FILE_ in values 9# .for .FILE. in values 10# .for _f_ in values 11# 12# See also: 13# varmod-loop.mk The ':@var@...@' modifier 14 15# A typical use case for a .for loop is to populate a variable with a list of 16# values depending on other variables. In simple cases, the same effect can 17# be achieved using the ':@var@${var}@' modifier. 18.undef NUMBERS 19.for num in 1 2 3 20NUMBERS+= ${num} 21.endfor 22.if ${NUMBERS} != "1 2 3" 23. error 24.endif 25 26 27# The .for loop also works for multiple iteration variables. 28# This is something that the modifier :@ cannot do as easily. 29.for name value in VARNAME value NAME2 value2 30${name}= ${value} 31.endfor 32.if ${VARNAME} != "value" || ${NAME2} != "value2" 33. error 34.endif 35 36 37# The .for loop splits the items at whitespace, taking quotes into account, 38# just like the :M or :S modifiers. 39# 40# Until 2012-06-03, the .for loop had split the items exactly at whitespace, 41# without taking the quotes into account. This had resulted in 10 words. 42.undef WORDS 43.for var in one t\ w\ o "three three" 'four four' `five six` 44WORDS+= counted 45.endfor 46.if ${WORDS:[#]} != 6 47. error 48.endif 49 50 51# In the body of the .for loop, the iteration variables can be accessed 52# like normal variables, even though they are not really variables. 53# 54# Instead, before interpreting the body of the .for loop, the body is 55# generated by replacing each expression ${var} with ${:U1}, ${:U2} and so 56# on. 57# 58# A noticeable effect of this implementation technique is that the .for 59# iteration variables and the normal global variables live in separate 60# namespaces and do not influence each other. The "scope" of the .for loop 61# variables is restricted to the current makefile, it does not reach over to 62# any included makefiles. 63var= value before 64var2= value before 65.for var var2 in 1 2 3 4 66.endfor 67.if ${var} != "value before" 68. warning After the .for loop, var must still have its original value. 69.endif 70.if ${var2} != "value before" 71. warning After the .for loop, var2 must still have its original value. 72.endif 73 74# Everything from the paragraph above also applies if the loop body is 75# empty. In this particular example, the items to be iterated are empty as 76# well. 77var= value before 78var2= value before 79.for var var2 in ${:U} 80.endfor 81.if ${var} != "value before" 82. warning After the .for loop, var must still have its original value. 83.endif 84.if ${var2} != "value before" 85. warning After the .for loop, var2 must still have its original value. 86.endif 87 88# Before for.c 1.39 from 2008-12-21, the values of the iteration variables 89# were simply inserted as plain text and then parsed as usual, which made it 90# possible to achieve all kinds of strange effects, such as generating '.if' 91# directives or inserting '$' characters in random places, thereby changing 92# how following '$' are interpreted. 93# 94# Before that date, the .for loop below expanded to: 95# EXPANSION+= value 96# Since that date, the .for loop below expands to: 97# EXPANSION${:U+}= value 98# 99EXPANSION= before 100EXPANSION+ = before 101.for plus in + 102EXPANSION${plus}= value 103.endfor 104.if ${EXPANSION} != "before" 105. error This must be a make from before 2009. 106.endif 107.if ${EXPANSION+} != "value" 108. error This must be a make from before 2009. 109.endif 110 111# When the outer .for loop is expanded, it sees the expression ${i} and 112# expands it. The inner loop then only sees the expression ${:Uouter} and 113# has nothing more to expand. 114.for i in outer 115. for i in inner 116# expect+1: outer 117. info ${i} 118. endfor 119.endfor 120 121 122# From https://gnats.netbsd.org/29985. 123# 124# Until 2008-12-21, the .for loop was expanded by replacing the variable 125# value literally in the body. This could lead to situations where the 126# characters from the variable value were interpreted as markup rather than 127# plain text. 128# 129# Until 2012-06-03, the .for loop had split the words at whitespace, without 130# taking quotes into account. This made it possible to have variable values 131# like "a:\ a:\file.txt" that ended in a single backslash. Since then, the 132# variable values have been replaced with expressions of the form ${:U...}, 133# which are not interpreted as code anymore. 134.for path in a:\ a:\file.txt d:\\ d:\\file.txt 135# expect+3: a:\ a:\file.txt 136# expect+2: d:\\ 137# expect+1: d:\\file.txt 138. info ${path} 139.endfor 140 141 142# Ensure that braces and parentheses are properly escaped by the .for loop. 143# Each line must print the same word 3 times. 144# See ForLoop_SubstBody. 145.for v in ( [ { ) ] } (()) [[]] {{}} )( ][ }{ 146# expect+12: ( ( ( 147# expect+11: [ [ [ 148# expect+10: { { { 149# expect+9: ) ) ) 150# expect+8: ] ] ] 151# expect+7: } } } 152# expect+6: (()) (()) (()) 153# expect+5: [[]] [[]] [[]] 154# expect+4: {{}} {{}} {{}} 155# expect+3: )( )( )( 156# expect+2: ][ ][ ][ 157# expect+1: }{ }{ }{ 158. info $v ${v} $(v) 159.endfor 160 161# Before 2023-05-09, the variable names could contain arbitrary characters, 162# except for whitespace, allowing for creative side effects, as usual for 163# arbitrary code injection. 164var= outer 165# expect+1: invalid character ':' in .for loop variable name 166.for var:Q in value "quoted" 167. info <${var}> <${var:Q}> <${var:Q:Q}> 168.endfor 169 170# Before 2023-05-09, when variable names could contain '$', the short 171# expression '$$' was preserved, the long expressions were substituted. 172# expect+1: invalid character '$' in .for loop variable name 173.for $ in value 174. info <$$> <${$}> <$($)> 175.endfor 176 177 178# https://gnats.netbsd.org/53146 mentions the idea of using a dynamic 179# variable name in .for loops, based on some other variable. The .for loops 180# are already tricky enough to understand in detail, even without this 181# possibility, therefore the variable names are restricted to using harmless 182# characters only. 183INDIRECT= direct 184# expect+1: invalid character '$' in .for loop variable name 185.for $(INDIRECT) in value 186# If the variable name could be chosen dynamically, the iteration variable 187# might have been 'direct', thereby expanding the expression '${direct}'. 188. info <$(INDIRECT)> <$(direct)> <$($(INDIRECT))> 189.endfor 190 191 192# Regular global variables and the "variables" from the .for loop don't 193# interfere with each other. In the following snippet, the variable 'DIRECT' 194# is used both as a global variable, as well as an iteration variable in the 195# .for loop. The expression '${INDIRECT}' refers to the global variable, not 196# to the one from the .for loop. 197DIRECT= global 198INDIRECT= ${DIRECT} 199.for DIRECT in iteration 200. if "${DIRECT} ${INDIRECT}" != "iteration global" 201. error 202. endif 203.endfor 204 205 206# XXX: A parse error or evaluation error in the items of the .for loop 207# should skip the whole loop. As of 2023-05-09, the loop is expanded as 208# usual. 209# expect+1: while evaluating "${:Uword2:Z}-after word3" with value "word2": Unknown modifier "Z" 210.for var in word1 before-${:Uword2:Z}-after word3 211# expect+3: XXX: Should not reach word1 212# expect+2: XXX: Should not reach before--after 213# expect+1: XXX: Should not reach word3 214. info XXX: Should not reach ${var} 215.endfor 216 217 218# An empty list of variables to the left of the 'in' is a parse error. 219.for in value # expect+0: no iteration variables in for 220. error 221.endfor 222 223# An empty list of iteration values to the right of the 'in' is accepted. 224# Unlike in the shell, it is not a parse error. 225.for var in 226. error 227.endfor 228 229# If the iteration values become empty after expanding the expressions, the 230# body of the loop is not evaluated. It is not a parse error. 231.for var in ${:U} 232. error 233.endfor 234 235 236# The loop body can be empty. 237.for var in 1 2 3 238.endfor 239 240 241# A mismatched .if inside a .for loop is detected each time when the loop body 242# is processed. 243.for var in value 244. if 0 245.endfor # expect+0: 1 open conditional 246 247# If there are no iteration values, the loop body is not processed, and the 248# check for mismatched conditionals is not performed. 249.for var in ${:U} 250. if 0 251.endfor 252 253 254# When a .for without the corresponding .endfor occurs in an inactive branch 255# of an .if, the .for directive is just skipped, it does not even need a 256# corresponding .endfor. In other words, the behavior of the parser depends 257# on the actual values of the conditions in the .if clauses. 258.if 0 259. for var in value # does not need a corresponding .endfor 260.endif 261.endfor # expect+0: for-less endfor 262.endif # expect+0: if-less endif 263 264 265# When a .for without the corresponding .endfor occurs in an active branch of 266# an .if, the parser just counts the number of .for and .endfor directives, 267# without looking at any other directives. 268.if 1 269. for var in value 270. endif # expect+0: if-less endif 271. endfor # no 'for-less endfor' 272.endif # no 'if-less endif' 273 274 275# Before for.c 1.172 from 2023-05-08, when make parsed a .for loop, it 276# assumed that there was no line continuation between the '.' and the 'for' 277# or 'endfor', as there is no practical reason to break the line at this 278# point. 279# 280# When make scanned the outer .for loop, it did not recognize the inner .for 281# loop as such and instead treated it as an unknown directive. The body of 282# the outer .for loop thus ended above the '.endfor'. 283# 284# When make scanned the inner .for loop, it did not recognize the inner 285# .endfor as such, which led to a parse error 'Unexpected end of file in .for 286# loop' from the '.endfor' line, followed by a second parse error 'for-less 287# .endfor' from the '.\\n endfor' line. 288.MAKEFLAGS: -df 289.for outer in o 290.\ 291 for inner in i 292.\ 293 endfor 294.endfor 295.MAKEFLAGS: -d0 296 297 298# When there is a variable definition 'scope=cmdline' from the command line 299# (which has higher precedence than global variables) and a .for loop iterates 300# over a variable of the same name, the expression '${scope}' expands to the 301# value from the .for loop. This is because when the body of the .for loop is 302# expanded, the expression '${scope}' is textually replaced with ${:Uloop}', 303# without resolving any other variable names (ForLoop_SubstBody). Later, when 304# the body of the .for loop is actually interpreted, the body text doesn't 305# contain the word 'scope' anymore. 306.MAKEFLAGS: scope=cmdline 307.for scope in loop 308. if ${scope} != "loop" 309. error 310. endif 311.endfor 312 313 314# Since at least 1993, iteration stops at the first newline. 315# Back then, the .newline variable didn't exist, therefore it was unlikely 316# that a newline ever occurred. 317.for var in a${.newline}b${.newline}c 318# expect+1: newline-item=(a) 319. info newline-item=(${var}) 320.endfor 321