Fix trivial -Wundef warnings

* See [Feature #17752]

Co-authored-by: xtkoba (Tee KOBAYASHI) <xtkoba+ruby@gmail.com>

16 files changed, 21 insertions, 19 deletions

diff --git a/builtin.c b/builtin.c
index 7c3653dab7..21fff95650 100644
--- a/builtin.c
+++ b/builtin.c
@@ -3,7 +3,7 @@
 #include "iseq.h"
 #include "builtin.h"
 
-#if CROSS_COMPILING
+#ifdef CROSS_COMPILING
 
 #define INCLUDED_BY_BUILTIN_C 1
 #include "mini_builtin.c"
diff --git a/builtin.h b/builtin.h
index 3b2f477654..5b4bda1e99 100644
--- a/builtin.h
+++ b/builtin.h
@@ -65,7 +65,7 @@ PUREFUNC(static inline VALUE rb_vm_lvar(rb_execution_context_t *ec, int index));
 static inline VALUE
 rb_vm_lvar(rb_execution_context_t *ec, int index)
 {
-#if VM_CORE_H_EC_DEFINED
+#if defined(VM_CORE_H_EC_DEFINED) && VM_CORE_H_EC_DEFINED
     return ec->cfp->ep[index];
 #else
     return rb_vm_lvar_exposed(ec, index);
diff --git a/dir.c b/dir.c
index 8ff812e8e7..fb31bd4f22 100644
--- a/dir.c
+++ b/dir.c
@@ -216,7 +216,7 @@ typedef enum {
 #else
 #define FNM_SYSCASE	0
 #endif
-#if _WIN32
+#ifdef _WIN32
 #define FNM_SHORTNAME	0x20
 #else
 #define FNM_SHORTNAME	0
diff --git a/eval_intern.h b/eval_intern.h
index 3238df1036..475fd4d3cf 100644
--- a/eval_intern.h
+++ b/eval_intern.h
@@ -144,7 +144,7 @@ LONG WINAPI rb_w32_stack_overflow_handler(struct _EXCEPTION_POINTERS *);
 
 #define EC_REPUSH_TAG() (void)(_ec->tag = &_tag)
 
-#if defined __GNUC__ && __GNUC__ == 4 && (__GNUC_MINOR__ >= 6 && __GNUC_MINOR__ <= 8) || __clang__
+#if defined __GNUC__ && __GNUC__ == 4 && (__GNUC_MINOR__ >= 6 && __GNUC_MINOR__ <= 8) || defined __clang__
 /* This macro prevents GCC 4.6--4.8 from emitting maybe-uninitialized warnings.
  * This macro also prevents Clang from dumping core in EC_EXEC_TAG().
  * (I confirmed Clang 4.0.1 and 5.0.0.)
diff --git a/gc.c b/gc.c
index 1507be6642..4eb5488463 100644
--- a/gc.c
+++ b/gc.c
@@ -830,7 +830,7 @@ enum {
 };
 #define HEAP_PAGE_ALIGN (1 << HEAP_PAGE_ALIGN_LOG)
 #define HEAP_PAGE_SIZE HEAP_PAGE_ALIGN
-#if defined(HAVE_MMAP) && (PAGE_SIZE <= HEAP_PAGE_SIZE)
+#if defined(HAVE_MMAP) && (!defined(PAGE_SIZE) || PAGE_SIZE <= HEAP_PAGE_SIZE)
 # define USE_MMAP_ALIGNED_ALLOC 1
 #else
 # define USE_MMAP_ALIGNED_ALLOC 0
diff --git a/hash.c b/hash.c
index 000e816781..ce0e72a017 100644
--- a/hash.c
+++ b/hash.c
@@ -800,7 +800,7 @@ ar_force_convert_table(VALUE hash, const char *file, int line)
     if (RHASH_AR_TABLE(hash)) {
         unsigned i, bound = RHASH_AR_TABLE_BOUND(hash);
 
-#if RHASH_CONVERT_TABLE_DEBUG
+#if defined(RHASH_CONVERT_TABLE_DEBUG) && RHASH_CONVERT_TABLE_DEBUG
         rb_obj_info_dump(hash);
         fprintf(stderr, "force_convert: %s:%d\n", file, line);
         RB_DEBUG_COUNTER_INC(obj_hash_force_convert);
diff --git a/include/ruby/internal/attr/const.h b/include/ruby/internal/attr/const.h
index b1f27e2606..c9e8577693 100644
--- a/include/ruby/internal/attr/const.h
+++ b/include/ruby/internal/attr/const.h
@@ -37,7 +37,7 @@
 #endif
 
 /** Enables #RBIMPL_ATTR_CONST if and only if. ! #RUBY_DEBUG. */
-#if !RUBY_DEBUG
+#if !defined(RUBY_DEBUG) || !RUBY_DEBUG
 # define RBIMPL_ATTR_CONST_UNLESS_DEBUG() RBIMPL_ATTR_CONST()
 #else
 # define RBIMPL_ATTR_CONST_UNLESS_DEBUG() /* void */
diff --git a/memory_view.c b/memory_view.c
index ce2803717b..9609ecae3f 100644
--- a/memory_view.c
+++ b/memory_view.c
@@ -671,7 +671,7 @@ extract_item_member(const uint8_t *ptr, const rb_memory_view_item_component_t *m
             return LL2NUM(val.ll);
         }
         else {
-#if SIZEOF_INT64_t == SIZEOF_LONG
+#if SIZEOF_INT64_T == SIZEOF_LONG
             return LONG2NUM(val.i64);
 #else
             return LL2NUM(val.i64);
@@ -683,7 +683,7 @@ extract_item_member(const uint8_t *ptr, const rb_memory_view_item_component_t *m
             return ULL2NUM(val.ull);
         }
         else {
-#if SIZEOF_UINT64_t == SIZEOF_LONG
+#if SIZEOF_UINT64_T == SIZEOF_LONG
             return ULONG2NUM(val.u64);
 #else
             return ULL2NUM(val.u64);
diff --git a/ractor_core.h b/ractor_core.h
index fb104cd22c..63279ebb98 100644
--- a/ractor_core.h
+++ b/ractor_core.h
@@ -261,7 +261,7 @@ static inline void
 rb_ractor_set_current_ec(rb_ractor_t *cr, rb_execution_context_t *ec)
 {
 #ifdef RB_THREAD_LOCAL_SPECIFIER
-  #if __APPLE__
+  #ifdef __APPLE__
     rb_current_ec_set(ec);
   #else
     ruby_current_ec = ec;
diff --git a/ruby.c b/ruby.c
index 21c2daa977..9ca7c2a2eb 100644
--- a/ruby.c
+++ b/ruby.c
@@ -1826,7 +1826,7 @@ process_options(int argc, char **argv, ruby_cmdline_options_t *opt)
     opt->script_name = rb_str_new_cstr(opt->script);
     opt->script = RSTRING_PTR(opt->script_name);
 
-#if _WIN32
+#ifdef _WIN32
     translit_char_bin(RSTRING_PTR(opt->script_name), '\\', '/');
 #elif defined DOSISH
     translit_char(RSTRING_PTR(opt->script_name), '\\', '/');
diff --git a/template/sizes.c.tmpl b/template/sizes.c.tmpl
index 848a29f4be..31060f5fea 100644
--- a/template/sizes.c.tmpl
+++ b/template/sizes.c.tmpl
@@ -43,7 +43,7 @@ Init_sizeof(void)
 %     next
 %   end
 %   cond = conditions[type]
-#if SIZEOF_<%= type.tr_cpp %> != 0<%= " && #{cond}" if cond %>
+#if defined(SIZEOF_<%= type.tr_cpp %>) && SIZEOF_<%= type.tr_cpp %> != 0<%= " && #{cond}" if cond %>
     DEFINE(<%= type %>, <%= type.tr_cpp %>);
 #endif
 % end
diff --git a/thread_pthread.h b/thread_pthread.h
index 1d6ea1385f..8b7583d266 100644
--- a/thread_pthread.h
+++ b/thread_pthread.h
@@ -100,7 +100,7 @@ native_tls_set(native_tls_key_t key, void *ptr)
 
 RUBY_SYMBOL_EXPORT_BEGIN
 #ifdef RB_THREAD_LOCAL_SPECIFIER
-  #if __APPLE__
+  #ifdef __APPLE__
     // on Darwin, TLS can not be accessed across .so
     struct rb_execution_context_struct *rb_current_ec();
     void rb_current_ec_set(struct rb_execution_context_struct *);
diff --git a/tool/mk_builtin_loader.rb b/tool/mk_builtin_loader.rb
index c1d2376a8b..309ff615c7 100644
--- a/tool/mk_builtin_loader.rb
+++ b/tool/mk_builtin_loader.rb
@@ -343,7 +343,7 @@ def mk_builtin_header file
     f.puts
     f.puts "  // arity_check"
     f.puts "COMPILER_WARNING_PUSH"
-    f.puts "#if GCC_VERSION_SINCE(5, 1, 0) || __clang__"
+    f.puts "#if GCC_VERSION_SINCE(5, 1, 0) || defined __clang__"
     f.puts "COMPILER_WARNING_ERROR(-Wincompatible-pointer-types)"
     f.puts "#endif"
     bs.each{|func, (argc, cfunc_name)|
diff --git a/vm.c b/vm.c
index 8c62d7dd91..ea8b21e7a5 100644
--- a/vm.c
+++ b/vm.c
@@ -3262,7 +3262,7 @@ static VALUE
 nsdr(VALUE self)
 {
     VALUE ary = rb_ary_new();
-#if HAVE_BACKTRACE
+#ifdef HAVE_BACKTRACE
 #include <execinfo.h>
 #define MAX_NATIVE_TRACE 1024
     static void *trace[MAX_NATIVE_TRACE];
diff --git a/vm_core.h b/vm_core.h
index f21d85032c..72120d5302 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -670,7 +670,7 @@ typedef struct rb_vm_struct {
 #endif
     const struct rb_callcache *global_cc_cache_table[VM_GLOBAL_CC_CACHE_TABLE_SIZE]; // vm_eval.c
 
-#if USE_VM_CLOCK
+#if defined(USE_VM_CLOCK) && USE_VM_CLOCK
     uint32_t clock;
 #endif
 
@@ -870,7 +870,7 @@ struct rb_execution_context_struct {
     /* interrupt flags */
     rb_atomic_t interrupt_flag;
     rb_atomic_t interrupt_mask; /* size should match flag */
-#if USE_VM_CLOCK
+#if defined(USE_VM_CLOCK) && USE_VM_CLOCK
     uint32_t checked_clock;
 #endif
 
@@ -1804,7 +1804,7 @@ static inline rb_execution_context_t *
 rb_current_execution_context(void)
 {
 #ifdef RB_THREAD_LOCAL_SPECIFIER
-  #if __APPLE__
+  #ifdef __APPLE__
     rb_execution_context_t *ec = rb_current_ec();
   #else
     rb_execution_context_t *ec = ruby_current_ec;
@@ -1891,7 +1891,7 @@ enum {
 static inline bool
 RUBY_VM_INTERRUPTED_ANY(rb_execution_context_t *ec)
 {
-#if USE_VM_CLOCK
+#if defined(USE_VM_CLOCK) && USE_VM_CLOCK
     uint32_t current_clock = rb_ec_vm_ptr(ec)->clock;
 
     if (current_clock != ec->checked_clock) {
diff --git a/vm_exec.c b/vm_exec.c
index 7aa56f6ad6..305ff90261 100644
--- a/vm_exec.c
+++ b/vm_exec.c
@@ -104,6 +104,8 @@ vm_exec_core(rb_execution_context_t *ec, VALUE initial)
 #else
     register rb_control_frame_t *reg_cfp;
     const VALUE *reg_pc;
+#define USE_MACHINE_REGS 0
+
 #endif
 
 #if USE_MACHINE_REGS