1# $NetBSD: cond-token-plain.mk,v 1.15 2021/12/30 02:14:55 rillig Exp $ 2# 3# Tests for plain tokens (that is, string literals without quotes) 4# in .if conditions. These are also called bare words. 5 6.MAKEFLAGS: -dc 7 8# The word 'value' after the '!=' is a bare word. 9.if ${:Uvalue} != value 10. error 11.endif 12 13# Using a '#' in a string literal in a condition leads to a malformed 14# condition since comment parsing is done in an early phase and removes the 15# '#' and everything after it long before the condition parser gets to see it. 16# 17# XXX: The error message is missing for this malformed condition. 18# The right-hand side of the comparison is just a '"', before unescaping. 19.if ${:U} != "#hash" 20. error 21.endif 22 23# To get a '#' into a condition, it has to be escaped using a backslash. 24# This prevents the comment parser from removing it, and in turn, it becomes 25# visible to CondParser_String. 26.if ${:U\#hash} != "\#hash" 27. error 28.endif 29 30# Since 2002-12-30, and still as of 2020-09-11, CondParser_Token handles 31# the '#' specially, even though at this point, there should be no need for 32# comment handling anymore. The comments are supposed to be stripped off 33# in a very early parsing phase. 34# 35# See https://gnats.netbsd.org/19596 for example makefiles demonstrating the 36# original problems. At that time, the parser didn't recognize the comment in 37# the line '.else # comment3'. This workaround is not needed anymore since 38# comments are stripped in an earlier phase. See "case '#'" in 39# CondParser_Token. 40# 41# XXX: Missing error message for the malformed condition. The right-hand 42# side before unescaping is double-quotes, backslash, backslash. 43.if ${:U\\} != "\\#hash" 44. error 45.endif 46 47# The right-hand side of a comparison is not parsed as a token, therefore 48# the code from CondParser_Token does not apply to it. 49# TODO: Explain the consequences. 50# TODO: Does this mean that more syntactic variants are allowed here? 51.if ${:U\#hash} != \#hash 52. error 53.endif 54 55# XXX: What is the purpose of treating an escaped '#' in the following 56# condition as a comment? And why only at the beginning of a token, 57# just as in the shell? 58.if 0 \# This is treated as a comment, but why? 59. error 60.endif 61 62# Ah, ok, this can be used to add an end-of-condition comment. But does 63# anybody really use this? This is neither documented nor obvious since 64# the '#' is escaped. It's much clearer to write a comment in the line 65# above the condition. 66.if ${0 \# comment :?yes:no} != no 67. error 68.endif 69.if ${1 \# comment :?yes:no} != yes 70. error 71.endif 72 73# Usually there is whitespace around the comparison operator, but this is 74# not required. 75.if ${UNDEF:Uundefined}!=undefined 76. error 77.endif 78.if ${UNDEF:U12345}>12345 79. error 80.endif 81.if ${UNDEF:U12345}<12345 82. error 83.endif 84.if (${UNDEF:U0})||0 85. error 86.endif 87 88# Only the comparison operator terminates the comparison operand, and it's 89# a coincidence that the '!' is both used in the '!=' comparison operator 90# as well as for negating a comparison result. 91# 92# The boolean operators '&' and '|' don't terminate a comparison operand. 93.if ${:Uvar}&&name != "var&&name" 94. error 95.endif 96.if ${:Uvar}||name != "var||name" 97. error 98.endif 99 100# A bare word may appear alone in a condition, without any comparison 101# operator. It is implicitly converted into defined(bare). 102.if bare 103. error 104.else 105. info A bare word is treated like defined(...), and the variable $\ 106 'bare' is not defined. 107.endif 108 109VAR= defined 110.if VAR 111. info A bare word is treated like defined(...). 112.else 113. error 114.endif 115 116# Bare words may be intermixed with variable expressions. 117.if V${:UA}R 118. info ok 119.else 120. error 121.endif 122 123# In bare words, even undefined variables are allowed. Without the bare 124# words, undefined variables are not allowed. That feels inconsistent. 125.if V${UNDEF}AR 126. info Undefined variables in bare words expand to an empty string. 127.else 128. error 129.endif 130 131.if 0${:Ux00} 132. error 133.else 134. info Numbers can be composed from literals and variable expressions. 135.endif 136 137.if 0${:Ux01} 138. info Numbers can be composed from literals and variable expressions. 139.else 140. error 141.endif 142 143# If the right-hand side is missing, it's a parse error. 144.if "" == 145. error 146.else 147. error 148.endif 149 150# If the left-hand side is missing, it's a parse error as well, but without 151# a specific error message. 152.if == "" 153. error 154.else 155. error 156.endif 157 158# The '\\' is not a line continuation. Neither is it an unquoted string 159# literal. Instead, it is parsed as a bare word (ParseWord), 160# and in that context, the backslash is just an ordinary character. The 161# function argument thus stays '\\' (2 backslashes). This string is passed 162# to FuncDefined, and since there is no variable named '\\', the condition 163# evaluates to false. 164.if \\ 165. error 166.else 167. info The variable '\\' is not defined. 168.endif 169 170${:U\\\\}= backslash 171.if \\ 172. info Now the variable '\\' is defined. 173.else 174. error 175.endif 176 177# Anything that doesn't start with a double quote is considered a "bare word". 178# Strangely, a bare word may contain double quotes inside. Nobody should ever 179# depend on this since it may well be unintended. See CondParser_String. 180.if "unquoted\"quoted" != unquoted"quoted 181. error 182.endif 183 184# FIXME: In CondParser_String, Var_Parse returns var_Error without a 185# corresponding error message. 186.if $$$$$$$$ != "" 187. error 188.else 189. error 190.endif 191 192# In a condition in an .if directive, the left-hand side must not be an 193# unquoted string literal. 194# expect+1: Malformed conditional (left == right) 195.if left == right 196.endif 197# Before cond.c 1.276 from 2021-09-21, a variable expression containing the 198# modifier ':?:' allowed unquoted string literals for the rest of the 199# condition. This was an unintended implementation mistake. 200# expect+1: Malformed conditional (${0:?:} || left == right) 201.if ${0:?:} || left == right 202.endif 203# This affected only the comparisons after the expression, so the following 204# was still a syntax error. 205# expect+1: Malformed conditional (left == right || ${0:?:}) 206.if left == right || ${0:?:} 207.endif 208 209# See cond-token-string.mk for similar tests where the condition is enclosed 210# in "quotes". 211 212.MAKEFLAGS: -d0 213 214 215# As of cond.c 1.320 from 2021-12-30, the code in CondParser_ComparisonOrLeaf 216# looks suspicious of evaluating the expression twice: first for parsing a 217# bare word and second for parsing the left-hand side of a comparison. 218# 219# In '.if' directives, the left-hand side of a comparison must not be a bare 220# word though, and this keeps CondParser_Leaf from evaluating the expression 221# for the second time. The right-hand side of a comparison may be a bare 222# word, but that side has no risk of being parsed more than once. 223# 224# expect+1: Malformed conditional (VAR.${IF_COUNT::+=1} != "") 225.if VAR.${IF_COUNT::+=1} != "" 226. error 227.else 228. error 229.endif 230.if ${IF_COUNT} != "1" 231. error 232.endif 233 234# A different situation is when CondParser.leftUnquotedOK is true. This 235# situation arises in expressions of the form ${cond:?yes:no}. As of 236# 2021-12-30, the condition in such an expression is evaluated before parsing 237# the condition, see varmod-ifelse.mk. To pass a variable expression to the 238# condition parser, it needs to be escaped. This rarely happens in practice, 239# in most cases the conditions are simple enough that it doesn't matter 240# whether the condition is first evaluated and then parsed, or vice versa. 241# A half-baked attempt at hiding this implementation detail is 242# CondParser.leftUnquotedOK, but that is a rather leaky abstraction. 243 244#.MAKEFLAGS: -dcv 245COND= VAR.$${MOD_COUNT::+=1} 246.if ${${COND} == "VAR.":?yes:no} != "yes" 247. error 248.endif 249 250# The value "1 1" demonstrates that the expression ${MOD_COUNT::+=1} was 251# evaluated twice. In practice, expressions that occur in conditions do not 252# have side effects, making this problem rather academic, but it is there. 253.if ${MOD_COUNT} != "1 1" 254. error 255.endif 256#.MAKEFLAGS: -d0 257