function profiling rewritten - more detailed info, supports global profiling

This commit is contained in:
Vern Paxson 2021-03-25 16:17:32 -07:00
parent bb3a69ebb3
commit 297adf3486
3 changed files with 896 additions and 124 deletions

View file

@ -1,5 +1,7 @@
// See the file "COPYING" in the main distribution directory for copyright.
#include <unistd.h>
#include "zeek/script_opt/ProfileFunc.h"
#include "zeek/Desc.h"
#include "zeek/Stmt.h"
@ -9,27 +11,97 @@
namespace zeek::detail {
TraversalCode ProfileFunc::PreStmt(const Stmt* s)
// Computes the profiling hash of a Obj based on its (deterministic)
// description.
p_hash_type p_hash(const Obj* o)
{
++num_stmts;
ODesc d;
d.SetDeterminism(true);
o->Describe(&d);
return p_hash(d.Description());
}
auto tag = s->Tag();
std::string script_specific_filename(const StmtPtr& body)
{
// The specific filename is taken from the location filename, making
// it absolute if necessary.
auto body_loc = body->GetLocationInfo();
auto bl_f = body_loc->filename;
ASSERT(bl_f != nullptr);
if ( compute_hash )
UpdateHash(int(tag));
if ( tag == STMT_INIT )
if ( bl_f[0] == '.' &&
(bl_f[1] == '/' || (bl_f[1] == '.' && bl_f[2] == '/')) )
{
for ( const auto& id : s->AsInitStmt()->Inits() )
inits.insert(id.get());
// Add working directory to avoid collisions over the
// same relative name.
static std::string working_dir;
if ( working_dir.size() == 0 )
{
char buf[8192];
getcwd(buf, sizeof buf);
working_dir = buf;
}
// Don't recurse into these, as we don't want to consider
// a local that only appears in an initialization as a
// relevant local.
return TC_ABORTSTMT;
return working_dir + "/" + bl_f;
}
switch ( tag ) {
return bl_f;
}
p_hash_type script_specific_hash(const StmtPtr& body, p_hash_type generic_hash)
{
auto bl_f = script_specific_filename(body);
return merge_p_hashes(generic_hash, p_hash(bl_f));
}
ProfileFunc::ProfileFunc(const Func* func, const StmtPtr& body)
{
Profile(func->GetType().get(), body);
}
ProfileFunc::ProfileFunc(const Expr* e)
{
if ( e->Tag() == EXPR_LAMBDA )
{
auto func = e->AsLambdaExpr();
for ( auto oid : func->OuterIDs() )
captures.insert(oid);
Profile(func->GetType()->AsFuncType(), func->Ingredients().body);
}
else
// We don't have a function type, so do the traversal
// directly.
e->Traverse(this);
}
void ProfileFunc::Profile(const FuncType* ft, const StmtPtr& body)
{
num_params = ft->Params()->NumFields();
TrackType(ft);
body->Traverse(this);
}
TraversalCode ProfileFunc::PreStmt(const Stmt* s)
{
stmts.push_back(s);
switch ( s->Tag() ) {
case STMT_INIT:
for ( const auto& id : s->AsInitStmt()->Inits() )
{
inits.insert(id.get());
TrackType(id->GetType());
}
// Don't traverse further into the statement, since we
// don't want to view the identifiers as locals unless
// they're also used elsewhere.
return TC_ABORTSTMT;
case STMT_WHEN:
++num_when_stmts;
@ -39,7 +111,8 @@ TraversalCode ProfileFunc::PreStmt(const Stmt* s)
// It doesn't do any harm for us to re-traverse the
// conditional, so we don't bother hand-traversing the
// rest of the when but just let the usual processing do it.
// rest of the "when", but just let the usual processing
// do it.
break;
case STMT_FOR:
@ -67,6 +140,8 @@ TraversalCode ProfileFunc::PreStmt(const Stmt* s)
// incomplete list of locals that need to be tracked.
auto sw = s->AsSwitchStmt();
bool is_type_switch = false;
for ( auto& c : *sw->Cases() )
{
auto idl = c->TypeCases();
@ -74,8 +149,15 @@ TraversalCode ProfileFunc::PreStmt(const Stmt* s)
{
for ( auto id : *idl )
locals.insert(id);
is_type_switch = true;
}
}
if ( is_type_switch )
type_switches.insert(sw);
else
expr_switches.insert(sw);
}
break;
@ -88,37 +170,74 @@ TraversalCode ProfileFunc::PreStmt(const Stmt* s)
TraversalCode ProfileFunc::PreExpr(const Expr* e)
{
++num_exprs;
exprs.push_back(e);
auto tag = e->Tag();
TrackType(e->GetType());
if ( compute_hash )
UpdateHash(int(tag));
switch ( tag ) {
switch ( e->Tag() ) {
case EXPR_CONST:
if ( compute_hash )
{
CheckType(e->GetType());
UpdateHash(e->AsConstExpr()->ValuePtr());
}
constants.push_back(e->AsConstExpr());
break;
case EXPR_NAME:
{
auto n = e->AsNameExpr();
auto id = n->Id();
if ( id->IsGlobal() )
globals.insert(id);
else
locals.insert(id);
if ( compute_hash )
if ( id->IsGlobal() )
{
UpdateHash({NewRef{}, id});
CheckType(e->GetType());
globals.insert(id);
all_globals.insert(id);
const auto& t = id->GetType();
if ( t->Tag() == TYPE_FUNC &&
t->AsFuncType()->Flavor() == FUNC_FLAVOR_EVENT )
events.insert(id->Name());
}
else
{
// This is a tad ugly. Unfortunately due to the
// weird way that Zeek function *declarations* work,
// there's no reliable way to get the list of
// parameters for a function *definition*, since
// they can have different names than what's present
// in the declaration. So we identify them directly,
// by knowing that they come at the beginning of the
// frame ... and being careful to avoid misconfusing
// a lambda capture with a low frame offset as a
// parameter.
if ( captures.count(id) == 0 &&
id->Offset() < num_params )
params.insert(id);
locals.insert(id);
}
// Turns out that NameExpr's can be constructed using a
// different Type* than that of the identifier itself,
// so be sure we track the latter too.
TrackType(id->GetType());
break;
}
case EXPR_FIELD:
{
auto f = e->AsFieldExpr()->Field();
addl_hashes.push_back(p_hash(f));
}
break;
case EXPR_ASSIGN:
{
if ( e->GetOp1()->Tag() == EXPR_REF )
{
auto lhs = e->GetOp1()->GetOp1();
if ( lhs->Tag() == EXPR_NAME )
assignees.insert(lhs->AsNameExpr()->Id());
}
// else this isn't a direct assignment.
break;
}
@ -134,7 +253,7 @@ TraversalCode ProfileFunc::PreExpr(const Expr* e)
}
auto n = f->AsNameExpr();
IDPtr func = {NewRef{}, n->Id()};
auto func = n->Id();
if ( ! func->IsGlobal() )
{
@ -142,6 +261,8 @@ TraversalCode ProfileFunc::PreExpr(const Expr* e)
return TC_CONTINUE;
}
all_globals.insert(func);
auto func_v = func->GetVal();
if ( func_v )
{
@ -156,28 +277,84 @@ TraversalCode ProfileFunc::PreExpr(const Expr* e)
when_calls.insert(bf);
}
else
BiF_calls.insert(func_vf);
BiF_globals.insert(func);
}
else
{
// We could complain, but for now we don't because
// We could complain, but for now we don't, because
// if we're invoked prior to full Zeek initialization,
// the value might indeed not there.
// the value might indeed not there yet.
// printf("no function value for global %s\n", func->Name());
}
// Recurse into the arguments.
auto args = c->Args();
args->Traverse(this);
// Do the following explicitly, since we won't be recursing
// into the LHS global.
// Note that the type of the expression and the type of the
// function can actually be *different* due to the NameExpr
// being constructed based on a forward reference and then
// the global getting a different (constructed) type when
// the function is actually declared. Geez. So hedge our
// bets.
TrackType(n->GetType());
TrackType(func->GetType());
TrackID(func);
return TC_ABORTSTMT;
}
case EXPR_EVENT:
events.insert(e->AsEventExpr()->Name());
{
auto ev = e->AsEventExpr()->Name();
events.insert(ev);
addl_hashes.push_back(p_hash(ev));
}
break;
case EXPR_LAMBDA:
++num_lambdas;
{
auto l = e->AsLambdaExpr();
lambdas.push_back(l);
for ( const auto& i : l->OuterIDs() )
{
locals.insert(i);
TrackID(i);
// See above re EXPR_NAME regarding the following
// logic.
if ( captures.count(i) == 0 &&
i->Offset() < num_params )
params.insert(i);
}
// Avoid recursing into the body.
return TC_ABORTSTMT;
}
case EXPR_SET_CONSTRUCTOR:
{
auto sc = static_cast<const SetConstructorExpr*>(e);
auto attrs = sc->GetAttrs();
if ( attrs )
constructor_attrs.insert(attrs.get());
}
break;
case EXPR_TABLE_CONSTRUCTOR:
{
auto tc = static_cast<const TableConstructorExpr*>(e);
auto attrs = tc->GetAttrs();
if ( attrs )
constructor_attrs.insert(attrs.get());
}
break;
default:
@ -187,32 +364,345 @@ TraversalCode ProfileFunc::PreExpr(const Expr* e)
return TC_CONTINUE;
}
void ProfileFunc::CheckType(const TypePtr& t)
TraversalCode ProfileFunc::PreID(const ID* id)
{
TrackID(id);
// There's no need for any further analysis of this ID.
return TC_ABORTSTMT;
}
void ProfileFunc::TrackType(const Type* t)
{
if ( ! t )
return;
if ( types.count(t) > 0 )
// We've already tracke it.
return;
types.insert(t);
ordered_types.push_back(t);
}
void ProfileFunc::TrackID(const ID* id)
{
if ( ! id )
return;
if ( ids.count(id) > 0 )
// Already tracked.
return;
ids.insert(id);
ordered_ids.push_back(id);
}
ProfileFuncs::ProfileFuncs(std::vector<FuncInfo>& funcs, is_compilable_pred pred)
{
for ( auto& f : funcs )
{
if ( f.ShouldSkip() )
continue;
auto pf = std::make_unique<ProfileFunc>(f.Func(), f.Body());
if ( ! pred || (*pred)(pf.get()) )
MergeInProfile(pf.get());
else
f.SetSkip(true);
f.SetProfile(std::move(pf));
func_profs[f.Func()] = f.Profile();
}
// We now have the main (starting) types used by all of the
// functions. Recursively compute their hashes.
ComputeTypeHashes(main_types);
// Computing the hashes can have marked expressions (seen in
// record attributes) for further analysis. Likewise, when
// doing the profile merges above we may have noted lambda
// expressions. Analyze these, and iteratively any further
// expressions that that analysis uncovers.
DrainPendingExprs();
// We now have all the information we need to form definitive,
// deterministic hashes.
ComputeBodyHashes(funcs);
}
void ProfileFuncs::MergeInProfile(ProfileFunc* pf)
{
all_globals.insert(pf->AllGlobals().begin(), pf->AllGlobals().end());
globals.insert(pf->Globals().begin(), pf->Globals().end());
constants.insert(pf->Constants().begin(), pf->Constants().end());
main_types.insert(main_types.end(),
pf->OrderedTypes().begin(), pf->OrderedTypes().end());
script_calls.insert(pf->ScriptCalls().begin(), pf->ScriptCalls().end());
BiF_globals.insert(pf->BiFGlobals().begin(), pf->BiFGlobals().end());
events.insert(pf->Events().begin(), pf->Events().end());
for ( auto& i : pf->Lambdas() )
{
lambdas.insert(i);
pending_exprs.push_back(i);
}
for ( auto& a : pf->ConstructorAttrs() )
AnalyzeAttrs(a);
}
void ProfileFuncs::DrainPendingExprs()
{
while ( pending_exprs.size() > 0 )
{
// Copy the pending expressions so we can loop over them
// while accruing additions.
auto pe = pending_exprs;
pending_exprs.clear();
for ( auto e : pe )
{
auto pf = std::make_shared<ProfileFunc>(e);
expr_profs[e] = pf;
MergeInProfile(pf.get());
// It's important to compute the hashes over the
// ordered types rather than the unordered. If type
// T1 depends on a recursive type T2, then T1's hash
// will vary with depending on whether we arrive at
// T1 via an in-progress traversal of T2 (in which
// case T1 will see the "stub" in-progress hash for
// T2), or via a separate type T3 (in which case it
// will see the full hash).
ComputeTypeHashes(pf->OrderedTypes());
}
}
}
void ProfileFuncs::ComputeTypeHashes(const std::vector<const Type*>& types)
{
for ( auto t : types )
(void) HashType(t);
}
void ProfileFuncs::ComputeBodyHashes(std::vector<FuncInfo>& funcs)
{
for ( auto& f : funcs )
if ( ! f.ShouldSkip() )
ComputeProfileHash(f.Profile());
for ( auto& l : lambdas )
ComputeProfileHash(ExprProf(l));
}
void ProfileFuncs::ComputeProfileHash(std::shared_ptr<ProfileFunc> pf)
{
p_hash_type h = 0;
// We add markers between each class of hash component, to
// prevent collisions due to elements with simple hashes
// (such as Stmt's or Expr's that are only represented by
// the hash of their tag).
h = merge_p_hashes(h, p_hash("stmts"));
for ( auto i : pf->Stmts() )
h = merge_p_hashes(h, p_hash(i->Tag()));
h = merge_p_hashes(h, p_hash("exprs"));
for ( auto i : pf->Exprs() )
h = merge_p_hashes(h, p_hash(i->Tag()));
h = merge_p_hashes(h, p_hash("ids"));
for ( auto i : pf->OrderedIdentifiers() )
h = merge_p_hashes(h, p_hash(i->Name()));
h = merge_p_hashes(h, p_hash("constants"));
for ( auto i : pf->Constants() )
h = merge_p_hashes(h, p_hash(i->Value()));
h = merge_p_hashes(h, p_hash("types"));
for ( auto i : pf->OrderedTypes() )
h = merge_p_hashes(h, HashType(i));
h = merge_p_hashes(h, p_hash("lambdas"));
for ( auto i : pf->Lambdas() )
h = merge_p_hashes(h, p_hash(i));
h = merge_p_hashes(h, p_hash("addl"));
for ( auto i : pf->AdditionalHashes() )
h = merge_p_hashes(h, i);
pf->SetHashVal(h);
}
p_hash_type ProfileFuncs::HashType(const Type* t)
{
if ( ! t )
return 0;
if ( type_hashes.count(t) > 0 )
// We've already done this Type*.
return type_hashes[t];
auto& tn = t->GetName();
if ( tn.size() > 0 && seen_types.count(tn) > 0 )
// No need to hash this in again, as we've already done so.
return;
if ( tn.size() > 0 && seen_type_names.count(tn) > 0 )
{
// We've already done a type with the same name, even
// though with a different Type*. Reuse its results.
auto seen_t = seen_type_names[tn];
auto h = type_hashes[seen_t];
if ( seen_type_ptrs.count(t.get()) > 0 )
// We've seen the raw pointer, even though it doesn't have
// a name.
return;
type_hashes[t] = h;
type_to_rep[t] = type_to_rep[seen_t];
seen_types.insert(tn);
seen_type_ptrs.insert(t.get());
return h;
}
UpdateHash(t);
auto h = p_hash(t->Tag());
// Enter an initial value for this type's hash. We'll update it
// at the end, but having it here first will prevent recursive
// records from leading to infinite recursion as we traverse them.
// It's okay that the initial value is degenerate, because if we access
// it during the traversal that will only happen due to a recursive
// type, in which case the other elements of that type will serve
// to differentiate its hash.
type_hashes[t] = h;
switch ( t->Tag() ) {
case TYPE_ADDR:
case TYPE_ANY:
case TYPE_BOOL:
case TYPE_COUNT:
case TYPE_DOUBLE:
case TYPE_ENUM:
case TYPE_ERROR:
case TYPE_INT:
case TYPE_INTERVAL:
case TYPE_OPAQUE:
case TYPE_PATTERN:
case TYPE_PORT:
case TYPE_STRING:
case TYPE_SUBNET:
case TYPE_TIME:
case TYPE_TIMER:
case TYPE_UNION:
case TYPE_VOID:
h = merge_p_hashes(h, p_hash(t));
break;
case TYPE_RECORD:
{
const auto& ft = t->AsRecordType();
auto n = ft->NumFields();
h = merge_p_hashes(h, p_hash("record"));
h = merge_p_hashes(h, p_hash(n));
for ( auto i = 0; i < n; ++i )
{
const auto& f = ft->FieldDecl(i);
h = merge_p_hashes(h, p_hash(f->id));
h = merge_p_hashes(h, HashType(f->type));
// We don't hash the field name, as in some contexts
// those are ignored.
if ( f->attrs )
{
h = merge_p_hashes(h, p_hash(f->attrs));
AnalyzeAttrs(f->attrs.get());
}
}
}
break;
case TYPE_TABLE:
{
auto tbl = t->AsTableType();
h = merge_p_hashes(h, p_hash("table"));
h = merge_p_hashes(h, p_hash("indices"));
h = merge_p_hashes(h, HashType(tbl->GetIndices()));
h = merge_p_hashes(h, p_hash("tbl-yield"));
h = merge_p_hashes(h, HashType(tbl->Yield()));
}
break;
case TYPE_FUNC:
{
auto ft = t->AsFuncType();
auto flv = ft->FlavorString();
h = merge_p_hashes(h, p_hash(flv));
h = merge_p_hashes(h, p_hash("params"));
h = merge_p_hashes(h, HashType(ft->Params()));
h = merge_p_hashes(h, p_hash("func-yield"));
h = merge_p_hashes(h, HashType(ft->Yield()));
}
break;
case TYPE_LIST:
{
auto& tl = t->AsTypeList()->GetTypes();
h = merge_p_hashes(h, p_hash("list"));
h = merge_p_hashes(h, p_hash(tl.size()));
for ( const auto& tl_i : tl )
h = merge_p_hashes(h, HashType(tl_i));
}
break;
case TYPE_VECTOR:
h = merge_p_hashes(h, p_hash("vec"));
h = merge_p_hashes(h, HashType(t->AsVectorType()->Yield()));
break;
case TYPE_FILE:
h = merge_p_hashes(h, p_hash("file"));
h = merge_p_hashes(h, HashType(t->AsFileType()->Yield()));
break;
case TYPE_TYPE:
h = merge_p_hashes(h, p_hash("type"));
h = merge_p_hashes(h, HashType(t->AsTypeType()->GetType()));
break;
}
void ProfileFunc::UpdateHash(const IntrusivePtr<zeek::Obj>& o)
type_hashes[t] = h;
if ( type_hash_reps.count(h) == 0 )
{ // No previous rep, so use this Type* for that.
type_hash_reps[h] = t;
type_to_rep[t] = t;
rep_types.push_back(t);
}
else
type_to_rep[t] = type_hash_reps[h];
if ( tn.size() > 0 )
seen_type_names[tn] = t;
return h;
}
void ProfileFuncs::AnalyzeAttrs(const Attributes* Attrs)
{
ODesc d;
o->Describe(&d);
std::string desc(d.Description());
auto h = std::hash<std::string>{}(desc);
MergeInHash(h);
}
auto attrs = Attrs->GetAttrs();
for ( const auto& a : attrs )
{
const Expr* e = a->GetExpr().get();
if ( e )
{
pending_exprs.push_back(e);
if ( e->Tag() == EXPR_LAMBDA )
lambdas.insert(e->AsLambdaExpr());
}
}
}
} // namespace zeek::detail

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@ -1,49 +1,170 @@
// See the file "COPYING" in the main distribution directory for copyright.
// Class for traversing a function body's AST to build up a profile
// of its various elements.
// Classes for traversing functions and their body ASTs to build up profiles
// of the various elements (types, globals, locals, lambdas, etc.) that appear.
// These profiles enable script optimization to make decisions regarding
// compilability and how to efficiently provide run-time components.
// For all of the following, we use the term "function" to refer to a single
// ScriptFunc/body pair, so an event handler or hook with multiple bodies
// is treated as multiple distinct "function"'s.
//
// One key element of constructing profiles concerns computing hashes over
// both the Zeek scripting types present in the functions, and over entire
// functions (which means computing hashes over each of the function's
// components). Hashes need to be (1) distinct (collision-free in practice)
// and (2) deterministic (across Zeek invocations, the same components always
// map to the same hashes). We need these properties because we use hashes
// to robustly identify identical instances of the same function, for example
// so we can recognize that an instance of the function definition seen in
// a script matches a previously compiled function body, so we can safely
// replace the function's AST with the compiled version).
//
// We profile functions collectively (via the ProfileFuncs class), rather
// than in isolation, because doing so (1) allows us to share expensive
// profiling steps (in particular, computing the hashes of types, as some
// of the Zeek script records get huge, and occur frequently), and (2) enables
// us to develop a global picture of all of the components germane to a set
// of functions. The global profile is built up in terms of individual
// profiles (via the ProfileFunc class), which identify each function's
// basic components, and then using these as starting points to build out
// the global profile and compute the hashes of functions and types.
#pragma once
#include "zeek/Expr.h"
#include "zeek/Stmt.h"
#include "zeek/Traverse.h"
#include "zeek/script_opt/ScriptOpt.h"
namespace zeek::detail {
// The type used to represent hashes. We use the mnemonic "p_hash" as
// short for "profile hash", to avoid confusion with hashes used elsehwere
// in Zeek (which are for the most part keyed, a property we explicitly
// do not want).
using p_hash_type = unsigned long long;
// Helper functions for computing/managing hashes.
inline p_hash_type p_hash(int val)
{ return std::hash<int>{}(val); }
inline p_hash_type p_hash(std::string val)
{ return std::hash<std::string>{}(val); }
inline p_hash_type p_hash(const char* val)
{ return p_hash(std::string(val)); }
extern p_hash_type p_hash(const Obj* o);
inline p_hash_type p_hash(const IntrusivePtr<Obj>& o)
{ return p_hash(o.get()); }
inline p_hash_type merge_p_hashes(p_hash_type h1, p_hash_type h2)
{
// Taken from Boost. See for example
// https://www.boost.org/doc/libs/1_35_0/doc/html/boost/hash_combine_id241013.html
// or
// https://stackoverflow.com/questions/4948780/magic-number-in-boosthash-combine
return h1 ^ (h2 + 0x9e3779b9 + (h1 << 6) + (h1 >> 2));
}
// Returns a filename associated with the given function body. Used to
// provide distinctness to identical function bodies seen in separate,
// potentially conflicting incremental compilations. This is only germane
// for allowing incremental compilation of subsets of the test suite, so
// if we decide to forgo that capability, we can remove this.
extern std::string script_specific_filename(const StmtPtr& body);
// Returns a incremental-compilation-specific hash for the given function
// body, given it's non-specific hash is "generic_hash".
extern p_hash_type script_specific_hash(const StmtPtr& body, p_hash_type generic_hash);
// Class for profiling the components of a single function (or expression).
class ProfileFunc : public TraversalCallback {
public:
// If the argument is true, then we compute a hash over the function's
// AST to (pseudo-)uniquely identify it.
ProfileFunc(bool _compute_hash = false)
{ compute_hash = _compute_hash; }
// Constructor used for the usual case of profiling a script
// function and one of its bodies.
ProfileFunc(const Func* func, const StmtPtr& body);
// Constructor for profiling an AST expression. This exists
// to support (1) profiling lambda expressions, and (2) traversing
// attribute expressions (such as &default=expr) to discover what
// components they include.
ProfileFunc(const Expr* func);
// See the comments for the associated member variables for each
// of these accessors.
const std::unordered_set<const ID*>& Globals() const
{ return globals; }
const std::unordered_set<const ID*>& AllGlobals() const
{ return all_globals; }
const std::unordered_set<const ID*>& Locals() const
{ return locals; }
const std::unordered_set<const ID*>& Params() const
{ return params; }
const std::unordered_set<const ID*>& Assignees() const
{ return assignees; }
const std::unordered_set<const ID*>& Inits() const
{ return inits; }
const std::vector<const Stmt*>& Stmts() const
{ return stmts; }
const std::vector<const Expr*>& Exprs() const
{ return exprs; }
const std::vector<const LambdaExpr*>& Lambdas() const
{ return lambdas; }
const std::vector<const ConstExpr*>& Constants() const
{ return constants; }
const std::unordered_set<const ID*>& UnorderedIdentifiers() const
{ return ids; }
const std::vector<const ID*>& OrderedIdentifiers() const
{ return ordered_ids; }
const std::unordered_set<const Type*>& UnorderedTypes() const
{ return types; }
const std::vector<const Type*>& OrderedTypes() const
{ return ordered_types; }
const std::unordered_set<ScriptFunc*>& ScriptCalls() const
{ return script_calls; }
const std::unordered_set<Func*>& BiFCalls() const
{ return BiF_calls; }
const std::unordered_set<const ID*>& BiFGlobals() const
{ return BiF_globals; }
const std::unordered_set<ScriptFunc*>& WhenCalls() const
{ return when_calls; }
const std::unordered_set<const char*>& Events() const
const std::unordered_set<std::string>& Events() const
{ return events; }
const std::unordered_set<const Attributes*>& ConstructorAttrs() const
{ return constructor_attrs; }
const std::unordered_set<const SwitchStmt*>& ExprSwitches() const
{ return expr_switches; }
const std::unordered_set<const SwitchStmt*>& TypeSwitches() const
{ return type_switches; }
bool DoesIndirectCalls() { return does_indirect_calls; }
std::size_t HashVal() { return hash_val; }
int NumParams() const { return num_params; }
int NumLambdas() const { return lambdas.size(); }
int NumWhenStmts() const { return num_when_stmts; }
int NumStmts() { return num_stmts; }
int NumWhenStmts() { return num_when_stmts; }
int NumExprs() { return num_exprs; }
int NumLambdas() { return num_lambdas; }
const std::vector<p_hash_type>& AdditionalHashes() const
{ return addl_hashes; }
// Set this function's hash to the given value; retrieve that value.
void SetHashVal(p_hash_type hash) { hash_val = hash; }
p_hash_type HashVal() const { return hash_val; }
protected:
// Construct the profile for the given function signature and body.
void Profile(const FuncType* ft, const StmtPtr& body);
TraversalCode PreStmt(const Stmt*) override;
TraversalCode PreExpr(const Expr*) override;
TraversalCode PreID(const ID*) override;
// Take note of the presence of a given type.
void TrackType(const Type* t);
void TrackType(const TypePtr& t) { TrackType(t.get()); }
// Take note of the presence of an identifier.
void TrackID(const ID* id);
// Globals seen in the function.
//
@ -51,79 +172,248 @@ protected:
// called in a call.
std::unordered_set<const ID*> globals;
// Same, but also includes globals only seen as called functions.
std::unordered_set<const ID*> all_globals;
// Locals seen in the function.
std::unordered_set<const ID*> locals;
// Same for locals seen in initializations, so we can find
// unused aggregates.
// The function's parameters. Empty if our starting point was
// profiling an expression.
std::unordered_set<const ID*> params;
// How many parameters the function has. The default value flags
// that we started the profile with an expression rather than a
// function.
int num_params = -1;
// Identifiers (globals, locals, parameters) that are assigned to.
// Does not include implicit assignments due to initializations,
// which are instead captured in "inits".
std::unordered_set<const ID*> assignees;
// Same for locals seen in initializations, so we can find,
// for example, unused aggregates.
std::unordered_set<const ID*> inits;
// Statements seen in the function. Does not include indirect
// statements, such as those in lambda bodies.
std::vector<const Stmt*> stmts;
// Expressions seen in the function. Does not include indirect
// expressions (such as those appearing in attributes of types).
std::vector<const Expr*> exprs;
// Lambdas seen in the function. We don't profile lambda bodies,
// but rather make them available for separate profiling if
// appropriate.
std::vector<const LambdaExpr*> lambdas;
// If we're profiling a lambda function, this holds the captures.
std::unordered_set<const ID*> captures;
// Constants seen in the function.
std::vector<const ConstExpr*> constants;
// Identifiers seen in the function.
std::unordered_set<const ID*> ids;
// The same, but in a deterministic order.
std::vector<const ID*> ordered_ids;
// Types seen in the function. A set rather than a vector because
// the same type can be seen numerous times.
std::unordered_set<const Type*> types;
// The same, but in a deterministic order, with duplicates removed.
std::vector<const Type*> ordered_types;
// Script functions that this script calls.
std::unordered_set<ScriptFunc*> script_calls;
// Same for BiF's.
std::unordered_set<Func*> BiF_calls;
// Same for BiF's, though for them we record the corresponding global
// rather than the BuiltinFunc*.
std::unordered_set<const ID*> BiF_globals;
// Script functions appearing in "when" clauses.
std::unordered_set<ScriptFunc*> when_calls;
// Names of generated events.
std::unordered_set<const char*> events;
std::unordered_set<std::string> events;
// Attributes seen in set or table constructors.
std::unordered_set<const Attributes*> constructor_attrs;
// Switch statements with either expression cases or type cases.
std::unordered_set<const SwitchStmt*> expr_switches;
std::unordered_set<const SwitchStmt*> type_switches;
// True if the function makes a call through an expression rather
// than simply a function's (global) name.
bool does_indirect_calls = false;
// Hash value. Only valid if constructor requested it.
std::size_t hash_val = 0;
// Additional values present in the body that should be factored
// into its hash.
std::vector<p_hash_type> addl_hashes;
// How many statements / when statements / lambda expressions /
// expressions appear in the function body.
int num_stmts = 0;
// Associated hash value.
p_hash_type hash_val = 0;
// How many when statements appear in the function body. We could
// track these individually, but to date all that's mattered is
// whether a given body contains any.
int num_when_stmts = 0;
int num_lambdas = 0;
int num_exprs = 0;
// Whether we're separately processing a "when" condition to
// mine out its script calls.
bool in_when = false;
};
// We only compute a hash over the function if requested, since
// it's somewhat expensive.
bool compute_hash;
// Function pointer for a predicate that determines whether a given
// profile is compilable. Alternatively we could derive subclasses
// from ProfileFuncs and use a virtual method for this, but that seems
// heavier-weight for what's really a simple notion.
typedef bool (*is_compilable_pred)(const ProfileFunc*);
// The following are for computing a consistent hash that isn't
// too profligate in how much it needs to compute over.
// Collectively profile an entire collection of functions.
class ProfileFuncs {
public:
// Updates entries in "funcs" to include profiles. If pred is
// non-nil, then it is called for each profile to see whether it's
// compilable, and, if not, the FuncInfo is marked as ShouldSkip().
ProfileFuncs(std::vector<FuncInfo>& funcs,
is_compilable_pred pred = nullptr);
// Checks whether we've already noted this type, and, if not,
// updates the hash with it.
void CheckType(const TypePtr& t);
// The following accessors provide a global profile across all of
// the (non-skipped) functions in "funcs". See the comments for
// the associated member variables for documentation.
const std::unordered_set<const ID*>& Globals() const
{ return globals; }
const std::unordered_set<const ID*>& AllGlobals() const
{ return all_globals; }
const std::unordered_set<const ConstExpr*>& Constants() const
{ return constants; }
const std::vector<const Type*>& MainTypes() const
{ return main_types; }
const std::vector<const Type*>& RepTypes() const
{ return rep_types; }
const std::unordered_set<ScriptFunc*>& ScriptCalls() const
{ return script_calls; }
const std::unordered_set<const ID*>& BiFGlobals() const
{ return BiF_globals; }
const std::unordered_set<const LambdaExpr*>& Lambdas() const
{ return lambdas; }
const std::unordered_set<std::string>& Events() const
{ return events; }
void UpdateHash(int val)
std::shared_ptr<ProfileFunc> FuncProf(const ScriptFunc* f)
{ return func_profs[f]; }
// This is only externally germane for LambdaExpr's.
std::shared_ptr<ProfileFunc> ExprProf(const Expr* e)
{ return expr_profs[e]; }
// Returns the "representative" Type* for the hash associated with
// the parameter (which might be the parameter itself).
const Type* TypeRep(const Type* orig)
{
auto h = std::hash<int>{}(val);
MergeInHash(h);
ASSERT(type_to_rep.count(orig) > 0);
return type_to_rep[orig];
}
void UpdateHash(const IntrusivePtr<Obj>& o);
// Returns the hash associated with the given type, computing it
// if necessary.
p_hash_type HashType(const TypePtr& t) { return HashType(t.get()); }
p_hash_type HashType(const Type* t);
void MergeInHash(std::size_t h)
{
// Taken from Boost. See for example
// https://www.boost.org/doc/libs/1_35_0/doc/html/boost/hash_combine_id241013.html
// or
// https://stackoverflow.com/questions/4948780/magic-number-in-boosthash-combine
hash_val ^= h + 0x9e3779b9 + (hash_val << 6) + (hash_val >> 2);
}
protected:
// Incorporate the given function profile into the global profile.
void MergeInProfile(ProfileFunc* pf);
// Types that we've already processed. Hashing types can be
// quite expensive since some of the common Zeek record types
// (e.g., notices) are huge, so useful to not do them more than
// once. We track two forms, one by name (if available) and one
// by raw pointer (if not). Doing so allows us to track named
// sub-records but also records that have no names.
std::unordered_set<std::string> seen_types;
std::unordered_set<const Type*> seen_type_ptrs;
// When traversing types, Zeek records can have attributes that in
// turn have expressions associated with them. The expressions can
// in turn have types, which might be records with further attribute
// expressions, etc. This method iteratively processes the list
// expressions we need to analyze until no new ones are added.
void DrainPendingExprs();
// Compute hashes for the given set of types. Potentially recursive
// upon discovering additional types.
void ComputeTypeHashes(const std::vector<const Type*>& types);
// Compute hashes to associate with each function
void ComputeBodyHashes(std::vector<FuncInfo>& funcs);
// Compute the hash associated with a single function profile.
void ComputeProfileHash(std::shared_ptr<ProfileFunc> pf);
// Analyze the expressions and lambdas appearing in a set of
// attributes.
void AnalyzeAttrs(const Attributes* Attrs);
// Globals seen across the functions, other than those solely seen
// as the function being called in a call.
std::unordered_set<const ID*> globals;
// Same, but also includes globals only seen as called functions.
std::unordered_set<const ID*> all_globals;
// Constants seen across the functions.
std::unordered_set<const ConstExpr*> constants;
// Types seen across the functions. Does not include subtypes.
// Deterministically ordered.
std::vector<const Type*> main_types;
// "Representative" types seen across the functions. Includes
// subtypes. These all have unique hashes, and are returned by
// calls to TypeRep(). Deterministically ordered.
std::vector<const Type*> rep_types;
// Maps a type to its representative (which might be itself).
std::unordered_map<const Type*, const Type*> type_to_rep;
// Script functions that get called.
std::unordered_set<ScriptFunc*> script_calls;
// Same for BiF's.
std::unordered_set<const ID*> BiF_globals;
// And for lambda's.
std::unordered_set<const LambdaExpr*> lambdas;
// Names of generated events.
std::unordered_set<std::string> events;
// Maps script functions to associated profiles. This isn't
// actually well-defined in the case of event handlers and hooks,
// which can have multiple bodies. However, this is only used
// in the context of analyzing a single-bodied function.
std::unordered_map<const ScriptFunc*, std::shared_ptr<ProfileFunc>> func_profs;
// Maps expressions to their profiles. This is only germane
// externally for LambdaExpr's, but internally it abets memory
// management.
std::unordered_map<const Expr*, std::shared_ptr<ProfileFunc>> expr_profs;
// These remaining member variables are only used internally,
// not provided via accessors:
// Maps types to their hashes.
std::unordered_map<const Type*, p_hash_type> type_hashes;
// An inverse mapping, to a representative for each distinct hash.
std::unordered_map<p_hash_type, const Type*> type_hash_reps;
// For types with names, tracks the ones we've already hashed,
// so we can avoid work for distinct pointers that refer to the
// same underlying type.
std::unordered_map<std::string, const Type*> seen_type_names;
// Expressions that we've discovered that we need to further
// profile. These can arise for example due to lambdas or
// record attributes.
std::vector<const Expr*> pending_exprs;
};

View file

@ -80,7 +80,7 @@ void optimize_func(ScriptFunc* f, std::shared_ptr<ProfileFunc> pf,
if ( analysis_options.optimize_AST )
{
pf = std::make_shared<ProfileFunc>(false);
pf = std::make_shared<ProfileFunc>(f, body);
body->Traverse(pf.get());
RD_Decorate reduced_rds(pf);
@ -110,7 +110,7 @@ void optimize_func(ScriptFunc* f, std::shared_ptr<ProfileFunc> pf,
}
// Profile the new body.
pf = std::make_shared<ProfileFunc>();
pf = std::make_shared<ProfileFunc>(f, body);
body->Traverse(pf.get());
// Compute its reaching definitions.
@ -202,15 +202,7 @@ void analyze_scripts()
// Now that everything's parsed and BiF's have been initialized,
// profile the functions.
std::unordered_map<const ScriptFunc*, std::shared_ptr<ProfileFunc>>
func_profs;
for ( auto& f : funcs )
{
f.SetProfile(std::make_shared<ProfileFunc>(true));
f.Body()->Traverse(f.Profile().get());
func_profs[f.Func()] = f.Profile();
}
auto pfs = std::make_unique<ProfileFuncs>(funcs);
// Figure out which functions either directly or indirectly
// appear in "when" clauses.
@ -253,7 +245,7 @@ void analyze_scripts()
{
when_funcs.insert(wf);
for ( auto& wff : func_profs[wf]->ScriptCalls() )
for ( auto& wff : pfs->FuncProf(wf)->ScriptCalls() )
{
if ( when_funcs.count(wff) > 0 )
// We've already processed this