1008360 - clang warning (treated as error) in disable-unified build: LayerSorter.cpp:156:18: warning: unused variable 'BLACK' [-Wunused-const-variable], and many more

Status: RESOLVED FIXED

(Core :: Graphics: Layers, defect)

Description

[Daniel Holbert [:dholbert]]

STR:
 Build with ac_add_options --disable-unified-compilation and recent clang.
 (I'm using clang 3.5)

ACTUAL RESULTS:
{
 0:21.98 Warning: -Wunused-const-variable in $SRCDIR/gfx/layers/LayerSorter.cpp: unused variable 'BLACK'
 0:21.98 $SRCDIR/gfx/layers/LayerSorter.cpp:156:18: warning: unused variable 'BLACK' [-Wunused-const-variable]
 0:21.98 static const int BLACK = 0;
 0:21.98                  ^
 0:21.98 Warning: -Wunused-const-variable in $SRCDIR/gfx/layers/LayerSorter.cpp: unused variable 'RED'
 0:21.98 $SRCDIR/gfx/layers/LayerSorter.cpp:157:18: warning: unused variable 'RED' [-Wunused-const-variable]
 0:21.98 static const int RED = 1;
 0:21.98                  ^
 0:21.98 Warning: -Wunused-const-variable in $SRCDIR/gfx/layers/LayerSorter.cpp: unused variable 'GREEN'
 0:21.98 $SRCDIR/gfx/layers/LayerSorter.cpp:158:18: warning: unused variable 'GREEN' [-Wunused-const-variable]
 0:21.98 static const int GREEN = 2;
 0:21.98                  ^
 0:21.98 Warning: -Wunused-const-variable in $SRCDIR/gfx/layers/LayerSorter.cpp: unused variable 'YELLOW'
 0:21.98 $SRCDIR/gfx/layers/LayerSorter.cpp:159:18: warning: unused variable 'YELLOW' [-Wunused-const-variable]
 0:21.98 static const int YELLOW = 3;
 0:21.98                  ^
 0:21.98 Warning: -Wunused-const-variable in $SRCDIR/gfx/layers/LayerSorter.cpp: unused variable 'BLUE'
 0:21.98 $SRCDIR/gfx/layers/LayerSorter.cpp:160:18: warning: unused variable 'BLUE' [-Wunused-const-variable]
 0:21.98 static const int BLUE = 4;
 0:21.98                  ^
 0:21.98 Warning: -Wunused-const-variable in $SRCDIR/gfx/layers/LayerSorter.cpp: unused variable 'MAGENTA'
 0:21.98 $SRCDIR/gfx/layers/LayerSorter.cpp:161:18: warning: unused variable 'MAGENTA' [-Wunused-const-variable]
 0:21.98 static const int MAGENTA = 5;
 0:21.98                  ^
 0:21.98 Warning: -Wunused-const-variable in $SRCDIR/gfx/layers/LayerSorter.cpp: unused variable 'CYAN'
 0:21.99 $SRCDIR/gfx/layers/LayerSorter.cpp:162:18: warning: unused variable 'CYAN' [-Wunused-const-variable]
 0:21.99 static const int CYAN = 6;
 0:21.99                  ^
 0:21.99 Warning: -Wunused-const-variable in $SRCDIR/gfx/layers/LayerSorter.cpp: unused variable 'WHITE'
 0:21.99 $SRCDIR/gfx/layers/LayerSorter.cpp:163:18: warning: unused variable 'WHITE' [-Wunused-const-variable]
 0:21.99 static const int WHITE = 7;
 0:21.99                  ^
}

I believe these warnings are treated as errors, if you have --enable-warnings-as-errors in your mozconfig.

Comment 1

[Daniel Holbert [:dholbert]]

So there are several issues here:
 (1) these constants are only used inside of the #ifdef USE_XTERM_COLORING, so they should be defined down there
 (2) In builds with USE_XTERM_COLORING is defined, most of the constants are still unused and will still spam these build warnings (errors)

Patch coming up to address both of these.

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: fix v1

This patch:
 (a) moves the variables into the #ifdef where they're used (or some of them are used, anyway)
 (b) comments out the variables that aren't used, so that they're there for documentation purposes, but the compiler won't complain about them.
 (c) adds constants XTERM_FOREGROUND_COLOR_OFFSET and XTERM_BACKGROUND_COLOR_OFFSET to clarify what the "30" and "40" magic numbers are there for.

Comment 3

[Daniel Holbert [:dholbert]]

I verified that this builds correctly when USE_XTERM_COLORING is explicitly defined & also when it's not-defined, BTW.

Comment 4

[Kartikaya Gupta (email:[e-mail])]

Comment on attachment 8420290 [details] [diff] [review]
fix v1

Review of attachment 8420290 [details] [diff] [review]:
-----------------------------------------------------------------

LGTM, thanks.

Comment 5

[Daniel Holbert [:dholbert]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/7e05c20bc99e

Comment 6

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/7e05c20bc99e