[Bug translator/17292] New: multi-line strings broken

["dsmith at redhat dot com" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=17292

            Bug ID: 17292
           Summary: multi-line strings broken
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: translator
          Assignee: systemtap at sourceware dot org
          Reporter: dsmith at redhat dot com

Multi-line strings don't seem to work in systemtap. (Are they supposed to?)

With the following script:

====
probe begin 
{
    str = "hello
there"
    printf("%s\n", str)
}
====

You get this:

====
# stap ./str.stp
parse error: Could not find matching closing quote
    at: junk 'hello' at ./str.stp:3:8
     source:     str = "hello
                       ^

1 parse error.
Pass 1: parse failed.  [man error::pass1]
====

The above seems reasonable. So, let's add a '\' to the end of the line:

====
probe begin 
{
    str = "hello\
there"
    printf("%s\n", str)
}
====

Here we get past the translator, but the resulting C code won't compile:

====
# stap ./str.stp
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c: In function
âprobe_2254â:
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:102:26: error:
missing terminating " character [-Werror]
       strlcpy (l->l_str, "hello
                          ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:102:7: error:
missing terminating " character
       strlcpy (l->l_str, "hello
       ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:103:6: error:
missing terminating " character [-Werror]
 there", MAXSTRINGLEN);
      ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:103:1: error:
missing terminating " character
 there", MAXSTRINGLEN);
 ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:104:7: error:
missing terminating " character [-Werror]
       "hello
       ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:104:7: error:
missing terminating " character
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:103:1: error:
âthereâ undeclared (first use in this function)
 there", MAXSTRINGLEN);
 ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:103:1: note:
each undeclared identifier is reported only once for each function it appears
in
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:105:1: error:
expected â)â before âthereâ
 there";
 ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:105:6: error:
missing terminating " character [-Werror]
 there";
      ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:105:1: error:
missing terminating " character
 there";
 ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:106:5: error:
too few arguments to function âstrlcpyâ
     });
     ^
In file included from include/linux/bitmap.h:8:0,
                 from include/linux/cpumask.h:11,
                 from
/usr/src/kernels/3.15.8-200.fc20.x86_64/arch/x86/include/asm/cpumask.h:4,
                 from
/usr/src/kernels/3.15.8-200.fc20.x86_64/arch/x86/include/asm/msr.h:10,
                 from
/usr/src/kernels/3.15.8-200.fc20.x86_64/arch/x86/include/asm/processor.h:20,
                 from
/usr/src/kernels/3.15.8-200.fc20.x86_64/arch/x86/include/asm/thread_info.h:23,
                 from include/linux/thread_info.h:54,
                 from
/usr/src/kernels/3.15.8-200.fc20.x86_64/arch/x86/include/asm/preempt.h:6,
                 from include/linux/preempt.h:18,
                 from include/linux/spinlock.h:50,
                 from include/linux/seqlock.h:35,
                 from include/linux/time.h:5,
                 from include/linux/stat.h:18,
                 from include/linux/module.h:10,
                 from /usr/local/share/systemtap/runtime/linux/runtime.h:14,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:24:
include/linux/string.h:26:8: note: declared here
 size_t strlcpy(char *, const char *, size_t);
        ^
/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.c:106:5: error:
expected â;â before â}â token
     });
     ^
cc1: all warnings being treated as errors
make[1]: *** [/tmp/stapLwuE5U/stap_1d9558597b8a3f10f9d97d340d0f13d3_927_src.o]
Error 1
make: *** [_module_/tmp/stapLwuE5U] Error 2
WARNING: kbuild exited with status: 2
Pass 4: compilation failed.  [man error::pass4]
====

OK, let's put '\\' at the end of the string:

====
probe begin 
{
    str = "hello\\
there"
    printf("%s\n", str)
}
====

Here we can't get past the translator:

====
# stap ./str.stp
parse error: Could not find matching closing quote
    at: junk 'hello\\' at ./str.stp:3:8
     source:     str = "hello\\
                       ^

1 parse error.
Pass 1: parse failed.  [man error::pass1]
====

OK, let's put '\\\' at the end:

====
probe begin 
{
    str = "hello\\\
there"
    printf("%s\n", str)
}
====

Here we get success (of a sort):

====
# stap ./str.stp
hello    here
====

The translator outputs valid C code, which got compiled, but the result isn't
what we were looking for. One of those backslashes got attached to the 't' in
'there' and got turned into a tab character.

(This bug might be related to bug #13371)

-- 
You are receiving this mail because:
You are the assignee for the bug.