commit 1570f17f97ad99ddf3f63745ab3571c1aa411141 Author: teor teor@torproject.org Date: Thu Sep 6 13:11:23 2018 +1000
Windows: Silence a spurious warning in the GetAdaptersAddresses cast
GetProcAddress() returns FARPROC, which is (long long int(*)()) on 64-bit Windows: https://msdn.microsoft.com/en-us/library/windows/desktop/ms683212(v=vs.85).a...
But GetAdaptersAddresses() is (long unsigned int(*)()), on both 32-bit and 64-bit Windows: https://docs.microsoft.com/en-us/windows/desktop/api/iphlpapi/nf-iphlpapi-ge...
So gcc 8 issues a spurious "incompatible function pointer" warning about the cast to GetAdaptersAddresses_fn_t.
Silence this warning by casting to a void function pointer, before the cast to GetAdaptersAddresses_fn_t.
This issue is already fixed by 26481 in 0.3.5 and later, by removing the lookup and cast.
Fixes bug 27465; bugfix on 0.2.3.11-alpha. --- changes/bug27465 | 5 +++++ src/common/address.c | 5 ++++- 2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/changes/bug27465 b/changes/bug27465 new file mode 100644 index 000000000..743b35130 --- /dev/null +++ b/changes/bug27465 @@ -0,0 +1,5 @@ + o Minor bugfixes (compilation): + - Silence a spurious compiler warning on the GetAdaptersAddresses + function pointer cast. This issue is already fixed by 26481 in + 0.3.5 and later, by removing the lookup and cast. + Fixes bug 27465; bugfix on 0.2.3.11-alpha. diff --git a/src/common/address.c b/src/common/address.c index 96b99fa08..794345a13 100644 --- a/src/common/address.c +++ b/src/common/address.c @@ -1492,7 +1492,10 @@ get_interface_addresses_win32(int severity, sa_family_t family) goto done; }
- if (!(fn = (GetAdaptersAddresses_fn_t) + /* Cast through a void function pointer, to silence a spurious compiler + * warning on 64-bit Windows. This cast is safe, because we are casting to + * the correct type for GetAdaptersAddresses(). */ + if (!(fn = (GetAdaptersAddresses_fn_t)(void(*)(void)) GetProcAddress(lib, "GetAdaptersAddresses"))) { log_fn(severity, LD_NET, "Unable to obtain pointer to " "GetAdaptersAddresses");