xref: /src/usr.bin/make/unit-tests/recursive.mk

# $NetBSD: recursive.mk,v 1.2 2020/08/06 05:52:45 rillig Exp $
#
# In -dL mode, a variable may get expanded before it makes sense.
# This would stop make from doing anything since the "recursive" error
# is fatal and exits immediately.
#
# The purpose of evaluating that variable early was just to detect
# whether there are unclosed variables.  It might be enough to parse the
# variable value without VARE_WANTRES for that purpose.
#
# Seen in pkgsrc/x11/libXfixes, and probably many more package that use
# GNU Automake.

AM_V_lt = $(am__v_lt_$(V))
am__v_lt_ = $(am__v_lt_$(AM_DEFAULT_VERBOSITY))
am__v_lt_0 = --silent
am__v_lt_1 =

# On 2020-08-06, make reported: "Variable am__v_lt_ is recursive."
libXfixes_la_LINK = ... $(AM_V_lt) ...

# somewhere later ...
AM_DEFAULT_VERBOSITY = 1


# The purpose of the -dL flag is to detect unclosed variables.  This
# can be achieved by just parsing the variable and not evaluating it.
#
# When the variable is only parsed but not evaluated, bugs in nested
# variables are not discovered.  But these are hard to produce anyway,
# therefore that's acceptable.  In most practical cases, the missing
# brace would be detected directly in the line where it is produced.
MISSING_BRACE_INDIRECT:=	${:U\${MISSING_BRACE}
UNCLOSED = $(MISSING_PAREN
UNCLOSED = ${MISSING_BRACE
UNCLOSED = ${MISSING_BRACE_INDIRECT}