fix a few compilation warnings

- remove unused variables and class fields
 - add support for gcc 4.5 & clang's __builtin_unreachable
 - fix 2 bugs related to strict aliasing
 - remove a few unused function parameters

Signed-off-by: Nuno Lopes <t-nclaud@microsoft.com>

src/util/bit_util.cpp

@@ -19,6 +19,7 @@ Revision History:
 #include"bit_util.h"
 #include"util.h"
 #include"debug.h"
+#include <cstring>
 
 /**
    \brief (Debugging version) Return the position of the most significant (set) bit of a
@@ -67,7 +68,11 @@ unsigned msb_pos(unsigned v) {
 */
 unsigned nlz_core(unsigned x) {
     SASSERT(x != 0);
+#ifdef __GNUC__
+    return __builtin_clz(x);
+#else
     return 31 - msb_pos(x);
+#endif
 }
 
 /**
@@ -92,8 +97,15 @@ unsigned nlz(unsigned sz, unsigned const * data) {
 */
 unsigned ntz_core(unsigned x) {
     SASSERT(x != 0);
+#ifdef __GNUC__
+    return __builtin_ctz(x);
+#else
     float f = static_cast<float>(x & static_cast<unsigned>(-static_cast<int>(x)));
-    return (*reinterpret_cast<unsigned *>(&f) >> 23) - 0x7f;
+    unsigned u;
+    SASSERT(sizeof(u) == sizeof(f));
+    memcpy(&u, &f, sizeof(u));
+    return (u >> 23) - 0x7f;
+#endif
 }
 
 /**

src/util/debug.cpp

@@ -24,7 +24,7 @@ Revision History:
 #include"str_hashtable.h"
 #include"z3_exception.h"
 
-volatile bool g_enable_assertions = true;
+static volatile bool g_enable_assertions = true;
 
 void enable_assertions(bool f) {
     g_enable_assertions = f;
@@ -41,7 +41,7 @@ void notify_assertion_violation(const char * fileName, int line, const char * co
     std::cerr << condition << "\n";
 }
 
-str_hashtable* g_enabled_debug_tags = 0;
+static str_hashtable* g_enabled_debug_tags = 0;
 
 static void init_debug_table() {
     if (!g_enabled_debug_tags) {

src/util/debug.h

@@ -29,6 +29,10 @@ bool assertions_enabled();
 #include<crtdbg.h>
 #endif
 
+#ifndef __has_builtin
+# define __has_builtin(x) 0
+#endif
+
 #include"error_codes.h"
 #include"warning.h"
 
@@ -53,7 +57,14 @@ bool is_debug_enabled(const char * tag);
 #define SASSERT(COND) DEBUG_CODE(if (assertions_enabled() && !(COND)) { notify_assertion_violation(__FILE__, __LINE__, #COND); INVOKE_DEBUGGER(); })
 #define CASSERT(TAG, COND) DEBUG_CODE(if (assertions_enabled() && is_debug_enabled(TAG) && !(COND)) { notify_assertion_violation(__FILE__, __LINE__, #COND); INVOKE_DEBUGGER(); })
 #define XASSERT(COND, EXTRA_CODE) DEBUG_CODE(if (assertions_enabled() && !(COND)) { notify_assertion_violation(__FILE__, __LINE__, #COND); { EXTRA_CODE } INVOKE_DEBUGGER(); })
+
+#if (defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 405)) || __has_builtin(__builtin_unreachable)
+// only available in gcc >= 4.5 and in newer versions of clang
+# define UNREACHABLE() __builtin_unreachable()
+#else
 #define UNREACHABLE() DEBUG_CODE(notify_assertion_violation(__FILE__, __LINE__, "UNREACHABLE CODE WAS REACHED."); INVOKE_DEBUGGER();)
+#endif
+
 #define NOT_IMPLEMENTED_YET() { std::cerr << "NOT IMPLEMENTED YET!\n"; UNREACHABLE(); exit(ERR_NOT_IMPLEMENTED_YET); } ((void) 0)
 
 #ifdef Z3DEBUG

src/util/gparams.cpp

@@ -22,7 +22,7 @@ Notes:
 
 extern void gparams_register_modules();
 
-char const * g_old_params_names[] = {
+static char const * g_old_params_names[] = {
     "arith_adaptive","arith_adaptive_assertion_threshold","arith_adaptive_gcd","arith_adaptive_propagation_threshold","arith_add_binary_bounds","arith_blands_rule_threshold","arith_branch_cut_ratio","arith_dump_lemmas","arith_eager_eq_axioms","arith_eager_gcd","arith_eq_bounds","arith_euclidean_solver","arith_expand_eqs","arith_force_simplex","arith_gcd_test","arith_ignore_int","arith_lazy_adapter","arith_lazy_pivoting","arith_max_lemma_size","arith_process_all_eqs","arith_propagate_eqs","arith_propagation_mode","arith_propagation_threshold","arith_prop_strategy","arith_random_initial_value","arith_random_lower","arith_random_seed","arith_random_upper","arith_reflect","arith_skip_big_coeffs","arith_small_lemma_size","arith_solver","arith_stronger_lemmas","array_always_prop_upward","array_canonize","array_cg","array_delay_exp_axiom","array_extensional","array_laziness","array_lazy_ieq","array_lazy_ieq_delay","array_solver","array_weak","async_commands","at_labels_cex","auto_config","bb_eager","bb_ext_gates","bb_quantifiers","bin_clauses","bit2int","bv2int_distribute","bv_blast_max_size","bv_cc","bv_enable_int2bv_propagation","bv_lazy_le","bv_max_sharing","bv_reflect","bv_solver","case_split","check_at_labels","check_proof","cnf_factor","cnf_mode","context_simplifier","dack","dack_eq","dack_factor","dack_gc","dack_gc_inv_decay","dack_threshold","default_qid","default_table","default_table_checked","delay_units","delay_units_threshold","der","display_config","display_dot_proof","display_error_for_visual_studio","display_features","display_proof","display_unsat_core","distribute_forall","dt_lazy_splits","dump_goal_as_smt","elim_and","elim_bounds","elim_nlarith_quantifiers","elim_quantifiers","elim_term_ite","ematching","engine","eq_propagation","hi_div0","ignore_bad_patterns","ignore_setparameter","instruction_max","inst_gen","interactive","internalizer_nnf","lemma_gc_factor","lemma_gc_half","lemma_gc_initial","lemma_gc_new_clause_activity","lemma_gc_new_clause_relevancy","lemma_gc_new_old_ratio","lemma_gc_old_clause_activity","lemma_gc_old_clause_relevancy","lemma_gc_strategy","lift_ite","lookahead_diseq","macro_finder","max_conflicts","max_counterexamples","mbqi","mbqi_force_template","mbqi_max_cexs","mbqi_max_cexs_incr","mbqi_max_iterations","mbqi_trace","minimize_lemmas","model","model_compact","model_completion","model_display_arg_sort","model_hide_unused_partitions","model_on_final_check","model_on_timeout","model_partial","model_v1","model_v2","model_validate","new_core2th_eq","ng_lift_ite","nl_arith","nl_arith_branching","nl_arith_gb","nl_arith_gb_eqs","nl_arith_gb_perturbate","nl_arith_gb_threshold","nl_arith_max_degree","nl_arith_rounds","nnf_factor","nnf_ignore_labels","nnf_mode","nnf_sk_hack","order","order_var_weight","order_weights","phase_selection","pi_arith","pi_arith_weight","pi_avoid_skolems","pi_block_looop_patterns","pi_max_multi_patterns","pi_non_nested_arith_weight","pi_nopat_weight","pi_pull_quantifiers","pi_use_database","pi_warnings","pp_bounded","pp_bv_literals","pp_bv_neg","pp_decimal","pp_decimal_precision","pp_fixed_indent","pp_flat_assoc","pp_max_depth","pp_max_indent","pp_max_num_lines","pp_max_ribbon","pp_max_width","pp_min_alias_size","pp_simplify_implies","pp_single_line","precedence","precedence_gen","pre_demodulator","pre_simplifier","pre_simplify_expr","profile_res_sub","progress_sampling_freq","proof_mode","propagate_booleans","propagate_values","pull_cheap_ite_trees","pull_nested_quantifiers","qi_conservative_final_check","qi_cost","qi_eager_threshold","qi_lazy_instantiation","qi_lazy_quick_checker","qi_lazy_threshold","qi_max_eager_multi_patterns","qi_max_instances","qi_max_lazy_multi_pattern_matching","qi_new_gen","qi_profile","qi_profile_freq","qi_promote_unsat","qi_quick_checker","quasi_macros","random_case_split_freq","random_initial_activity","random_seed","recent_lemma_threshold","reduce_args","refine_inj_axiom","relevancy","relevancy_lemma","rel_case_split_order","restart_adaptive","restart_agility_threshold","restart_factor","restart_initial","restart_strategy","restricted_quasi_macros","simplify_clauses","smtlib2_compliant","smtlib_category","smtlib_dump_lemmas","smtlib_logic","smtlib_source_info","smtlib_trace_path","soft_timeout","solver","spc_bs","spc_es","spc_factor_subsumption_index_opt","spc_initial_subsumption_index_opt","spc_max_subsumption_index_features","spc_min_func_freq_subsumption_index","spc_num_iterations","spc_trace","statistics","strong_context_simplifier","tick","trace","trace_file_name","type_check","user_theory_persist_axioms","user_theory_preprocess_axioms","verbose","warning","well_sorted_check","z3_solver_ll_pp","z3_solver_smt_pp", 0 };
 
 bool is_old_param_name(symbol const & name) {
@@ -35,7 +35,7 @@ bool is_old_param_name(symbol const & name) {
     return false;
 }
 
-char const * g_params_renames[] = {
+static char const * g_params_renames[] = {
     "proof_mode", "proof",
     "soft_timeout", "timeout",
     "mbqi", "smt.mbqi",

src/util/hwf.h

@@ -28,6 +28,12 @@ class hwf {
     friend class hwf_manager;
     double value;
     hwf & operator=(hwf const & other) { UNREACHABLE(); return *this; }
+    uint64 get_raw() const {
+      uint64 n;
+      SASSERT(sizeof(n) == sizeof(value));
+      memcpy(&n, &value, sizeof(value));
+      return n;
+    }
 
 public:    
     hwf() {}
@@ -122,16 +128,15 @@ public:
     
     
     bool sgn(hwf const & x) const { 
-        uint64 raw = *reinterpret_cast<uint64 const *>(&x.value);
-        return (raw & 0x8000000000000000ull) != 0; 
+        return (x.get_raw() & 0x8000000000000000ull) != 0; 
     }
 
     const uint64 sig(hwf const & x) const { 
-        return *reinterpret_cast<uint64 const *>(&x.value) & 0x000FFFFFFFFFFFFFull;
+        return x.get_raw() & 0x000FFFFFFFFFFFFFull;
     }
 
     const int exp(hwf const & x) const {         
-        return ((*reinterpret_cast<uint64 const *>(&x.value) & 0x7FF0000000000000ull) >> 52) - 1023;
+        return ((x.get_raw() & 0x7FF0000000000000ull) >> 52) - 1023;
     }
 
     bool is_nan(hwf const & x);
@@ -151,7 +156,7 @@ public:
     void mk_pinf(hwf & o);
     void mk_ninf(hwf & o);
     
-    unsigned hash(hwf const & a) { return hash_ull(*reinterpret_cast<const unsigned long long*>(&a.value)); }
+    unsigned hash(hwf const & a) { return hash_ull(a.get_raw()); }
 
     inline void set_rounding_mode(mpf_rounding_mode rm);
 

src/util/memory_manager.cpp

@@ -27,14 +27,14 @@ void mem_finalize();
 out_of_memory_error::out_of_memory_error():z3_error(ERR_MEMOUT) {
 }
 
-volatile bool g_memory_out_of_memory  = false;
-bool       g_memory_initialized       = false;
-long long  g_memory_alloc_size        = 0;
-long long  g_memory_max_size          = 0;
-long long  g_memory_max_used_size     = 0;
-long long  g_memory_watermark         = 0;
-bool       g_exit_when_out_of_memory  = false;
-char const * g_out_of_memory_msg      = "ERROR: out of memory";
+static volatile bool g_memory_out_of_memory  = false;
+static bool       g_memory_initialized       = false;
+static long long  g_memory_alloc_size        = 0;
+static long long  g_memory_max_size          = 0;
+static long long  g_memory_max_used_size     = 0;
+static long long  g_memory_watermark         = 0;
+static bool       g_exit_when_out_of_memory  = false;
+static char const * g_out_of_memory_msg      = "ERROR: out of memory";
 
 void memory::exit_when_out_of_memory(bool flag, char const * msg) {
     g_exit_when_out_of_memory = flag;

src/util/warning.cpp

@@ -60,11 +60,11 @@ void myInvalidParameterHandler(
 #define END_ERR_HANDLER() {}
 #endif
 
-bool g_warning_msgs   = true;
-bool g_use_std_stdout = false;
-std::ostream* g_error_stream = 0;
-std::ostream* g_warning_stream = 0;
-bool g_show_error_msg_prefix = true;
+static bool g_warning_msgs   = true;
+static bool g_use_std_stdout = false;
+static std::ostream* g_error_stream = 0;
+static std::ostream* g_warning_stream = 0;
+static bool g_show_error_msg_prefix = true;
 
 void send_warnings_to_stdout(bool flag) {
     g_use_std_stdout = flag;