1# $NetBSD: recursive.mk,v 1.7 2023/10/19 18:24:33 rillig Exp $ 2# 3# In -dL mode, a variable may get expanded before it makes sense. 4# This would stop make from doing anything since the "recursive" error 5# is fatal and exits immediately. 6# 7# The purpose of evaluating that variable early was just to detect 8# whether there are unclosed variables. The variable value is therefore 9# parsed with VARE_PARSE_ONLY for that purpose. 10# 11 12.MAKEFLAGS: -dL 13 14 15AM_V_lt= ${am__v_lt_${V}} 16am__v_lt_= ${am__v_lt_${AM_DEFAULT_VERBOSITY}} 17am__v_lt_0= --silent 18am__v_lt_1= 19 20# Since parse.c 1.243 from 2020-07-31 and before parse.c 1.249 from 21# 2020-08-06, when make ran in -dL mode, it reported: "Variable am__v_lt_ is 22# recursive." 23# 24# Seen in pkgsrc/x11/libXfixes, and probably many more package that use 25# GNU Automake. 26libXfixes_la_LINK= ... ${AM_V_lt} ... 27 28 29# The purpose of the -dL flag is to detect unclosed variables. This 30# can be achieved by just parsing the variable and not evaluating it. 31# 32# When the variable is only parsed but not evaluated, bugs in nested 33# variables are not discovered. But these are hard to produce anyway, 34# therefore that's acceptable. In most practical cases, the missing 35# brace would be detected directly in the line where it is produced. 36MISSING_BRACE_INDIRECT:= ${:U\${MISSING_BRACE} 37# expect+1: Unclosed variable "MISSING_PAREN" 38UNCLOSED= $(MISSING_PAREN 39# expect+1: Unclosed variable "MISSING_BRACE" 40UNCLOSED= ${MISSING_BRACE 41UNCLOSED= ${MISSING_BRACE_INDIRECT} 42