Pattern match behavior between 3.80 and 3.81

[Tom Skrainar]

I'm seeing a strange difference between 3.80 and 3.81 regarding what Make thinks a stem should be in a pattern rule.  As far as I can tell, 3.80 does the Right Thing, whereas 
3.81 doesn't.  Looking at the first rule below, it seems the "_charsAfterUnderscore" is matching when it shouldn't.

The makefile is as follows:

------------------------------------------------------------------------------
topsrcdir := ../..

# Macro path definitions for use in rules
FOO_DIR :=              $(topsrcdir)/stuff/include
FOO_INSTDIR :=          $(topsrcdir)/include
 
# Macros defining source files/programs and built headers
FOO_SCRIPTFILES :=      GenerateSomeStuff.pl
HEADER_FILES :=         Foo16_charsAfterUnderscore.h Foo32_charsAfterUnderscore.h \
                        Foo16.h Foo32.h

# Add full paths to file locations
FOO_SCRIPTS :=          $(FOO_SCRIPTFILES)
FOO_GENHDRS :=          $(addprefix $(FOO_DIR)/, $(HEADER_FILES))
FOO_INSTHDRS :=         $(addprefix $(FOO_INSTDIR)/, $(FOO_HDRFILES))

.PHONY: install

install : $(FOO_INSTHDRS) $(FOO_GENHDRS)

# generate decode tables
$(FOO_DIR)/Foo%_charsAfterUnderscore.h: $(FOO_DIR)/Foo%.h $(FOO_SCRIPTS)
    @echo "TARGET is $@, STEM is $*"
    @echo "Generating include file Foo$*_charsAfterUnderscore.h"
    @echo "DEBUG: would have invoked perl GenerateSomeStuff.pl $* $@"

# prototype for decode and execute functions
$(FOO_DIR)/Foo%.h: $(FOO_SCRIPTS)
    @echo "TARGET is $@, STEM is $*"
    @echo "Generating include file Foo$*.h"
    @echo "DEBUG: would have invoked perl 
GenerateSomeStuff.pl $* $@"

------------------------------------------------------------------------------

In 3.80, both rules trigger with a stem of "16" or "32":

(using args -r --debug=i):

$ make -r --debug=i
GNU Make 3.80
Copyright (C) 2002  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Reading makefiles...
Updating goal targets....
 File `install' does not exist.
   File `../../stuff/include/Foo16_charsAfterUnderscore.h' does not exist.
   Looking for an implicit rule for `../../stuff/include/Foo16_charsAfterUnderscore.h'.
   Trying pattern rule with stem `16'.
   Trying implicit prerequisite `../../stuff/include/Foo16.h'.
   Trying rule prerequisite `GenerateSomeStuff.pl'.
   Found an implicit rule for `../../stuff/include/Foo16_charsAfterUnderscore.h'.
     File `../../stuff/include/Foo16.h' does not exist.
     Looking for an implicit rule for `../../stuff/include/Foo16.h'.
     Trying pattern rule with stem `16'.
     Trying rule prerequisite `GenerateSomeStuff.pl'.
     Found an implicit rule for `../../stuff/include/Foo16.h'.
       Looking for an implicit rule for `GenerateSomeStuff.pl'.
       No implicit rule found for `GenerateSomeStuff.pl'.
    Must remake target `../../stuff/include/Foo16.h'.
TARGET is ../../stuff/include/Foo16.h, STEM is 16
Generating include file Foo16.h
DEBUG: would have invoked perl GenerateSomeStuff.pl 16 ../../stuff/include/Foo16.h

[...]



Now in 3.81.... 

first make is "Trying pattern rule with stem `16'" (GOOD)
then starts 
"Trying pattern rule with stem `16_charsAfterUnderscore'" (NOT WHAT I EXPECTED)


$ make -r --debug=i

[...]

Updating goal targets....
 File `install' does not exist.
   File `../../stuff/include/Foo16_charsAfterUnderscore.h' does not exist.
   Looking for an implicit rule for `../../stuff/include/Foo16_charsAfterUnderscore.h'.
   Trying pattern rule with stem `16'.
   Trying implicit prerequisite `../../stuff/include/Foo16.h'.
   Trying pattern rule with stem `16_charsAfterUnderscore'.
   Trying rule prerequisite `GenerateSomeStuff.pl'.
   Found an implicit rule for `../../stuff/include/Foo16_charsAfterUnderscore.h'.
     Looking for an implicit rule for `GenerateSomeStuff.pl'.
     No implicit rule found for `GenerateSomeStuff.pl'.
  Must remake target `../../stuff/include/Foo16_charsAfterUnderscore.h'.
TARGET is ../../stuff/include/Foo16_charsAfterUnderscore.h, STEM is 16_charsAfterUnderscore
Generating include file Foo16_charsAfterUnderscore.h
DEBUG: would have invoked perl GenerateSomeStuff.pl 16_charsAfterUnderscore ../../stuff/include/Foo16_charsAfterUnderscore.h


Any insight (Bug? Me doing something wrong?) into this would be greatly appreciated.

Thanks,

Tom