Added CheckReturn facility to Loki.

git-svn-id: svn://svn.code.sf.net/p/loki-lib/code/trunk@824 7ec92016-0320-0410-acc4-a06ded1c099a

Loki.sln

@@ -1,6 +1,6 @@
 
 Microsoft Visual Studio Solution File, Format Version 9.00
-# Visual C++ Express 2005
+# Visual Studio 2005
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "Library", "src\library.vcproj", "{CBDB8E7A-4286-4AE3-A190-BA33D7C53FF0}"
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "Factory", "test\Factory\Factory.vcproj", "{925D5863-2F77-41B7-96F1-CC814762C40F}"
@@ -57,6 +57,8 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "Function", "test\Function\F
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "CachedFactory", "test\CachedFactory\CachedFactory.vcproj", "{8D186AB4-E544-42D6-B192-1AE2C946875E}"
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "CheckReturn", "test\CheckReturn\CheckReturn.vcproj", "{C0826A05-9143-4545-B5DE-811C188CB54E}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Win32 = Debug|Win32
@@ -139,6 +141,10 @@ Global
 		{8D186AB4-E544-42D6-B192-1AE2C946875E}.Debug|Win32.Build.0 = Debug|Win32
 		{8D186AB4-E544-42D6-B192-1AE2C946875E}.Release|Win32.ActiveCfg = Release|Win32
 		{8D186AB4-E544-42D6-B192-1AE2C946875E}.Release|Win32.Build.0 = Release|Win32
+		{C0826A05-9143-4545-B5DE-811C188CB54E}.Debug|Win32.ActiveCfg = Debug|Win32
+		{C0826A05-9143-4545-B5DE-811C188CB54E}.Debug|Win32.Build.0 = Debug|Win32
+		{C0826A05-9143-4545-B5DE-811C188CB54E}.Release|Win32.ActiveCfg = Release|Win32
+		{C0826A05-9143-4545-B5DE-811C188CB54E}.Release|Win32.Build.0 = Release|Win32
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

include/loki/CheckReturn.h

@@ -0,0 +1,96 @@
+////////////////////////////////////////////////////////////////////////////////
+// The Loki Library
+// Copyright (c) 2007 by Rich Sposato
+// Permission to use, copy, modify, distribute and sell this software for any 
+//     purpose is hereby granted without fee, provided that the above copyright 
+//     notice appear in all copies and that both that copyright notice and this 
+//     permission notice appear in supporting documentation.
+// The author makes no representations about the 
+//     suitability of this software for any purpose. It is provided "as is" 
+//     without express or implied warranty.
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef LOKI_CHECK_RETURN_INC_
+#define LOKI_CHECK_RETURN_INC_
+
+// $Id$
+
+
+#include <assert.h>
+
+namespace Loki
+{
+
+// ----------------------------------------------------------------------------
+
+////////////////////////////////////////////////////////////////////////////////
+///  \class CheckReturn
+///
+///  \par Purpose
+///  C++ provides no mechanism within the language itself to force code to
+///  check the return value from a function call.  This simple class provides
+///  a mechanism by which programmers can force calling functions to check the
+///  return value.  Or at least make them consciously choose to disregard the
+///  return value.  If the calling function fails to use or store the return
+///  value, the destructor asserts.
+///
+///  \par Return Type
+///  The returned value is copied into CheckReturn rather than accessed via a
+///  a reference or pointer since return value could be local to a function.
+///  CheckReturn works best when the return type is a built-in primitive (bool,
+///  int, etc...) a pointer, or an enum (such as an error condition enum).  It
+///  can work with other types that have cheap copy operations.
+////////////////////////////////////////////////////////////////////////////////
+
+template < class Value >
+class CheckReturn
+{
+public:
+
+    /// Conversion constructor changes Value type to CheckReturn type.
+    inline CheckReturn( Value value ) :
+        m_value( value ), m_checked( false ) {}
+
+    /// Copy-constructor allows functions to call another function within the
+    /// return statement.  The other CheckReturn's m_checked flag is set since
+    /// its duty has been passed to the m_checked flag in this one.
+    inline CheckReturn( const CheckReturn & that ) :
+        m_value( that.m_value ), m_checked( false )
+    { that.m_checked = true; }
+
+    /// Destructor checks if return value was used.
+    inline ~CheckReturn( void )
+    {
+        // If this assertion fails, then a function failed to check the
+        // return value from a function call.
+        assert( m_checked );
+    }
+
+    /// Conversion operator changes CheckReturn back to Value type.
+    inline operator Value ( void )
+    {
+        m_checked = true;
+        return m_value;
+    }
+
+private:
+    /// Default constructor not implemented.
+    CheckReturn( void );
+
+    /// Copy-assignment operator not implemented.
+    CheckReturn & operator = ( const CheckReturn & that );
+
+    /// Copy of returned value.
+    Value m_value;
+
+    /// Flag for whether calling function checked return value yet.
+    mutable bool m_checked;
+};
+
+// ----------------------------------------------------------------------------
+
+} // namespace Loki
+
+#endif // end file guardian
+
+// $Log$

test/CachedFactory/CachedFactory.vcproj

@@ -1,9 +1,9 @@
 <?xml version="1.0" encoding="Windows-1252"?>
 <VisualStudioProject
 	ProjectType="Visual C++"
-	Version="8,00"
+	Version="8.00"
 	Name="CachedFactory"
-	ProjectGUID="{925D5863-2F77-41B7-96F1-CC814762C40F}"
+	ProjectGUID="{8D186AB4-E544-42D6-B192-1AE2C946875E}"
 	RootNamespace="CachedFactory"
 	Keyword="Win32Proj"
 	>

test/CheckReturn/CheckReturn.dev

@@ -0,0 +1,69 @@
+[Project]
+FileName=CheckReturn.dev
+Name=CheckReturn
+UnitCount=2
+Type=1
+Ver=1
+ObjFiles=
+Includes=../../include
+Libs=
+PrivateResource=
+ResourceIncludes=
+MakeIncludes=
+Compiler=
+CppCompiler=
+Linker=
+IsCpp=1
+Icon=
+ExeOutput=
+ObjectOutput=
+OverrideOutput=0
+OverrideOutputName=CheckReturn.exe
+HostApplication=
+Folders=
+CommandLine=
+UseCustomMakefile=0
+CustomMakefile=
+IncludeVersionInfo=0
+SupportXPThemes=0
+CompilerSet=0
+CompilerSettings=1000001000000001000000
+
+[Unit1]
+FileName=main.cpp
+CompileCpp=1
+Folder=CheckReturn
+Compile=1
+Link=1
+Priority=1000
+OverrideBuildCmd=0
+BuildCmd=
+
+[Unit2]
+FileName=..\..\include\loki\CheckReturn.h
+CompileCpp=1
+Folder=CheckReturn
+Compile=1
+Link=1
+Priority=1000
+OverrideBuildCmd=0
+BuildCmd=
+
+[VersionInfo]
+Major=0
+Minor=1
+Release=1
+Build=1
+LanguageID=1033
+CharsetID=1252
+CompanyName=
+FileVersion=
+FileDescription=Developed using the Dev-C++ IDE
+InternalName=
+LegalCopyright=
+LegalTrademarks=
+OriginalFilename=
+ProductName=
+ProductVersion=
+AutoIncBuildNr=0
+

test/CheckReturn/CheckReturn.vcproj

@@ -0,0 +1,198 @@
+<?xml version="1.0" encoding="Windows-1252"?>
+<VisualStudioProject
+	ProjectType="Visual C++"
+	Version="8.00"
+	Name="CheckReturn"
+	ProjectGUID="{C0826A05-9143-4545-B5DE-811C188CB54E}"
+	RootNamespace="CheckReturn"
+	Keyword="Win32Proj"
+	>
+	<Platforms>
+		<Platform
+			Name="Win32"
+		/>
+	</Platforms>
+	<ToolFiles>
+	</ToolFiles>
+	<Configurations>
+		<Configuration
+			Name="Debug|Win32"
+			OutputDirectory="$(SolutionDir)$(ConfigurationName)"
+			IntermediateDirectory="$(ConfigurationName)"
+			ConfigurationType="1"
+			CharacterSet="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				Optimization="0"
+				AdditionalIncludeDirectories="..\..\include"
+				PreprocessorDefinitions="WIN32;_DEBUG;_CONSOLE"
+				StringPooling="true"
+				MinimalRebuild="true"
+				BasicRuntimeChecks="3"
+				RuntimeLibrary="3"
+				UsePrecompiledHeader="0"
+				WarningLevel="4"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="3"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				LinkIncremental="2"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+		<Configuration
+			Name="Release|Win32"
+			OutputDirectory="$(SolutionDir)$(ConfigurationName)"
+			IntermediateDirectory="$(ConfigurationName)"
+			ConfigurationType="1"
+			CharacterSet="1"
+			WholeProgramOptimization="1"
+			>
+			<Tool
+				Name="VCPreBuildEventTool"
+			/>
+			<Tool
+				Name="VCCustomBuildTool"
+			/>
+			<Tool
+				Name="VCXMLDataGeneratorTool"
+			/>
+			<Tool
+				Name="VCWebServiceProxyGeneratorTool"
+			/>
+			<Tool
+				Name="VCMIDLTool"
+			/>
+			<Tool
+				Name="VCCLCompilerTool"
+				AdditionalIncludeDirectories="..\..\include"
+				PreprocessorDefinitions="WIN32;NDEBUG;_CONSOLE"
+				RuntimeLibrary="2"
+				UsePrecompiledHeader="0"
+				WarningLevel="4"
+				Detect64BitPortabilityProblems="true"
+				DebugInformationFormat="0"
+			/>
+			<Tool
+				Name="VCManagedResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCResourceCompilerTool"
+			/>
+			<Tool
+				Name="VCPreLinkEventTool"
+			/>
+			<Tool
+				Name="VCLinkerTool"
+				LinkIncremental="1"
+				GenerateDebugInformation="true"
+				SubSystem="1"
+				OptimizeReferences="2"
+				EnableCOMDATFolding="2"
+				TargetMachine="1"
+			/>
+			<Tool
+				Name="VCALinkTool"
+			/>
+			<Tool
+				Name="VCManifestTool"
+			/>
+			<Tool
+				Name="VCXDCMakeTool"
+			/>
+			<Tool
+				Name="VCBscMakeTool"
+			/>
+			<Tool
+				Name="VCFxCopTool"
+			/>
+			<Tool
+				Name="VCAppVerifierTool"
+			/>
+			<Tool
+				Name="VCWebDeploymentTool"
+			/>
+			<Tool
+				Name="VCPostBuildEventTool"
+			/>
+		</Configuration>
+	</Configurations>
+	<References>
+	</References>
+	<Files>
+		<Filter
+			Name="Source Files"
+			Filter="cpp;c;cc;cxx;def;odl;idl;hpj;bat;asm;asmx"
+			UniqueIdentifier="{4FC737F1-C7A5-4376-A066-2A32D752A2FF}"
+			>
+			<File
+				RelativePath=".\main.cpp"
+				>
+			</File>
+		</Filter>
+		<Filter
+			Name="Header Files"
+			Filter="h;hpp;hxx;hm;inl;inc;xsd"
+			UniqueIdentifier="{93995380-89BD-4b04-88EB-625FBE52EBFB}"
+			>
+			<File
+				RelativePath="..\..\include\loki\CheckReturn.h"
+				>
+			</File>
+		</Filter>
+	</Files>
+	<Globals>
+	</Globals>
+</VisualStudioProject>

test/CheckReturn/main.cpp

@@ -0,0 +1,155 @@
+////////////////////////////////////////////////////////////////////////////////
+// The Loki Library
+// Copyright (c) 2007 Rich Sposato
+// Permission to use, copy, modify, distribute and sell this software for any 
+//     purpose is hereby granted without fee, provided that the above copyright 
+//     notice appear in all copies and that both that copyright notice and this 
+//     permission notice appear in supporting documentation.
+// The author makes no representations about the 
+//     suitability of this software for any purpose. It is provided "as is" 
+//     without express or implied warranty.
+////////////////////////////////////////////////////////////////////////////////
+
+// $Id$
+
+#include <loki/CheckReturn.h>
+
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+
+// ----------------------------------------------------------------------------
+
+typedef ::Loki::CheckReturn< bool > BoolReturn;
+
+typedef ::Loki::CheckReturn< string > StringReturn;
+
+
+// ----------------------------------------------------------------------------
+
+bool NoCheckRequired( void )
+{
+    return true;
+}
+
+// ----------------------------------------------------------------------------
+
+BoolReturn CheckRequired( void )
+{
+    return BoolReturn( true );
+}
+
+// ----------------------------------------------------------------------------
+
+BoolReturn CheckRequired( bool value )
+{
+    // By passing false into CheckRequired, CheckRequired calls an overloaded
+    // version of CheckRequired, thus demonstrating that one can use a function
+    // call within the return statement and not have to create a named
+    // temporary variable.
+    if ( !value )
+        return CheckRequired();
+
+    return BoolReturn( value );
+}
+
+// ----------------------------------------------------------------------------
+
+string GetString( void )
+{
+    return string( "a" );
+}
+
+// ----------------------------------------------------------------------------
+
+StringReturn MustUseString( const char * s )
+{
+    return StringReturn( s );
+}
+
+// ----------------------------------------------------------------------------
+
+void StringEater( const string & s )
+{
+    (void)s;
+}
+
+// ----------------------------------------------------------------------------
+
+int main( unsigned int argc, const char * argv[] )
+{
+
+    if ( 2 == argc )
+    {
+        const char * const a = argv[ argc - 1 ];
+
+        // okay to call without storing or using return value.
+        GetString();
+        cout << "Called GetString without using return value." << endl;
+
+        // Should not assert since caller stores return value.
+        const string s = MustUseString( a );
+        cout << "Called MustUseString and stored return value." << endl;
+
+        {
+            // Should not assert since caller passes return value into another
+            // function, thus converting CheckReturn back into actual type.
+            StringEater( MustUseString( a ) );
+            cout <<
+                "Called MustUseString and passed return value into another function."
+                << endl;
+        }
+
+        // This should assert since caller does not check return value.
+        MustUseString( s.c_str() );
+        cout << "Should assert before this line!  How did we get here?" << endl;
+    }
+
+
+    // okay to call without storing or using return value.
+    NoCheckRequired();
+    cout << "Called NoCheckRequired without using return value." << endl;
+
+    // Should not assert since caller stores return value.
+    bool okay = CheckRequired();
+    cout << "Called CheckRequired and stored return value." << endl;
+
+    if ( CheckRequired( okay ) )
+    {
+        cout << "Called CheckRequired and used return value." << endl;
+    }
+
+    {
+        // Should not assert since caller stores return value ...
+        BoolReturn checkBool = CheckRequired();
+        // and then deliberately ignores it before destructor runs.
+        (bool)checkBool;
+        cout << "Called CheckRequired, stored return value, and ignored it."
+             << endl;
+    }
+
+    {
+        // This should not assert since caller deliberately chooses to not
+        // check return value by casting to return value to correct type.
+        (bool)CheckRequired();
+    }
+
+    {
+        // This should not assert since caller deliberately chooses to not
+        // check return value by casting to return value to correct type.
+        (bool)CheckRequired( false );
+        cout << "Made a nested call to CheckRequired." << endl;
+    }
+
+    // This should assert since caller does not check return value.
+    CheckRequired();
+    cout << "Should assert before this line!  How did we get here?" << endl;
+
+	return 0;
+}
+
+// ----------------------------------------------------------------------------
+
+// $Log$

test/Function/Function.vcproj

@@ -1,9 +1,9 @@
 <?xml version="1.0" encoding="Windows-1252"?>
 <VisualStudioProject
 	ProjectType="Visual C++"
-	Version="8,00"
+	Version="8.00"
 	Name="Function"
-	ProjectGUID="{925D5863-2F77-41B7-96F1-CC814762C40F}"
+	ProjectGUID="{2DE18D06-0F3A-4C6D-AF2B-40E074B3C3DC}"
 	RootNamespace="Function"
 	Keyword="Win32Proj"
 	>

test/SmallObj/SmallObjBench.cpp

@@ -274,8 +274,6 @@ template<
 void testSize()
 {
 
-//#define LOKI_ALLOCATOR_PARAMETERS ::Loki::SingleThreaded, 4096, 128, 4, Loki::NoDestroy
-
     typedef Base<Size, void> A;
     typedef Base<Size, Loki::SmallObject< ThreadingModel, chunkSize,
         maxSmallObjectSize, objectAlignSize, LifetimePolicy, MutexPolicy > > B;