A method has conditional code that always evaluates to true
or false
at run time. This leads to dead code in the false
branch of the condition.
By default, this rule analyzes the entire codebase, but this is configurable.
Rule descriptionMethods can have conditional code, such as if statements, binary expressions (==
, !=
, <
, >
), null checks, etc. For example, consider the following code:
public void M(int i, int j)
{
if (i != 0)
{
return;
}
if (j != 0)
{
return;
}
// Below condition will always evaluate to 'false' as 'i' and 'j' are both '0' here.
if (i != j)
{
// Code in this 'if' branch is dead code.
// It can either be removed or refactored.
...
}
}
C# and VB compilers perform analysis of conditional checks involving compile-time constant values that always evaluate to true
or false
. This analyzer performs data flow analysis of non-constant variables to determine redundant conditional checks involving non-constant values. In the preceding code, the analyzer determines that i
and j
are both 0
for all code paths that reach i != j
check. Hence, this check will always evaluate to false
at run time. The code inside the if statement is dead code and can be removed or refactored. Similarly, the analyzer tracks nullness of variables and reports redundant null checks.
Note
This analyzer performs an expensive dataflow analysis of non-constant values. This can increase the overall compile time on certain code bases.
When to suppress warningsIt's safe to suppress a violation of this rule if you're not concerned about the maintainability of your code. It is also fine to suppress violations that are identified to be false positives. These are possible in the presence of concurrent code that can execute from multiple threads.
Suppress a warningIf you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.
#pragma warning disable CA1508
// The code that's violating the rule is on this line.
#pragma warning restore CA1508
To disable the rule for a file, folder, or project, set its severity to none
in the configuration file.
[*.{cs,vb}]
dotnet_diagnostic.CA1508.severity = none
For more information, see How to suppress code analysis warnings.
Configure code to analyzeUse the following options to configure which parts of your codebase to run this rule on.
In addition, the following dataflow analysisârelated options apply to this rule:
You can configure these options for just this rule, for all rules they apply to, or for all rules in this category (Maintainability) that they apply to. For more information, see Code quality rule configuration options.
Exclude specific symbolsYou can exclude specific symbols, such as types and methods, from analysis by setting the excluded_symbol_names option. For example, to specify that the rule should not run on any code within types named MyType
, add the following key-value pair to an .editorconfig file in your project:
dotnet_code_quality.CAXXXX.excluded_symbol_names = MyType
Note
Replace the XXXX
part of CAXXXX
with the ID of the applicable rule.
Allowed symbol name formats in the option value (separated by |
):
M:
for methods, T:
for types, and N:
for namespaces..ctor
for constructors and .cctor
for static constructors.Examples:
Option Value Summarydotnet_code_quality.CAXXXX.excluded_symbol_names = MyType
Matches all symbols named MyType
. dotnet_code_quality.CAXXXX.excluded_symbol_names = MyType1|MyType2
Matches all symbols named either MyType1
or MyType2
. dotnet_code_quality.CAXXXX.excluded_symbol_names = M:NS.MyType.MyMethod(ParamType)
Matches specific method MyMethod
with the specified fully qualified signature. dotnet_code_quality.CAXXXX.excluded_symbol_names = M:NS1.MyType1.MyMethod1(ParamType)|M:NS2.MyType2.MyMethod2(ParamType)
Matches specific methods MyMethod1
and MyMethod2
with the respective fully qualified signatures. Exclude specific types and their derived types
You can exclude specific types and their derived types from analysis by setting the excluded_type_names_with_derived_types option. For example, to specify that the rule should not run on any methods within types named MyType
and their derived types, add the following key-value pair to an .editorconfig file in your project:
dotnet_code_quality.CAXXXX.excluded_type_names_with_derived_types = MyType
Note
Replace the XXXX
part of CAXXXX
with the ID of the applicable rule.
Allowed symbol name formats in the option value (separated by |
):
T:
prefix.Examples:
Option value Summarydotnet_code_quality.CAXXXX.excluded_type_names_with_derived_types = MyType
Matches all types named MyType
and all of their derived types. dotnet_code_quality.CAXXXX.excluded_type_names_with_derived_types = MyType1|MyType2
Matches all types named either MyType1
or MyType2
and all of their derived types. dotnet_code_quality.CAXXXX.excluded_type_names_with_derived_types = M:NS.MyType
Matches specific type MyType
with given fully qualified name and all of its derived types. dotnet_code_quality.CAXXXX.excluded_type_names_with_derived_types = M:NS1.MyType1|M:NS2.MyType2
Matches specific types MyType1
and MyType2
with the respective fully qualified names, and all of their derived types. See also
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4