Prover: richer exit code to better detect completeness issues (#978)

* feat(exit): make sure that keccak uses 77 when overflowing and not a panic message

* feat(exit): makes PadAssign return a 77 when vector builder overflows

* feat(exit): adds a toggle mechanism for the exiting strategy

* feat(unsatisfied): adds exiting when encountering an unsatisfied constraint

* adds the toggle for the exit when finding unsatisfied constraints

* feat(77): uses the 77 exit code to tell when we have too many merkle proofs

* fix log for modexp

prover/backend/execution/prove.go

@@ -11,6 +11,7 @@ import (
 	"github.com/consensys/linea-monorepo/prover/config"
 	public_input "github.com/consensys/linea-monorepo/prover/public-input"
 	"github.com/consensys/linea-monorepo/prover/utils"
+	"github.com/consensys/linea-monorepo/prover/utils/exit"
 	"github.com/consensys/linea-monorepo/prover/utils/profiling"
 	"github.com/consensys/linea-monorepo/prover/zkevm"
 	"github.com/sirupsen/logrus"
@@ -26,6 +27,10 @@ func Prove(cfg *config.Config, req *Request, large bool) (*Response, error) {
 	// Set MonitorParams before any proving happens
 	profiling.SetMonitorParams(cfg)
 
+	// This instructs the [exit] package to actually exit when [OnLimitOverflow]
+	// or [OnSatisfiedConstraints] are called.
+	exit.ActivateExitOnIssue()
+
 	var resp Response
 
 	// TODO @gbotrel wrap profiling in the caller; so that we can properly return errors
@@ -146,7 +151,8 @@ func mustProveAndPass(
 
 		logrus.Info("Sanity-checking the inner-proof")
 		if err := fullZkEvm.VerifyInner(proof); err != nil {
-			utils.Panic("The prover did not pass: %v", err)
+			logrus.Errorf("The sanity-check of the inner-proof did not pass: %v", err)
+			exit.OnUnsatisfiedConstraints()
 		}
 
 		// wait for setup to be loaded

prover/protocol/compiler/lookup/prover.go

@@ -11,7 +11,9 @@ import (
 	"github.com/consensys/linea-monorepo/prover/protocol/wizard"
 	"github.com/consensys/linea-monorepo/prover/protocol/wizardutils"
 	"github.com/consensys/linea-monorepo/prover/utils"
+	"github.com/consensys/linea-monorepo/prover/utils/exit"
 	"github.com/consensys/linea-monorepo/prover/utils/parallel"
+	"github.com/sirupsen/logrus"
 )
 
 // proverTaskAtRound implements the [wizard.ProverAction] interface. It gathers
@@ -257,12 +259,16 @@ func (a mAssignmentTask) run(run *wizard.ProverRuntime) {
 			}
 
 			if hasFilter && !filter[k].IsOne() {
-				utils.Panic(
+				logrus.Errorf(
 					"the filter column `%v` has a non-binary value at position `%v`: (%v)",
 					a.SFilter[i].GetColID(),
 					k,
 					filter[k].String(),
 				)
+
+				// Even if this is unconstrained, this is still worth interrupting the
+				// prover because it "should" be a binary column.
+				exit.OnUnsatisfiedConstraints()
 			}
 
 			var (
@@ -279,10 +285,12 @@ func (a mAssignmentTask) run(run *wizard.ProverRuntime) {
 				for j := range tableRow {
 					tableRow[j] = a.S[i][j].GetColAssignmentAt(run, k)
 				}
-				utils.Panic(
+				logrus.Errorf(
 					"entry %v of the table %v is not included in the table. tableRow=%v",
 					k, nameTable([][]ifaces.Column{a.S[i]}), vector.Prettify(tableRow),
 				)
+
+				exit.OnUnsatisfiedConstraints()
 			}
 
 			mFrag, posInFragM := posInM[0], posInM[1]

prover/protocol/compiler/univariates/local_opening_point.go

@@ -112,7 +112,7 @@ func (ctx localOpeningCtx) verifier(assi *wizard.VerifierRuntime) error {
 	}
 
 	if len(ys) != len(newParams.Ys) {
-		utils.Panic("the ys do not have the same length")
+		return fmt.Errorf("the ys do not have the same length")
 	}
 
 	errMsg := "fixed point compiler verifier failed\n"

prover/protocol/compiler/univariates/multi_to_single_point.go

@@ -2,12 +2,14 @@ package univariates
 
 import (
 	"fmt"
-	ppool "github.com/consensys/linea-monorepo/prover/utils/parallel/pool"
 	"math/big"
 	"reflect"
 	"runtime"
 	"sync"
 
+	"github.com/consensys/linea-monorepo/prover/utils/exit"
+	ppool "github.com/consensys/linea-monorepo/prover/utils/parallel/pool"
+
 	"github.com/consensys/gnark/frontend"
 	"github.com/sirupsen/logrus"
 
@@ -322,7 +324,8 @@ func (ctx mptsCtx) accumulateQuotients(run *wizard.ProverRuntime) {
 						panicMsg += fmt.Sprintf("\t\tfor %v, P(x) = %v\n", q.Pols[i].GetColID(), params.Ys[i].String())
 					}
 
-					utils.Panic("%vremainder was %v (while reducing %v from query %v) \n", panicMsg, rem.String(), polHandle.GetColID(), ctx.hs[hpos])
+					logrus.Errorf("%vremainder was %v (while reducing %v from query %v) \n", panicMsg, rem.String(), polHandle.GetColID(), ctx.hs[hpos])
+					exit.OnUnsatisfiedConstraints()
 				}
 			}
 

prover/protocol/dedicated/plonk/alignment.go

@@ -2,7 +2,6 @@ package plonk
 
 import (
 	"fmt"
-	"os"
 	"sync"
 
 	"github.com/consensys/gnark-crypto/ecc"
@@ -17,6 +16,7 @@ import (
 	"github.com/consensys/linea-monorepo/prover/protocol/wizard"
 	"github.com/consensys/linea-monorepo/prover/symbolic"
 	"github.com/consensys/linea-monorepo/prover/utils"
+	"github.com/consensys/linea-monorepo/prover/utils/exit"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/net/context"
 	"golang.org/x/sync/errgroup"
@@ -96,7 +96,7 @@ func (ci *CircuitAlignmentInput) prepareWitnesses(run *wizard.ProverRuntime) {
 			// Don't use the fatal level here because we want to control the exit code
 			// to be 77.
 			logrus.Errorf("fatal=%v", err)
-			os.Exit(77)
+			exit.OnLimitOverflow()
 		}
 
 		if ci.InputFiller == nil {

prover/utils/exit/exit.go

@@ -0,0 +1,46 @@
+package exit
+
+import (
+	"os"
+	"runtime/debug"
+)
+
+var (
+	activateExitOnIssue bool
+)
+
+// ActivateExitOnIssue tells the program to actually exit when [OnLimitOverflow]
+// or [OnSatisfiedConstraints] are called. This has to be manually called at the
+// beginning of the program if we want the behavior to take place. This is
+// to avoid having it running in the tests.
+func ActivateExitOnIssue() {
+	activateExitOnIssue = true
+}
+
+const (
+	limitOverflowExitCode          = 77
+	unsatisfiedConstraintsExitCode = 78
+)
+
+// This function will exit the program with the exit code [limitOverflowExitCode]
+// but only if the activateExitOnIssue flag is set to true. Otherwise, it will
+// just panic.
+func OnLimitOverflow() {
+
+	debug.PrintStack()
+
+	if !activateExitOnIssue {
+		panic("limit overflow")
+	}
+	os.Exit(limitOverflowExitCode)
+}
+
+func OnUnsatisfiedConstraints() {
+
+	debug.PrintStack()
+
+	if !activateExitOnIssue {
+		panic("unsatisfied constraints")
+	}
+	os.Exit(unsatisfiedConstraintsExitCode)
+}

prover/zkevm/arithmetization/arithmetization.go

@@ -74,7 +74,7 @@ func (a *Arithmetization) Assign(run *wizard.ProverRuntime, traceFile string) {
 	// Performs a compatibility check by comparing the constraints
 	// commit of zkevm.bin with the constraints commit of the trace file.
 	// Panics if an incompatibility is detected.
-	if *a.Settings.IgnoreCompatibilityCheck == false {
+	if !*a.Settings.IgnoreCompatibilityCheck {
 		var errors []string
 
 		zkevmBinCommit, ok := a.Metadata.String("commit")

prover/zkevm/arithmetization/assignment.go

@@ -3,7 +3,6 @@ package arithmetization
 import (
 	"errors"
 	"fmt"
-	"os"
 
 	"github.com/consensys/go-corset/pkg/air"
 	"github.com/consensys/go-corset/pkg/trace"
@@ -12,6 +11,7 @@ import (
 	"github.com/consensys/linea-monorepo/prover/maths/field"
 	"github.com/consensys/linea-monorepo/prover/protocol/ifaces"
 	"github.com/consensys/linea-monorepo/prover/protocol/wizard"
+	"github.com/consensys/linea-monorepo/prover/utils/exit"
 	"github.com/sirupsen/logrus"
 )
 
@@ -48,7 +48,7 @@ func AssignFromLtTraces(run *wizard.ProverRuntime, schema *air.Schema, expTraces
 
 	if err77 != nil {
 		logrus.Errorf("Error code 77 %v", err77)
-		os.Exit(TraceOverflowExitCode)
+		exit.OnLimitOverflow()
 	}
 
 	for id := uint(0); id < numCols; id++ {

prover/zkevm/arithmetization/files.go

@@ -16,8 +16,6 @@ import (
 	"github.com/consensys/go-corset/pkg/util/collection/typed"
 )
 
-const TraceOverflowExitCode = 77
-
 // Embed the whole constraint system at compile time, so no
 // more need to keep it in sync
 //

prover/zkevm/prover/common/vector_builder.go

@@ -6,7 +6,9 @@ import (
 	"github.com/consensys/linea-monorepo/prover/protocol/ifaces"
 	"github.com/consensys/linea-monorepo/prover/protocol/wizard"
 	"github.com/consensys/linea-monorepo/prover/utils"
+	"github.com/consensys/linea-monorepo/prover/utils/exit"
 	"github.com/consensys/linea-monorepo/prover/utils/types"
+	"github.com/sirupsen/logrus"
 )
 
 // VectorBuilder is a convenience structure to assign columns by appending
@@ -153,6 +155,13 @@ func (vb *VectorBuilder) PushAddr(addr types.EthAddress) {
 // PadAndAssign pads and assign the column built by `vb` using `v` as padding
 // value and assigning into `run`.
 func (vb *VectorBuilder) PadAndAssign(run *wizard.ProverRuntime, v ...field.Element) {
+
+	if len(vb.slice) > vb.column.Size() {
+		logrus.Errorf("the slice size %v is larger than the column size %v", len(vb.slice), vb.column.Size())
+		// We print the stack to help debugging
+		exit.OnLimitOverflow()
+	}
+
 	paddingValue := field.Zero()
 	if len(v) > 0 {
 		paddingValue = v[0]

prover/zkevm/prover/hash/keccak/keccakf/keccakf.go

@@ -11,7 +11,9 @@ import (
 	"github.com/consensys/linea-monorepo/prover/protocol/ifaces"
 	"github.com/consensys/linea-monorepo/prover/protocol/wizard"
 	"github.com/consensys/linea-monorepo/prover/utils"
+	"github.com/consensys/linea-monorepo/prover/utils/exit"
 	"github.com/consensys/linea-monorepo/prover/utils/parallel"
+	"github.com/sirupsen/logrus"
 )
 
 const (
@@ -127,7 +129,8 @@ func (mod *Module) Assign(
 	// If the number of keccakf constraints is larger than what the module
 	// is sized for, then, we cannot prove everything.
 	if numKeccakf > mod.MaxNumKeccakf {
-		utils.Panic("Too many keccakf %v > %v", numKeccakf, mod.MaxNumKeccakf)
+		logrus.Errorf("Too many keccakf %v > %v", numKeccakf, mod.MaxNumKeccakf)
+		exit.OnLimitOverflow()
 	}
 
 	lu := mod.lookups

prover/zkevm/prover/modexp/module_assignement.go

@@ -1,11 +1,10 @@
 package modexp
 
 import (
-	"os"
-
 	"github.com/consensys/linea-monorepo/prover/maths/field"
 	"github.com/consensys/linea-monorepo/prover/protocol/wizard"
 	"github.com/consensys/linea-monorepo/prover/utils"
+	"github.com/consensys/linea-monorepo/prover/utils/exit"
 	"github.com/consensys/linea-monorepo/prover/zkevm/prover/common"
 	"github.com/sirupsen/logrus"
 )
@@ -88,12 +87,12 @@ func (mod *Module) Assign(run *wizard.ProverRuntime) {
 
 	if modexpCountSmall > mod.MaxNb256BitsInstances {
 		logrus.Errorf("limit overflow: the modexp (256 bits) count is %v and the limit is %v\n", modexpCountSmall, mod.MaxNb256BitsInstances)
-		os.Exit(77)
+		exit.OnLimitOverflow()
 	}
 
 	if modexpCountLarge > mod.MaxNb4096BitsInstances {
-		logrus.Errorf("limit overflow: the modexp (4096 bits) count is %v and the limit is %v\n", modexpCountSmall, mod.MaxNb4096BitsInstances)
-		os.Exit(77)
+		logrus.Errorf("limit overflow: the modexp (4096 bits) count is %v and the limit is %v\n", modexpCountLarge, mod.MaxNb4096BitsInstances)
+		exit.OnLimitOverflow()
 	}
 
 	builder.isActive.PadAndAssign(run, field.Zero())

prover/zkevm/prover/statemanager/accumulator/assign.go

@@ -12,7 +12,9 @@ import (
 	"github.com/consensys/linea-monorepo/prover/protocol/dedicated/merkle"
 	"github.com/consensys/linea-monorepo/prover/protocol/wizard"
 	"github.com/consensys/linea-monorepo/prover/utils"
+	"github.com/consensys/linea-monorepo/prover/utils/exit"
 	"github.com/consensys/linea-monorepo/prover/utils/types"
+	"github.com/sirupsen/logrus"
 )
 
 // leafOpenings represents the structure for leaf openings
@@ -207,7 +209,8 @@ func (am *Module) Assign(
 
 	// Sanity check on the size
 	if len(builder.leaves) > am.MaxNumProofs {
-		utils.Panic("We have registered %v proofs which is more than the maximum number of proofs %v", len(builder.leaves), am.MaxNumProofs)
+		logrus.Errorf("We have registered %v proofs which is more than the maximum number of proofs %v", len(builder.leaves), am.MaxNumProofs)
+		exit.OnLimitOverflow()
 	}
 
 	// Assignments of columns