# $NetBSD: varname.mk,v 1.11 2023/06/01 20:56:35 rillig Exp $ # # Tests for special variables, such as .MAKE or .PARSEDIR. # And for variable names in general. .MAKEFLAGS: -dv # In variable names, braces are allowed, but they must be balanced. # Parentheses and braces may be mixed. VAR{{{}}}= 3 braces .if "${VAR{{{}}}}" != "3 braces" . error .endif # In variable expressions, the parser works differently. It doesn't treat # braces and parentheses equally, therefore the first closing brace already # marks the end of the variable name. VARNAME= VAR((( ${VARNAME}= 3 open parentheses .if "${VAR(((}}}}" != "3 open parentheses}}}" . error .endif # In the above test, the variable name is constructed indirectly. Neither # of the following expressions produces the intended effect. # # This is not a variable assignment since the parentheses and braces are not # balanced. At the end of the line, there are still 3 levels open, which # means the variable name is not finished. # expect+2: Error in archive specification: "VAR" # expect+1: No closing parenthesis in archive specification ${:UVAR(((}= try1 # On the left-hand side of a variable assignments, the backslash is not parsed # as an escape character, therefore the parentheses still count to the nesting # level, which at the end of the line is still 3. Therefore this is not a # variable assignment as well. # expect+1: Invalid line type ${:UVAR\(\(\(}= try2 # To assign to a variable with an arbitrary name, the variable name has to # come from an external source, not the text that is parsed in the assignment # itself. This is exactly the reason why further above, the indirect # ${VARNAME} works, while all other attempts fail. ${VARNAME}= try3 .MAKEFLAGS: -d0 # All variable names of a scope are stored in the same hash table, using a # simple hash function. Ensure that HashTable_Find handles collisions # correctly and that the correct variable is looked up. The strings "0x" and # "1Y" have the same hash code, as 31 * '0' + 'x' == 31 * '1' + 'Y'. V.0x= 0x V.1Y= 1Y .if ${V.0x} != "0x" || ${V.1Y} != "1Y" . error .endif # The string "ASDZguv", when used as a prefix of a variable name, keeps the # hash code unchanged, its own hash code is 0. ASDZguvV.0x= 0x ASDZguvV.1Y= 1Y .if ${ASDZguvV.0x} != "0x" . error .elif ${ASDZguvV.1Y} != "1Y" . error .endif # Ensure that variables with the same hash code whose name is a prefix of the # other can be accessed. In this case, the shorter variable name is defined # first to make it appear later in the bucket of the hash table. ASDZguv= once ASDZguvASDZguv= twice .if ${ASDZguv} != "once" . error .elif ${ASDZguvASDZguv} != "twice" . error .endif # Ensure that variables with the same hash code whose name is a prefix of the # other can be accessed. In this case, the longer variable name is defined # first to make it appear later in the bucket of the hash table. ASDZguvASDZguv.param= twice ASDZguv.param= once .if ${ASDZguv.param} != "once" . error .elif ${ASDZguvASDZguv.param} != "twice" . error .endif all: