From 182ae75290ceead287ec72d9a1f2a5fc7c650a64 Mon Sep 17 00:00:00 2001
From: Paul Fultz II <pfultz2@yahoo.com>
Date: Wed, 31 Mar 2021 15:07:54 -0500
Subject: [PATCH] Fix issue 10216: FP containerOutOfBounds with std::array
 initialized with = {} (#3190)

---
 lib/valueflow.cpp      | 22 ++++++++++++++--------
 test/testvalueflow.cpp | 21 ++++++++++++++-------
 2 files changed, 28 insertions(+), 15 deletions(-)

diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index 38d760afd..a7b269663 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -6212,6 +6212,7 @@ static std::vector<ValueFlow::Value> getInitListSize(const Token* tok, const Lib
 
 static void valueFlowContainerSize(TokenList *tokenlist, SymbolDatabase* symboldatabase, ErrorLogger * /*errorLogger*/, const Settings *settings)
 {
+    std::map<int, std::size_t> static_sizes;
     // declaration
     for (const Variable *var : symboldatabase->variableList()) {
         if (!var || !var->isLocal() || var->isPointer() || var->isReference() || var->isStatic())
@@ -6225,15 +6226,15 @@ static void valueFlowContainerSize(TokenList *tokenlist, SymbolDatabase* symbold
         if (!Token::Match(var->nameToken(), "%name% ;") &&
             !(Token::Match(var->nameToken(), "%name% {") && Token::simpleMatch(var->nameToken()->next()->link(), "} ;")))
             continue;
+        if (var->valueType()->container->size_templateArgNo >= 0) {
+            if (var->dimensions().size() == 1 && var->dimensions().front().known)
+                static_sizes[var->declarationId()] = var->dimensions().front().num;
+            continue;
+        }
         std::vector<ValueFlow::Value> values{ValueFlow::Value{0}};
         values.back().valueType = ValueFlow::Value::ValueType::CONTAINER_SIZE;
         values.back().setKnown();
-        if (var->valueType()->container->size_templateArgNo >= 0) {
-            if (var->dimensions().size() == 1 && var->dimensions().front().known)
-                values.back().intvalue = var->dimensions().front().num;
-            else
-                continue;
-        } else if (Token::simpleMatch(var->nameToken()->next(), "{")) {
+        if (Token::simpleMatch(var->nameToken()->next(), "{")) {
             const Token* initList = var->nameToken()->next();
             values = getInitListSize(initList, var->valueType()->container);
         }
@@ -6244,7 +6245,12 @@ static void valueFlowContainerSize(TokenList *tokenlist, SymbolDatabase* symbold
     // after assignment
     for (const Scope *functionScope : symboldatabase->functionScopes) {
         for (const Token *tok = functionScope->bodyStart; tok != functionScope->bodyEnd; tok = tok->next()) {
-            if (Token::Match(tok, "%name%|;|{|} %var% = %str% ;")) {
+            if (static_sizes.count(tok->varId()) > 0) {
+                ValueFlow::Value value(static_sizes.at(tok->varId()));
+                value.valueType = ValueFlow::Value::ValueType::CONTAINER_SIZE;
+                value.setKnown();
+                setTokenValue(const_cast<Token*>(tok), value, settings);
+            } else if (Token::Match(tok, "%name%|;|{|} %var% = %str% ;")) {
                 const Token *containerTok = tok->next();
                 if (containerTok && containerTok->valueType() && containerTok->valueType()->container && containerTok->valueType()->container->stdStringLike) {
                     ValueFlow::Value value(Token::getStrLength(containerTok->tokAt(2)));
@@ -6254,7 +6260,7 @@ static void valueFlowContainerSize(TokenList *tokenlist, SymbolDatabase* symbold
                 }
             } else if (Token::Match(tok, "%name%|;|{|}|> %var% = {") && Token::simpleMatch(tok->linkAt(3), "} ;")) {
                 const Token* containerTok = tok->next();
-                if (astIsContainer(containerTok)) {
+                if (astIsContainer(containerTok) && containerTok->valueType()->container->size_templateArgNo < 0) {
                     std::vector<ValueFlow::Value> values = getInitListSize(tok->tokAt(3), containerTok->valueType()->container);
                     for (const ValueFlow::Value& value : values)
                         valueFlowContainerForward(containerTok->next(), containerTok->variable(), value, tokenlist);
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index 611595c90..2147193a9 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -5008,6 +5008,13 @@ private:
                "}\n";
         ASSERT_EQUALS(0U, tokenValues(code, "str . front").size());
 
+        code = "void f() {\n"
+               "  std::vector<int> ints{};\n"
+               "  ints.front();\n"
+               "}";
+        ASSERT_EQUALS("",
+                      isKnownContainerSizeValue(tokenValues(code, "ints . front", ValueFlow::Value::ValueType::CONTAINER_SIZE), 0));
+
         code = "void f() {\n"
                "  std::vector<int> ints{};\n"
                "  ints.front();\n"
@@ -5037,19 +5044,19 @@ private:
         ASSERT_EQUALS("",
                       isKnownContainerSizeValue(tokenValues(code, "ints . front", ValueFlow::Value::ValueType::CONTAINER_SIZE), 0));
 
-        code = "void f() {\n"
-               "  std::vector<int> ints = {1};\n"
-               "  ints.front();\n"
-               "}";
-        ASSERT_EQUALS("",
-                      isKnownContainerSizeValue(tokenValues(code, "ints . front", ValueFlow::Value::ValueType::CONTAINER_SIZE), 1));
-
         code = "void f(std::string str) {\n"
                "    if (str == \"123\")\n"
                "        bool x = str.empty();\n"
                "}\n";
         ASSERT_EQUALS("",
                       isKnownContainerSizeValue(tokenValues(code, "str . empty", ValueFlow::Value::ValueType::CONTAINER_SIZE), 3));
+        
+        code = "int f() {\n"
+               "    std::array<int, 10> a = {};\n"
+               "    return a.front();\n"
+               "}\n";
+        ASSERT_EQUALS("",
+                      isKnownContainerSizeValue(tokenValues(code, "a . front", ValueFlow::Value::ValueType::CONTAINER_SIZE), 10));
 
         code = "void f(std::string str) {\n"
                "    if (str == \"123\") {\n"