Where i can find information about Environment variables for use with cgo

Hello all
I try to find information about the flag that is used with cgo without any luck
all i have the page that list them :help package - cmd/go/internal/help - Go Packages
but what each flag is doing ? for example
CGO_LDFLAGS_ALLOW

A help package - cmd/go/internal/help - Go Packages

CGO_LDFLAGS, CGO_LDFLAGS_ALLOW, CGO_LDFLAGS_DISALLOW
Like CGO_CFLAGS, CGO_CFLAGS_ALLOW, and CGO_CFLAGS_DISALLOW,
but for the linker.

then above it says

CGO_CFLAGS_ALLOW
A regular expression specifying additional flags to allow
to appear in #cgo CFLAGS source code directives.
Does not apply to the CGO_CFLAGS environment variable.

1 Like

The CGO_LDFLAGS_ALLOW environment variable is used in conjunction with cgo (the mechanism for calling C code from Go) to control which linker flags are allowed when cgo is compiling Go code that includes C code.

When you use cgo to compile Go code that includes C code, the Go compiler may pass flags to the C compiler and linker. These flags may affect how the C code is compiled and linked into the final executable. The CGO_LDFLAGS_ALLOW environment variable allows you to specify a list of linker flags that are allowed to be passed from cgo to the linker when compiling your code. Any flags not in this list will be rejected, potentially preventing unintended or unsafe behavior.

For example, you might set CGO_LDFLAGS_ALLOW to allow only specific linker flags that are known to be safe and necessary for your project, while rejecting all others to minimize the risk of accidentally introducing vulnerabilities or other issues.

Each flag in the CGO_LDFLAGS_ALLOW list should be separated by a space or a comma.

Here’s an example of how you might use CGO_LDFLAGS_ALLOW:

export CGO_LDFLAGS_ALLOW=“-L/usr/local/lib -lfoo -Wl,-rpath,/usr/local/lib”

This would allow the -L/usr/local/lib, -lfoo, and -Wl,-rpath,/usr/local/lib flags to be passed to the linker by cgo, while rejecting any other flags.