59675 - Occurences of uninitialized variables being used before being set (in layout)

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Rich Burridge]

For more details on this problem, see:

http://bugzilla.mozilla.org/show_bug.cgi?id=59652

This bug is just for the warnings in various source files in the Layout
module:

/layout/base/src/nsDocumentViewer.cpp
nsDocumentViewer.cpp:650: warning: `nsresult rv' might be used uninitialized in
----
/layout/html/base/src/nsBlockFrame.cpp
nsBlockFrame.cpp:1524: warning: `PRTime start' might be used uninitialized in
this function
nsBlockFrame.cpp:1525: warning: `PRInt32 ctc' might be used uninitialized in
this function
nsBlockFrame.cpp:6385: warning: `PRTime start' might be used uninitialized in
this function
nsBlockFrame.cpp:6386: warning: `PRInt32 drawnLines' might be used uninitialized
in this function
----
/layout/html/base/src/nsFrame.cpp
nsFrame.cpp:3306: warning: `class nsIFrame * thisBlock' might be used
uninitialized in this function
nsFrame.cpp:3336: warning: `class nsIFrame * thisBlock' might be used
uninitialized in this function
----
/layout/html/base/src/nsHTMLReflowState.cpp
nsHTMLReflowState.cpp:249: warning: `nsCSSFrameType frameType' might be used
uninitialized in this function
----
/layout/html/base/src/nsImageMap.cpp
nsImageMap.cpp:955: warning: `nsresult rv' might be used uninitialized in this
function
----
/layout/html/base/src/nsPresShell.cpp
nsPresShell.cpp:3805: warning: `class nsIFrame * lastInFlow' might be used
uninitialized in this function
nsPresShell.cpp:5104: warning: `PRTime beforeReflow' might be used uninitialized
in this function
nsPresShell.cpp:5104: warning: `PRTime afterReflow' might be used uninitialized
----
/layout/html/base/src/nsSplittableFrame.cpp
nsSplittableFrame.cpp:94: warning: `class nsSplittableFrame * firstInFlow' might
be used uninitialized in this function
nsSplittableFrame.cpp:106: warning: `class nsSplittableFrame * lastInFlow' might
be used uninitialized in this function
----
/layout/html/base/src/nsTextFrame.cpp
nsTextFrame.cpp:1004: warning: `nscolor foreColor' might be used uninitialized
in this function
nsTextFrame.cpp:1158: warning: `class nsIFrame * lastInFlow' might be used
uninitialized in this function
nsTextFrame.cpp:1511: warning: `nscolor overColor' might be used uninitialized
in this function
nsTextFrame.cpp:1512: warning: `nscolor underColor' might be used uninitialized
nsTextFrame.cpp:1513: warning: `nscolor strikeColor' might be used uninitialized
in this function
nsTextFrame.cpp:3307: warning: `PRBool keepSearching' might be used
uninitialized in this function
----
/layout/html/document/src/nsFrameSetFrame.cpp
nsFrameSetFrame.cpp:977: warning: `PRBool * verBordersVis' might be used
uninitialized in this function
nsFrameSetFrame.cpp:978: warning: `class nsHTMLFramesetBorderFrame **
verBorders' might be used uninitialized in this function
nsFrameSetFrame.cpp:979: warning: `nscolor * verBorderColors' might be used
uninitialized in this function
nsFrameSetFrame.cpp:980: warning: `PRBool * horBordersVis' might be used
uninitialized in this function
nsFrameSetFrame.cpp:981: warning: `class nsHTMLFramesetBorderFrame **
horBorders' might be used uninitialized in this function
nsFrameSetFrame.cpp:982: warning: `nscolor * horBorderColors' might be used
uninitialized in this function
nsFrameSetFrame.cpp:983: warning: `PRInt32 * childTypes' might be used
uninitialized in this function
nsFrameSetFrame.cpp:987: warning: `struct nsBorderColor * childBorderColors'
might be used uninitialized in this function
nsFrameSetFrame.cpp:988: warning: `nscolor borderColor' might be used
uninitialized in this function
----
/layout/html/forms/src/nsIsIndexFrame.cpp
nsIsIndexFrame.cpp:189: warning: `nsresult result' might be used uninitialized
in this function
nsIsIndexFrame.cpp:340: warning: `nsresult result' might be used uninitialized
in this function
----
/layout/html/style/src/nsCSSParser.cpp
nsCSSParser.cpp:2299: warning: `enum nsCSSUnit units' might be used
uninitialized in this function
----
/layout/html/style/src/nsCSSRendering.cpp
nsCSSRendering.cpp:225: warning: `nscoord outsideEdge' might be used
uninitialized in this function
nsCSSRendering.cpp:225: warning: `nscoord insideEdge' might be used
uninitialized in this function
nsCSSRendering.cpp:225: warning: `nscoord outsideTL' might be used uninitialized
in this function
nsCSSRendering.cpp:225: warning: `nscoord insideTL' might be used uninitialized
nsCSSRendering.cpp:225: warning: `nscoord outsideBR' might be used uninitialized
in this function
nsCSSRendering.cpp:226: warning: `nscoord insideBR' might be used uninitialized
----
/layout/html/style/src/nsCSSStyleRule.cpp
nsCSSStyleRule.cpp:1653: warning: `enum nsSystemAttrID sysID' might be used
uninitialized in this function
nsCSSStyleRule.cpp:2786: warning: `enum nsStyleContentType type' might be used
uninitialized in this function
----
/layout/html/style/src/nsStyleUtil.cpp
nsStyleUtil.cpp:276: warning: `PRInt32 * column' might be used uninitialized in
----
/layout/html/table/src/nsCellMap.cpp
nsCellMap.cpp:948: warning: `PRInt32 endColIndex' might be used uninitialized in
this function
----
/layout/html/table/src/nsTableOuterFrame.cpp
nsTableOuterFrame.cpp:1096: warning: `nsresult rv' might be used uninitialized
in this function
----
/layout/html/table/src/nsTableRowFrame.cpp
nsTableRowFrame.cpp:1309: warning: `nsresult rv' might be used uninitialized in
----
/layout/html/table/src/nsTableRowGroupFrame.cpp
nsTableRowGroupFrame.cpp:1775: warning: `class nsIFrame * tempFrame' might be
used uninitialized in this function
----
/layout/html/table/src/nsTableBorderCollapser.cpp
nsTableBorderCollapser.cpp:796: warning: `struct nsStyleSpacing *
winningStyleBorder' might be used uninitialized in this function
----
 
/layout/xml/document/src/nsXMLContentSink.cpp
nsXMLContentSink.cpp: In method `nsresult
nsXMLContentSink::DidBuildModel(int)':nsXMLContentSink.cpp:261: warning:
`nsresult rv' might be used uninitialized in
----
 
/layout/xul/base/src/nsBoxToBlockAdaptor.cpp
nsBoxToBlockAdaptor.cpp:503: warning: `nsresult rv' might be used uninitialized
../../../../dist/include/nsAReadableString.h:1085: warning: `int whichString'
might be used uninitialized in this function
----
/layout/xul/base/src/nsBoxFrame.cpp
nsBoxFrame.cpp:1418: warning: `nscoord onePixel' might be used uninitialized in
----

Comment 1

[Heikki Toivonen (remove -bugzilla when emailing directly)]

I will at least start with the XML stuff.

Comment 2

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Attachment: (Av1) Fix docviewer, blockframe, imagemap, xml

Comment 3

[Johnny Stenback (:jst)]

Appart from "PRTime x = 0;" having to be changed to "PRTime x = LL_ZERO();" (to
compile on the mac) the attached diff looks fine with me, r=jst

Comment 4

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Attachment: (Av1b) Previous patch with LL_ZERO [Checked in: Comment 6]

Comment 5

[Chris Waterson]

sr=waterson

Comment 6

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Checked in fixes to docviewer, blockframe, imagemap & xml. Passing on to
pollmann who seems to be in charge of nsFrameSetFrame.cpp at least. Feel free to
fix any other places you feel comfortable with...

Please fix cases where the compiler is actually wrong (i.e. we do not use
variable unitialized even if the compiler warns). Safe warnings make it harder
to find the real warnings...

Comment 7

[Eric Pollmann]

Attachment: (Bv1) patch nsFrameSetFrame and nsIsIndexFrame (hand edits, not valid patch) [Checked in: Comment 8]

Comment 8

[Eric Pollmann]

Checked in fixes to nsFrameSetFrame.cpp and nsIsIndexFrame.cpp

Handing off to Marc for changes to core layout, CC'ing Chris for table changes.

Comment 9

[Aleksey Nogin]

Currently (http://tinderbox.mozilla.org/SeaMonkey/warn1010706660.6236.html) I
see the following warnings:

layout/base/src/nsBidiPresUtils.cpp:166
 `nsresult rv' might be used uninitialized in this function

layout/base/src/nsBidiPresUtils.cpp:222
 `PRInt32 contentOffset' might be used uninitialized in this function

layout/base/src/nsBidiPresUtils.cpp:228
 `PRBool isTextFrame' might be used uninitialized in this function

layout/base/src/nsBidiPresUtils.cpp:585
 `nscoord dWidth' might be used uninitialized in this function

layout/base/src/nsPresContext.cpp:327
 `struct nsFont * font' might be used uninitialized in this function

layout/html/base/src/nsBlockFrame.cpp:707
 `class nsSpaceManager * spaceManager' might be used uninitialized in this function

layout/html/base/src/nsBlockFrame.cpp:708
 `class nsSpaceManager * oldSpaceManager' might be used uninitialized in this
function

layout/html/base/src/nsFrame.cpp:3692
 `class nsIFrame * newFrame' might be used uninitialized in this function

layout/html/base/src/nsHTMLReflowState.cpp:308
 `nsCSSFrameType frameType' might be used uninitialized in this function

layout/html/base/src/nsPresShell.cpp:6246
 `PRTime beforeReflow' might be used uninitialized in this function
 `PRTime afterReflow' might be used uninitialized in this function

layout/html/base/src/nsSplittableFrame.cpp:109
 `class nsSplittableFrame * firstInFlow' might be used uninitialized in this
function

layout/html/base/src/nsSplittableFrame.cpp:121
 `class nsSplittableFrame * lastInFlow' might be used uninitialized in this function

layout/html/base/src/nsTextFrame.cpp:1172
 `nscolor foreColor' might be used uninitialized in this function

layout/html/base/src/nsTextFrame.cpp:1351
 `class nsIFrame * lastInFlow' might be used uninitialized in this function

layout/html/base/src/nsTextFrame.cpp:1736
 `nscolor overColor' might be used uninitialized in this function

layout/html/base/src/nsTextFrame.cpp:1737
 `nscolor underColor' might be used uninitialized in this function

layout/html/base/src/nsTextFrame.cpp:1738
 `nscolor strikeColor' might be used uninitialized in this function

layout/html/base/src/nsTextFrame.cpp:1742
 `nscolor overrideColor' might be used uninitialized in this function

layout/html/base/src/nsTextFrame.cpp:3082
 `const char * text' might be used uninitialized in this function

layout/html/base/src/nsTextFrame.cpp:4064
 `PRBool keepSearching' might be used uninitialized in this function

layout/html/style/src/nsCSSRendering.cpp:1753
 `int shrinkage' might be used uninitialized in this function
 `int startRadius' might be used uninitialized in this function`int endRadius'
might be used uninitialized in this function


layout/html/style/src/nsCSSRendering.cpp:257
 `int outsideEdge' might be used uninitialized in this function
 `int insideEdge' might be used uninitialized in this function`int outsideTL'
might be used uninitialized in this function`int insideTL' might be used
uninitialized in this function`int outsideBR' might be used uninitialized in
this function

layout/html/style/src/nsCSSRendering.cpp:258
 `int insideBR' might be used uninitialized in this function

layout/html/table/src/BasicTableLayoutStrategy.cpp:830
 `nscoord divisor' might be used uninitialized in this function

layout/html/table/src/BasicTableLayoutStrategy.cpp:831
 `nscoord numerator' might be used uninitialized in this function

layout/html/table/src/nsCellMap.cpp:996
 `PRInt32 endColIndex' might be used uninitialized in this function

layout/html/table/src/nsTableFrame.cpp:5091
 `void * value' might be used uninitialized in this function

layout/html/table/src/nsTableFrame.cpp:5092
 `void (* dtorFunc)(nsIPresContext *, nsIFrame *, nsIAtom *, void *)' might be
used uninitialized in this function

layout/xul/base/src/nsBoxFrame.cpp:1647
 `nscoord onePixel' might be used uninitialized in this function

layout/xul/base/src/nsBoxObject.cpp:68
 `class nsISupports * foundInterface' might be used uninitialized in this function

layout/xul/base/src/nsBoxToBlockAdaptor.cpp:582
 `nsresult rv' might be used uninitialized in this function

layout/xul/base/src/nsTextBoxFrame.cpp:331
 `nscolor overColor' might be used uninitialized in this function

layout/xul/base/src/nsTextBoxFrame.cpp:332
 `nscolor underColor' might be used uninitialized in this function

layout/xul/base/src/nsTextBoxFrame.cpp:333
 `nscolor strikeColor' might be used uninitialized in this function

layout/xul/base/src/outliner/src/nsOutlinerContentView.cpp:190
 `class nsISupports * foundInterface' might be used uninitialized in this function

layout/xul/base/src/outliner/src/nsOutlinerSelection.cpp:271
 `class nsISupports * foundInterface' might be used uninitialized in this function

Comment 10

[Aleksey Nogin]

Attachment: 48 warning in layout

These are the warnings listed in
http://tinderbox.mozilla.org/SeaMonkey/warn1012854360.1135.html (Mon, 04 Feb
2002 15:26 EST)

I am very surprized this was postponed until after 1.0 - these warning should
be relatively easy to fix and fixing them is quite likely to make Mozilla more
stable...

Comment 11

[Aleksey Nogin]

Attachment: 44 warning in layout (Wed, 06 Mar 2002 14:19 EST)

Currently (http://tinderbox.mozilla.org/SeaMonkey/warn1015442340.18286.html -
Wed, 06 Mar 2002 14:19 EST) there are 44 "xxx might be use uninitialized"
warnings in layout:

6 in layout/base/src:
   nsBidi.cpp - 1 
   nsBidiPresUtils.cpp - 4
   nsPresContext.cpp - 1
15 in layout/html/base/src :
   nsBlockFrame.cpp - 2
   nsFrame.cpp - 1
   nsHTMLReflowState.cpp - 1
   nsPresShell.cpp - 1
   nsSplittableFrame.cpp - 2
   nsTextFrame.cpp - 8
3 in layout/html/style/src:
   nsCSSRendering.cpp - 3
5 in layout/html/table/src:
   BasicTableLayoutStrategy.cpp - 2
   nsCellMap.cpp - 3
8 in layout/xul/base/src:
   nsBoxFrame.cpp - 1
   nsBoxObject.cpp - 1
   nsBoxToBlockAdaptor.cpp - 1
   nsTextBoxFrame.cpp - 3
   nsOutlinerContentView.cpp - 1
   nsOutlinerSelection.cpp - 1

Comment 12

[Aleksey Nogin]

Today's check-in for bug 126473 fixed 3 warnings in layout/xul, there are now 41
of them left in layout.

Comment 13

[Aleksey Nogin]

Today's checkin to bug 137094 fixed the two
layout/html/base/src/nsBlockFrame.cpp warnings.

Current list of files in layout with "may be used uninitialized" warnings:

layout/base/src/nsBidi.cpp
layout/base/src/nsBidiPresUtils.cpp
layout/base/src/nsPresContext.cpp
layout/html/base/src/nsFrame.cpp
layout/html/base/src/nsHTMLReflowState.cpp
layout/html/base/src/nsPresShell.cpp
layout/html/base/src/nsSplittableFrame.cpp
layout/html/base/src/nsTextFrame.cpp
layout/html/style/src/nsCSSRendering.cpp
layout/html/table/src/BasicTableLayoutStrategy.cpp
layout/html/table/src/nsCellMap.cpp
layout/xul/base/src/nsBoxFrame.cpp
layout/xul/base/src/nsBoxToBlockAdaptor.cpp
layout/xul/base/src/nsTextBoxFrame.cpp

Comment 14

[Christopher Hoess (gone)]

->Misc Code

Comment 15

[Boris Zbarsky [:bzbarsky]]

How about an up-to-date list here?

Comment 16

[Christopher Hoess (gone)]

The current list:

/layout/base/src/nsPresContext.cpp
/layout/html/base/src/nsFrame.cpp
/layout/html/base/src/nsHTMLReflowState.cpp
/layout/html/base/src/nsPresShell.cpp
/layout/html/base/src/nsTextFrame.cpp
/layout/html/style/src/nsCSSRendering.cpp
/layout/xul/base/src/nsTextBoxFrame.cpp

Comment 17

[Aleksey Nogin]

Attachment: 26 warnings in layout (Mon, 09 Jun 2003 13:35 PDT)

Count by file:

layout/base/src/nsPresContext.cpp - 1
layout/html/base/src/nsFrame.cpp - 3
layout/html/base/src/nsHTMLReflowState.cpp - 1
layout/html/base/src/nsPresShell.cpp - 1
layout/html/base/src/nsTextFrame.cpp - 8
layout/html/style/src/nsCSSRendering.cpp - 9
layout/xul/base/src/nsTextBoxFrame.cpp - 3

Comment 18

[Serge Gautherie (:sgautherie)]

(for the record)
Bug 230397 patch Bv1b belonged to this bug.

Comment 19

[Serge Gautherie (:sgautherie)]

Attachment: (Cv1) <nsTextBoxFrame.cpp>

This patch comes from bug 132141 (which was resolved as duplicate...):
The compiler is confused by all the |if()| :-|

Comment 20

[Serge Gautherie (:sgautherie)]

Comment on attachment 146149 [details] [diff] [review]
(Cv1) <nsTextBoxFrame.cpp>


I have no compiler: Could you compile/test/review this patch ? Thanks.

Comment 21

[jag (Peter Annema)]

Comment on attachment 146149 [details] [diff] [review]
(Cv1) <nsTextBoxFrame.cpp>

Another way to tackle this is to merge these two pieces of code and do the
drawing where currently the color is assigned. That way you can completely get
rid of overColor, underColor and strikeColor. hasDecorations seems to be
superfluous too.

Comment 22

[Serge Gautherie (:sgautherie)]

Attachment: (Cv1b) <nsTextBoxFrame.cpp>

Cv1, with comment 21 suggestion(s).

Comment 23

[Serge Gautherie (:sgautherie)]

Attachment: (Cv1c) <nsTextBoxFrame.cpp>

Cv1b, with |vis| reuse.

Comment 24

[Serge Gautherie (:sgautherie)]

Comment on attachment 146974 [details] [diff] [review]
(Cv1c) <nsTextBoxFrame.cpp>


I wonder if line 434 could be fully removed:
{{
433	    if (buffer) {
434	      const nsStyleVisibility* vis = GetStyleVisibility();
435	      nsBidiDirection direction =
}}
as there is line 331
{{
330	// Align our text within the overall rect by checking our text-align
property.
331	const nsStyleVisibility* vis = GetStyleVisibility();
332	const nsStyleText* textStyle = GetStyleText();
}}
or if it does need to be called again.

Comment 25

[Serge Gautherie (:sgautherie)]

Comment on attachment 146974 [details] [diff] [review]
(Cv1c) <nsTextBoxFrame.cpp>


I wonder if line 434 could be fully removed:
{{
433	    if (buffer) {
434	      const nsStyleVisibility* vis = GetStyleVisibility();
435	      nsBidiDirection direction =
}}
as there is line 331
{{
330	// Align our text within the overall rect by checking our text-align
property.
331	const nsStyleVisibility* vis = GetStyleVisibility();
332	const nsStyleText* textStyle = GetStyleText();
}}
or if it does need to be called again.

I have no compiler: Could you compile/test/review this patch ? Thanks.

Comment 26

[Atul Aggarwal]

Surprisingly, there is no warning at all in the layout/ code (using gcc4.6.1). Hence closing this bug.