perf probe: Fix !dwarf build

Fix the !drawf build.

This uses the existing NO_DWARF_SUPPORT mechanism we use for that,
but it's really fragile and needs a cleanup. (in a separate patch)

1) Such uses:

 #ifndef NO_DWARF_SUPPORT

are double inverted logic a'la 'not not'. Instead the flag should
be called DWARF_SUPPORT.

2) Furthermore, assymetric #ifdef polluted code flow like:

        if (need_dwarf)
 #ifdef NO_DWARF_SUPPORT
                die("Debuginfo-analysis is not supported");
 #else   /* !NO_DWARF_SUPPORT */
                pr_debug("Some probes require debuginfo.\n");

        fd = open_vmlinux();

is very fragile and not acceptable. Instead of that helper functions
should be created and the dwarf/no-dwarf logic should be separated more
cleanly.

3) Local variable #ifdefs like this:

 #ifndef NO_DWARF_SUPPORT
        int fd;
 #endif

Are fragile as well and should be eliminated. Helper functions achieve
that too.

Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100316220612.32050.33806.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 64dea6c..f333269 100644 (file)
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1012,8 +1012,10 @@ end_dwarf:
        if (!sym)
                die("Kernel symbol \'%s\' not found - probe not added.",
                    tev->point.symbol);
+#ifndef NO_DWARF_SUPPORT
 found:
        close(fd);
+#endif
        return ntevs;
 }
 
@@ -1172,10 +1174,13 @@ void show_line_range(struct line_range *lr)
        unsigned int l = 1;
        struct line_node *ln;
        FILE *fp;
+#ifndef NO_DWARF_SUPPORT
        int fd, ret;
+#endif
 
        /* Search a line range */
        init_vmlinux();
+#ifndef NO_DWARF_SUPPORT
        fd = open_vmlinux();
        if (fd < 0)
                die("Could not open debuginfo file.");
@@ -1183,6 +1188,7 @@ void show_line_range(struct line_range *lr)
        if (ret <= 0)
                die("Source line is not found.\n");
        close(fd);
+#endif
 
        setup_pager();