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1 <?xml version="1.0" encoding="utf-8"?> |
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2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
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3 <!-- This component and the accompanying materials are made available under the terms of the License |
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4 "Eclipse Public License v1.0" which accompanies this distribution, |
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5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
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6 <!-- Initial Contributors: |
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7 Nokia Corporation - initial contribution. |
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8 Contributors: |
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9 --> |
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10 <!DOCTYPE concept |
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11 PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
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12 <concept id="GUID-DF1B3C55-2CFC-49C8-88A2-D10925ECAC3E" xml:lang="en"><title>Known |
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13 Issues</title><shortdesc/><prolog><metadata><keywords/></metadata></prolog><conbody> |
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14 <section id="GUID-EB71EFD6-DBEC-4C0F-B9E5-3370204AE18A"><title>ARM RVCT compiler |
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15 issues with STLport</title><p>Due to a defect in the ARM RVCT compiler versions |
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16 2.2, 3.1 and 4.0, building STLport v4 or STLport-based applications, creates |
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17 some invalid export entries in DEF files. To workaround this issue, perform |
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18 the following steps:</p><ol> |
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19 <li id="GUID-D5C91387-CF86-4D65-ACAF-05A5500DA090"><p>Use the GCCE compiler |
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20 to generate the DEF file, if it is not available.</p></li> |
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21 <li id="GUID-A0D36B39-ECEB-431A-80FD-6005542F4D7F"><p>Ignore the warnings |
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22 generated by the ARM RVCT compiler.</p><note>When you ignore the warnings, |
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23 do not freeze the invalid export entries in the DEF file using the ARM RVCT |
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24 compiler.</note></li> |
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25 </ol></section> |
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26 <section id="GUID-DDE6596E-1A67-4219-8822-45A82C39DF0B-GENID-1-8-1-11-1-1-9-1-6-1-3-2"> <title>Use |
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27 of Global Destructor</title> <p>Symbian does not invoke destructors |
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28 of global objects upon program termination. For example, in the code below, |
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29 the destructor <codeph>~foo()</codeph> is not called upon program termination. |
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30 At the moment, it is advised not to perform any important operations using |
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31 destructors.</p><codeblock xml:space="preserve">#include |
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32 using namespace std; |
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33 class foo |
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34 { |
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35 public: |
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36 foo() |
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37 { |
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38 cout <<"Entering foo\n"; |
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39 } |
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40 ~foo() |
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41 { |
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42 cout <<"Leaving foo\n"; |
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43 } |
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44 }; |
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45 foo foo_bar; |
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46 int main(void) |
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47 { |
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48 return 0; |
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49 } |
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50 |
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51 </codeblock> </section> |
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52 <section id="GUID-DDE6596E-1A67-4219-8822-45A82C39DF0B-GENID-1-8-1-11-1-1-9-1-6-1-3-3"> <title>Issues |
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53 with <codeph>new</codeph> operator</title> <p>Throwing <codeph>bad_alloc</codeph> or |
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54 any object from new on ARMV5 platfrom crashes. RVCT reports an exception when <codeph>new</codeph> throws <codeph>bad_alloc</codeph>. |
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55 The problem occurs even if the user throws any object from within an overloaded |
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56 operator <codeph>new</codeph>. The following new signatures are affected:</p><codeblock xml:space="preserve">void *operator new(unsigned int aSize); |
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57 void *operator new[](unsigned int aSize); |
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58 </codeblock><p>The following code snippet is an example that depicts the problem:</p><codeblock xml:space="preserve">class Dummy |
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59 { |
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60 }; |
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61 void *operator new(unsigned int aSize) |
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62 { |
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63 void* __y = malloc(aSize); |
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64 // try to simulate bad alloc |
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65 if (__y == 0) |
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66 { |
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67 throw Dummy(); //this will result in a crash |
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68 } |
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69 return __y; |
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70 } |
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71 </codeblock><p>To implement user owned overloaded version of new, the user |
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72 must implement them as class specific. The other way this could be achieved |
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73 is by defining new similar to:</p><codeblock xml:space="preserve">void* operator new(size_t s,newarg) throw (std::bad_alloc)</codeblock><p>and |
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74 invoking it as:</p><codeblock xml:space="preserve">Myclass* my = new(S60) Myclass()</codeblock> |
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75 </section> |
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76 <section id="GUID-DDE6596E-1A67-4219-8822-45A82C39DF0B-GENID-1-8-1-11-1-1-9-1-6-1-3-4"> <title>The <codeph>id</codeph> Member |
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77 Issue</title> <p>The <codeph>id</codeph> member variable of facet classes |
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78 cannot be accessed directly, it has to be accessed via the <codeph>GetFacetLocaleId()</codeph> interface.</p><p>Following |
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79 code snippet is an example that illustrates how to <codeph>uselocale::id</codeph> while |
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80 writing an application on top of the Standard Template Library (STL). Declare |
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81 a static method <codeph>GetFacetLocaleId()</codeph> instead of the member |
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82 variable id when, defining a class <codeph>base_facet</codeph> inherited from <codeph>locale::facet</codeph> in |
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83 a header file.</p><codeblock xml:space="preserve">//b_facet.h |
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84 class base_facet : public locale::facet |
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85 { |
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86 public: |
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87 static locale::id; |
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88 GetFacetLocaleId(); // in place of static locale::id |
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89 id; |
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90 }; |
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91 </codeblock><p>In the source file define the method <codeph>GetFacetLocaleId()</codeph>. </p><codeblock xml:space="preserve">//b_facet.cpp |
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92 locale::id base_facet_id; |
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93 locale::id& base_facet::GetFacetLocaleId() |
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94 { |
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95 return base_facet_id; |
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96 } |
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97 </codeblock> </section> |
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98 <section id="GUID-0EBB7F0F-2C2D-4707-BD53-96DC40443CAF"><title>Interleaving |
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99 Symbian and Standard C++ Code</title><p>The user must exercise caution while |
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100 using <codeph>try</codeph> or <codeph>catch</codeph>, and <codeph>trap</codeph> while |
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101 interleaving Symbian C++ and Standard C++ code. Adapter code is required to |
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102 handover or suppress exception coming from the Standard C++ to Symbian C++ |
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103 code.</p><p>Following code snippet illustrates how to use the adaptor code. |
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104 Adaptor code can be a part of DLLA. </p><p><b>DLL A - Symbian C++ code</b></p><codeblock xml:space="preserve">void CDoIt::Doit() |
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105 { |
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106 class foo *p = new __foo__(); |
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107 p->bar(); |
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108 delete p; |
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109 }; |
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110 </codeblock><p><b>DLLB - Standard C++ code</b></p><codeblock xml:space="preserve">class foo { |
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111 public: |
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112 foo(); //constructor |
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113 bar(); // throw exception |
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114 }; |
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115 </codeblock><p><b>DLLC - Adaptor code</b></p><codeblock xml:space="preserve">class __foo__ { |
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116 foo *p; |
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117 public: |
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118 __foo__(); |
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119 bar(); |
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120 }; |
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121 |
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122 void __foo__::__foo__() |
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123 { |
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124 int err = 0; |
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125 try { |
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126 p = new foo(); |
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127 } catch { |
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128 err = some error |
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129 } |
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130 User::LeaveIfError(err); |
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131 }; |
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132 void __foo__::bar() |
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133 { |
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134 int err = 0; |
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135 try { |
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136 p->bar(); |
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137 } catch { |
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138 err = some error |
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139 } |
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140 User::LeaveIfError(err); |
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141 }; |
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142 </codeblock></section> |
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143 </conbody></concept> |