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Last update: 1997-05-20
9945-2-123
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Topic: MAKEFLAGS processing in make
Relevant Sections: 6.2.3, 6.2.5.3, 6.2.7.2
Defect Report:
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From: [email protected] (Mark Funkenhauser)
Date: Tue, 9 May 1995 16:52:57 -0400 (EDT)
Dear Standards Board,
I would like to an request official, binding interpretation
from WG15 concerning the following point in ISO/IEC
9945-2:1993 (POSIX.2).
Issue 1:
From Section 6.2.5.3, lines 296-305, it says that
"The MAKEFLAGS variable shall be accessed from the environment
before the makefile is read. At this time, all of the options
... not already included in 'MAKEFLAGS' shall be added to
the 'MAKEFLAGS' macro."
This assignment of the 'MAKEFLAGS' macro is not referenced
in 6.2.7.4, lines 482-490, where it describes macro assignments,
so it is unspecified what the relationship is between this macro
assignment and assignments from other different sources
in terms of if/when this macro can be replaced from another source.
Q1: what is the precedence for this macro assignment
with respect to precedence list lines 485-490?
[ Note: .2b/D10.9 already contains wording changes for lines 482-490
but this case is not handled there either ]
Proposed Solution for .2b:
The 'MAKEFLAGS' macro created in this circumstance, should
be between (1) and (2) (between line 485 and 486)
and add to beginning of line 308 :
"The value of the MAKEFLAGS environment variable shall
not be used as the 'MAKEFLAGS' macro."
[ Rationale: we want MAKEFLAGS macro to contain all the options from
the command line and from MAKEFLAGS env. variable.
and we don't want the env. variable overriding this new value
We do want to override this value if 'MAKEFLAGS' macro
is defined in the makefile.
So, putting it before (2) is necessary to avoid problems with
the reversal of (2) and (3) when -e is specified,
and ensuring MAKEFLAGS env. variable is not turned into a macro
ensures that environment variables in (2) do not override. ]
Issue 2:
From lines 298-300
"At this time, all of the options (except -f and -p)
and command line macros not already included in 'MAKEFLAGS' shall
be added to the 'MAKEFLAGS' macro."
Q2: The question is why are command line macros, and macros from
the MAKEFLAGS environment variable, being added to the 'MAKEFLAGS'
macro? Was this non-historical behaviour intentional?
a) This seems inconsistent with lines 377-379 which describes
the creation of the MAKEFLAGS variable containing all options
on the comand line except of the -f and -p options.
Why are command line macros not included here too?
b) This behaviour has never been true in any historical implementation.
There seems to be good reason for *not* doing this.
For example, given a command line of
make CFLAGS="-s -g"
according to line 298-300, there should be a 'MAKEFLAGS' macro
created which is then put into the environment equivalent to this:
MAKEFLAGS="CFLAGS=-s -g"
but now when a 2nd level make gets invoked from a makefile command,
it will see inherit this MAKEFLAGS environment and will interpret
it as one 1 macro "CFLAGS=-s" and 1 option "-g".
Since "-g" is not a valid option, the 2nd level make will exit
with an error message.
The rationale did not give any reason for this new behaviour
and its not clear what advantage this provides since
macros are automatically included in the environment and
vice versa which means 2nd level make's will automatically
inherit these values.
Proposed solution for .2b:
Remove "and command line macros" from line 298.
Thank you for your attention to this matter.
Mark Funkenhauser
Interpretation response
------------------------
Issue 1:
The standard does not speak to this issue, and as such no conformance
distinction can be made between alternative implementations based on this.
This is being referred to the sponsor.
Issue 2:
The text on page 669, lines 296-305, and page 571, lines 377-380 are in
conflict and as such the standard is unclear on this issue, and no
conformance distinction can be made between alternative implementations
based on this. This is being referred to the sponsor.
Rationale
-------------
None.
Forwarded to Interpretations group: May 16 1995
Proposed resolution forwarded: Aug 11 1995
Finalized: Sept 12 1995