[oe] [PATCH][meta-qt5][master/jethro] qtscript/qtwebkit: disable thumb for armv4 and armv5 only to fix segfault on armv7

[Andreas Müller]

We have a simple application containing a QWebView which segfaulted during
loading a page on a CortexA9 (armv7 thumb2). After enabling debug information
for qtwebkit and remote debug session the point of segfault was detected in

Source/JavaScriptCore/llint/LowLevelInterpreter.asm:1082
  callSlowPath(_llint_slow_path_new_func_exp)

Further digging around lead to similar source in:

* qtwebkit: Source/JavaScriptCore/assembler/ARMv7Assembler.h
* qtscript: src/3rdparty/javascriptcore/JavaScriptCore/assembler/ARMv7Assembler.h

In these files a class ARMThumbImmediate is declared and used in many places.
This lead me to the suspicion that compiligng for armv7 expects thumb support.

The following tests were performed:

* our application is working fine again
* qtscript and qtwebkit were build with
  'ARM_INSTRUCTION_SET = "thumb"' => TUNE_FEATURES = "arm armv5 thumb dsp"
  for qemuarm without issues

This is a partial/rebased revert of:
commit 932b32c1c9e9a3ac833c82ff9273683345056ec7
Author: Martin Jansa <Martin.Jansa at gmail.com>
Date:   Wed Apr 22 15:33:01 2015 +0200

    qtscript,qtwebking: disable thumb

    * qemuarm builds fail when thumb is enabled

    Signed-off-by: Martin Jansa <Martin.Jansa at gmail.com>

Signed-off-by: Andreas Müller <schnitzeltony at googlemail.com>
---
 recipes-qt/qt5/qtscript_git.bb | 3 ++-
 recipes-qt/qt5/qtwebkit_git.bb | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/recipes-qt/qt5/qtscript_git.bb b/recipes-qt/qt5/qtscript_git.bb
index c6dca51..c53217a 100644
--- a/recipes-qt/qt5/qtscript_git.bb
+++ b/recipes-qt/qt5/qtscript_git.bb
@@ -22,7 +22,8 @@ LIC_FILES_CHKSUM = " \
 #{standard input}:23: Error: selected processor does not support Thumb mode `stmdb sp!,{r4-r8,lr}'
 #{standard input}:30: Error: lo register required -- `ldmia sp!,{r4-r8,lr}'
 #{standard input}:43: Error: lo register required -- `ldmia sp!,{r4-r8,lr}'
-ARM_INSTRUCTION_SET = "arm"
+ARM_INSTRUCTION_SET_armv4 = "arm"
+ARM_INSTRUCTION_SET_armv5 = "arm"
 
 DEPENDS += "qtbase"
 
diff --git a/recipes-qt/qt5/qtwebkit_git.bb b/recipes-qt/qt5/qtwebkit_git.bb
index 862abd2..a952306 100644
--- a/recipes-qt/qt5/qtwebkit_git.bb
+++ b/recipes-qt/qt5/qtwebkit_git.bb
@@ -15,7 +15,8 @@ DEPENDS += "qtbase qtdeclarative icu ruby-native sqlite3 glib-2.0 libxslt"
 # | {standard input}: Assembler messages:
 # | {standard input}:106: Error: invalid immediate: 983040 is out of range
 # | {standard input}:106: Error: value of 983040 too large for field of 2 bytes at 146
-ARM_INSTRUCTION_SET = "arm"
+ARM_INSTRUCTION_SET_armv4 = "arm"
+ARM_INSTRUCTION_SET_armv5 = "arm"
 
 SRC_URI += "\
     file://0001-qtwebkit-fix-QA-issue-bad-RPATH.patch \
-- 
2.5.0