[bug #33344] Undefined variables introduce leading whitespace during variable assignment

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?33344>

                 Summary: Undefined variables introduce leading whitespace
during variable assignment
                 Project: make
            Submitted by: None
            Submitted on: Thu 19 May 2011 01:27:22 AM UTC
                Severity: 3 - Normal
              Item Group: Bug
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
       Component Version: 3.82
        Operating System: POSIX-Based
           Fixed Release: None
           Triage Status: None

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Details:

A null variable as the first item of a variable definition introduces leading
white space, which breaks an archive target and seems at variance to the GNU
Make Manual, Section 6.5, Setting Variables: "Whitespace ... immediately after
the ‘=’ is ignored."

A commonly used idiom illustrates the problem:

# Enumerate source files:
CCSRC.c =
CCCSRC.cc = larry.cc curly.cc moe.cc

# Compute the object files:
OBJECTS_FAIL = $(CCSRC.c:.c=.o) $(CCCSRC.cc:.cc=.o)
OBJECTS_SUCCESS = $(CCCSRC.cc:.cc=.o) $(CCSRC.c:.c=.o)

OBJECTS_FAIL will have a leading space, whereas _SUCCESS will not. This space
causes archive pre-requisites to fail (new for 3.82):

fail: printF libfail.a($(OBJECTS_FAIL))

----------------
A test case demonstrating the discrepancy is attached.
This problem was found using:
GNU Make 3.82 on Linux 2.6.37.6 x86_64 GNU/Linux

Running the same case under Make 3.81 shows the same leading space, but
archive pre-requisites will succeed.






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File Attachments:


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Date: Thu 19 May 2011 01:27:22 AM UTC  Name: stooges.mk  Size: 2kB   By: None

<http://savannah.gnu.org/bugs/download.php?file_id=23424>

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