varmod.mk revision 1.6
1 # $NetBSD: varmod.mk,v 1.6 2022/08/06 07:06:58 rillig Exp $ 2 # 3 # Tests for variable modifiers, such as :Q, :S,from,to or :Ufallback. 4 5 # As of 2022-08-06, the possible behaviors during parsing are: 6 # 7 # * `strict`: the parsing style used by most modifiers: 8 # * either uses `ParseModifierPart` or parses the modifier literal 9 # * other modifiers may follow, separated by a ':' 10 # 11 # * `greedy`: calls `ParseModifierPart` with `ch->endc`; this means 12 # that no further modifiers are parsed in that expression. 13 # 14 # * `no-colon`: after parsing this modifier, the following modifier 15 # does not need to be separated by a colon. 16 # Omitting this colon is bad style. 17 # 18 # * `individual`: parsing this modifier does not follow the common 19 # pattern of calling `ParseModifierPart`. 20 # 21 # The SysV column says whether a parse error in the modifier falls back 22 # trying the `:from=to` System V modifier. 23 # 24 # | **Operator** | **Behavior** | **Remarks** | **SysV** | 25 # |--------------|--------------|--------------------|----------| 26 # | `!` | no-colon | | no | 27 # | `:=` | greedy | | yes | 28 # | `?:` | greedy | | no | 29 # | `@` | no-colon | | no | 30 # | `C` | no-colon | | no | 31 # | `D` | individual | custom parser | N/A | 32 # | `E` | strict | | yes | 33 # | `H` | strict | | yes | 34 # | `L` | no-colon | | N/A | 35 # | `M` | individual | custom parser | N/A | 36 # | `N` | individual | custom parser | N/A | 37 # | `O` | strict | only literal value | no | 38 # | `P` | no-colon | | N/A | 39 # | `Q` | strict | | yes | 40 # | `R` | strict | | yes | 41 # | `S` | no-colon | | N/A | 42 # | `T` | strict | | N/A | 43 # | `U` | individual | custom parser | N/A | 44 # | `[` | strict | | no | 45 # | `_` | individual | strcspn | yes | 46 # | `gmtime` | strict | only literal value | yes | 47 # | `hash` | strict | | N/A | 48 # | `localtime` | strict | only literal value | yes | 49 # | `q` | strict | | yes | 50 # | `range` | strict | | N/A | 51 # | `sh` | strict | | N/A | 52 # | `t` | strict | | no | 53 # | `u` | strict | | yes | 54 # | `from=to` | greedy | SysV, fallback | N/A | 55 56 DOLLAR1= $$ 57 DOLLAR2= ${:U\$} 58 59 # To get a single '$' sign in the value of a variable expression, it has to 60 # be written as '$$' in a literal variable value. 61 # 62 # See Var_Parse, where it calls Var_Subst. 63 .if ${DOLLAR1} != "\$" 64 . error 65 .endif 66 67 # Another way to get a single '$' sign is to use the :U modifier. In the 68 # argument of that modifier, a '$' is escaped using the backslash instead. 69 # 70 # See Var_Parse, where it calls Var_Subst. 71 .if ${DOLLAR2} != "\$" 72 . error 73 .endif 74 75 # It is also possible to use the :U modifier directly in the expression. 76 # 77 # See Var_Parse, where it calls Var_Subst. 78 .if ${:U\$} != "\$" 79 . error 80 .endif 81 82 # XXX: As of 2020-09-13, it is not possible to use '$$' in a variable name 83 # to mean a single '$'. This contradicts the manual page, which says that 84 # '$' can be escaped as '$$'. 85 .if ${$$:L} != "" 86 . error 87 .endif 88 89 # In lint mode, make prints helpful error messages. 90 # For compatibility, make does not print these error messages in normal mode. 91 # Should it? 92 .MAKEFLAGS: -dL 93 .if ${$$:L} != "" 94 . error 95 .endif 96 97 # A '$' followed by nothing is an error as well. 98 .if ${:Uword:@word@${word}$@} != "word" 99 . error 100 .endif 101 102 # The variable modifier :P does not fall back to the SysV modifier. 103 # Therefore the modifier :P=RE generates a parse error. 104 # XXX: The .error should not be reached since the variable expression is 105 # malformed, and this error should be propagated up to Cond_EvalLine. 106 VAR= STOP 107 .if ${VAR:P=RE} != "STORE" 108 . error 109 .endif 110 111 all: # nothing 112
Indexes created Wed Oct 01 19:09:53 GMT 2025