perf(all): add prealloc

fuzzer/fuzzer.go

@@ -268,7 +268,7 @@ func (fz *Fuzzer) chain(steps []Step, pl plan.Plan) {
 	// Second, create our list of execCalls based on the list of plan.Calls.
 	// We do not yet fully populate the arguments for an execCall,
 	// which we will do on a subsequent pass.
-	var execCalls []execCall
+	execCalls := make([]execCall, len(pl.Calls))
 	for i := range pl.Calls {
 		// Based on the plan, compute index into the user's Step list.
 		s := int(pl.Calls[i].StepIndex) % len(steps)
@@ -281,7 +281,7 @@ func (fz *Fuzzer) chain(steps []Step, pl plan.Plan) {
 			args:     []argument{}, // empty to start, we will fill in below.
 		}
 
-		execCalls = append(execCalls, ec)
+		execCalls[i] = ec
 	}
 
 	// Third, create arguments as needed for each execCall,

gen/genfuncs.go

@@ -183,11 +183,11 @@ func emitIndependentWrapper(emit emitFunc, function mod.Func, constructors []mod
 		return fmt.Errorf("%w: %s has 0 input params", errNoFunctionsMatch, function.FuncName)
 	}
 
-	var paramReprs []paramRepr
+	paramReprs := make([]paramRepr, len(inputParams))
 	for i, v := range inputParams {
 		typeStringWithSelector := types.TypeString(v.Type(), defaultQualifier)
 		paramName := avoidCollision(v, i, localPkg, inputParams)
-		paramReprs = append(paramReprs, paramRepr{paramName: paramName, typ: typeStringWithSelector, v: v})
+		paramReprs[i] = paramRepr{paramName: paramName, typ: typeStringWithSelector, v: v}
 	}
 
 	// Check if we have an interface or function pointer in our desired parameters,

gen/genfuncsloop.go

@@ -313,11 +313,11 @@ func emitChainTarget(emit emitFunc, function mod.Func, qualifyAll bool) error {
 		inputParams = append(inputParams, v)
 	}
 
-	var paramReprs []paramRepr
+	paramReprs := make([]paramRepr, len(inputParams))
 	for i, v := range inputParams {
 		typeStringWithSelector := types.TypeString(v.Type(), defaultQualifier)
 		paramName := avoidCollision(v, i, localPkg, inputParams)
-		paramReprs = append(paramReprs, paramRepr{paramName: paramName, typ: typeStringWithSelector, v: v})
+		paramReprs[i] = paramRepr{paramName: paramName, typ: typeStringWithSelector, v: v}
 	}
 
 	// Check if we have an interface or function pointer in our desired parameters,
@@ -458,11 +458,11 @@ func emitChainStep(emit emitFunc, function mod.Func, constructor mod.Func, quali
 		inputParams = append(inputParams, v)
 	}
 
-	var paramReprs []paramRepr
+	paramReprs := make([]paramRepr, len(inputParams))
 	for i, v := range inputParams {
 		typeStringWithSelector := types.TypeString(v.Type(), defaultQualifier)
 		paramName := avoidCollision(v, i, localPkg, inputParams)
-		paramReprs = append(paramReprs, paramRepr{paramName: paramName, typ: typeStringWithSelector, v: v})
+		paramReprs[i] = paramRepr{paramName: paramName, typ: typeStringWithSelector, v: v}
 	}
 
 	// Check if we have an interface or function pointer in our desired parameters,