Simon J. Gerraty 2c3632d14f Update to bmake-20200902
Lots of code refactoring, simplification and cleanup.
Lots of new unit-tests providing much higher code coverage.
All courtesy of rillig at netbsd.

Other significant changes:

o new read-only variable .SHELL which provides the path of the shell
  used to run scripts (as defined by  the .SHELL target).

o variable parsing detects more errors.

o new debug option -dl: LINT mode, does the equivalent of := for all
  variable assignments so that file and line number are reported for
  variable parse errors.
2020-09-05 19:29:42 +00:00

43 lines
996 B
Makefile

# $NetBSD: envfirst.mk,v 1.2 2020/07/27 18:57:42 rillig Exp $
#
# The -e option makes environment variables stronger than global variables.
.if ${FROM_ENV} != value-from-env
.error ${FROM_ENV}
.endif
# Try to override the variable; this does not have any effect.
FROM_ENV= value-from-mk
.if ${FROM_ENV} != value-from-env
.error ${FROM_ENV}
.endif
# Try to append to the variable; this also doesn't have any effect.
FROM_ENV+= appended
.if ${FROM_ENV} != value-from-env
.error ${FROM_ENV}
.endif
# The default assignment also cannot change the variable.
FROM_ENV?= default
.if ${FROM_ENV} != value-from-env
.error ${FROM_ENV}
.endif
# Neither can the assignment modifiers.
.if ${FROM_ENV::=from-condition}
.endif
.if ${FROM_ENV} != value-from-env
.error ${FROM_ENV}
.endif
# Even .undef doesn't work since it only affects the global context,
# which is independent from the environment variables.
.undef FROM_ENV
.if ${FROM_ENV} != value-from-env
.error ${FROM_ENV}
.endif
all:
@: nothing