escape.mk revision 1.11
1 # $Id: escape.mk,v 1.11 2020/01/07 20:50:12 rillig Exp $ 2 # 3 # Test backslash escaping. 4 5 # Extracts from the POSIX 2008 specification 6 # <http://pubs.opengroup.org/onlinepubs/9699919799/utilities/make.html>: 7 # 8 # Comments start with a <number-sign> ( '#' ) and continue until an 9 # unescaped <newline> is reached. 10 # 11 # When an escaped <newline> (one preceded by a <backslash>) is found 12 # anywhere in the makefile except in a command line, an include 13 # line, or a line immediately preceding an include line, it shall 14 # be replaced, along with any leading white space on the following 15 # line, with a single <space>. 16 # 17 # When an escaped <newline> is found in a command line in a 18 # makefile, the command line shall contain the <backslash>, the 19 # <newline>, and the next line, except that the first character of 20 # the next line shall not be included if it is a <tab>. 21 # 22 # When an escaped <newline> is found in an include line or in a 23 # line immediately preceding an include line, the behavior is 24 # unspecified. 25 # 26 # Notice that the behaviour of <backslash><backslash> or 27 # <backslash><anything other than newline> is not mentioned. I think 28 # this implies that <backslash> should be taken literally everywhere 29 # except before <newline>. 30 # 31 # Our practice, despite what POSIX might say, is that "\#" 32 # in a variable assignment stores "#" as part of the value. 33 # The "\" is not taken literally, and the "#" does not begin a comment. 34 # 35 # Also, our practice is that an even number of backslashes before a 36 # newline in a variable assignment simply stores the backslashes as part 37 # of the value, and treats the newline as though it was not escaped. 38 # Similarly, an even number of backslashes before a newline in a 39 # command simply uses the backslashes as part of the command, but 40 # does not escape the newline. This is compatible with GNU make. 41 42 all: .PHONY 43 # We will add dependencies like "all: yet-another-test" later. 44 45 # Some variables to be expanded in tests 46 # 47 a = aaa 48 A = ${a} 49 50 # Backslash at end of line in a comment\ 51 should continue the comment. \ 52 # This is also tested in comment.mk. 53 54 __printvars: .USE .MADE 55 @echo ${.TARGET} 56 ${.ALLSRC:@v@ printf "%s=:%s:\n" ${v:Q} ${${v}:Q}; @} 57 58 # Embedded backslash in variable should be taken literally. 59 # 60 VAR1BS = 111\111 61 VAR1BSa = 111\${a} 62 VAR1BSA = 111\${A} 63 VAR1BSda = 111\$${a} 64 VAR1BSdA = 111\$${A} 65 VAR1BSc = 111\# backslash escapes comment char, so this is part of the value 66 VAR1BSsc = 111\ # This is a comment. Value ends with <backslash><space> 67 68 all: var-1bs 69 var-1bs: .PHONY __printvars VAR1BS VAR1BSa VAR1BSA VAR1BSda VAR1BSdA \ 70 VAR1BSc VAR1BSsc 71 72 # Double backslash in variable should be taken as two literal backslashes. 73 # 74 VAR2BS = 222\\222 75 VAR2BSa = 222\\${a} 76 VAR2BSA = 222\\${A} 77 VAR2BSda = 222\\$${a} 78 VAR2BSdA = 222\\$${A} 79 VAR2BSc = 222\\# backslash does not escape comment char, so this is a comment 80 VAR2BSsc = 222\\ # This is a comment. Value ends with <backslash><backslash> 81 82 all: var-2bs 83 var-2bs: .PHONY __printvars VAR2BS VAR2BSa VAR2BSA VAR2BSda VAR2BSdA \ 84 VAR2BSc VAR2BSsc 85 86 # Backslash-newline in a variable setting is replaced by a single space. 87 # 88 VAR1BSNL = 111\ 89 111 90 VAR1BSNLa = 111\ 91 ${a} 92 VAR1BSNLA = 111\ 93 ${A} 94 VAR1BSNLda = 111\ 95 $${a} 96 VAR1BSNLdA = 111\ 97 $${A} 98 VAR1BSNLc = 111\ 99 # this should be processed as a comment 100 VAR1BSNLsc = 111\ 101 # this should be processed as a comment 102 103 all: var-1bsnl 104 var-1bsnl: .PHONY 105 var-1bsnl: .PHONY __printvars \ 106 VAR1BSNL VAR1BSNLa VAR1BSNLA VAR1BSNLda VAR1BSNLdA \ 107 VAR1BSNLc VAR1BSNLsc 108 109 # Double-backslash-newline in a variable setting. 110 # Both backslashes should be taken literally, and the newline is NOT escaped. 111 # 112 # The second lines below each end with '=' so that they will not 113 # generate syntax errors regardless of whether or not they are 114 # treated as part of the value. 115 # 116 VAR2BSNL = 222\\ 117 222= 118 VAR2BSNLa = 222\\ 119 ${a}= 120 VAR2BSNLA = 222\\ 121 ${A}= 122 VAR2BSNLda = 222\\ 123 $${a}= 124 VAR2BSNLdA = 222\\ 125 $${A}= 126 VAR2BSNLc = 222\\ 127 # this should be processed as a comment 128 VAR2BSNLsc = 222\\ 129 # this should be processed as a comment 130 131 all: var-2bsnl 132 var-2bsnl: .PHONY __printvars \ 133 VAR2BSNL VAR2BSNLa VAR2BSNLA VAR2BSNLda VAR2BSNLdA \ 134 VAR2BSNLc VAR2BSNLsc 135 136 # Triple-backslash-newline in a variable setting. 137 # First two should be taken literally, and last should escape the newline. 138 # 139 # The second lines below each end with '=' so that they will not 140 # generate syntax errors regardless of whether or not they are 141 # treated as part of the value. 142 # 143 VAR3BSNL = 333\\\ 144 333= 145 VAR3BSNLa = 333\\\ 146 ${a}= 147 VAR3BSNLA = 333\\\ 148 ${A}= 149 VAR3BSNLda = 333\\\ 150 $${a}= 151 VAR3BSNLdA = 333\\\ 152 $${A}= 153 VAR3BSNLc = 333\\\ 154 # this should be processed as a comment 155 VAR3BSNLsc = 333\\\ 156 # this should be processed as a comment 157 158 all: var-3bsnl 159 var-3bsnl: .PHONY __printvars \ 160 VAR3BSNL VAR3BSNLa VAR3BSNLA VAR3BSNLda VAR3BSNLdA \ 161 VAR3BSNLc VAR3BSNLsc 162 163 # Backslash-newline in a variable setting, plus any amount of white space 164 # on the next line, is replaced by a single space. 165 # 166 VAR1BSNL00= first line\ 167 168 # above line is entirely empty, and this is a comment 169 VAR1BSNL0= first line\ 170 no space on second line 171 VAR1BSNLs= first line\ 172 one space on second line 173 VAR1BSNLss= first line\ 174 two spaces on second line 175 VAR1BSNLt= first line\ 176 one tab on second line 177 VAR1BSNLtt= first line\ 178 two tabs on second line 179 VAR1BSNLxx= first line\ 180 many spaces and tabs [ ] on second line 181 182 all: var-1bsnl-space 183 var-1bsnl-space: .PHONY __printvars \ 184 VAR1BSNL00 VAR1BSNL0 VAR1BSNLs VAR1BSNLss VAR1BSNLt VAR1BSNLtt \ 185 VAR1BSNLxx 186 187 # Backslash-newline in a command is retained. 188 # 189 # The "#" in "# second line without space" makes it a comment instead 190 # of a syntax error if the preceding line is parsed incorretly. 191 # The ":" in "third line':" makes it look like the start of a 192 # target instead of a syntax error if the first line is parsed incorrectly. 193 # 194 all: cmd-1bsnl 195 cmd-1bsnl: .PHONY 196 @echo ${.TARGET} 197 echo :'first line\ 198 #second line without space\ 199 third line': 200 echo :'first line\ 201 second line spaces should be retained': 202 echo :'first line\ 203 second line tab should be elided': 204 echo :'first line\ 205 only one tab should be elided, second tab remains' 206 207 # When backslash-newline appears at the end of a command script, 208 # both the backslash and the newline should be passed to the shell. 209 # The shell should elide the backslash-newline. 210 # 211 all: cmd-1bsnl-eof 212 cmd-1bsnl-eof: 213 @echo ${.TARGET} 214 echo :'command ending with backslash-newline'; \ 215 216 # above line must be blank 217 218 # Double-backslash-newline in a command. 219 # Both backslashes are retained, but the newline is not escaped. 220 # XXX: This may differ from POSIX, but matches gmake. 221 # 222 # When make passes two backslashes to the shell, the shell will pass one 223 # backslash to the echo commant. 224 # 225 all: cmd-2bsnl 226 cmd-2bsnl: .PHONY 227 @echo ${.TARGET} 228 echo take one\\ 229 # this should be a comment 230 echo take two\\ 231 echo take three\\ 232 233 # Triple-backslash-newline in a command is retained. 234 # 235 all: cmd-3bsnl 236 cmd-3bsnl: .PHONY 237 @echo ${.TARGET} 238 echo :'first line\\\ 239 #second line without space\\\ 240 third line': 241 echo :'first line\\\ 242 second line spaces should be retained': 243 echo :'first line\\\ 244 second line tab should be elided': 245 echo :'first line\\\ 246 only one tab should be elided, second tab remains' 247
Indexes created Wed Oct 01 18:09:54 GMT 2025