argumentSize: Clarify error message

lib/checkbufferoverrun.cpp

@@ -804,18 +804,26 @@ void CheckBufferOverrun::argumentSize()
                         err = true;
                 }
                 if (err)
-                    argumentSizeError(tok, tok->str(), argument->name());
+                    argumentSizeError(tok, tok->str(), paramIndex, callargs[paramIndex]->expressionString(), calldata->variable(), argument);
             }
         }
     }
 }
 
-void CheckBufferOverrun::argumentSizeError(const Token *tok, const std::string &functionName, const std::string &varname)
+void CheckBufferOverrun::argumentSizeError(const Token *tok, const std::string &functionName, nonneg int paramIndex, const std::string &paramExpression, const Variable *paramVar, const Variable *functionArg)
 {
-    reportError(tok, Severity::warning, "argumentSize",
+    const std::string strParamNum = std::to_string(paramIndex + 1) + getOrdinalText(paramIndex + 1);
+    ErrorPath errorPath;
+    errorPath.emplace_back(tok, "Function '" + functionName + "' is called");
+    if (functionArg)
+        errorPath.emplace_back(functionArg->nameToken(), "Declaration of " + strParamNum + " function argument.");
+    if (paramVar)
+        errorPath.emplace_back(paramVar->nameToken(), "Passing buffer '" + paramVar->name() + "' to function that is declared here");
+    errorPath.emplace_back(tok, "");
+
+    reportError(errorPath, Severity::warning, "argumentSize",
                 "$symbol:" + functionName + '\n' +
-                "$symbol:" + varname + '\n' +
+                "Buffer '" + paramExpression + "' is too small, the function '" + functionName + "' expects a bigger buffer in " + strParamNum + " argument", CWE_ARGUMENT_SIZE, Certainty::normal);
-                "The array '" + varname + "' is too small, the function '" + functionName + "' expects a bigger one.", CWE_ARGUMENT_SIZE, Certainty::normal);
 }
 
 //---------------------------------------------------------------------------

lib/checkbufferoverrun.h

@@ -85,7 +85,7 @@ public:
         c.arrayIndexThenCheckError(nullptr, "i");
         c.bufferOverflowError(nullptr, nullptr, Certainty::normal);
         c.objectIndexError(nullptr, nullptr, true);
-        c.argumentSizeError(nullptr, "function", "buffer");
+        c.argumentSizeError(nullptr, "function", 1, "buffer", nullptr, nullptr);
     }
 
     /** @brief Parse current TU and extract file info */
@@ -117,7 +117,7 @@ private:
     void terminateStrncpyError(const Token *tok, const std::string &varname);
 
     void argumentSize();
-    void argumentSizeError(const Token *tok, const std::string &functionName, const std::string &varname);
+    void argumentSizeError(const Token *tok, const std::string &functionName, nonneg int paramIndex, const std::string &paramExpression, const Variable *paramVar, const Variable *functionArg);
 
     void objectIndex();
     void objectIndexError(const Token *tok, const ValueFlow::Value *v, bool known);

test/testbufferoverrun.cpp

@@ -2862,26 +2862,40 @@ private:
     }
 
     void buffer_overrun_function_array_argument() {
+        setMultiline();
+
         check("void f(char a[10]);\n"
               "void g() {\n"
               "    char a[2];\n"
               "    f(a);\n"
               "}");
-        ASSERT_EQUALS("[test.cpp:4]: (warning) The array 'a' is too small, the function 'f' expects a bigger one.\n", errout.str());
+        ASSERT_EQUALS("test.cpp:4:warning:Buffer 'a' is too small, the function 'f' expects a bigger buffer in 1st argument\n"
+                      "test.cpp:4:note:Function 'f' is called\n"
+                      "test.cpp:1:note:Declaration of 1st function argument.\n"
+                      "test.cpp:3:note:Passing buffer 'a' to function that is declared here\n"
+                      "test.cpp:4:note:Buffer 'a' is too small, the function 'f' expects a bigger buffer in 1st argument\n", errout.str());
 
         check("void f(float a[10][3]);\n"
               "void g() {\n"
               "    float a[2][3];\n"
               "    f(a);\n"
               "}");
-        ASSERT_EQUALS("[test.cpp:4]: (warning) The array 'a' is too small, the function 'f' expects a bigger one.\n", errout.str());
+        ASSERT_EQUALS("test.cpp:4:warning:Buffer 'a' is too small, the function 'f' expects a bigger buffer in 1st argument\n"
+                      "test.cpp:4:note:Function 'f' is called\n"
+                      "test.cpp:1:note:Declaration of 1st function argument.\n"
+                      "test.cpp:3:note:Passing buffer 'a' to function that is declared here\n"
+                      "test.cpp:4:note:Buffer 'a' is too small, the function 'f' expects a bigger buffer in 1st argument\n", errout.str());
 
         check("void f(int a[20]);\n"
               "void g() {\n"
               "    int a[2];\n"
               "    f(a);\n"
               "}");
-        ASSERT_EQUALS("[test.cpp:4]: (warning) The array 'a' is too small, the function 'f' expects a bigger one.\n", errout.str());
+        ASSERT_EQUALS("test.cpp:4:warning:Buffer 'a' is too small, the function 'f' expects a bigger buffer in 1st argument\n"
+                      "test.cpp:4:note:Function 'f' is called\n"
+                      "test.cpp:1:note:Declaration of 1st function argument.\n"
+                      "test.cpp:3:note:Passing buffer 'a' to function that is declared here\n"
+                      "test.cpp:4:note:Buffer 'a' is too small, the function 'f' expects a bigger buffer in 1st argument\n", errout.str());
 
         check("void f(int a[]) {\n"
               "  switch (2) {\n"