From e82767910c649f160d6701e47f606f3b8dde4b29 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Sun, 12 Aug 2012 23:29:28 -0400 Subject: Add some basic profiling support to the evaluator Setting the environment variable NIX_COUNT_CALLS to 1 enables some basic profiling in the evaluator. It will count calls to functions and primops as well as evaluations of attributes. For example, to see where evaluation of a NixOS configuration spends its time: $ NIX_SHOW_STATS=1 NIX_COUNT_CALLS=1 ./src/nix-instantiate/nix-instantiate '' -A system --readonly-mode ... calls to 39 primops: 239532 head 233962 tail 191252 hasAttr ... calls to 1595 functions: 224157 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:19' 221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:14' 221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:10' ... evaluations of 7088 attributes: 167377 undefined position 132459 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:119:41' 47322 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:13:21' ... --- src/libutil/util.hh | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/libutil/util.hh') diff --git a/src/libutil/util.hh b/src/libutil/util.hh index edb7c0fa6c..dc38a53ca2 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -17,6 +17,9 @@ namespace nix { #define foreach(it_type, it, collection) \ for (it_type it = (collection).begin(); it != (collection).end(); ++it) +#define foreach_reverse(it_type, it, collection) \ + for (it_type it = (collection).rbegin(); it != (collection).rend(); ++it) + /* Return an environment variable. */ string getEnv(const string & key, const string & def = ""); -- cgit 1.4.1