From a363a9da65d253fa7354ce5fd630f4f94df934cc Mon Sep 17 00:00:00 2001 From: Michael Witten Date: Wed, 17 Apr 2013 02:23:16 +0000 Subject: [PATCH] perf tools: Revert regression in configuration of Python support Among other things, the following: commit 31160d7feab786c991780d7f0ce2755a469e0e5e Date: Tue Jan 8 16:22:36 2013 -0500 perf tools: Fix GNU make v3.80 compatibility issue attempts to aid the user by tapping into an existing error message, as described in the commit message: ... Also fix an issue where _get_attempt was called with only one argument. This prevented the error message from printing the name of the variable that can be used to fix the problem. or more precisely: -$(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2))) +$(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2),$(1))) However, The "missing" argument was in fact missing on purpose; it's absence is a signal that the error message should be skipped, because the failure would be due to the default value, not any user-supplied value. This can be seen in how `_ge_attempt' uses `gea_err' (in the config/utilities.mak file): _ge_attempt = $(if $(get-executable),$(get-executable),$(_gea_warn)$(call _gea_err,$(2))) _gea_warn = $(warning The path '$(1)' is not executable.) _gea_err = $(if $(1),$(error Please set '$(1)' appropriately)) That is, because the argument is no longer missing, the value `$(1)' (associated with `_gea_err') always evaluates to true, thus always triggering the error condition that is meant to be reserved for only the case when a user explicitly supplies an invalid value. Concretely, the result is a regression in the Makefile's configuration of python support; rather than gracefully disable support when the relevant executables cannot be found according to default values, the build process halts in error as though the user explicitly supplied the values. This new commit simply reverts the offending one-line change. Reported-by: Pekka Enberg Link: http://lkml.kernel.org/r/CAOJsxLHv17Ys3M7P5q25imkUxQW6LE_vABxh1N3Tt7Mv6Ho4iw@mail.gmail.com Signed-off-by: Michael Witten --- tools/perf/config/utilities.mak | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/config/utilities.mak b/tools/perf/config/utilities.mak index faffb52fcf80..94d2d4f9c35d 100644 --- a/tools/perf/config/utilities.mak +++ b/tools/perf/config/utilities.mak @@ -173,7 +173,7 @@ _ge-abspath = $(if $(is-executable),$(1)) # Usage: absolute-executable-path-or-empty = $(call get-executable-or-default,variable,default) # define get-executable-or-default -$(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2),$(1))) +$(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2))) endef _ge_attempt = $(if $(get-executable),$(get-executable),$(_gea_warn)$(call _gea_err,$(2))) _gea_warn = $(warning The path '$(1)' is not executable.)