fuzz: avoid redundant dup key checks when creating Miniscript nodes

darosior · darosior · commit c1b7bd047f47 · 2023-02-17T12:41:04.000+01:00
Check it only once on the top level node.

Running libfuzzer with -runs=0 against the qa-assets corpus (1b9ddc96586769d92b1b62775f397b7f1a63f142).
Without this patch:
	miniscript_stable: Done 6616 runs in 118 second(s)
	miniscript_smart: Done 13182 runs in 253 second(s)
With this patch:
	miniscript_stable: Done 6616 runs in 57 second(s)
	miniscript_smart: Done 13182 runs in 124 second(s)
diff --git a/src/test/fuzz/miniscript.cpp b/src/test/fuzz/miniscript.cpp
@@ -253,7 +253,9 @@ using Type = miniscript::Type;
 using miniscript::operator"" _mst;
 
 //! Construct a miniscript node as a shared_ptr.
-template<typename... Args> NodeRef MakeNodeRef(Args&&... args) { return miniscript::MakeNodeRef<CPubKey>(KEY_COMP, std::forward<Args>(args)...); }
+template<typename... Args> NodeRef MakeNodeRef(Args&&... args) {
+    return miniscript::MakeNodeRef<CPubKey>(miniscript::internal::NoDupCheck{}, std::forward<Args>(args)...);
+}
 
 /** Information about a yet to be constructed Miniscript node. */
 struct NodeInfo {
@@ -762,6 +764,7 @@ NodeRef GenNode(F ConsumeNode, Type root_type = ""_mst, bool strict_valid = fals
         }
     }
     assert(stack.size() == 1);
+    stack[0]->DuplicateKeyCheck(KEY_COMP);
     return std::move(stack[0]);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -253,7 +253,9 @@ using Type = miniscript::Type;`
`253`	`253`	`using miniscript::operator"" _mst;`
`254`	`254`
`255`	`255`	`//! Construct a miniscript node as a shared_ptr.`
`256`		`-template<typename... Args> NodeRef MakeNodeRef(Args&&... args) { return miniscript::MakeNodeRef<CPubKey>(KEY_COMP, std::forward<Args>(args)...); }`
	`256`	`+template<typename... Args> NodeRef MakeNodeRef(Args&&... args) {`
	`257`	`+ return miniscript::MakeNodeRef<CPubKey>(miniscript::internal::NoDupCheck{}, std::forward<Args>(args)...);`
	`258`	`+}`
`257`	`259`
`258`	`260`	`/** Information about a yet to be constructed Miniscript node. */`
`259`	`261`	`struct NodeInfo {`
`@@ -762,6 +764,7 @@ NodeRef GenNode(F ConsumeNode, Type root_type = ""_mst, bool strict_valid = fals`
`762`	`764`	`}`
`763`	`765`	`}`
`764`	`766`	`assert(stack.size() == 1);`
	`767`	`+ stack[0]->DuplicateKeyCheck(KEY_COMP);`
`765`	`768`	`return std::move(stack[0]);`
`766`	`769`	`}`
`767`	`770`