Clang treat warning as error (#578)

* bpf_xdp_adjust_head Part 2

* Fix csum_diff algorithm to use 1's complement arithmetic.

* treat warning as error

docs/GettingStarted.md

@@ -98,7 +98,7 @@ On the attacker machine, do the following:
 1. Start performance monitor and add UDPv4 Datagrams/sec
 2. Show that 200K packets per second are being received
 3. Show & explain code of droppacket.c
-4. Compile droppacket.c ```clang -target bpf -O2 -Wall -c droppacket.c -o droppacket.o```
+4. Compile droppacket.c ```clang -target bpf -O2 -Werror -c droppacket.c -o droppacket.o```
 5. Show eBPF byte code for droppacket.o ```netsh ebpf show disassembly droppacket.o xdp```
 6. Show that the verifier checks the code ```netsh ebpf show verification droppacket.o xdp```
 7. Launch netsh ```netsh```
@@ -108,7 +108,7 @@ On the attacker machine, do the following:
 11. Unload program ```delete program <id>``` where <id> is the ID noted above.
 12. Show UDP datagrams received drop to back up to ~200K per second
 13. Modify droppacket.c to be unsafe - Comment out line 20 & 21
-14. Compile droppacket.c ```clang -target bpf -O2 -Wall -c droppacket.c -o droppacket.o```
+14. Compile droppacket.c ```clang -target bpf -O2 -Werror -c droppacket.c -o droppacket.o```
 15. Show that the verifier rejects the code ```netsh ebpf show verification droppacket.o xdp```
 16. Show that loading the program fails ```netsh ebpf add program droppacket.o xdp```
 

docs/tutorial.md

@@ -31,7 +31,7 @@ anything.
 **Step 2)** Compile optimized code with clang as follows:
 
 ```
-> clang -target bpf -Wall -O2 -c bpf.c -o bpf.o
+> clang -target bpf -Werror -O2 -c bpf.c -o bpf.o
 ```
 
 This will compile bpf.c (into bpf.o in this example) using bpf as the assembly format,
@@ -61,7 +61,7 @@ for this walkthrough we will put the result into a separate .o file,
 bpf-d.o in this example:
 
 ```
-> clang -target bpf -Wall -g -O2 -c bpf.c -o bpf-d.o
+> clang -target bpf -Werror -g -O2 -c bpf.c -o bpf-d.o
 ```
 
 
@@ -162,7 +162,7 @@ int anotherfunc()
 If we now compile the above code as before we can see the new list of sections.
 
 ```
-> clang -target bpf -Wall -O2 -c bpf2.c -o bpf2.o
+> clang -target bpf -Werror -O2 -c bpf2.c -o bpf2.o
 
 > llvm-objdump --triple=bpf -h bpf2.o
 
@@ -619,7 +619,7 @@ Let's compile it and see what it looks like.   Here we compile with `-g`
 to include source line info:
 
 ```
-> clang -target bpf -Wall -g -O2 -c helpers.c -o helpers.o
+> clang -target bpf -Werror -g -O2 -c helpers.c -o helpers.o
 
 > llvm-objdump --triple bpf -S helpers.o
 
@@ -702,7 +702,7 @@ happens if we didn't compile with `-O2`?  The disassembly looks instead
 like this:
 
 ```
-> clang -target bpf -Wall -g -c helpers.c -o helpers.o
+> clang -target bpf -Werror -g -c helpers.c -o helpers.o
 
 > llvm-objdump --triple bpf -S helpers.o
 
@@ -821,7 +821,7 @@ using the map parameters specified.  We can see the fields encoded
 into the `maps` section as follows:
 
 ```
-> clang -target bpf -Wall -g -O2 -c maponly.c -o maponly.o
+> clang -target bpf -Werror -g -O2 -c maponly.c -o maponly.o
 > llvm-objdump -s -section maps maponly.o
 
 maponly.o:      file format ELF64-BPF

tests/sample/bindmonitor.c

@@ -1,9 +1,9 @@
 // Copyright (c) Microsoft Corporation
 // SPDX-License-Identifier: MIT
 
-// clang -O2 -Wall -c bindmonitor.c -o bindmonitor_jit.o
+// clang -O2 -Werror -c bindmonitor.c -o bindmonitor_jit.o
 //
-// For bpf code: clang -target bpf -O2 -Wall -c bindmonitor.c -o bindmonitor.o
+// For bpf code: clang -target bpf -O2 -Werror -c bindmonitor.c -o bindmonitor.o
 // this passes the checker
 
 #include "bpf_helpers.h"

tests/sample/divide_by_zero.c

@@ -1,9 +1,9 @@
 // Copyright (c) Microsoft Corporation
 // SPDX-License-Identifier: MIT
 
-// clang -O2 -Wall -c divide_by_zero.c -o divide_by_zero_jit.o
+// clang -O2 -Werror -c divide_by_zero.c -o divide_by_zero_jit.o
 //
-// For bpf code: clang -target bpf -O2 -Wall -c divide_by_zero.c -o divide_by_zero.o
+// For bpf code: clang -target bpf -O2 -Werror -c divide_by_zero.c -o divide_by_zero.o
 // this passes the checker
 
 #include "bpf_helpers.h"

tests/sample/droppacket.c

@@ -1,9 +1,9 @@
 // Copyright (c) Microsoft Corporation
 // SPDX-License-Identifier: MIT
 
-// clang -O2 -Wall -c droppacket.c -o dropjit.o
+// clang -O2 -Werror -c droppacket.c -o dropjit.o
 //
-// For bpf code: clang -target bpf -O2 -Wall -c droppacket.c -o droppacket.o
+// For bpf code: clang -target bpf -O2 -Werror -c droppacket.c -o droppacket.o
 // this passes the checker
 
 #include "bpf_helpers.h"

tests/sample/droppacket_unsafe.c

@@ -1,9 +1,9 @@
 // Copyright (c) Microsoft Corporation
 // SPDX-License-Identifier: MIT
 
-// clang -O2 -Wall -c droppacket_unsafe.c -o droppacket_unsafe_jit.o
+// clang -O2 -Werror -c droppacket_unsafe.c -o droppacket_unsafe_jit.o
 //
-// For bpf code: clang -target bpf -O2 -Wall -c droppacket_unsafe.c -o droppacket_unsafe.o
+// For bpf code: clang -target bpf -O2 -Werror -c droppacket_unsafe.c -o droppacket_unsafe.o
 // this passes the checker
 
 #include "bpf_helpers.h"

tests/sample/encap_reflect_packet.c

@@ -9,7 +9,7 @@ encapsulate_ipv4_reflect_packet(xdp_md_t* ctx)
     int rc = XDP_DROP;
 
     // Adjust XDP context to allocate space for outer IPv4 header.
-    if (bpf_xdp_adjust_head(ctx, -sizeof(IPV4_HEADER)) < 0)
+    if (bpf_xdp_adjust_head(ctx, (int)-sizeof(IPV4_HEADER)) < 0)
         goto Done;
 
     // The new ethernet header will be at the beginning of the expanded buffer.
@@ -38,12 +38,12 @@ encapsulate_ipv4_reflect_packet(xdp_md_t* ctx)
     IPV4_HEADER* inner_ipv4_header = (IPV4_HEADER*)next_header;
 
     // Copy over the old ethernet header to the new one.
-    memcpy(new_ethernet_header, old_ethernet_header, sizeof(ETHERNET_HEADER));
+    __builtin_memcpy(new_ethernet_header, old_ethernet_header, sizeof(ETHERNET_HEADER));
     // Swap the MAC addresses.
     swap_mac_addresses(new_ethernet_header);
 
     // Copy over the inner IP header to the encap IP header.
-    memcpy(outer_ipv4_header, inner_ipv4_header, sizeof(IPV4_HEADER));
+    __builtin_memcpy(outer_ipv4_header, inner_ipv4_header, sizeof(IPV4_HEADER));
     // Swap the IP addresses.
     swap_ipv4_addresses(outer_ipv4_header);
     // Adjust header fields.
@@ -67,7 +67,7 @@ encapsulate_ipv6_reflect_packet(xdp_md_t* ctx)
     int rc = XDP_DROP;
 
     // Adjust XDP context to allocate space for outer IPv6 header.
-    if (bpf_xdp_adjust_head(ctx, -sizeof(IPV6_HEADER)) < 0)
+    if (bpf_xdp_adjust_head(ctx, (int)-sizeof(IPV6_HEADER)) < 0)
         goto Done;
 
     // The new ethernet header will be at the beginning of the expanded buffer.
@@ -96,12 +96,12 @@ encapsulate_ipv6_reflect_packet(xdp_md_t* ctx)
     IPV6_HEADER* inner_ipv6_header = (IPV6_HEADER*)next_header;
 
     // Copy over the old ethernet header to the new one.
-    memcpy(new_ethernet_header, old_ethernet_header, sizeof(ETHERNET_HEADER));
+    __builtin_memcpy(new_ethernet_header, old_ethernet_header, sizeof(ETHERNET_HEADER));
     // Swap the MAC addresses.
     swap_mac_addresses(new_ethernet_header);
 
     // Copy over the inner IP header to the encap IP header.
-    memcpy(outer_ipv6_header, inner_ipv6_header, sizeof(IPV6_HEADER));
+    __builtin_memcpy(outer_ipv6_header, inner_ipv6_header, sizeof(IPV6_HEADER));
     // Swap the IP addresses.
     swap_ipv6_addresses(outer_ipv6_header);
     // Adjust header fields.

tests/sample/sample.vcxproj

@@ -92,42 +92,52 @@
   <ItemGroup>
     <CustomBuild Include="bindmonitor.c">
       <FileType>CppCode</FileType>
-      <Command>clang -target bpf -O2 -Wall -c %(Filename).c -o %(Filename).o</Command>
+      <Command>clang -target bpf -O2 -Werror -c %(Filename).c -o %(Filename).o</Command>
       <Outputs>%(Filename).o;%(Outputs)</Outputs>
       <TreatOutputAsContent Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</TreatOutputAsContent>
       <TreatOutputAsContent Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</TreatOutputAsContent>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
     </CustomBuild>
     <CustomBuild Include="bpf.c">
       <FileType>CppCode</FileType>
-      <Command>clang -target bpf -O2 -Wall -c %(Filename).c -o %(Filename).o</Command>
+      <Command>clang -target bpf -O2 -Werror -c %(Filename).c -o %(Filename).o</Command>
       <Outputs>%(Filename).o;%(Outputs)</Outputs>
       <TreatOutputAsContent>true</TreatOutputAsContent>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
     </CustomBuild>
     <CustomBuild Include="bpf_call.c">
       <FileType>CppCode</FileType>
-      <Command>clang -target bpf -O2 -Wall -c %(Filename).c -o %(Filename).o</Command>
+      <Command>clang -target bpf -O2 -Werror -c %(Filename).c -o %(Filename).o</Command>
       <Outputs>%(Filename).o;%(Outputs)</Outputs>
       <TreatOutputAsContent>true</TreatOutputAsContent>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
     </CustomBuild>
     <CustomBuild Include="reflect_packet.c">
       <FileType>CppCode</FileType>
-      <Command>clang -target bpf -O2 -Wall -c %(Filename).c -o %(Filename).o</Command>
+      <Command>clang -target bpf -O2 -Werror -c %(Filename).c -o %(Filename).o</Command>
       <Outputs>%(Filename).o;%(Outputs)</Outputs>
       <TreatOutputAsContent>true</TreatOutputAsContent>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -I../xdp -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -I../xdp -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -I../xdp -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -I../xdp -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
+      <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
+    </CustomBuild>
+    <CustomBuild Include="encap_reflect_packet.c">
+      <FileType>CppCode</FileType>
+      <Command>clang -target bpf -O2 -Werror -c %(Filename).c -o %(Filename).o</Command>
+      <Outputs>%(Filename).o;%(Outputs)</Outputs>
+      <TreatOutputAsContent>true</TreatOutputAsContent>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -I../xdp -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -I../xdp -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
     </CustomBuild>
@@ -143,21 +153,21 @@
     </CustomBuild>
     <CustomBuild Include="test_sample_ebpf.c">
       <FileType>CppCode</FileType>
-      <Command>clang -target bpf -O2 -Wall -c %(Filename).c -o %(Filename).o</Command>
+      <Command>clang -target bpf -O2 -Werror -c %(Filename).c -o %(Filename).o</Command>
       <Outputs>%(Filename).o;%(Outputs)</Outputs>
       <TreatOutputAsContent>true</TreatOutputAsContent>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -I./ext/inc -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -I./ext/inc -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -I./ext/inc -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -I./ext/inc -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
     </CustomBuild>
     <CustomBuild Include="droppacket.c">
       <FileType>CppCode</FileType>
-      <Command>clang -target bpf -O2 -Wall -c %(Filename).c -o %(Filename).o</Command>
+      <Command>clang -target bpf -O2 -Werror -c %(Filename).c -o %(Filename).o</Command>
       <Outputs>%(Filename).o;%(Outputs)</Outputs>
       <TreatOutputAsContent>true</TreatOutputAsContent>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
     </CustomBuild>
@@ -168,8 +178,8 @@
   <ItemGroup>
     <CustomBuild Include="divide_by_zero.c">
       <FileType>CppCode</FileType>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
       <TreatOutputAsContent Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</TreatOutputAsContent>
@@ -179,10 +189,10 @@
   <ItemGroup>
     <CustomBuild Include="droppacket_unsafe.c">
       <FileType>CppCode</FileType>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
       <TreatOutputAsContent Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</TreatOutputAsContent>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <TreatOutputAsContent Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</TreatOutputAsContent>
     </CustomBuild>
@@ -190,8 +200,8 @@
   <ItemGroup>
     <CustomBuild Include="tail_call.c">
       <FileType>CppCode</FileType>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
       <TreatOutputAsContent Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</TreatOutputAsContent>
@@ -201,8 +211,8 @@
   <ItemGroup>
     <CustomBuild Include="tail_call_bad.c">
       <FileType>CppCode</FileType>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
       <TreatOutputAsContent Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</TreatOutputAsContent>
@@ -212,8 +222,8 @@
   <ItemGroup>
     <CustomBuild Include="map_in_map.c">
       <FileType>CppCode</FileType>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
       <TreatOutputAsContent Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</TreatOutputAsContent>
@@ -221,8 +231,8 @@
     </CustomBuild>
     <CustomBuild Include="tail_call_map.c">
       <FileType>CppCode</FileType>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
       <TreatOutputAsContent Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</TreatOutputAsContent>
@@ -230,11 +240,11 @@
     </CustomBuild>
     <CustomBuild Include="test_utility_helpers.c">
       <FileType>CppCode</FileType>
-      <Command>clang -target bpf -O2 -Wall -c %(Filename).c -o %(Filename).o</Command>
+      <Command>clang -target bpf -O2 -Werror -c %(Filename).c -o %(Filename).o</Command>
       <Outputs>%(Filename).o;%(Outputs)</Outputs>
       <TreatOutputAsContent>true</TreatOutputAsContent>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
-      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Wall -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
+      <Command Condition="'$(Configuration)|$(Platform)'=='Release|x64'">clang -g -target bpf -O2 -Werror -I../../include -c %(Filename).c -o $(OutputPath)%(Filename).o</Command>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">$(OutputPath)%(Filename).o</Outputs>
       <Outputs Condition="'$(Configuration)|$(Platform)'=='Release|x64'">$(OutputPath)%(Filename).o</Outputs>
     </CustomBuild>

tests/sample/xdp_common.h

@@ -9,9 +9,9 @@ inline void
 swap_mac_addresses(ETHERNET_HEADER* ethernet_header)
 {
     mac_address_t mac = {0};
-    memcpy(mac, ethernet_header->Destination, sizeof(mac_address_t));
-    memcpy(ethernet_header->Destination, ethernet_header->Source, sizeof(mac_address_t));
-    memcpy(ethernet_header->Source, mac, sizeof(mac_address_t));
+    __builtin_memcpy(mac, ethernet_header->Destination, sizeof(mac_address_t));
+    __builtin_memcpy(ethernet_header->Destination, ethernet_header->Source, sizeof(mac_address_t));
+    __builtin_memcpy(ethernet_header->Source, mac, sizeof(mac_address_t));
 }
 
 inline void
@@ -26,9 +26,9 @@ inline void
 swap_ipv6_addresses(IPV6_HEADER* ipv6_header)
 {
     ipv6_address_t address = {0};
-    memcpy(address, ipv6_header->DestinationAddress, sizeof(ipv6_address_t));
-    memcpy(ipv6_header->DestinationAddress, ipv6_header->SourceAddress, sizeof(ipv6_address_t));
-    memcpy(ipv6_header->SourceAddress, address, sizeof(ipv6_address_t));
+    __builtin_memcpy(address, ipv6_header->DestinationAddress, sizeof(ipv6_address_t));
+    __builtin_memcpy(ipv6_header->DestinationAddress, ipv6_header->SourceAddress, sizeof(ipv6_address_t));
+    __builtin_memcpy(ipv6_header->SourceAddress, address, sizeof(ipv6_address_t));
 }
 
 inline int