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Q66773: Based Variable EXTRN Directive Wrongly Located in ASM Listing

Article: Q66773
Product(s): See article
Version(s): 6.00 6.00a | 6.00 6.00a
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | buglist6.00 buglist6.00a _based | mspl13_c
Last Modified: 10-NOV-1990

The Microsoft C Optimizing Compiler provides options for generating
assembly language listings from C source files. In cases where based
allocation is used, the assembly language listings produced with /Fa
(.ASM files) and /Fc (.COD files) contain an error. The EXTRN
directive emitted for based variables is located in the wrong place.

The EXTRN directive for a based variable should be located between the
SEGMENT and ENDS directives for the segment in which the variable is
declared to reside. This allows MASM to generate the correct fixups
for references to this variable, which in turn enables LINK to detect
whether the variable is actually defined in the specified segment.

To workaround this problem, edit the .ASM or .COD listing so that the
EXTRN directives for based variables are located between the correct
SEGMENT and ENDS directives.

Note that this problem also occurs for functions specified in an
alloc_text pragma.

Microsoft has confirmed this to be a problem in C versions 6.00 and
6.00a. We are researching this problem and will post new information
here as it becomes available.

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