CMakeLists: Specify -Wextra on linux builds

Allows reporting more cases where logic errors may exist, such as
implicit fallthrough cases, etc.

We currently ignore unused parameters, since we currently have many
cases where this is intentional (virtual interfaces).

While we're at it, we can also tidy up any existing code that causes
warnings. This also uncovered a few bugs as well.

3 files changed, 15 insertions, 10 deletions

diff --git a/src/video_core/shader/decode/image.cpp b/src/video_core/shader/decode/image.cpp
index 0dd7a1196..85ee9aa5e 100644
--- a/src/video_core/shader/decode/image.cpp
+++ b/src/video_core/shader/decode/image.cpp
@@ -352,8 +352,10 @@ u32 ShaderIR::DecodeImage(NodeBlock& bb, u32 pc) {
                         registry.ObtainBoundSampler(static_cast<u32>(instr.image.index.Value()));
                 } else {
                     const Node image_register = GetRegister(instr.gpr39);
-                    const auto [base_image, buffer, offset] = TrackCbuf(
-                        image_register, global_code, static_cast<s64>(global_code.size()));
+                    const auto result = TrackCbuf(image_register, global_code,
+                                                  static_cast<s64>(global_code.size()));
+                    const auto buffer = std::get<1>(result);
+                    const auto offset = std::get<2>(result);
                     descriptor = registry.ObtainBindlessSampler(buffer, offset);
                 }
                 if (!descriptor) {
@@ -497,9 +499,12 @@ Image& ShaderIR::GetImage(Tegra::Shader::Image image, Tegra::Shader::ImageType t
 
 Image& ShaderIR::GetBindlessImage(Tegra::Shader::Register reg, Tegra::Shader::ImageType type) {
     const Node image_register = GetRegister(reg);
-    const auto [base_image, buffer, offset] =
+    const auto result =
         TrackCbuf(image_register, global_code, static_cast<s64>(global_code.size()));
 
+    const auto buffer = std::get<1>(result);
+    const auto offset = std::get<2>(result);
+
     const auto it =
         std::find_if(std::begin(used_images), std::end(used_images),
                      [buffer = buffer, offset = offset](const Image& entry) {
diff --git a/src/video_core/shader/shader_ir.cpp b/src/video_core/shader/shader_ir.cpp
index 8852c8a1b..822674926 100644
--- a/src/video_core/shader/shader_ir.cpp
+++ b/src/video_core/shader/shader_ir.cpp
@@ -56,8 +56,7 @@ Node ShaderIR::GetConstBuffer(u64 index_, u64 offset_) {
     const auto index = static_cast<u32>(index_);
     const auto offset = static_cast<u32>(offset_);
 
-    const auto [entry, is_new] = used_cbufs.try_emplace(index);
-    entry->second.MarkAsUsed(offset);
+    used_cbufs.try_emplace(index).first->second.MarkAsUsed(offset);
 
     return MakeNode<CbufNode>(index, Immediate(offset));
 }
@@ -66,8 +65,7 @@ Node ShaderIR::GetConstBufferIndirect(u64 index_, u64 offset_, Node node) {
     const auto index = static_cast<u32>(index_);
     const auto offset = static_cast<u32>(offset_);
 
-    const auto [entry, is_new] = used_cbufs.try_emplace(index);
-    entry->second.MarkAsUsedIndirect();
+    used_cbufs.try_emplace(index).first->second.MarkAsUsedIndirect();
 
     Node final_offset = [&] {
         // Attempt to inline constant buffer without a variable offset. This is done to allow
@@ -166,6 +164,7 @@ Node ShaderIR::ConvertIntegerSize(Node value, Register::Size size, bool is_signe
                                 std::move(value), Immediate(16));
         value = SignedOperation(OperationCode::IArithmeticShiftRight, is_signed, NO_PRECISE,
                                 std::move(value), Immediate(16));
+        return value;
     case Register::Size::Word:
         // Default - do nothing
         return value;
diff --git a/src/video_core/shader/track.cpp b/src/video_core/shader/track.cpp
index 10739b37d..224943ad9 100644
--- a/src/video_core/shader/track.cpp
+++ b/src/video_core/shader/track.cpp
@@ -27,8 +27,9 @@ std::pair<Node, s64> FindOperation(const NodeBlock& code, s64 cursor,
 
         if (const auto conditional = std::get_if<ConditionalNode>(&*node)) {
             const auto& conditional_code = conditional->GetCode();
-            auto [found, internal_cursor] = FindOperation(
+            auto result = FindOperation(
                 conditional_code, static_cast<s64>(conditional_code.size() - 1), operation_code);
+            auto& found = result.first;
             if (found) {
                 return {std::move(found), cursor};
             }
@@ -186,8 +187,8 @@ std::tuple<Node, u32, u32> ShaderIR::TrackCbuf(Node tracked, const NodeBlock& co
 std::optional<u32> ShaderIR::TrackImmediate(Node tracked, const NodeBlock& code, s64 cursor) const {
     // Reduce the cursor in one to avoid infinite loops when the instruction sets the same register
     // that it uses as operand
-    const auto [found, found_cursor] =
-        TrackRegister(&std::get<GprNode>(*tracked), code, cursor - 1);
+    const auto result = TrackRegister(&std::get<GprNode>(*tracked), code, cursor - 1);
+    const auto& found = result.first;
     if (!found) {
         return {};
     }