avoid a few str copies + symbol hiding

src/api/api_config_params.cpp

@@ -48,7 +48,7 @@ extern "C" {
         env_params::updt_params();
     }
 
-    std::string g_Z3_global_param_get_buffer;
+    static std::string g_Z3_global_param_get_buffer;
     
     Z3_bool_opt Z3_API Z3_global_param_get(Z3_string param_id, Z3_string_ptr param_value) {
         memory::initialize(UINT_MAX);

src/api/api_context.cpp

@@ -155,8 +155,6 @@ namespace api {
         m_error_code = Z3_OK; 
     }
 
-
-
     void context::check_searching() {
         if (m_searching) { 
             set_error_code(Z3_INVALID_USAGE, "cannot use function while searching"); // TBD: error code could be fixed.
@@ -168,8 +166,8 @@ namespace api {
         return const_cast<char *>(m_string_buffer.c_str());
     }
     
-    char * context::mk_external_string(std::string const & str) {
-        m_string_buffer = str;
+    char * context::mk_external_string(std::string && str) {
+        m_string_buffer = std::move(str);
         return const_cast<char *>(m_string_buffer.c_str());
     }
 
@@ -466,17 +464,11 @@ extern "C" {
         }
     }
 
-
     Z3_API char const * Z3_get_error_msg(Z3_context c, Z3_error_code err) {
         LOG_Z3_get_error_msg(c, err);
         return _get_error_msg(c, err);
     }
 
-    Z3_API char const * Z3_get_error_msg_ex(Z3_context c, Z3_error_code err) {
-        return Z3_get_error_msg(c, err);
-    }
-
-
     void Z3_API Z3_set_ast_print_mode(Z3_context c, Z3_ast_print_mode mode) {
         Z3_TRY;
         LOG_Z3_set_ast_print_mode(c, mode);

src/api/api_context.h

@@ -179,7 +179,7 @@ namespace api {
         // Store a copy of str in m_string_buffer, and return a reference to it.
         // This method is used to communicate local/internal strings with the "external world"
         char * mk_external_string(char const * str);
-        char * mk_external_string(std::string const & str);
+        char * mk_external_string(std::string && str);
 
         // Create a numeral of the given sort
         expr * mk_numeral_core(rational const & n, sort * s);

src/api/api_goal.cpp

@@ -189,7 +189,7 @@ extern "C" {
         std::string result = buffer.str();
         SASSERT(result.size() > 0);
         result.resize(result.size()-1);
-        return mk_c(c)->mk_external_string(result);
+        return mk_c(c)->mk_external_string(std::move(result));
         Z3_CATCH_RETURN("");
     }
 
@@ -207,7 +207,7 @@ extern "C" {
         std::string result = buffer.str();
         SASSERT(result.size() > 0);
         result.resize(result.size()-1);
-        return mk_c(c)->mk_external_string(result);
+        return mk_c(c)->mk_external_string(std::move(result));
         Z3_CATCH_RETURN("");
     }
 

src/api/api_model.cpp

@@ -478,7 +478,7 @@ extern "C" {
             model_v2_pp(buffer, *(to_model_ref(m)), p.partial());
             result = buffer.str();
         }
-        return mk_c(c)->mk_external_string(result);
+        return mk_c(c)->mk_external_string(std::move(result));
         Z3_CATCH_RETURN(nullptr);
     }
 

src/api/api_seq.cpp

@@ -106,8 +106,7 @@ extern "C" {
             SET_ERROR_CODE(Z3_INVALID_ARG, "expression is not a string literal");
             return "";
         }
-        std::string s = str.encode();
-        return mk_c(c)->mk_external_string(s);
+        return mk_c(c)->mk_external_string(str.encode());
         Z3_CATCH_RETURN("");
     }
 

src/api/api_stats.cpp

@@ -34,7 +34,7 @@ extern "C" {
         result = buffer.str();
         SASSERT(result.size() > 0);
         result.resize(result.size()-1);
-        return mk_c(c)->mk_external_string(result);
+        return mk_c(c)->mk_external_string(std::move(result));
         Z3_CATCH_RETURN("");
     }