feature: added new tool resolve-inlines to resolve inlined functions in the backtrace aggregation dump from sample-bt and etc.

Author: agentzh

README.markdown

@@ -40,6 +40,7 @@ Table of Contents
     * [ngx-lua-conn-pools](#ngx-lua-conn-pools)
     * [check-debug-info](#check-debug-info)
     * [ngx-phase-handlers](#ngx-phase-handlers)
+    * [resolve-inlines](#resolve-inlines)
 * [Community](#community)
     * [English Mailing List](#english-mailing-list)
     * [Chinese Mailing List](#chinese-mailing-list)
@@ -1361,6 +1362,23 @@ Here is another example for an Nginx worker process with quite a few Nginx modul
 
 [Back to TOC](#table-of-contents)
 
+resolve-inlines
+---------------
+
+This tool calls the `addr2line` utility to resolve the inlined function frames generated by those `sample-*` tools like [sample-bt](#sample-bt).
+
+It accepts two command-line arguments, the `.bt` file and the executable file.
+
+For example,
+
+```
+resolve-inlines a.bt /path/to/nginx > new-a.bt
+```
+
+Right now, inlined functions in PIC (Position-Indenpendent Code) are not yet supported but are technically feasiable. (Patches welcome!)
+
+[Back to TOC](#table-of-contents)
+
 Community
 =========
 

resolve-inlines

@@ -0,0 +1,76 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+my $infile = shift;
+open my $in, $infile or
+    die "Cannot open $infile for reading: $!\n";
+
+my $execfile = shift;
+
+my $cached_limit = 10000;
+my $cached_count = 0;
+my %cached;
+my $tip = 1;
+while (<$in>) {
+    if (/^\t\d+$/) {
+        $tip = 1;
+        print;
+        next;
+    }
+    if (/^ (0x[0-9a-f]+)\b/i) {
+        my $stack = $1;
+        my $line = $_;
+
+        my $frames = $cached{$stack};
+        if (!$frames) {
+            $frames = [];
+            my $addr;
+            if (!$tip) {
+                no warnings 'portable';
+                $addr = hex($stack);
+                # XXX I don't know why I need to substract by 1,
+                # but I need it to get the correct result at least with
+                # gcc 4.8
+                $addr = sprintf("%x", $addr - 1);
+
+            } else {
+                $addr = $stack;
+            }
+            my $out = `addr2line -fsip -e $execfile $addr`;
+            #warn "$addr: $out";
+            open my $t, "<", \$out;
+            while (<$t>) {
+                if (/(\w+) at (\S+:\d+)/) {
+                    push @$frames, [$1, $2];
+                    #warn "$1\n";
+                }
+            }
+            close $t;
+            if (++$cached_count > $cached_limit) {
+                # prevent the cache from growing forever...
+                %cached = ();
+            }
+            $cached{$stack} = $frames;
+        }
+        if (@$frames > 1) {
+            #warn "HIT";
+            for my $fr (@$frames) {
+                my ($func, $loc) = @$fr;
+                print " $stack : $func+0x0/0x0 [$loc]\n";
+            }
+
+        } else {
+            print $line;
+        }
+        #print "@frames\n";
+        #print "$cnt\n";
+
+    } else {
+        print;
+    }
+    undef $tip;
+}
+
+close $in;