CODEWITHSUNDEEP
makefilegnu-make
jww
jww

Reputation: 102246

% not matching zero or more characters in rule?

According to the manual on Defining and Redefining Pattern Rules (and if I am reading it correctly):

‘%’ character matching any sequence of zero or more characters...

But the following is not matching both bench.cpp and bench2.cpp:

bench%.o : bench%.cpp
    $(CXX) $(CXXFLAGS) -DCRYPTOPP_DATA_DIR='"$(PREFIX)/share/cryptopp"' -c $<

%.o : %.cpp 
    $(CXX) $(CXXFLAGS) -c $<

Here's what I see when running make:

$ rm bench*.o
$ make static dynamic cryptest.exe PREFIX=/usr/local
make: Nothing to be done for `static'.
make: Nothing to be done for `dynamic'.
g++ -DNDEBUG -g -O2 -fPIC -march=native -pipe -c bench.cpp
g++ -DNDEBUG -g -O2 -fPIC -march=native -pipe -DCRYPTOPP_DATA_DIR='"/usr/local/share/cryptopp"' -c bench2.cpp

Above, both bench.cpp and bench2.cpp should have -DCRYPTOPP_DATA_DIR='"/usr/local/share/cryptopp"'. I also tried using the asterisk (*) with no joy.

How do I craft a rule that matches both bench.cpp and bench2.cpp?

Upvotes: 1

Views: 176

Answers (2)

jww
jww

Reputation: 102246

Well, I happened to stumble across the proper section of the documentation on this.

According to 4.4 Using Wildcard Characters in File Names, I should probably use an asterisk in this case.

And according to Stallman and the GNUMake manual, % is not a wildcard for specifying file names:

A single file name can specify many files using wildcard characters. The wildcard characters in make are ‘*’, ‘?’ and ‘[…]’ ...

Upvotes: 1

mb14
mb14

Reputation: 22596

According to the link you provided

A pattern rule contains the character ‘%’ (exactly one of them) in the target; otherwise, it looks exactly like an ordinary rule. The target is a pattern for matching file names; the ‘%’ matches any nonempty substring, while other characters match only themselves.

So % doesn't match empty strings.

‘%’ character matching any sequence of zero or more characters...

refers to the definition of vpath which is totally different.

I'm afraid you'll have to use bench1 instead of bench. Alternatively you can use macro to defines 2 rules but write it only once.

Upvotes: 1

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