C and C++ rules for Please

This repo defines a Please plugin for building C and C++ code.

C and C++ build actions are very similar and can be intermingled freely (following the usual language rules); the main reason for separating them is to allow defining different tools and compiler flags for the two.

Basic usage

# Add this to plugins/BUILD 
plugin_repo(
    name = "cc",
    revision = "v1.0.0",
)

# Subinclude from the plugin
subinclude("///plugins/cc//build_defs:cc")

# Compile some C code
cc_library(
    name = "foo",
    srcs = ["foo.c"],
    # Headers are specified separately so they can be exposed to other rules
    hdrs = ["foo.h"],
)

cc_binary(
   name = "main",
   srcs = ["main.c"],
   deps = [":foo"],
)

Build definitions

There are several different targets available providing different rules:

//build_defs:cc

Contains the following C++ rules that use cpp_tool, default_opt_cppflags, default_dbg_cppflags and test_main.

• cc_library()
• cc_binary()
• cc_test()
• cc_object()
• cc_static_library()
• cc_shared_object()
• cc_module() (N.B. this is still experimental)

And the following C rules that use cc_tool, default_opt_cflags and default_dbg_cflags:

• c_library()
• c_binary()
• c_test()
• c_object()
• c_static_library()
• c_shared_object()

See the docstring for each rule for more specific detail on what they each do.

Configuration

This plugin can be configured by adding fields to the [Plugin "cc"] section in your .plzconfig. The available configuration settings are documented here.

CCTool

The tool used by c_xxx() build definitions to compile C code. Defaults to gcc.

[Plugin "cc"]
CCTool = clang

CPPTool

The tool used by cc_xxx() build definitions to compile C++ code. Defaults to g++.

[Plugin "cc"]
CPPTool = clang++

ARTool

The tool used to manipulate .a archives. Defaults to ar.

[Plugin "cc"]
ARTool = ar

DefaultOptCFlags

Default flags used to compile C code. Defaults to -std=c99 -O3 -pipe -DNDEBUG -Wall -Werror.

[Plugin "cc"]
DefaultOptCFlags = -std=c99
DefaultOptCFlags = -O3

DefaultDbgCFlags

Default flags used to compile C code for debugging. Defaults to -std=c99 -g3 -pipe -DDEBUG -Wall -Werror.

[Plugin "cc"]
DefaultDbgCFlags = -std=c99
DefaultDbgCFlags = -O3

DefaultOptCppFlags

Default flags used to compile C++ code. Defaults to -std=c++11 -O3 -pipe -DNDEBUG -Wall -Werror.

[Plugin "cc"]
DefaultOptCppFlags = -std=c99
DefaultOptCppFlags =-O3

DefaultDbgCppFlags

Default flags used to compile C++ code for debugging. Defaults to -std=c++11 -g3 -pipe -DDEBUG -Wall -Werror.

[Plugin "cc"]
DefaultDbgCppFlags = -std=c99
DefaultDbgCppFlags = -O3

DefaultLDFlags

Default flags to pass when linking C and C++ code. Defaults to -lpthread -ldl.

[Plugin "cc"]
DefaultLDFlags = -ldl

PkgConfigPath

Controls the PKG_CONFIG_PATH environment variable used by pkg_config. Not set by default.

[Plugin "cc"]
PackageConfigPath = /opt/toolchain/pkg_configs

TestMain

A cc_library(), c_library(), or otherwise compatible rule containing the entry point to run tests. Defaults to //unitest-pp:main in this plugin.

[Plugin "cc"]
TestMain = //third_party/cc:gtest_main

DsymTool

On macOS, the tool used to create debug symbols. Defaults to dsymutil.

[Plugin "cc"]
DsymTool = dsymutil

DefaultNamespace

The default C++ namespace to use. By default, no namespace is used.

[Plugin "cc"]
DefaultNamespace = foo

Compatibility

This plugin is compatible with the same operating systems as Please itself:

• Darwin (amd64, arm64)
• FreeBSD (amd64)
• Linux (amd64, arm64)

and is compatible with the following tools:

• C/C++ compilers:
  • GCC >= 9
  • Clang >= 11
  • Apple Clang in Xcode >= 15.0.1
• Linkers:
  • GNU ld >= 2.38
  • GNU gold >= 1.15
  • LLD >= 11
  • ld64 in Xcode >= 15.0.1
  • Apple ld in Xcode >= 15.0.1

The build definitions are likely to work fine with some older versions of these tools too, although they have only been tested on the versions listed above. Please report any bugs you encounter.