1# $NetBSD: directive-for.mk,v 1.20 2023/05/10 13:03:06 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# expect-all 16 17# A typical use case for a .for loop is to populate a variable with a list of 18# values depending on other variables. In simple cases, the same effect can 19# be achieved using the ':@var@${var}@' modifier. 20.undef NUMBERS 21.for num in 1 2 3 22NUMBERS+= ${num} 23.endfor 24.if ${NUMBERS} != "1 2 3" 25. error 26.endif 27 28 29# The .for loop also works for multiple iteration variables. 30# This is something that the modifier :@ cannot do. 31.for name value in VARNAME value NAME2 value2 32${name}= ${value} 33.endfor 34.if ${VARNAME} != "value" || ${NAME2} != "value2" 35. error 36.endif 37 38 39# The .for loop splits the items at whitespace, taking quotes into account, 40# just like the :M or :S modifiers. 41# 42# Until 2012-06-03, the .for loop had split the items exactly at whitespace, 43# without taking the quotes into account. This had resulted in 10 words. 44.undef WORDS 45.for var in one t\ w\ o "three three" 'four four' `five six` 46WORDS+= counted 47.endfor 48.if ${WORDS:[#]} != 6 49. error 50.endif 51 52 53# In the body of the .for loop, the iteration variables can be accessed 54# like normal variables, even though they are not really variables. 55# 56# Instead, before interpreting the body of the .for loop, the body is 57# generated by replacing each expression ${var} with ${:U1}, ${:U2} and so 58# on. 59# 60# A noticeable effect of this implementation technique is that the .for 61# iteration variables and the normal global variables live in separate 62# namespaces and do not influence each other. The "scope" of the .for loop 63# variables is restricted to the current makefile, it does not reach over to 64# any included makefiles. 65var= value before 66var2= value before 67.for var var2 in 1 2 3 4 68.endfor 69.if ${var} != "value before" 70. warning After the .for loop, var must still have its original value. 71.endif 72.if ${var2} != "value before" 73. warning After the .for loop, var2 must still have its original value. 74.endif 75 76# Everything from the paragraph above also applies if the loop body is 77# empty. In this particular example, the items to be iterated are empty as 78# well. 79var= value before 80var2= value before 81.for var var2 in ${:U} 82.endfor 83.if ${var} != "value before" 84. warning After the .for loop, var must still have its original value. 85.endif 86.if ${var2} != "value before" 87. warning After the .for loop, var2 must still have its original value. 88.endif 89 90# Until 2008-12-21, the values of the iteration variables were simply 91# inserted as plain text and then parsed as usual, which made it possible 92# to achieve all kinds of strange effects, such as generating '.if' 93# directives or inserting '$' characters in random places, thereby changing 94# how following '$' are interpreted. 95# 96# Before that date, the .for loop below expanded to: 97# EXPANSION+= value 98# Since that date, the .for loop below expands to: 99# EXPANSION${:U+}= value 100# 101EXPANSION= before 102EXPANSION+ = before 103.for plus in + 104EXPANSION${plus}= value 105.endfor 106.if ${EXPANSION} != "before" 107. error This must be a make from before 2009. 108.endif 109.if ${EXPANSION+} != "value" 110. error This must be a make from before 2009. 111.endif 112 113# When the outer .for loop is expanded, it sees the expression ${i} and 114# expands it. The inner loop then only sees the expression ${:Uouter} and 115# has nothing more to expand. 116.for i in outer 117. for i in inner 118# expect+1: outer 119. info ${i} 120. endfor 121.endfor 122 123 124# From https://gnats.netbsd.org/29985. 125# 126# Until 2008-12-21, the .for loop was expanded by replacing the variable 127# value literally in the body. This could lead to situations where the 128# characters from the variable value were interpreted as markup rather than 129# plain text. 130# 131# Until 2012-06-03, the .for loop had split the words at whitespace, without 132# taking quotes into account. This made it possible to have variable values 133# like "a:\ a:\file.txt" that ended in a single backslash. Since then, the 134# variable values have been replaced with expressions of the form ${:U...}, 135# which are not interpreted as code anymore. 136.for path in a:\ a:\file.txt d:\\ d:\\file.txt 137. info ${path} 138.endfor 139# expect-2: a:\ a:\file.txt 140# expect-3: d:\\ 141# expect-4: d:\\file.txt 142 143 144# Ensure that braces and parentheses are properly escaped by the .for loop. 145# Each line must print the same word 3 times. 146# See ForLoop_SubstBody. 147.for v in ( [ { ) ] } (()) [[]] {{}} )( ][ }{ 148. info $v ${v} $(v) 149.endfor 150# expect-02: ( ( ( 151# expect-03: [ [ [ 152# expect-04: { { { 153# expect-05: ) ) ) 154# expect-06: ] ] ] 155# expect-07: } } } 156# expect-08: (()) (()) (()) 157# expect-09: [[]] [[]] [[]] 158# expect-10: {{}} {{}} {{}} 159# expect-11: )( )( )( 160# expect-12: ][ ][ ][ 161# expect-13: }{ }{ }{ 162 163# Before 2023-05-09, the variable names could contain arbitrary characters, 164# except for whitespace, allowing for creative side effects, as usual for 165# arbitrary code injection. 166var= outer 167# expect+1: invalid character ':' in .for loop variable name 168.for var:Q in value "quoted" 169. info <${var}> <${var:Q}> <${var:Q:Q}> 170.endfor 171 172# Before 2023-05-09, when variable names could contain '$', the short 173# expression '$$' was preserved, the long expressions were substituted. 174# expect+1: invalid character '$' in .for loop variable name 175.for $ in value 176. info <$$> <${$}> <$($)> 177.endfor 178 179 180# https://gnats.netbsd.org/53146 mentions the idea of using a dynamic 181# variable name in .for loops, based on some other variable. The .for loops 182# are already tricky enough to understand in detail, even without this 183# possibility, therefore the variable names are restricted to using harmless 184# characters only. 185INDIRECT= direct 186# expect+1: invalid character '$' in .for loop variable name 187.for $(INDIRECT) in value 188# If the variable name could be chosen dynamically, the iteration variable 189# might have been 'direct', thereby expanding the expression '${direct}'. 190. info <$(INDIRECT)> <$(direct)> <$($(INDIRECT))> 191.endfor 192 193 194# XXX: A parse error or evaluation error in the items of the .for loop 195# should skip the whole loop. As of 2023-05-09, the loop is expanded as 196# usual. 197# expect+1: Unknown modifier "Z" 198.for var in word1 ${:Uword2:Z} word3 199. info XXX: Not reached ${var} 200.endfor 201# expect-2: XXX: Not reached word1 202# expect-3: XXX: Not reached word3 203 204 205# An empty list of variables to the left of the 'in' is a parse error. 206.for in value # expect+0: no iteration variables in for 207. error 208.endfor 209 210# An empty list of iteration values to the right of the 'in' is accepted. 211# Unlike in the shell, it is not a parse error. 212.for var in 213. error 214.endfor 215 216# If the iteration values become empty after expanding the expressions, the 217# body of the loop is not evaluated. It is not a parse error. 218.for var in ${:U} 219. error 220.endfor 221 222 223# The loop body can be empty. 224.for var in 1 2 3 225.endfor 226 227 228# A mismatched .if inside a .for loop is detected each time when the loop body 229# is processed. 230.for var in value 231. if 0 232.endfor # expect+0: 1 open conditional 233 234# If there are no iteration values, the loop body is not processed, and the 235# check for mismatched conditionals is not performed. 236.for var in ${:U} 237. if 0 238.endfor 239 240 241# When a .for without the corresponding .endfor occurs in an inactive branch 242# of an .if, the .for directive is just skipped, it does not even need a 243# corresponding .endfor. In other words, the behavior of the parser depends 244# on the actual values of the conditions in the .if clauses. 245.if 0 246. for var in value # does not need a corresponding .endfor 247.endif 248.endfor # expect+0: for-less endfor 249.endif # expect+0: if-less endif 250 251 252# When a .for without the corresponding .endfor occurs in an active branch of 253# an .if, the parser just counts the number of .for and .endfor directives, 254# without looking at any other directives. 255.if 1 256. for var in value 257. endif # expect+0: if-less endif 258. endfor # no 'for-less endfor' 259.endif # no 'if-less endif' 260 261 262# Before for.c 1.172 from 2023-05-08, when make parsed a .for loop, it 263# assumed that there was no line continuation between the '.' and the 'for' 264# or 'endfor', as there is no practical reason to break the line at this 265# point. 266# 267# When make scanned the outer .for loop, it did not recognize the inner .for 268# loop as such and instead treated it as an unknown directive. The body of 269# the outer .for loop thus ended above the '.endfor'. 270# 271# When make scanned the inner .for loop, it did not recognize the inner 272# .endfor as such, which led to a parse error 'Unexpected end of file in .for 273# loop' from the '.endfor' line, followed by a second parse error 'for-less 274# .endfor' from the '.\\n endfor' line. 275.MAKEFLAGS: -df 276.for outer in o 277.\ 278 for inner in i 279.\ 280 endfor 281.endfor 282.MAKEFLAGS: -d0 283 284 285# When there is a variable definition 'scope=cmdline' from the command line 286# (which has higher precedence than global variables) and a .for loop iterates 287# over a variable of the same name, the expression '${scope}' expands to the 288# value from the .for loop. This is because when the body of the .for loop is 289# expanded, the expression '${scope}' is textually replaced with ${:Uloop}', 290# without resolving any other variable names (ForLoop_SubstBody). Later, when 291# the body of the .for loop is actually interpreted, the body text doesn't 292# contain the word 'scope' anymore. 293.MAKEFLAGS: scope=cmdline 294.for scope in loop 295. if ${scope} != "loop" 296. error 297. endif 298.endfor 299 300 301# Since at least 1993, iteration stops at the first newline. 302# Back then, the .newline variable didn't exist, therefore it was unlikely 303# that a newline ever occurred. 304.for var in a${.newline}b${.newline}c 305. info newline-item=(${var}) 306.endfor 307# expect-2: newline-item=(a) 308