Fix many Tofino warnings.

backends/tofino/bf-p4c/arch/fromv1.0/stateful_alu.cpp

@@ -231,7 +231,6 @@ class CreateSaluApplyFunction : public Inspector {
     int expr_idx[NUM_EXPR_INDEX_T] = {0};
     Util::SourceInfo expr_src_info[NUM_EXPR_INDEX_T];
     Util::SourceInfo expr_pred_src_info[NUM_EXPR_INDEX_T];
-    const IR::Statement *output = nullptr;
     const Util::SourceInfo *applyLoc = nullptr;
     enum expr_index_t { LO1, LO2, HI1, HI2, OUT, UNUSED } expr_index = UNUSED;
     bool saturating = false;

backends/tofino/bf-p4c/arch/fromv1.0/v1_converters.h

@@ -78,15 +78,17 @@ class ControlConverter : public Transform {
         CHECK_NULL(structure);
     }
 
-    const IR::Node *postorder(IR::Declaration_Instance *node) {
+    const IR::Node *postorder(IR::Declaration_Instance *node) override {
         return substitute<IR::Declaration_Instance>(node);
     }
 
-    const IR::Node *postorder(IR::MethodCallStatement *node) {
+    const IR::Node *postorder(IR::MethodCallStatement *node) override {
         return substitute<IR::MethodCallStatement>(node);
     }
 
-    const IR::Node *postorder(IR::Property *node) { return substitute<IR::Property>(node); }
+    const IR::Node *postorder(IR::Property *node) override {
+        return substitute<IR::Property>(node);
+    }
 
     const IR::Node *postorder(IR::BFN::TnaControl *node) override;
 

backends/tofino/bf-p4c/arch/psa/psa.cpp

@@ -450,7 +450,7 @@ class TranslateProgram : public Inspector {
         return;
     }
 
-    void postorder(const IR::ParserState *state) {
+    void postorder(const IR::ParserState *state) override {
         auto ctxt = findContext<IR::P4Parser>();
         CHECK_NULL(ctxt);
         for (auto stmt : state->components) {

backends/tofino/bf-p4c/common/field_defuse.cpp

@@ -636,7 +636,7 @@ static inline auto getParserRangeDefMatcher(const PhvInfo &phv, const PHV::Field
     le_bitrange range = bits ? *bits : StartLen(0, f->size);
     // note that we need to capture f (pointer) and range by value to avoid dangling reference,
     // but phv by reference (it is large and we got it by reference)
-    return [&phv, range, f](const FieldDefUse::locpair &lp) {
+    return [&phv, range](const FieldDefUse::locpair &lp) {
         le_bitrange rng;
         if (!(lp.first->is<IR::BFN::ParserState>() || lp.first->is<IR::BFN::Parser>()))
             return false;

backends/tofino/bf-p4c/control-plane/bfruntime_arch_handler.h

@@ -100,11 +100,11 @@ struct CounterlikeTraits<::BFN::CounterExtern<BFN::Arch::TNA>> {
 /// CounterlikeTraits specialization for BFN::CounterExtern for PSA
 template <>
 struct CounterlikeTraits<::BFN::CounterExtern<BFN::Arch::PSA>> {
-    static const cstring name() { return "counter"_cs; }
-    static const cstring directPropertyName() { return "psa_direct_counter"_cs; }
-    static const cstring typeName() { return "Counter"_cs; }
-    static const cstring directTypeName() { return "DirectCounter"_cs; }
-    static const cstring sizeParamName() { return "n_counters"_cs; }
+    static cstring name() { return "counter"_cs; }
+    static cstring directPropertyName() { return "psa_direct_counter"_cs; }
+    static cstring typeName() { return "Counter"_cs; }
+    static cstring directTypeName() { return "DirectCounter"_cs; }
+    static cstring sizeParamName() { return "n_counters"_cs; }
     static ::barefoot::CounterSpec::Unit mapUnitName(const cstring name) {
         using ::barefoot::CounterSpec;
         if (name == "PACKETS")
@@ -519,8 +519,7 @@ struct SnapshotFieldInfo {
     uint32_t id;
     int32_t bitwidth;
     bool operator==(const SnapshotFieldInfo &s) const {
-        if (s.name == name && s.id == id && s.bitwidth == bitwidth) return true;
-        return false;
+        return s.name == name && s.id == id && s.bitwidth == bitwidth;
     }
     bool operator<(const SnapshotFieldInfo &s) const { return (id < s.id); }
 };
@@ -2392,7 +2391,7 @@ class BFRuntimeArchHandlerPSA final : public BFRuntimeArchHandlerCommon<Arch::PS
         implementationString = "psa_implementation"_cs;
     }
 
-    void postCollect(const P4RuntimeSymbolTableIface &symbols) {
+    void postCollect(const P4RuntimeSymbolTableIface &symbols) override {
         (void)symbols;
         // analyze action profiles / selectors and build a mapping from action
         // profile / selector name to the set of tables referencing them
@@ -2439,15 +2438,15 @@ class BFRuntimeArchHandlerPSA final : public BFRuntimeArchHandlerCommon<Arch::PS
         collectExternInstanceCommon(symbols, externBlock);
     }
 
-    void collectExternFunction(P4RuntimeSymbolTableIface *, const P4::ExternFunction *) {}
+    void collectExternFunction(P4RuntimeSymbolTableIface *, const P4::ExternFunction *) override {}
 
     void addExternInstance(const P4RuntimeSymbolTableIface &symbols, p4configv1::P4Info *p4info,
-                           const IR::ExternBlock *externBlock) {
+                           const IR::ExternBlock *externBlock) override {
         addExternInstanceCommon(symbols, p4info, externBlock, defaultPipeName);
     }
 
     void addExternFunction(const P4RuntimeSymbolTableIface &, p4configv1::P4Info *,
-                           const P4::ExternFunction *) {}
+                           const P4::ExternFunction *) override {}
 };
 
 /// The architecture handler builder implementation for Tofino.

backends/tofino/bf-p4c/logging/constrained_fields.h

@@ -96,7 +96,7 @@ class ConstrainedField : public LoggableEntity {
     bool sameContainerGroup = false;
 
  public:
-    ConstrainedField() {}
+    ConstrainedField() = default;
     explicit ConstrainedField(const cstring &name);
 
     const cstring &getName() const { return name; }
@@ -116,7 +116,7 @@ class ConstrainedField : public LoggableEntity {
     const Constraints::DigestConstraint &getDigest() const { return digest; }
 
     void setContainerSize(const Constraints::ContainerSizeConstraint &containerSize);
-    const Constraints::ContainerSizeConstraint getContainerSize() const { return containerSize; }
+    Constraints::ContainerSizeConstraint getContainerSize() const { return containerSize; }
 
     void setBottomBits(bool b);
     bool hasBottomBits() const { return deparsedBottomBits; }
@@ -134,7 +134,7 @@ class ConstrainedField : public LoggableEntity {
     bool hasNoHoles() const { return noHoles; }
 
     void setSameContainerGroup(bool b);
-    bool hasSameContainerGroup() { return sameContainerGroup; }
+    bool hasSameContainerGroup() const { return sameContainerGroup; }
 };
 
 typedef std::map<cstring, ConstrainedField> ConstrainedFieldMap;

backends/tofino/bf-p4c/logging/resources_clot.h

@@ -19,13 +19,11 @@
 #ifndef _BACKENDS_TOFINO_BF_P4C_LOGGING_RESOURCES_CLOT_H_
 #define _BACKENDS_TOFINO_BF_P4C_LOGGING_RESOURCES_CLOT_H_
 
-/* clang-format off */
 #include <map>
 #include <vector>
-#include "ir/ir.h"
 
 #include "backends/tofino/bf-p4c/logging/resources_schema.h"
-/* clang-format on */
+#include "ir/ir.h"
 
 using Logging::Resources_Schema_Logger;
 class ClotInfo;  // Forward declaration
@@ -50,7 +48,7 @@ class ClotResourcesLogging : public ParserInspector {
 
     std::vector<ClotUsage *> &getUsageData(gress_t gress, unsigned tag);
 
-    bool preorder(const IR::BFN::LoweredParserState *state);
+    bool preorder(const IR::BFN::LoweredParserState *state) override;
     void end_apply() override;
 
     void collectClotUsages(const IR::BFN::LoweredParserMatch *match,

backends/tofino/bf-p4c/mau/action_analysis.cpp

@@ -1154,7 +1154,6 @@ bool ActionAnalysis::init_simple_alignment(const ActionParam &read, ContainerAct
 
     if (read.type == ActionParam::ACTIONDATA) {
         le_bitrange read_bits;
-        cstring key;
         if (cont_action.is_deposit_field_variant || cont_action.convert_instr_to_deposit_field ||
             cont_action.convert_instr_to_byte_rotate_merge || cont_action.name == "set") {
             // if the instruction is or could be a deposit field or byte rotate, then we don't

backends/tofino/bf-p4c/mau/action_format.cpp

@@ -2101,7 +2101,6 @@ const ALUParameter *Format::Use::find_param_alloc(UniqueLocationKey &key,
     Log::TempIndent indent;
     LOG3("  Finding ALU Param with container " << indent << indent << key.container
                                                << " for action " << key.action_name);
-    bool container_match = false;
     for (auto alu_position : action_alu_positions) {
         LOG3(alu_position);
         if (alu_position.alu_op->container() != key.container) continue;
@@ -2113,7 +2112,6 @@ const ALUParameter *Format::Use::find_param_alloc(UniqueLocationKey &key,
                   "in container %s in action %s",
                   key.container, key.action_name);
         rv = loc;
-        container_match |= alu_position.alu_op->container() == key.container;
         if (alu_pos_p) *alu_pos_p = new ALUPosition(alu_position);
     }
     if (!rv) {

backends/tofino/bf-p4c/mau/determine_power_usage.cpp

@@ -289,10 +289,8 @@ void DeterminePowerUsage::postorder(const IR::MAU::Table *t) {
         } else if (mem.type == Memories::Use::EXACT) {
             // One unit of depth in each way is accessed on a table read.
             // Total RAMs accessed will then be the sum of the widths of ways.
-            int num_ways = 0;
             for (auto way : t->ways) {
                 // LOG4("  exact match width = " << way.width);
-                ++num_ways;
                 match_table.ram_read += way.width;
             }
             mau_features_->has_exact_[t->gress][t->stage()] = true;

backends/tofino/bf-p4c/mau/gateway.cpp

@@ -1287,7 +1287,7 @@ bool BuildGatewayMatch::preorder(const IR::Expression *e) {
         const IR::Expression *tmp;
         BUG_CHECK(orig_mask == donemask, "failed to match all bits of %s",
                   (tmp = findContext<IR::Operation::Relation>()) ? tmp : e);
-        BUG_CHECK((mask ^ upper_bit_mask) << shift == 0, "Didn't cover all bytes");
+        BUG_CHECK(((mask ^ upper_bit_mask) << shift) == 0, "Didn't cover all bytes");
         match_field = {};
     }
     return false;
@@ -1375,7 +1375,7 @@ void BuildGatewayMatch::constant(big_int c) {
             }
             LOG6("    match now " << match);
         }
-        BUG_CHECK((mask ^ upper_bits_mask) << shift == 0, "Didn't cover all bytes");
+        BUG_CHECK(((mask ^ upper_bits_mask) << shift) == 0, "Didn't cover all bytes");
         match_field = {};
     } else {
         BUG("Invalid context for constant in BuildGatewayMatch");

backends/tofino/bf-p4c/mau/instruction_selection.cpp

@@ -3197,12 +3197,12 @@ class ExpandInstructions : public MauTransform {
         }
     }
 
-    IR::Node *preorder(IR::MAU::Action *act) {
+    IR::Node *preorder(IR::MAU::Action *act) override {
         check_action_data_bus_params(act);
         return act;
     }
 
-    IR::Node *postorder(IR::Expression *expr) {
+    IR::Node *postorder(IR::Expression *expr) override {
         auto orig_expr = getOriginal<IR::Expression>();
         BUG_CHECK(orig_expr, "Couldn't find original IR node");
 

backends/tofino/bf-p4c/mau/jbay_next_table.cpp

@@ -349,7 +349,7 @@ class JbayNextTable::FindNextTableUse : public MauTableInspector {
         return r1.second > r2.first && r2.second > r1.first;
     }
 
-    profile_t init_apply(const IR::Node *root) {
+    profile_t init_apply(const IR::Node *root) override {
         self.use_next_table.clear();
         tables.clear();
         return MauTableInspector::init_apply(root);
@@ -360,7 +360,7 @@ class JbayNextTable::FindNextTableUse : public MauTableInspector {
         // containing seq, if that was useful.  Probably almost never useful?
         if (!t->next.empty()) tables.push_back(t);
     }
-    void postorder(const IR::BFN::Pipe *) {
+    void postorder(const IR::BFN::Pipe *) override {
         std::stable_sort(tables.begin(), tables.end(),
                          [this](const IR::MAU::Table *a, const IR::MAU::Table *b) {
                              return self.control_dep.paths(a) > self.control_dep.paths(b);

backends/tofino/bf-p4c/mau/stateful_alu.cpp

@@ -1581,12 +1581,12 @@ bool CreateSaluInstruction::isComplexInstruction(const IR::Operation_Binary *op)
     // IR::L* operators (LAnd, LOr, etc.) are working with predicates
 
     bool ret = false;
-    for (auto oper : {op->left, op->right}) {
-        ret |= oper->is<IR::Add>() | oper->is<IR::AddSat>();
-        ret |= oper->is<IR::Sub>() | oper->is<IR::SubSat>();
-        ret |= oper->is<IR::BAnd>() | oper->is<IR::BOr>() | oper->is<IR::BXor>();
-        ret |= oper->is<IR::Div>() | oper->is<IR::Mod>();
-        ret |= oper->is<IR::Neg>();
+    for (const auto *oper : {op->left, op->right}) {
+        ret = ret || oper->is<IR::Add>() || oper->is<IR::AddSat>();
+        ret = ret || oper->is<IR::Sub>() || oper->is<IR::SubSat>();
+        ret = ret || oper->is<IR::BAnd>() || oper->is<IR::BOr>() || oper->is<IR::BXor>();
+        ret = ret || oper->is<IR::Div>() || oper->is<IR::Mod>();
+        ret = ret || oper->is<IR::Neg>();
     }
 
     return ret;

backends/tofino/bf-p4c/mau/table_placement.cpp

@@ -4881,7 +4881,7 @@ std::ostream &operator<<(std::ostream &out, TablePlacement::choice_t choice) {
         "control dom set has more placeable tables",
         "average chain length of control dom set",
         "default choice"};
-    if (choice < sizeof(choice_names) / sizeof(choice_names[0])) {
+    if (static_cast<uint64_t>(choice) < sizeof(choice_names) / sizeof(choice_names[0])) {
         out << choice_names[choice];
     } else {
         out << "unknown choice <0x" << hex(choice) << ">";
@@ -5476,7 +5476,6 @@ IR::Node *TransformTables::preorder(IR::MAU::Table *tbl) {
         return tbl;
     }
     int stage_table = 0;
-    int prev_entries = 0;
     IR::Vector<IR::MAU::Table> *rv = new IR::Vector<IR::MAU::Table>;
     IR::MAU::Table *prev = 0;
     IR::MAU::Table *atcam_last = nullptr;
@@ -5679,7 +5678,6 @@ IR::Node *TransformTables::preorder(IR::MAU::Table *tbl) {
         stage_table++;
         prev = table_part;
         if (atcam_last) prev = atcam_last;
-        prev_entries += pl->entries;
     }
     BUG_CHECK(!rv->empty(), "Failed to place any stage tables for %s", tbl->name);
     return rv;

backends/tofino/bf-p4c/mau/tofino/input_xbar.cpp

@@ -2098,7 +2098,6 @@ bool IXBar::allocHashWay(const IR::MAU::Table *tbl, const LayoutOption *layout_o
     }
     // Calculation of the separate select bits among many stages
     unsigned free_bits = 0;
-    unsigned used_bits = 0;
 
     for (int bit = 0; bit < IXBar::get_hash_single_bits(); bit++) {
         if (!(hash_single_bit_inuse[bit] & hf_hash_table_input)) {
@@ -2107,7 +2106,6 @@ bool IXBar::allocHashWay(const IR::MAU::Table *tbl, const LayoutOption *layout_o
     }
     for (auto &way_use : alloc.way_use) {
         BUG_CHECK(way_use.select.lo == RAM_SELECT_BIT_START, "invalid select range for tofino");
-        used_bits |= way_use.select_mask;
     }
 
     if (way_bits == 0) {
@@ -3796,7 +3794,6 @@ void IXBar::XBarHashDist::immediate_inputs() {
         auto hash = pos.second->to<ActionData::Hash>();
         if (hash == nullptr) continue;
         le_bitrange immed_range = {pos.first, pos.first + hash->size() - 1};
-        int bits_seen = 0;
         for (int i = 0; i < 2; i++) {
             le_bitrange immed_impact = {i * HASH_DIST_BITS, (i + 1) * HASH_DIST_BITS - 1};
             auto boost_sl = toClosedRange<RangeUnit::Bit, Endian::Little>(
@@ -3810,7 +3807,6 @@ void IXBar::XBarHashDist::immediate_inputs() {
             func->slice(hash_range);
             HashDistDest_t dest = static_cast<HashDistDest_t>(i);
             alloc_reqs.emplace_back(func, hash_dist_range, dest, 0);
-            bits_seen += overlap.size();
         }
     }
 }

backends/tofino/bf-p4c/mau/tofino/memories.cpp

@@ -3530,11 +3530,9 @@ bool Memories::allocate_all_swbox_users() {
     }
 
     if (!action_bus_users.empty() || !synth_bus_users.empty()) {
-        int act_unused = 0;
-        for (auto abu : action_bus_users) act_unused += abu->left_to_place();
+        for (auto abu : action_bus_users) abu->left_to_place();
 
-        int sup_unused = 0;
-        for (auto sbu : synth_bus_users) sup_unused += sbu->left_to_place();
+        for (auto sbu : synth_bus_users) sbu->left_to_place();
 
         failure_reason = "allocate_all_swbox_users failed"_cs;
         LOG4(failure_reason);
@@ -4034,10 +4032,9 @@ bool Memories::allocate_all_gw() {
         }
     }
 
-    int search_bus_free = 0;
     for (int i = 0; i < SRAM_ROWS; i++) {
         for (int j = 0; j < 2; j++) {
-            if (sram_search_bus[i][j].free()) search_bus_free++;
+            sram_search_bus[i][j].free();
         }
     }
 
@@ -4061,7 +4058,6 @@ bool Memories::allocate_all_no_match_miss() {
     // so this is essentially what I'm doing.  More discussion is needed with the driver
     // team in order to determine if this is correct, or if this has to go through ternary and
     // tind tables
-    size_t no_match_tables_allocated = 0;
     for (auto *ta : no_match_miss_tables) {
         for (auto u_id : ta->allocation_units(nullptr, false, UniqueAttachedId::TIND_PP)) {
             auto &alloc = (*ta->memuse)[u_id];
@@ -4086,8 +4082,6 @@ bool Memories::allocate_all_no_match_miss() {
                 failure_reason = "failed to place no match miss "_cs + u_id.build_name();
                 LOG4(failure_reason);
                 return false;
-            } else {
-                no_match_tables_allocated++;
             }
         }
     }