Using Clang instead of GCC - Revision history

imported>Artturin: Undoing a edit because it's not exactly true and is because of a bug, linked the issue

2023-10-15T03:08:11Z

Undoing a edit because it's not exactly true and is because of a bug, linked the issue

← Older revision		Revision as of 03:08, 15 October 2023
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	You can use Clang instead of GCC as a C compiler for any package by overriding <code>stdenv</code>, which contains the compilation toolchain, with:		You can use Clang instead of GCC as a compiler for any package by overriding <code>stdenv</code>, which contains the compilation toolchain, with:
	<syntaxhighlight lang="nix">		<syntaxhighlight lang="nix">
	stdenv = pkgs.clangStdenv;		stdenv = pkgs.clangStdenv;
Line 10:		Line 10:
	Depending on the case you may want to set this value in different location, and using different mechanism.		Depending on the case you may want to set this value in different location, and using different mechanism.

	~~Unlike <code>gcc</code>,~~ you ~~can not use the~~ <code>~~clang</code> command to compile C++. You must use the <code>clang++</code> command. Using clang to compile C++ will likely result in "~~fatal error: ... file not found~~" errors~~ on standard library <code>#include</code> directives. ~~This differs from Linux distributions like Debian and Arch Linux. If a project doesn't respect CXX and expects <code>clang<~~/~~code> to compile C++, it will fail to build.~~		Note you may get errors like <code>fatal error: ... file not found</code> on standard library <code>#include</code> directives, because of this bug https://github.com/NixOS/nixpkgs/issues/150655

	== Globally, in a package repository tree ==		== Globally, in a package repository tree ==

imported>Widlarizer: Clang is not a C++ compiler

2023-10-13T08:34:18Z

Clang is not a C++ compiler

← Older revision		Revision as of 08:34, 13 October 2023
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	You can use Clang instead of GCC as a compiler for any package by overriding <code>stdenv</code>, which contains the compilation toolchain, with:		You can use Clang instead of GCC as a C compiler for any package by overriding <code>stdenv</code>, which contains the compilation toolchain, with:
	<syntaxhighlight lang="nix">		<syntaxhighlight lang="nix">
	stdenv = pkgs.clangStdenv;		stdenv = pkgs.clangStdenv;
Line 10:		Line 10:
	Depending on the case you may want to set this value in different location, and using different mechanism.		Depending on the case you may want to set this value in different location, and using different mechanism.

			Unlike <code>gcc</code>, you can not use the <code>clang</code> command to compile C++. You must use the <code>clang++</code> command. Using clang to compile C++ will likely result in "fatal error: ... file not found" errors on standard library <code>#include</code> directives. This differs from Linux distributions like Debian and Arch Linux. If a project doesn't respect CXX and expects <code>clang</code> to compile C++, it will fail to build.

	== Globally, in a package repository tree ==		== Globally, in a package repository tree ==

imported>Artturin: add replaceStdenv

2023-09-01T02:48:19Z

add replaceStdenv

← Older revision		Revision as of 02:48, 1 September 2023
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	If you have a set of packages in a repository tree, you can set the		If you have a set of packages in a repository tree, you can set the
	<code>stdenv</code> value in the scope where the <code>callPackage</code> are		<code>stdenv</code> value in the scope where the <code>callPackage</code> are
	called. Be carefull '''all the packages present in the scope will be built with Clang'''		called. Be carefull '''all the packages present in the scope will be built with Clang'''
	because the <code>callPackage</code> that resolves the package function		because the <code>callPackage</code> that resolves the package function
	inputs will use the <code>pkgs.clangStdenv</code> for all packages.		inputs will use the <code>pkgs.clangStdenv</code> for all packages.
Line 27:		Line 27:
	}		}
	</syntaxhighlight>		</syntaxhighlight>

			or import nixpkgs with replaceStdenv.

			<syntaxhighlight lang="nix">
			import <nixpkgs> { config = { replaceStdenv = ({ pkgs }: pkgs.clangStdenv); }; }
			</syntaxhighlight>


	== For a specific package in a repository tree ==		== For a specific package in a repository tree ==

imported>Milahu: revert my last edit: add section: ld: cannot find -lstdc++

2023-01-24T15:19:08Z

revert my last edit: add section: ld: cannot find -lstdc++

← Older revision		Revision as of 15:19, 24 January 2023
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	}		}
	</syntaxhighlight>		</syntaxhighlight>

	~~== Troubleshooting ==~~

	~~=== ld: cannot find -lstdc++ ===~~

	~~Problem: The C++ standard library (libstdc++.so) is missing~~

	~~Fix: Replace <code>pkgs.llvmPackages.stdenv</code> with <code>pkgs.llvmPackages.libcxxStdenv</code>~~

	== See also ==		== See also ==

imported>Milahu: add section: ld: cannot find -lstdc++

2023-01-24T15:11:24Z

add section: ld: cannot find -lstdc++

← Older revision		Revision as of 15:11, 24 January 2023
Line 93:		Line 93:
	}		}
	</syntaxhighlight>		</syntaxhighlight>

			== Troubleshooting ==

			=== ld: cannot find -lstdc++ ===

			Problem: The C++ standard library (libstdc++.so) is missing

			Fix: Replace <code>pkgs.llvmPackages.stdenv</code> with <code>pkgs.llvmPackages.libcxxStdenv</code>

	== See also ==		== See also ==

imported>Milahu: add link to C#Use_a_different_compiler_version

2022-07-13T07:55:28Z

add link to C#Use_a_different_compiler_version

← Older revision		Revision as of 07:55, 13 July 2022
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	</syntaxhighlight>		</syntaxhighlight>

			== See also ==

			* [[C#Use_a_different_compiler_version\|C # Use a different compiler version]]

	[[Category:Nixpkgs]]		[[Category:Nixpkgs]]

imported>Symphorien: explain how to get a specific version of clang

2020-08-11T12:38:21Z

explain how to get a specific version of clang

← Older revision		Revision as of 12:38, 11 August 2020
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	<syntaxhighlight lang="nix">		<syntaxhighlight lang="nix">
	stdenv = pkgs.clangStdenv;		stdenv = pkgs.clangStdenv;
			</syntaxhighlight>
			or to get a specific version of clang:
			<syntaxhighlight lang="nix">
			stdenv = pkgs.llvmPackages_9.stdenv;
	</syntaxhighlight>		</syntaxhighlight>

imported>Symphorien: add an example of nix-shell with clang

2020-08-11T12:32:22Z

add an example of nix-shell with clang

@@ Line 78: / Line 78: @@
 nix-build ./hello_with_clan.nix
 </syntaxhighlight>
 [[Category:Nixpkgs]]

imported>Mickours: Adding more details + different scenario

2018-08-31T12:55:36Z

Adding more details + different scenario

@@ Line 1: / Line 1: @@
-You can use Clang instead of GCC as a compiler for any package by overriding `stdenv`:
+You can use Clang instead of GCC as a compiler for any package by overriding <code>stdenv</code>, which contains the compilation toolchain, with:
 <syntaxhighlight lang="nix">
-{ pkgs, my_package }:
+rec {
-my_package.override {
+    foo_gcc = callPackage ./foo { };
      # use Clang instead of GCC
      stdenv = pkgs.clangStdenv;
@@ Line 9: / Line 75: @@
 </syntaxhighlight>
 [[Category:Nixpkgs]]

imported>Mickours: Add the trick to override package and build with Clang

2018-05-02T15:03:02Z

Add the trick to override package and build with Clang

New page

You can use Clang instead of GCC as a compiler for any package by overriding `stdenv`:

<syntaxhighlight lang="nix">
{ pkgs, my_package }:
my_package.override {
# use Clang instead of GCC
stdenv = pkgs.clangStdenv;
}
</syntaxhighlight>

[[Category:Nixpkgs]]