PRB: Spaces in Inference Rules Corrupt NMAKE Macro Expansion

• Microsoft NMAKE Utility for MS-DOS, versions 1.01, 1.1, 1.11, 1.12, 1.13, 1.2, 1.3, and 1.4
• Microsoft NMAKE Utility for OS/2, versions 1.01, 1.11, 1.12, 1.13, and 1.21
• Microsoft NMAKE Utility for Windows NT, versions 1.4 and 1.5

SYMPTOMS

An attempt to use an NMAKE default macro fails and NMAKE generates a message such as the following:

   warning u4006: special macro undefined : '$<'

CAUSE

A space has been inserted between the name of the target and the dependent extensions in an inference rule.

RESOLUTION

In an inference rule, list the dependent file extension followed by the target file extension without any intervening embedded spaces.

MORE INFORMATION

The following makefile examples demonstrate a few of the problems that can result when spaces are embedded in an inference rule. In both cases below, note that the embedded spaces cause NMAKE to run commands incorrectly. If you modify the files to remove the spaces, NMAKE generates the desired commands.

Sample Makefile 1

# The command executed by NMAKE: # # cl {.}

{.}.c {c:\objs\}.obj:

   cl $*

Sample Makefile 2

# The command executed by NMAKE: # # cl

.c .obj:

  cl $<

myfile.obj: myfile.c