Updated GenLibDeps.pl to employ "use strict" to help prevent uses of variables

that have not yet been defined.

Removed used of grep and sed when parsing the results of "nm". This was
originally motivated because if the user has specified options to grep using
the environment variable GREP_OPTIONS this could break the script. Piping
through grep/sed/sort/uniq is also (to my understanding) not necessary, and
the equivalent operations can be done much faster in the Perl script.

Using a crude benchmark, these changes resulted in a 3x speedup in the
execution of GenLibDeps.pl.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44372 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/utils/GenLibDeps.pl b/utils/GenLibDeps.pl
index 419d8f92d866d62cf43d074f8d702a8cbfa924f7..16aed89474895983f348a5b4d80cf4f3eab53165 100755 (executable)
--- a/utils/GenLibDeps.pl
+++ b/utils/GenLibDeps.pl
@@ -8,6 +8,7 @@
 #
 # Syntax:   GenLibDeps.pl [-flat] <directory_with_libraries_in_it> [path_to_nm_binary]
 #
+use strict;
 
 # Parse arguments... 
 my $FLAT = 0;
@@ -47,8 +48,8 @@ if (!defined($nmPath) || $nmPath eq "") {
 opendir DIR,$Directory;
 my @files = readdir DIR;
 closedir DIR;
-@libs = grep(/libLLVM.*\.a$/,sort(@files));
-@objs = grep(/LLVM.*\.o$/,sort(@files));
+my @libs = grep(/libLLVM.*\.a$/,sort(@files));
+my @objs = grep(/LLVM.*\.o$/,sort(@files));
 
 # Declare the hashes we will use to keep track of the library and object file
 # symbol definitions.
@@ -56,10 +57,11 @@ my %libdefs;
 my %objdefs;
 
 # Gather definitions from the libraries
-foreach $lib (@libs ) {
-  open DEFS, 
-    "$nmPath -g $Directory/$lib | grep ' [ABCDGRST] ' | sed -e 's/^[0-9A-Fa-f]* [ABCDGRST] //' | sort | uniq |";
+foreach my $lib (@libs ) {
+  open DEFS, "$nmPath -g $Directory/$lib|";
   while (<DEFS>) {
+    next if (! / [ABCDGRST] /);
+    s/^[^ ]* [ABCDGRST] //;    
     chomp($_);
     $libdefs{$_} = $lib;
   }
@@ -67,10 +69,11 @@ foreach $lib (@libs ) {
 }
 
 # Gather definitions from the object files.
-foreach $obj (@objs ) {
-  open DEFS, 
-    "$nmPath -g $Directory/$obj | grep ' [ABCDGRST] ' | sed -e 's/^[0-9A-Fa-f]* [ABCDGRST] //' | sort | uniq |";
+foreach my $obj (@objs ) {
+  open DEFS, "$nmPath -g $Directory/$obj |";
   while (<DEFS>) {
+    next if (! / [ABCDGRST] /);
+    s/^[^ ]* [ABCDGRST] //;
     chomp($_);
     $objdefs{$_} = $obj;
   }
@@ -100,7 +103,7 @@ sub gen_one_entry {
       $DepLibs{$libdefs{$_}} = [] unless exists $DepLibs{$libdefs{$_}};
       push(@{$DepLibs{$libdefs{$_}}}, $_);
     } elsif (defined($objdefs{$_}) && $objdefs{$_} ne $lib) {
-      $libroot = $lib;
+      my $libroot = $lib;
       $libroot =~ s/lib(.*).a/$1/;
       if ($objdefs{$_} ne "$libroot.o") {
         $DepLibs{$objdefs{$_}} = [] unless exists $DepLibs{$objdefs{$_}};
@@ -115,14 +118,14 @@ sub gen_one_entry {
       if ($WHY) {
         print "\n";
         my @syms = @{$DepLibs{$key}};
-        foreach $sym (@syms) {
+        foreach my $sym (@syms) {
           print "  $sym\n";
         }
       }
     } else {
       print "    <li>$key</li>\n";
     }
-    $suffix = substr($key,length($key)-1,1);
+    my $suffix = substr($key,length($key)-1,1);
     $key =~ s/(.*)\.[oa]/$1/;
     if ($suffix eq "a") {
       if (!$FLAT) { print DOT "$lib_ns -> $key [ weight=0 ];\n" };
@@ -169,7 +172,7 @@ if (!$FLAT) {
 }
 
 # Print libraries first
-foreach $lib (@libs) {
+foreach my $lib (@libs) {
   gen_one_entry($lib);
 }
 
@@ -196,7 +199,7 @@ if (!$FLAT) {
 }
 
 # Print objects second
-foreach $obj (@objs) {
+foreach my $obj (@objs) {
   gen_one_entry($obj);
 }