URL:
<http://savannah.gnu.org/bugs/?21670>
Summary: implicit rule ignored for prerequisite that is
produced by .DEFAULT
Project: make
Submitted by: egerer
Submitted on: Thursday 11/29/2007 at 12:52
Severity: 3 - Normal
Item Group: Bug
Status: None
Privacy: Public
Assigned to: None
Open/Closed: Open
Discussion Lock: Any
Component Version: 3.81
Operating System: POSIX-Based
Fixed Release: None
_______________________________________________________
Details:
I've found a problem with GNU make 3.81 (built for i686-pc-linux-gnu).
The following makefile can be used to recreate the problem:
# -------------------------------------
CC = cc
.SUFFIXES:
.SUFFIXES: .c .o
.c.o:
$(CC) -c $<
.DEFAULT:
@if [ -f backup/$< ]; then \
ln -s backup/$< . ;\
echo "ln -s backup/$< .";\
else \
echo "'$<' does not exist.";\
false;\
fi
prog: hello.c hello.o
$(CC) -o $@ hello.o
# -------------------------------------
The directory that contains this makefile should also
contain a subdirectory named "backup". That subdirectory
should contain a simple C source file named "hello.c".
Running "make" should create the file "hello.o" from the
file "hello.c" that is produced (in the current directory)
by the commands specified for the special built-in target
".DEFAULT".
Creation of the file "hello.c" works fine, but "make"
fails to produce "hello.o".
Here are the commands to reproduce the problem:
$ ls
backup makefile
$ ls backup
hello.c
$ cat backup/hello.c
#include <stdio.h>
int main(void)
{
printf("hello, world\n");
return 0;
}
$ make -r
ln -s backup/hello.c .
'hello.o' does not exist.
make: *** [hello.o] Error 1
$ ls
backup hello.c makefile
$
After this I've run "make" in the debug mode:
$ rm hello.c
$ make -rd | nl -ba
1 GNU Make 3.81
2 Copyright (C) 2006 Free Software Foundation, Inc.
3 This is free software; see the source for copying conditions.
4 There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
5 PARTICULAR PURPOSE.
6
7 This program built for i686-pc-linux-gnu
8 Reading makefiles...
9 Reading makefile `makefile'...
10 Updating makefiles....
11 Considering target file `makefile'.
12 Looking for an implicit rule for `makefile'.
13 No implicit rule found for `makefile'.
14 Using default commands for `makefile'.
15 Finished prerequisites of target file `makefile'.
16 No need to remake target `makefile'.
17 Updating goal targets....
18 Considering target file `prog'.
19 File `prog' does not exist.
20 Considering target file `hello.c'.
21 File `hello.c' does not exist.
22 Looking for an implicit rule for `hello.c'.
23 No implicit rule found for `hello.c'.
24 Using default commands for `hello.c'.
25 Finished prerequisites of target file `hello.c'.
26 Must remake target `hello.c'.
27 Putting child 0x080774d8 (hello.c) PID 10332 on the chain.
28 Live child 0x080774d8 (hello.c) PID 10332
29 ln -s backup/hello.c .
30 Reaping winning child 0x080774d8 PID 10332
31 Removing child 0x080774d8 PID 10332 from chain.
32 Successfully remade target file `hello.c'.
33 Considering target file `hello.o'.
34 File `hello.o' does not exist.
35 Looking for an implicit rule for `hello.o'.
36 Trying pattern rule with stem `hello'.
37 Trying implicit prerequisite `hello.c'.
38 Trying pattern rule with stem `hello'.
39 Trying implicit prerequisite `hello.c'.
40 Looking for a rule with intermediate file `hello.c'.
41 Avoiding implicit rule recursion.
42 No implicit rule found for `hello.o'.
43 Using default commands for `hello.o'.
44 Finished prerequisites of target file `hello.o'.
45 Must remake target `hello.o'.
46 Putting child 0x080777f0 (hello.o) PID 10335 on the chain.
47 Live child 0x080777f0 (hello.o) PID 10335
48 'hello.o' does not exist.
49 Reaping losing child 0x080777f0 PID 10335
make: *** [hello.o] Error 1
50 Removing child 0x080777f0 PID 10335 from chain.
When "make" looks for an implicit rule for "hello.o" (line 35-41)
it should recognize that the target `hello.o' could be build
from the implicit prerequisite `hello.c' by applying the command
specified for the double-suffix rule ".c.o:" (line 6 of makefile).
In my opinion, it is a bug that GNU make 3.81 finds no implicit
rule for "hello.o" (line 42).
_______________________________________________________
File Attachments:
-------------------------------------------------------
Date: Thursday 11/29/2007 at 12:52 Name: makefile Size: 332B By: egerer
<http://savannah.gnu.org/bugs/download.php?file_id=14507>
-------------------------------------------------------
Date: Thursday 11/29/2007 at 12:52 Name: hello.c Size: 79B By: egerer
<http://savannah.gnu.org/bugs/download.php?file_id=14508>
_______________________________________________________
Reply to this item at:
<http://savannah.gnu.org/bugs/?21670>
_______________________________________________
Message sent via/by Savannah
http://savannah.gnu.org/
_______________________________________________
Bug-make mailing list
Bug-make@gnu.org
http://lists.gnu.org/mailman/listinfo/bug-make
