diff options
Diffstat (limited to 'scripts/recordmcount.pl')
| -rwxr-xr-x | scripts/recordmcount.pl | 106 |
1 files changed, 86 insertions, 20 deletions
diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl index 36c8355c555..1891cf9743f 100755 --- a/scripts/recordmcount.pl +++ b/scripts/recordmcount.pl @@ -119,17 +119,19 @@ $mv = "mv" if ((length $mv) == 0); #print STDERR "running: $P '$arch' '$objdump' '$objcopy' '$cc' '$ld' " . # "'$nm' '$rm' '$mv' '$inputfile'\n"; -my %locals; -my %convert; +my %locals; # List of local (static) functions +my %weak; # List of weak functions +my %convert; # List of local functions used that needs conversion my $type; my $section_regex; # Find the start of a section -my $function_regex; # Find the name of a function (return func name) +my $function_regex; # Find the name of a function + # (return offset and func name) my $mcount_regex; # Find the call site to mcount (return offset) if ($arch eq "x86_64") { $section_regex = "Disassembly of section"; - $function_regex = "<(.*?)>:"; + $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:"; $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount([+-]0x[0-9a-zA-Z]+)?\$"; $type = ".quad"; @@ -141,7 +143,7 @@ if ($arch eq "x86_64") { } elsif ($arch eq "i386") { $section_regex = "Disassembly of section"; - $function_regex = "<(.*?)>:"; + $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:"; $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$"; $type = ".long"; @@ -158,7 +160,6 @@ if ($arch eq "x86_64") { my $text_found = 0; my $read_function = 0; my $opened = 0; -my $text = ""; my $mcount_section = "__mcount_loc"; my $dirname; @@ -186,46 +187,111 @@ my $mcount_s = $dirname . "/.tmp_mc_" . $prefix . ".s"; my $mcount_o = $dirname . "/.tmp_mc_" . $prefix . ".o"; # -# Step 1: find all the local symbols (static functions). +# Step 1: find all the local (static functions) and weak symbols. +# 't' is local, 'w/W' is weak (we never use a weak function) # open (IN, "$nm $inputfile|") || die "error running $nm"; while (<IN>) { if (/^[0-9a-fA-F]+\s+t\s+(\S+)/) { $locals{$1} = 1; + } elsif (/^[0-9a-fA-F]+\s+([wW])\s+(\S+)/) { + $weak{$2} = $1; } } close(IN); +my @offsets; # Array of offsets of mcount callers +my $ref_func; # reference function to use for offsets +my $offset = 0; # offset of ref_func to section beginning + +## +# update_funcs - print out the current mcount callers +# +# Go through the list of offsets to callers and write them to +# the output file in a format that can be read by an assembler. +# +sub update_funcs +{ + return if ($#offsets < 0); + + defined($ref_func) || die "No function to reference"; + + # A section only had a weak function, to represent it. + # Unfortunately, a weak function may be overwritten by another + # function of the same name, making all these offsets incorrect. + # To be safe, we simply print a warning and bail. + if (defined $weak{$ref_func}) { + print STDERR + "$inputfile: WARNING: referencing weak function" . + " $ref_func for mcount\n"; + return; + } + + # is this function static? If so, note this fact. + if (defined $locals{$ref_func}) { + $convert{$ref_func} = 1; + } + + # Loop through all the mcount caller offsets and print a reference + # to the caller based from the ref_func. + for (my $i=0; $i <= $#offsets; $i++) { + if (!$opened) { + open(FILE, ">$mcount_s") || die "can't create $mcount_s\n"; + $opened = 1; + print FILE "\t.section $mcount_section,\"a\",\@progbits\n"; + } + printf FILE "\t%s %s + %d\n", $type, $ref_func, $offsets[$i] - $offset; + } +} + # # Step 2: find the sections and mcount call sites # open(IN, "$objdump -dr $inputfile|") || die "error running $objdump"; +my $text; + while (<IN>) { # is it a section? if (/$section_regex/) { $read_function = 1; + # print out any recorded offsets + update_funcs() if ($text_found); + + # reset all markers and arrays $text_found = 0; + undef($ref_func); + undef(@offsets); + # section found, now is this a start of a function? } elsif ($read_function && /$function_regex/) { - $read_function = 0; $text_found = 1; - $text = $1; - # is this function static? If so, note this fact. - if (defined $locals{$text}) { - $convert{$text} = 1; + $offset = hex $1; + $text = $2; + + # if this is either a local function or a weak function + # keep looking for functions that are global that + # we can use safely. + if (!defined($locals{$text}) && !defined($weak{$text})) { + $ref_func = $text; + $read_function = 0; + } else { + # if we already have a function, and this is weak, skip it + if (!defined($ref_func) || !defined($weak{$text})) { + $ref_func = $text; + } } - # is this a call site to mcount? If so, print the offset from the section - } elsif ($text_found && /$mcount_regex/) { - if (!$opened) { - open(FILE, ">$mcount_s") || die "can't create $mcount_s\n"; - $opened = 1; - print FILE "\t.section $mcount_section,\"a\",\@progbits\n"; - } - print FILE "\t$type $text + 0x$1\n"; + } + + # is this a call site to mcount? If so, record it to print later + if ($text_found && /$mcount_regex/) { + $offsets[$#offsets + 1] = hex $1; } } +# dump out anymore offsets that may have been found +update_funcs() if ($text_found); + # If we did not find any mcount callers, we are done (do nothing). if (!$opened) { exit(0); |