From cf7f74dfa74abadc2db6c711f0602328c2dd410a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Oliver=20St=C3=B6neberg?=
 <firewave@users.noreply.github.com>
Date: Tue, 10 Sep 2024 11:31:13 +0200
Subject: [PATCH] refs #11342 - Library: avoid redundant lookups in `getarg()`
 (#6791)

---
 lib/library.cpp      | 33 +++++++++++++++++++--------------
 lib/library.h        |  6 ++++--
 test/testlibrary.cpp |  8 ++++++--
 3 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/lib/library.cpp b/lib/library.cpp
index 17ca05ee6cf..21922b0fa65 100644
--- a/lib/library.cpp
+++ b/lib/library.cpp
@@ -1249,16 +1249,14 @@ int Library::getReallocId(const Token *tok, int arg) const
 
 const Library::ArgumentChecks * Library::getarg(const Token *ftok, int argnr) const
 {
-    if (isNotLibraryFunction(ftok))
+    const Function* func = nullptr;
+    if (isNotLibraryFunction(ftok, &func))
         return nullptr;
-    const std::unordered_map<std::string, Function>::const_iterator it1 = mData->mFunctions.find(getFunctionName(ftok));
-    if (it1 == mData->mFunctions.cend())
-        return nullptr;
-    const std::map<int,ArgumentChecks>::const_iterator it2 = it1->second.argumentChecks.find(argnr);
-    if (it2 != it1->second.argumentChecks.cend())
+    const std::map<int,ArgumentChecks>::const_iterator it2 = func->argumentChecks.find(argnr);
+    if (it2 != func->argumentChecks.cend())
         return &it2->second;
-    const std::map<int,ArgumentChecks>::const_iterator it3 = it1->second.argumentChecks.find(-1);
-    if (it3 != it1->second.argumentChecks.cend())
+    const std::map<int,ArgumentChecks>::const_iterator it3 = func->argumentChecks.find(-1);
+    if (it3 != func->argumentChecks.cend())
         return &it3->second;
     return nullptr;
 }
@@ -1414,7 +1412,7 @@ Library::Container::Yield Library::getContainerYield(const Token* const cond)
 }
 
 // returns true if ftok is not a library function
-bool Library::isNotLibraryFunction(const Token *ftok) const
+bool Library::isNotLibraryFunction(const Token *ftok, const Function **func) const
 {
     if (ftok->isKeyword() || ftok->isStandardType())
         return true;
@@ -1426,10 +1424,10 @@ bool Library::isNotLibraryFunction(const Token *ftok) const
     if (ftok->varId())
         return true;
 
-    return !matchArguments(ftok, getFunctionName(ftok));
+    return !matchArguments(ftok, getFunctionName(ftok), func);
 }
 
-bool Library::matchArguments(const Token *ftok, const std::string &functionName) const
+bool Library::matchArguments(const Token *ftok, const std::string &functionName, const Function **func) const
 {
     if (functionName.empty())
         return false;
@@ -1444,10 +1442,17 @@ bool Library::matchArguments(const Token *ftok, const std::string &functionName)
         if (argCheck.second.optional && (firstOptionalArg == -1 || firstOptionalArg > argCheck.first))
             firstOptionalArg = argCheck.first;
 
-        if (argCheck.second.formatstr || argCheck.second.variadic)
-            return args <= callargs;
+        if (argCheck.second.formatstr || argCheck.second.variadic) {
+            const bool b = args <= callargs;
+            if (b && func)
+                *func = &it->second;
+            return b;
+        }
     }
-    return (firstOptionalArg < 0) ? args == callargs : (callargs >= firstOptionalArg-1 && callargs <= args);
+    const bool b = (firstOptionalArg < 0) ? args == callargs : (callargs >= firstOptionalArg-1 && callargs <= args);
+    if (b && func)
+        *func = &it->second;
+    return b;
 }
 
 const std::map<std::string, Library::WarnInfo>& Library::functionwarn() const
diff --git a/lib/library.h b/lib/library.h
index eaa4003ea24..8e8db581c00 100644
--- a/lib/library.h
+++ b/lib/library.h
@@ -163,9 +163,11 @@ class CPPCHECKLIB Library {
 
     const WarnInfo* getWarnInfo(const Token* ftok) const;
 
+    struct Function;
+
     // returns true if ftok is not a library function
-    bool isNotLibraryFunction(const Token *ftok) const;
-    bool matchArguments(const Token *ftok, const std::string &functionName) const;
+    bool isNotLibraryFunction(const Token *ftok, const Function **func = nullptr) const;
+    bool matchArguments(const Token *ftok, const std::string &functionName, const Function **func = nullptr) const;
 
     enum class UseRetValType : std::uint8_t { NONE, DEFAULT, ERROR_CODE };
     UseRetValType getUseRetValType(const Token* ftok) const;
diff --git a/test/testlibrary.cpp b/test/testlibrary.cpp
index 6cdabd7f9b1..f7ec83ac323 100644
--- a/test/testlibrary.cpp
+++ b/test/testlibrary.cpp
@@ -191,7 +191,9 @@ class TestLibrary : public TestFixture {
             Token::createMutualLinks(tokenList.front()->next(), tokenList.back()->previous());
             tokenList.createAst();
 
-            ASSERT(!library.isNotLibraryFunction(tokenList.front()));
+            const Library::Function* func = nullptr;
+            ASSERT(!library.isNotLibraryFunction(tokenList.front(), &func));
+            ASSERT(func);
         }
         {
             TokenList tokenList(&settings);
@@ -200,7 +202,9 @@ class TestLibrary : public TestFixture {
             Token::createMutualLinks(tokenList.front()->next(), tokenList.back()->previous());
             tokenList.createAst();
 
-            ASSERT(!library.isNotLibraryFunction(tokenList.front()));
+            const Library::Function* func = nullptr;
+            ASSERT(!library.isNotLibraryFunction(tokenList.front(), &func));
+            ASSERT(func);
         }
         {
             TokenList tokenList(&settings);