freebsd-skq/contrib/bmake/unit-tests/deptgt-makeflags.mk
Simon J. Gerraty e2eeea75eb Merge bmake-20201117
o allow env var MAKE_OBJDIR_CHECK_WRITABLE=no to skip writable
  checks in InitObjdir.  Explicit .OBJDIR target always allows
  read-only directory.

o More code cleanup and refactoring.

o More unit tests

MFC after:	1 week
2020-11-20 06:02:31 +00:00

94 lines
2.8 KiB
Makefile

# $NetBSD: deptgt-makeflags.mk,v 1.6 2020/11/15 20:20:58 rillig Exp $
#
# Tests for the special target .MAKEFLAGS in dependency declarations,
# which adds command line options later, at parse time.
#
# In these unit tests, it is often used to temporarily toggle the debug log
# during parsing.
# The -D option sets a variable in the "Global" scope and thus can be
# undefined later.
.MAKEFLAGS: -D VAR
.if ${VAR} != 1
. error
.endif
# Variables that are set via the -D command line option are normal global
# variables and can thus be undefined later.
.undef VAR
.if defined(VAR)
. error
.endif
# The -D command line option can define a variable again, after it has been
# undefined.
.MAKEFLAGS: -D VAR
.if ${VAR} != 1
. error
.endif
# The "dependency" for .MAKEFLAGS is split into words, interpreting the usual
# quotes and escape sequences from the backslash.
.MAKEFLAGS: VAR="value"' with'\ spaces
.if ${VAR} != "value with spaces"
. error
.endif
# Variables set on the command line as VAR=value are placed in the
# "Command" scope and thus cannot be undefined.
.undef VAR
.if ${VAR} != "value with spaces"
. error
.endif
# When parsing this line, each '$$' becomes '$', resulting in '$$$$'.
# This is assigned to the variable DOLLAR.
# In the condition, that variable is expanded, and at that point, each '$$'
# becomes '$' again, the final expression is thus '$$'.
.MAKEFLAGS: -dcv
.MAKEFLAGS: DOLLAR=$$$$$$$$
.if ${DOLLAR} != "\$\$"
.endif
.MAKEFLAGS: -d0
# An empty command line is skipped.
.MAKEFLAGS: # none
# Escape sequences like \n are interpreted.
# The following line looks as if it assigned a newline to nl, but it doesn't.
# Instead, the \n ends up as a line that is then interpreted as a variable
# assignment. At that point, the line is simply "nl=\n", and the \n is
# skipped since it is whitespace (see Parse_IsVar).
.MAKEFLAGS: nl="\n"
.if ${nl} != ""
. error
.endif
# Next try at defining another newline variable. Since whitespace around the
# variable value is trimmed, two empty variable expressions surround the
# literal newline now. This prevents the newline from being skipped during
# parsing. The ':=' assignment operator expands the empty variable
# expressions, leaving only the newline as the variable value.
#
# This is one of the very few ways (maybe even the only one) to inject literal
# newlines into a line that is being parsed. This may confuse the parser.
# For example, in cond.c the parser only expects horizontal whitespace (' '
# and '\t'), but no newlines.
#.MAKEFLAGS: -dcpv
.MAKEFLAGS: nl:="$${:U}\n$${:U}"
.if ${nl} != ${.newline}
. error
.endif
#.MAKEFLAGS: -d0
# Unbalanced quotes produce an error message. If they occur anywhere in the
# command line, the whole command line is skipped.
.MAKEFLAGS: VAR=previous
.MAKEFLAGS: VAR=initial UNBALANCED='
.if ${VAR} != "previous"
. error
.endif
all:
@:;