all: Use defined values for defines

... instead of defined/undefined names, so that -Wundef can catch
mistakes.

30 files changed, 177 insertions, 180 deletions

diff --git a/meson.build b/meson.build
index c2b10873..8db3189b 100644
--- a/meson.build
+++ b/meson.build
@@ -182,12 +182,12 @@ config_h = configuration_data()
 
 config_h.set_quoted('GETTEXT_PACKAGE', vte_gettext_domain)
 config_h.set_quoted('VERSION', vte_version)
-config_h.set('VTE_DEBUG', enable_debug)
-config_h.set('WITH_A11Y', get_option('a11y'))
-config_h.set('WITH_FRIBIDI', get_option('fribidi'))
-config_h.set('WITH_GNUTLS', get_option('gnutls'))
-config_h.set('WITH_ICU', get_option('icu'))
-config_h.set('WITH_SIXEL', get_option('sixel'))
+config_h.set10('VTE_DEBUG', enable_debug)
+config_h.set10('WITH_A11Y', get_option('a11y'))
+config_h.set10('WITH_FRIBIDI', get_option('fribidi'))
+config_h.set10('WITH_GNUTLS', get_option('gnutls'))
+config_h.set10('WITH_ICU', get_option('icu'))
+config_h.set10('WITH_SIXEL', get_option('sixel'))
 
 ver = glib_min_req_version.split('.')
 config_h.set('GLIB_VERSION_MIN_REQUIRED', '(G_ENCODE_VERSION(' + ver[0] + ',' + ver[1] + '))')
@@ -423,7 +423,7 @@ foreach func: check_functions
   if __reqd
     assert(__have, __name + ' not found')
   else
-    config_h.set('HAVE_' + __name.underscorify().to_upper(), __have)
+    config_h.set10('HAVE_' + __name.underscorify().to_upper(), __have)
   endif
 endforeach
 
@@ -644,7 +644,7 @@ else
   systemd_dep = dependency('', required: false)
 endif
 
-config_h.set('WITH_SYSTEMD', systemd_dep.found())
+config_h.set10('WITH_SYSTEMD', systemd_dep.found())
 
 # Write config.h
 
diff --git a/src/app/app.cc b/src/app/app.cc
index 9809af61..e574a272 100644
--- a/src/app/app.cc
+++ b/src/app/app.cc
@@ -766,7 +766,7 @@ public:
                           "Use a GtkScrolledWindow", nullptr },
                         { "shell", 'S', G_OPTION_FLAG_REVERSE | G_OPTION_FLAG_HIDDEN,
                           G_OPTION_ARG_NONE, &no_shell, nullptr, nullptr },
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
                         { "test-mode", 0, 0, G_OPTION_ARG_NONE, &test_mode,
                           "Enable test mode", nullptr },
 #endif
@@ -3159,7 +3159,7 @@ main(int argc,
                gdk_window_set_debug_updates(true);
 #endif /* VTE_GTK == 3 */
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
        if (options.test_mode) {
                vte_set_test_flags(VTE_TEST_FLAGS_ALL);
                options.allow_window_ops = true;
diff --git a/src/bidi.cc b/src/bidi.cc
index 7adf74a4..76f0fcb3 100644
--- a/src/bidi.cc
+++ b/src/bidi.cc
@@ -42,7 +42,7 @@
 
 #include <config.h>
 
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
 #include <fribidi.h>
 #endif
 
@@ -51,7 +51,7 @@
 #include "vtedefines.hh"
 #include "vteinternal.hh"
 
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
 static_assert (sizeof (FriBidiChar) == sizeof (gunichar), "Unexpected FriBidiChar size");
 #endif
 
@@ -178,7 +178,7 @@ BidiRow::vis_get_shaped_char(vte::grid::column_t col, vteunistr s) const
 }
 
 
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
 static inline bool
 is_arabic(gunichar c)
 {
@@ -349,7 +349,7 @@ BidiRunner::explicit_line(vte::grid::row_t row, bool rtl, bool do_shaping)
                 }
         }
 
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
         if (do_shaping)
                 explicit_line_shape(row);
 #endif
@@ -374,7 +374,7 @@ BidiRunner::paragraph(vte::grid::row_t start, vte::grid::row_t end,
                 return;
         }
 
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
         /* Have a consistent limit on the number of rows in a paragraph
          * that can get implicit BiDi treatment, which is independent from
          * the current scroll position. */
@@ -399,7 +399,7 @@ BidiRunner::explicit_paragraph(vte::grid::row_t start, vte::grid::row_t end,
         }
 }
 
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
 /* Figure out the mapping for the implicit paragraph between the given rows.
  * Returns success. */
 bool
@@ -766,7 +766,7 @@ vte_bidi_get_mirror_char (vteunistr unistr, gboolean mirror_box_drawing, vteunis
                 if (G_UNLIKELY (mirror_box_drawing))
                         base_ch_mirrored = 0x2500 + mirrored_2500[base_ch - 0x2500];
         } else {
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
                 /* Prefer the FriBidi variant as that's more likely to be in sync with the rest of our BiDi stuff. */
                 fribidi_get_mirror_char (base_ch, &base_ch_mirrored);
 #else
diff --git a/src/bidi.hh b/src/bidi.hh
index 5faec854..7b69dc12 100644
--- a/src/bidi.hh
+++ b/src/bidi.hh
@@ -98,13 +98,13 @@ public:
 private:
         RingView *m_ringview;
 
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
         void explicit_line_shape(vte::grid::row_t row);
 #endif
 
         void explicit_line(vte::grid::row_t row, bool rtl, bool do_shaping);
         void explicit_paragraph(vte::grid::row_t start, vte::grid::row_t end, bool rtl, bool do_shaping);
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
         bool implicit_paragraph(vte::grid::row_t start, vte::grid::row_t end, bool do_shaping);
 #endif
 };
diff --git a/src/cxx-utils.hh b/src/cxx-utils.hh
index cc2b2215..c74c0f3a 100644
--- a/src/cxx-utils.hh
+++ b/src/cxx-utils.hh
@@ -46,7 +46,7 @@ inline constexpr auto to_integral(E e) noexcept
         return static_cast<std::underlying_type_t<E>>(e);
 }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 void log_exception(char const* func = __builtin_FUNCTION(),
                    char const* filename = __builtin_FILE(),
                    int const line = __builtin_LINE()) noexcept;
diff --git a/src/debug.cc b/src/debug.cc
index 4185a57a..2d56f085 100644
--- a/src/debug.cc
+++ b/src/debug.cc
@@ -27,7 +27,7 @@ guint _vte_debug_flags;
 void
 _vte_debug_init(void)
 {
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
   const GDebugKey keys[] = {
     { "misc",         VTE_DEBUG_MISC         },
     { "io",           VTE_DEBUG_IO           },
@@ -73,7 +73,7 @@ const char *
 _vte_debug_sequence_to_string(const char *str,
                               gssize length)
 {
-#if defined(VTE_DEBUG)
+#if VTE_DEBUG
         static const char codes[][6] = {
                 "NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "BEL",
                 "BS", "HT", "LF", "VT", "FF", "CR", "SO", "SI",
@@ -126,7 +126,7 @@ _vte_debug_sequence_to_string(const char *str,
 #endif /* VTE_DEBUG */
 }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 static bool
 hexdump_line(GString* str,
              size_t ofs,
@@ -157,7 +157,7 @@ _vte_debug_hexdump(char const* str,
                    uint8_t const* buf,
                    size_t len)
 {
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         GString* s = g_string_new(str);
         g_string_append_printf(s, " len = 0x%x = %u\n", (unsigned int)len, (unsigned int)len);
 
diff --git a/src/debug.h b/src/debug.h
index da1d51d8..7b02a896 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -87,13 +87,13 @@ _vte_debug_on(guint flags)
 	return (_vte_debug_flags & flags) != 0;
 }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 #define _VTE_DEBUG_IF(flags) if (G_UNLIKELY (_vte_debug_on (flags)))
 #else
 #define _VTE_DEBUG_IF(flags) if (0)
 #endif
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 #if defined(__GNUC__) && G_HAVE_GNUC_VARARGS
 #define _vte_debug_print(flags, fmt, ...) \
 	G_STMT_START { _VTE_DEBUG_IF(flags) g_printerr(fmt, ##__VA_ARGS__); } G_STMT_END
diff --git a/src/decoder-cat.cc b/src/decoder-cat.cc
index 79fda186..5d6e943f 100644
--- a/src/decoder-cat.cc
+++ b/src/decoder-cat.cc
@@ -36,7 +36,7 @@
 #include "libc-glue.hh"
 #include "utf8.hh"
 
-#ifdef WITH_ICU
+#if WITH_ICU
 #include "icu-decoder.hh"
 #include "icu-glue.hh"
 #endif
@@ -214,7 +214,7 @@ public:
 
 }; // class Sink
 
-#ifdef WITH_ICU
+#if WITH_ICU
 
 static std::unique_ptr<vte::base::ICUDecoder>
 make_decoder(Options const& options)
@@ -320,7 +320,7 @@ private:
                 g_free(buf);
         }
 
-#ifdef WITH_ICU
+#if WITH_ICU
         template<class Functor>
         void
         process_file_icu(int fd,
@@ -394,7 +394,7 @@ private:
                      Options const& options,
                      Functor& func)
         {
-#ifdef WITH_ICU
+#if WITH_ICU
                 auto decoder = std::unique_ptr<vte::base::ICUDecoder>{};
                 if (options.charset()) {
                         decoder = make_decoder(options);
@@ -412,7 +412,7 @@ private:
                                 return false;
                         }
 
-#ifdef WITH_ICU
+#if WITH_ICU
                         if (decoder) {
                                 process_file_icu(fd, options, decoder.get(), func);
                         } else
@@ -528,7 +528,7 @@ main(int argc,
         }
 
         if (options.list()) {
-#ifdef WITH_ICU
+#if WITH_ICU
                 auto charsets = vte::base::get_icu_charsets(true);
                 for (auto i = 0; charsets[i]; ++i)
                         g_print("%s\n", charsets[i]);
diff --git a/src/fonts-pangocairo.cc b/src/fonts-pangocairo.cc
index 91ed62f3..803a9438 100644
--- a/src/fonts-pangocairo.cc
+++ b/src/fonts-pangocairo.cc
@@ -157,13 +157,13 @@ FontInfo::cache_ascii()
 		ufi->using_cairo_glyph.scaled_font = cairo_scaled_font_reference (scaled_font);
 		ufi->using_cairo_glyph.glyph_index = glyph;
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 		m_coverage_count[0]++;
 		m_coverage_count[(unsigned)uinfo->coverage()]++;
 #endif
 	}
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 	_vte_debug_print (VTE_DEBUG_PANGOCAIRO,
 			  "vtepangocairo: %p cached %d ASCII letters\n",
 			  (void*)this, m_coverage_count[0]);
@@ -278,7 +278,7 @@ FontInfo::~FontInfo()
 	g_hash_table_remove(s_font_info_for_context,
                             pango_layout_get_context(m_layout.get()));
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 	_vte_debug_print (VTE_DEBUG_PANGOCAIRO,
 			  "vtepangocairo: %p freeing font_info.  coverages %d = %d + %d + %d\n",
 			  (void*)this,
@@ -534,7 +534,7 @@ FontInfo::get_unistr_info(vteunistr c)
 	/* release internal layout resources */
 	pango_layout_set_text(m_layout.get(), "", -1);
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 	m_coverage_count[0]++;
 	m_coverage_count[uinfo->m_coverage]++;
 #endif
diff --git a/src/fonts-pangocairo.hh b/src/fonts-pangocairo.hh
index 587e6421..da5faa2e 100644
--- a/src/fonts-pangocairo.hh
+++ b/src/fonts-pangocairo.hh
@@ -261,7 +261,7 @@ private:
         // FIXME: use std::string
 	GString* m_string{nullptr};
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 	/* profiling info */
 	int m_coverage_count[4]{0, 0, 0, 0};
 #endif
diff --git a/src/glib-glue.cc b/src/glib-glue.cc
index e4903f3b..190c879b 100644
--- a/src/glib-glue.cc
+++ b/src/glib-glue.cc
@@ -56,7 +56,7 @@ exception_append_to_string(std::exception const& e,
         }
 }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 
 void log_exception(char const* func,
                    char const* filename,
@@ -123,7 +123,7 @@ catch (...)
 namespace glib {
 
 bool set_error_from_exception(GError** error
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
                               , char const* func
                               , char const* filename
                               , int const line
@@ -143,7 +143,7 @@ try
                 what = "Unknown exception"sv;
         }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         auto msg = vte::glib::take_string(g_strdup_printf("Caught exception in %s [%s:%d]: %s",
                                                           func, filename, line,
                                                           what.c_str()));
@@ -163,7 +163,7 @@ try
 catch (...)
 {
         vte::log_exception();
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         g_set_error(error,
                     VTE_EXCEPTION_ERROR,
                     VTE_EXCEPTION_GENERIC,
diff --git a/src/glib-glue.hh b/src/glib-glue.hh
index b3a97858..1897b5cb 100644
--- a/src/glib-glue.hh
+++ b/src/glib-glue.hh
@@ -133,7 +133,7 @@ public:
         Timer(callback_type callback,
               char const* name)
                 : m_callback(callback)
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
                 , m_name(name)
 #endif
         {
@@ -208,7 +208,7 @@ public:
 
 private:
         callback_type m_callback{};
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         char const* m_name{nullptr};
 #endif
         guint m_source_id{0};
@@ -241,7 +241,7 @@ private:
 
         inline void set_source_name() const noexcept
         {
-                #ifdef VTE_DEBUG
+                #if VTE_DEBUG
                 g_source_set_name_by_id(m_source_id, m_name);
                 #endif
         }
@@ -267,7 +267,7 @@ private:
 };
 
 bool set_error_from_exception(GError** error
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
                               , char const* func = __builtin_FUNCTION()
                               , char const* filename = __builtin_FILE()
                               , int const line = __builtin_LINE()
diff --git a/src/keymap.cc b/src/keymap.cc
index 6c82d96a..00fad07a 100644
--- a/src/keymap.cc
+++ b/src/keymap.cc
@@ -29,7 +29,7 @@
 #include "debug.h"
 #include "keymap.h"
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 static void
 _vte_keysym_print(guint keyval,
                   guint modifiers)
diff --git a/src/missing.cc b/src/missing.cc
index ebaba4e1..c769fb40 100644
--- a/src/missing.cc
+++ b/src/missing.cc
@@ -44,7 +44,7 @@
  * Copyright 2000 Red Hat, Inc.
  */
 
-#ifndef HAVE_FDWALK
+#if !HAVE_FDWALK
 
 #ifdef __linux__
 
@@ -140,7 +140,7 @@ getrlimit_NOFILE_max(void)
         return RLIM_INFINITY;
 }
 
-#ifndef HAVE_CLOSE_RANGE
+#if !HAVE_CLOSE_RANGE
 
 int
 close_range(unsigned int first_fd,
@@ -257,7 +257,7 @@ fdwalk(int (*cb)(void *data, int fd),
 }
 #endif /* !HAVE_FDWALK */
 
-#ifndef HAVE_STRCHRNUL
+#if !HAVE_STRCHRNUL
 /* Copied from glib */
 char*
 strchrnul(char const* s,
diff --git a/src/missing.hh b/src/missing.hh
index 0d92f4c7..9dd4c4b1 100644
--- a/src/missing.hh
+++ b/src/missing.hh
@@ -43,17 +43,17 @@
 #define NSIG (8 * sizeof(sigset_t))
 #endif
 
-#ifndef HAVE_FDWALK
+#if !HAVE_FDWALK
 int fdwalk(int (*cb)(void* data, int fd),
            void* data);
 #endif
 
-#ifndef HAVE_STRCHRNUL
+#if !HAVE_STRCHRNUL
 char* strchrnul(char const* s,
                 int c);
 #endif
 
-#ifndef HAVE_CLOSE_RANGE
+#if !HAVE_CLOSE_RANGE
 int close_range(unsigned int first,
                 unsigned int last,
                 unsigned int flags);
diff --git a/src/parser-cat.cc b/src/parser-cat.cc
index 5fade9db..973ecdd2 100644
--- a/src/parser-cat.cc
+++ b/src/parser-cat.cc
@@ -40,7 +40,7 @@
 #include "utf8.hh"
 #include "vtedefines.hh"
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 #include "sixel-parser.hh"
 #endif
 
@@ -58,7 +58,7 @@ enum class DataSyntax {
         ECMA48_UTF8,
         /* ECMA48_PCTERM, */
         /* ECMA48_ECMA35, */
-        #ifdef WITH_SIXEL
+        #if WITH_SIXEL
         DECSIXEL,
         #endif
 };
@@ -154,7 +154,7 @@ private:
         std::string m_str;
         bool m_plain;
         bool m_codepoints;
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         char32_t m_sixel_st;
 #endif
 
@@ -389,7 +389,7 @@ private:
                 }
         }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
         void
         print_params(vte::sixel::Sequence const& seq) noexcept
@@ -463,7 +463,7 @@ public:
                         printout();
         }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
         void SIXEL_CMD(vte::sixel::Sequence const& seq) noexcept
         {
@@ -494,7 +494,7 @@ public:
         void enter_data_syntax(DataSyntax syntax) noexcept
         {
                 switch (syntax) {
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 case DataSyntax::DECSIXEL: {
                         GreenAttr green(this);
                         print_literal("<SIXEL[");
@@ -511,7 +511,7 @@ public:
                                bool success) noexcept
         {
                 switch (syntax) {
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 case DataSyntax::DECSIXEL:
                         if (success) {
                                 GreenAttr green(this);
@@ -718,7 +718,7 @@ private:
                 }
         }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         char32_t m_sixel_st{0};
         bool m_seen_sixel_commands{false};
         bool m_seen_sixel_data{false};
@@ -753,7 +753,7 @@ public:
                         check_sgr(seq);
                         break;
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 case VTE_CMD_DECSIXEL:
                         /* OR mode is a nonstandard NetBSD/x68k extension that is
                          * not supported in VTE.
@@ -776,7 +776,7 @@ public:
                 }
         }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
         void SIXEL(uint8_t raw) noexcept
         {
@@ -894,7 +894,7 @@ public:
         void enter_data_syntax(DataSyntax syntax) noexcept
         {
                 switch (syntax) {
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 case DataSyntax::DECSIXEL:
                         m_sixel_st = 0;
                         m_seen_sixel_commands = m_seen_sixel_data = false;
@@ -922,7 +922,7 @@ class Sink {
 public:
         void VT(vte::parser::Sequence const& seq) noexcept { }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         void SIXEL(uint8_t raw) noexcept { }
         void SIXEL_CMD(vte::sixel::Sequence const& seq) noexcept { }
         void SIXEL_ST(char32_t st) noexcept { }
@@ -956,7 +956,7 @@ private:
         vte::base::UTF8Decoder m_utf8_decoder{};
         vte::parser::Parser m_parser{};
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         vte::sixel::Parser m_sixel_parser{};
 #endif
 
@@ -971,7 +971,7 @@ private:
                         m_utf8_decoder.reset();
                         break;
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 case DataSyntax::DECSIXEL:
                         m_sixel_parser.reset();
                         break;
@@ -995,7 +995,7 @@ private:
         {
                 m_delegate.VT(seq);
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 if (G_UNLIKELY(!m_no_sixel &&
                                seq.command() == VTE_CMD_DECSIXEL &&
                                seq.is_unripe())) {
@@ -1070,7 +1070,7 @@ private:
                 return bufend;
         }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
         uint8_t const*
         process_data_decsixel(uint8_t const* const bufstart,
@@ -1124,7 +1124,7 @@ private:
                                         sptr = process_data_utf8(sptr, bufend, eos);
                                         break;
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                                 case DataSyntax::DECSIXEL:
                                         sptr = process_data_decsixel(sptr, bufend, eos);
                                         break;
@@ -1192,7 +1192,7 @@ public:
                 memset(&m_cmd_stats, 0, sizeof(m_cmd_stats));
                 m_bench_times = g_array_new(false, true, sizeof(int64_t));
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 m_parser.set_dispatch_unripe(!m_no_sixel);
 #endif
         }
@@ -1345,7 +1345,7 @@ public:
                           "Output unicode code points by number", nullptr },
                         { "lint", 'l', 0, G_OPTION_ARG_NONE, &lint,
                           "Check input", nullptr },
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                         { "no-sixel", 0, 0, G_OPTION_ARG_NONE, &no_sixel,
                           "Disable DECSIXEL processing", nullptr },
 #endif
diff --git a/src/pty.cc b/src/pty.cc
index 52d21fb7..9075719a 100644
--- a/src/pty.cc
+++ b/src/pty.cc
@@ -280,7 +280,7 @@ Pty::set_size(int rows,
 	memset(&size, 0, sizeof(size));
 	size.ws_row = rows > 0 ? rows : 24;
 	size.ws_col = columns > 0 ? columns : 80;
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         size.ws_ypixel = size.ws_row * cell_height_px;
         size.ws_xpixel = size.ws_col * cell_width_px;
 #endif
diff --git a/src/reflect.c b/src/reflect.c
index d51ae1f6..83e21ca2 100644
--- a/src/reflect.c
+++ b/src/reflect.c
@@ -150,7 +150,7 @@ text_changed_insert(AtkObject *obj, gint offset, gint length, gpointer data)
 		p = g_utf8_next_char(p);
 	}
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 	if ((getenv("REFLECT_VERBOSE") != NULL) &&
 	    (atol(getenv("REFLECT_VERBOSE")) != 0)) {
 		g_printerr("Inserted %d chars ('%.*s') at %d,",
@@ -176,7 +176,7 @@ text_changed_delete(AtkObject *obj, gint offset, gint length, gpointer data)
 		}
 		g_array_remove_index(contents, i);
 	}
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 	if ((getenv("REFLECT_VERBOSE") != NULL) &&
 	    (atol(getenv("REFLECT_VERBOSE")) != 0)) {
 		g_printerr("Deleted %d chars at %d.\n", length, offset);
diff --git a/src/ring.cc b/src/ring.cc
index 23d79600..cf24dd71 100644
--- a/src/ring.cc
+++ b/src/ring.cc
@@ -25,7 +25,7 @@
 
 #include <string.h>
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
 #include "cxx-utils.hh"
 
@@ -54,7 +54,7 @@ using namespace vte::base;
  * VteRing: A buffer ring
  */
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 void
 Ring::validate() const
 {
@@ -204,7 +204,7 @@ Ring::hyperlink_maybe_gc(row_t increment)
                 hyperlink_gc();
 }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
 void
 Ring::image_gc_region() noexcept
@@ -713,7 +713,7 @@ Ring::reset()
         m_start = m_writable = m_end;
         m_cached_row_num = (row_t)-1;
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         m_image_by_top_map.clear();
         m_image_map.clear();
         m_next_image_priority = 0;
@@ -1303,7 +1303,7 @@ Ring::rewrap(column_t columns,
 	gsize paragraph_len;  /* excluding trailing '\n' */
 	gsize attr_offset;
 	gsize old_ring_end;
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 	auto image_it = m_image_by_top_map.begin();
 #endif
 
@@ -1441,7 +1441,7 @@ Ring::rewrap(column_t columns,
 							}
 						}
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 						if (!rewrap_images_in_range(image_it,
                                                                             new_record.text_start_offset,
                                                                             text_offset,
@@ -1498,7 +1498,7 @@ Ring::rewrap(column_t columns,
 			}
 		}
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 		if (!rewrap_images_in_range(image_it,
                                             new_record.text_start_offset,
                                             paragraph_end_text_offset,
@@ -1538,7 +1538,7 @@ Ring::rewrap(column_t columns,
 	g_free(marker_text_offsets);
 	g_free(new_markers);
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         try {
                 rebuild_image_top_map();
         } catch (...) {
@@ -1551,7 +1551,7 @@ Ring::rewrap(column_t columns,
 	return;
 
 err:
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 	_vte_debug_print(VTE_DEBUG_RING,
 			"Error while rewrapping\n");
 	g_assert_not_reached();
@@ -1650,7 +1650,7 @@ Ring::write_contents(GOutputStream* stream,
 	return true;
 }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
 /**
  * Ring::append_image:
diff --git a/src/ring.hh b/src/ring.hh
index 54223904..2db7fec5 100644
--- a/src/ring.hh
+++ b/src/ring.hh
@@ -27,7 +27,7 @@
 #include "vterowdata.hh"
 #include "vtestream.h"
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 #include "cairo-glue.hh"
 #include "image.hh"
 #include <map>
@@ -108,7 +108,7 @@ public:
 
 private:
 
-        #ifdef VTE_DEBUG
+        #if VTE_DEBUG
         void validate() const;
         #endif
 
@@ -235,7 +235,7 @@ private:
                                                  An idx is allocated on hover even if the cell is scrolled out to the streams. */
         row_t m_hyperlink_maybe_gc_counter{0};  /* Do a GC when it reaches 65536. */
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
 private:
         size_t m_next_image_priority{0};
diff --git a/src/sixel-context.cc b/src/sixel-context.cc
index 20238ac6..aea5b990 100644
--- a/src/sixel-context.cc
+++ b/src/sixel-context.cc
@@ -23,7 +23,7 @@
 #include <cmath>
 #include <cstdint>
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 #include "debug.h"
 #include "libc-glue.hh"
 #endif
@@ -473,7 +473,7 @@ Context::image_cairo() noexcept
                                                                               image_height(),
                                                                               stride));
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         _VTE_DEBUG_IF(VTE_DEBUG_IMAGE) {
                 static auto num = 0;
 
diff --git a/src/spawn.cc b/src/spawn.cc
index e231105c..e3052448 100644
--- a/src/spawn.cc
+++ b/src/spawn.cc
@@ -39,7 +39,7 @@
 
 #include "glib-glue.hh"
 
-#ifdef WITH_SYSTEMD
+#if WITH_SYSTEMD
 #include "systemd.hh"
 #endif
 
@@ -529,7 +529,7 @@ SpawnOperation::~SpawnOperation()
 bool
 SpawnOperation::prepare(vte::glib::Error& error)
 {
-#ifndef WITH_SYSTEMD
+#if !WITH_SYSTEMD
         if (context().require_systemd_scope()) {
                 error.set_literal(G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
                                   "systemd not available");
@@ -713,7 +713,7 @@ SpawnOperation::run(vte::glib::Error& error) noexcept
 
         /* Spawn succeeded */
 
-#ifdef WITH_SYSTEMD
+#if WITH_SYSTEMD
         if (context().systemd_scope() &&
             !vte::systemd::create_scope_for_pid_sync(m_pid,
                                                      m_timeout, // FIXME: recalc timeout
diff --git a/src/vte.cc b/src/vte.cc
index e047db61..9f331a38 100644
--- a/src/vte.cc
+++ b/src/vte.cc
@@ -78,11 +78,9 @@
 #include "cxx-utils.hh"
 #include "gobject-glue.hh"
 
-#ifdef WITH_A11Y
+#if WITH_A11Y
 #if VTE_GTK == 3
 #include "vteaccess.h"
-#else
-#undef WITH_A11Y
 #endif /* VTE_GTK == 3 */
 #endif /* WITH_A11Y */
 
@@ -90,7 +88,7 @@
 
 using namespace std::literals;
 
-#ifndef HAVE_ROUND
+#if !HAVE_ROUND
 static inline double round(double x) {
 	if(x - floor(x) < 0.5) {
 		return floor(x);
@@ -98,7 +96,7 @@ static inline double round(double x) {
 		return ceil(x);
 	}
 }
-#endif
+#endif /* !HAVE_ROUND */
 
 #define WORD_CHAR_EXCEPTIONS_DEFAULT "-#%&+,./=?@\\_~\302\267"sv
 
@@ -274,7 +272,7 @@ vte_g_array_fill(GArray *array, gconstpointer item, guint final_size)
 void
 Terminal::unset_widget() noexcept
 {
-#ifdef WITH_A11Y
+#if WITH_A11Y && VTE_GTK == 3
         set_accessible(nullptr);
 #endif
 
@@ -2146,7 +2144,7 @@ Terminal::set_encoding(char const* charset,
         auto const to_utf8 = bool{charset == nullptr || g_ascii_strcasecmp(charset, "UTF-8") == 0};
         auto const primary_is_current = (current_data_syntax() == primary_data_syntax());
 
-#ifdef WITH_ICU
+#if WITH_ICU
         /* Note that if the current data syntax is not a primary one, the change
          * will only be applied when returning to the primrary data syntax.
          */
@@ -3149,7 +3147,7 @@ not_inserted:
         m_line_wrapped = line_wrapped;
 }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
 void
 Terminal::insert_image(ProcessingContext& context,
@@ -3543,13 +3541,13 @@ Terminal::process_incoming()
                         process_incoming_utf8(context, *chunk);
                         break;
 
-#ifdef WITH_ICU
+#if WITH_ICU
                 case DataSyntax::ECMA48_PCTERM:
                         process_incoming_pcterm(context, *chunk);
                         break;
 #endif
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 case DataSyntax::DECSIXEL:
                         process_incoming_decsixel(context, *chunk);
                         break;
@@ -3571,7 +3569,7 @@ Terminal::process_incoming()
                         m_incoming_queue.pop();
         }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         /* Some safety checks: ensure the visible parts of the buffer
          * are all in the buffer. */
         g_assert_cmpint(m_screen->insert_delta, >=, _vte_ring_delta(m_screen->row_data));
@@ -3672,18 +3670,18 @@ Terminal::process_incoming_utf8(ProcessingContext& context,
                 case vte::base::UTF8Decoder::ACCEPT: {
                         auto rv = m_parser.feed(m_utf8_decoder.codepoint());
                         if (G_UNLIKELY(rv < 0)) {
-#ifdef DEBUG
+#if VTE_DEBUG
                                 uint32_t c = m_utf8_decoder.codepoint();
                                 char c_buf[7];
                                 g_snprintf(c_buf, sizeof(c_buf), "%lc", c);
                                 char const* wp_str = g_unichar_isprint(c) ? c_buf : _vte_debug_sequence_to_string(c_buf, -1);
                                 _vte_debug_print(VTE_DEBUG_PARSER, "Parser error on U+%04X [%s]!\n",
                                                  c, wp_str);
-#endif
+#endif /* VTE_DEBUG */
                                 break;
                         }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
                         if (rv != VTE_SEQ_NONE)
                                 g_assert((bool)seq);
 #endif
@@ -3764,7 +3762,7 @@ switched_data_syntax:
         chunk.set_begin_reading(ip);
 }
 
-#ifdef WITH_ICU
+#if WITH_ICU
 
 /* Note that this is mostly a copy of process_incoming_utf8() above; any non-charset-decoding
  * related changes made here need to be made there, too.
@@ -3789,7 +3787,7 @@ Terminal::process_incoming_pcterm(ProcessingContext& context,
                 case vte::base::ICUDecoder::Result::eSomething: {
                         auto rv = m_parser.feed(decoder.codepoint());
                         if (G_UNLIKELY(rv < 0)) {
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
                                 uint32_t c = decoder.codepoint();
                                 char c_buf[7];
                                 g_snprintf(c_buf, sizeof(c_buf), "%lc", c);
@@ -3800,7 +3798,7 @@ Terminal::process_incoming_pcterm(ProcessingContext& context,
                                 break;
                         }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
                         if (rv != VTE_SEQ_NONE)
                                 g_assert((bool)seq);
 #endif
@@ -3897,7 +3895,7 @@ Terminal::process_incoming_pcterm(ProcessingContext& context,
 
 #endif /* WITH_ICU */
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 
 void
 Terminal::process_incoming_decsixel(ProcessingContext& context,
@@ -4272,7 +4270,7 @@ Terminal::send_child(std::string_view const& data)
                         _vte_byte_array_append(m_outgoing, data.data(), data.size());
                 break;
 
-#ifdef WITH_ICU
+#if WITH_ICU
         case DataSyntax::ECMA48_PCTERM: {
                 auto converted = m_converter->convert(data);
 
@@ -6285,7 +6283,7 @@ Terminal::get_selected_text(GArray *attributes)
                         attributes);
 }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 unsigned int
 Terminal::checksum_area(vte::grid::row_t start_row,
                                   vte::grid::column_t start_col,
@@ -7773,7 +7771,7 @@ Terminal::Terminal(vte::platform::Widget* w,
 
         update_view_extents();
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         if (g_test_flags != 0) {
                 feed("\e[1m\e[31mWARNING:\e[39m Test mode enabled. This is insecure!\e[0m\n\e[G"sv, false);
         }
@@ -8302,7 +8300,7 @@ Terminal::draw_cells(vte::view::DrawingContext::TextRequest* items,
                                 }
                         }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                         if (back == VTE_DEFAULT_BG) {
                                 /* Clear cells in order to properly overdraw images */
                                 m_draw.clear(xl,
@@ -9299,7 +9297,7 @@ Terminal::paint_im_preedit_string()
 void
 Terminal::widget_draw(cairo_t* cr) noexcept
 {
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         _VTE_DEBUG_IF(VTE_DEBUG_LIFECYCLE | VTE_DEBUG_WORK | VTE_DEBUG_UPDATES) do {
                 auto clip_rect = cairo_rectangle_int_t{};
                 if (!gdk_cairo_get_clip_rectangle (cr, &clip_rect))
@@ -9377,7 +9375,7 @@ Terminal::draw(cairo_t* cr,
         int allocated_width, allocated_height;
         int extra_area_for_cursor;
         bool text_blink_enabled_now;
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         VteRing *ring = m_screen->row_data;
 #endif
         gint64 now = 0;
@@ -9422,7 +9420,7 @@ Terminal::draw(cairo_t* cr,
                         allocated_height - m_border.top - m_border.bottom);
         cairo_clip(cr);
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 	/* Draw images */
 	if (m_images_enabled) {
 		vte::grid::row_t top_row = first_displayed_row();
@@ -9995,7 +9993,7 @@ Terminal::reset_decoder()
                 m_utf8_decoder.reset();
                 break;
 
-#ifdef WITH_ICU
+#if WITH_ICU
         case DataSyntax::ECMA48_PCTERM:
                 m_converter->decoder().reset();
                 break;
@@ -10013,7 +10011,7 @@ Terminal::reset_data_syntax()
                 return;
 
         switch (current_data_syntax()) {
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         case DataSyntax::DECSIXEL:
                 m_sixel_context->reset();
                 break;
@@ -10029,7 +10027,7 @@ Terminal::reset_data_syntax()
 void
 Terminal::reset_graphics_color_registers()
 {
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         if (m_sixel_context)
                 m_sixel_context->reset_colors();
 #endif
@@ -10139,7 +10137,7 @@ Terminal::reset(bool clear_tabstops,
 	/* Clear modifiers. */
 	m_modifiers = 0;
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         if (m_sixel_context)
                 m_sixel_context->reset_colors();
 #endif
diff --git a/src/vtegtk.cc b/src/vtegtk.cc
index fa7856d9..a461129c 100644
--- a/src/vtegtk.cc
+++ b/src/vtegtk.cc
@@ -64,15 +64,13 @@
 
 #include <cairo-gobject.h>
 
-#ifdef WITH_A11Y
+#if WITH_A11Y
 #if VTE_GTK == 3
 #include "vteaccess.h"
-#else
-#undef WITH_A11Y
 #endif /* VTE_GTK == 3 */
 #endif /* WITH_A11Y */
 
-#ifdef WITH_ICU
+#if WITH_ICU
 #include "icu-glue.hh"
 #endif
 
@@ -157,7 +155,7 @@ private:
         std::shared_ptr<vte::platform::Widget> m_widget;
 };
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 G_DEFINE_TYPE_WITH_CODE(VteTerminal, vte_terminal, GTK_TYPE_WIDGET,
                         {
                                 VteTerminal_private_offset =
@@ -1217,7 +1215,7 @@ catch (...)
 static void
 vte_terminal_class_init(VteTerminalClass *klass)
 {
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 	{
                 _vte_debug_init();
 		_vte_debug_print(VTE_DEBUG_LIFECYCLE,
@@ -2148,7 +2146,7 @@ vte_terminal_class_init(VteTerminalClass *klass)
          */
         pspecs[PROP_ENABLE_SIXEL] =
                 g_param_spec_boolean ("enable-sixel", nullptr, nullptr,
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                                       VTE_SIXEL_ENABLED_DEFAULT,
 #else
                                       false,
@@ -2506,7 +2504,7 @@ vte_terminal_class_init(VteTerminalClass *klass)
 #endif
 
 #if VTE_GTK == 3
-#ifdef WITH_A11Y
+#if WITH_A11Y
         /* a11y */
         gtk_widget_class_set_accessible_type(widget_class, VTE_TYPE_TERMINAL_ACCESSIBLE);
 #endif
@@ -2528,32 +2526,32 @@ const char *
 vte_get_features (void) noexcept
 {
         return
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
                 "+BIDI"
 #else
                 "-BIDI"
 #endif
                 " "
-#ifdef WITH_GNUTLS
+#if WITH_GNUTLS
                 "+GNUTLS"
 #else
                 "-GNUTLS"
 #endif
                 " "
-#ifdef WITH_ICU
+#if WITH_ICU
                 "+ICU"
 #else
                 "-ICU"
 #endif
                 " "
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 "+SIXEL"
 #else
                 "-SIXEL"
 #endif
 #ifdef __linux__
                 " "
-#ifdef WITH_SYSTEMD
+#if WITH_SYSTEMD
                 "+SYSTEMD"
 #else
                 "-SYSTEMD"
@@ -2575,17 +2573,17 @@ VteFeatureFlags
 vte_get_feature_flags(void) noexcept
 {
         return VteFeatureFlags(0ULL |
-#ifdef WITH_FRIBIDI
+#if WITH_FRIBIDI
                                VTE_FEATURE_FLAG_BIDI |
 #endif
-#ifdef WITH_ICU
+#if WITH_ICU
                                VTE_FEATURE_FLAG_ICU |
 #endif
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                                VTE_FEATURE_FLAG_SIXEL |
 #endif
 #ifdef __linux__
-#ifdef WITH_SYSTEMD
+#if WITH_SYSTEMD
                                VTE_FEATURE_FLAG_SYSTEMD |
 #endif
 #endif // __linux__
@@ -2679,7 +2677,7 @@ vte_get_user_shell (void) noexcept
 void
 vte_set_test_flags(guint64 flags) noexcept
 {
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         g_test_flags = flags;
 #endif
 }
@@ -2704,7 +2702,7 @@ char **
 vte_get_encodings(gboolean include_aliases) noexcept
 try
 {
-#ifdef WITH_ICU
+#if WITH_ICU
         return vte::base::get_icu_charsets(include_aliases != FALSE);
 #else
         char *empty[] = { nullptr };
@@ -2741,7 +2739,7 @@ try
 {
         g_return_val_if_fail(encoding != nullptr, false);
 
-#ifdef WITH_ICU
+#if WITH_ICU
         return vte::base::get_icu_charset_supported(encoding);
 #else
         return false;
@@ -4313,7 +4311,7 @@ warn_if_callback(VteSelectionFunc func,
         if (!func)
                 return;
 
-#ifndef VTE_DEBUG
+#if !VTE_DEBUG
         static gboolean warned = FALSE;
         if (warned)
                 return;
@@ -4335,7 +4333,7 @@ warn_if_attributes(void* array,
         if (!array)
                 return;
 
-#ifndef VTE_DEBUG
+#if !VTE_DEBUG
         static gboolean warned = FALSE;
         if (warned)
                 return;
@@ -6654,7 +6652,7 @@ vte_terminal_set_enable_sixel(VteTerminal *terminal,
                               gboolean enabled) noexcept
 try
 {
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         g_return_if_fail(VTE_IS_TERMINAL(terminal));
 
         if (WIDGET(terminal)->set_sixel_enabled(enabled != FALSE))
@@ -6678,7 +6676,7 @@ gboolean
 vte_terminal_get_enable_sixel(VteTerminal *terminal) noexcept
 try
 {
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         g_return_val_if_fail(VTE_IS_TERMINAL(terminal), FALSE);
 
         return WIDGET(terminal)->sixel_enabled();
diff --git a/src/vteinternal.hh b/src/vteinternal.hh
index b9f77891..6c27e767 100644
--- a/src/vteinternal.hh
+++ b/src/vteinternal.hh
@@ -63,19 +63,18 @@
 #include <variant>
 #include <vector>
 
-#ifdef WITH_A11Y
+#if WITH_A11Y
 #if VTE_GTK == 3
 #include "vteaccess.h"
 #else
-#undef WITH_A11Y
 #endif
 #endif
 
-#ifdef WITH_ICU
+#if WITH_ICU
 #include "icu-converter.hh"
 #endif
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
 #include "sixel-context.hh"
 #endif
 
@@ -265,7 +264,7 @@ public:
 
         void unset_widget() noexcept;
 
-#ifdef WITH_A11Y
+#if WITH_A11Y && VTE_GTK == 3
         /* Accessible */
         vte::glib::RefPtr<VteTerminalAccessible> m_accessible{};
 #endif
@@ -314,13 +313,13 @@ public:
         enum class DataSyntax {
                 /* The primary data syntax is always one of the following: */
                 ECMA48_UTF8,
-                #ifdef WITH_ICU
+                #if WITH_ICU
                 ECMA48_PCTERM,
                 #endif
                 /* ECMA48_ECMA35, not supported */
 
                 /* The following can never be primary data syntax: */
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                 DECSIXEL,
 #endif
         };
@@ -367,7 +366,7 @@ public:
 	/* Output data queue. */
         VteByteArray *m_outgoing; /* pending input characters */
 
-#ifdef WITH_ICU
+#if WITH_ICU
         /* Legacy charset support */
         std::unique_ptr<vte::base::ICUConverter> m_converter;
 #endif /* WITH_ICU */
@@ -376,14 +375,14 @@ public:
         {
                 switch (primary_data_syntax()) {
                 case DataSyntax::ECMA48_UTF8:   return "UTF-8";
-                #ifdef WITH_ICU
+                #if WITH_ICU
                 case DataSyntax::ECMA48_PCTERM: return m_converter->charset().c_str();
                 #endif
                 default: g_assert_not_reached(); return nullptr;
                 }
         }
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         std::unique_ptr<vte::sixel::Context> m_sixel_context{};
 #endif
 
@@ -807,7 +806,7 @@ public:
                          bool insert,
                          bool invalidate_now);
 
-        #ifdef WITH_SIXEL
+        #if WITH_SIXEL
         void insert_image(ProcessingContext& context,
                           vte::Freeable<cairo_surface_t> image_surface) /* throws */;
         #endif
@@ -833,11 +832,11 @@ public:
         void process_incoming();
         void process_incoming_utf8(ProcessingContext& context,
                                    vte::base::Chunk& chunk);
-        #ifdef WITH_ICU
+        #if WITH_ICU
         void process_incoming_pcterm(ProcessingContext& context,
                                      vte::base::Chunk& chunk);
         #endif
-        #ifdef WITH_SIXEL
+        #if WITH_SIXEL
         void process_incoming_decsixel(ProcessingContext& context,
                                        vte::base::Chunk& chunk);
         #endif
@@ -1168,7 +1167,7 @@ public:
         void queue_child_exited();
         void queue_eof();
 
-#ifdef WITH_A11Y
+#if WITH_A11Y && VTE_GTK == 3
 
         void set_accessible(VteTerminalAccessible* accessible) noexcept
         {
@@ -1211,7 +1210,7 @@ public:
         inline constexpr void emit_text_modified() const noexcept { }
         inline constexpr void emit_text_scrolled(long delta) const noexcept { }
 
-#endif /* WITH_A11Y */
+#endif /* WITH_A11Y && VTE_GTK == 3*/
 
         void emit_pending_signals();
         void emit_increase_font_size();
diff --git a/src/vteseq.cc b/src/vteseq.cc
index 55315da6..768615f7 100644
--- a/src/vteseq.cc
+++ b/src/vteseq.cc
@@ -72,7 +72,7 @@ enum {
 void
 vte::parser::Sequence::print() const noexcept
 {
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         auto c = m_seq != nullptr ? terminator() : 0;
         char c_buf[7];
         g_snprintf(c_buf, sizeof(c_buf), "%lc", c);
@@ -2403,7 +2403,7 @@ Terminal::DA1(vte::parser::Sequence const& seq)
                 return;
 
         reply(seq, VTE_REPLY_DECDA1R, {65, 1,
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
                                        m_sixel_enabled ? 4 : -2 /* skip */,
 #endif
                                        9});
@@ -3541,7 +3541,7 @@ Terminal::DECRQCRA(vte::parser::Sequence const& seq)
         unsigned int idx = 0;
         int id = seq.collect1(idx);
 
-#ifndef VTE_DEBUG
+#if !VTE_DEBUG
         /* Send a dummy reply */
         return reply(seq, VTE_REPLY_DECCKSR, {id}, "0000");
 #else
@@ -4410,7 +4410,7 @@ Terminal::DECSIXEL(vte::parser::Sequence const& seq)
          *             DEC PPLV2 § 5.4
          */
 
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         auto process_sixel = false;
         auto mode = vte::sixel::Parser::Mode{};
         if (m_sixel_enabled) {
@@ -4420,7 +4420,7 @@ Terminal::DECSIXEL(vte::parser::Sequence const& seq)
                         mode = vte::sixel::Parser::Mode::UTF8;
                         break;
 
-#ifdef WITH_ICU
+#if WITH_ICU
                 case DataSyntax::ECMA48_PCTERM:
                         /* It's not really clear how DECSIXEL should be processed in PCTERM mode.
                          * The DEC documentation available isn't very detailed on PCTERM mode,
@@ -8936,7 +8936,7 @@ Terminal::XTERM_SMGRAPHICS(vte::parser::Sequence const& seq)
         auto status = 3, rv0 = -2, rv1 = -2;
 
         switch (attr) {
-#ifdef WITH_SIXEL
+#if WITH_SIXEL
         case 0: /* Colour registers.
                  *
                  * VTE doesn't support changing the number of colour registers, so always
diff --git a/src/vtestream-file.h b/src/vtestream-file.h
index 1ab68fd5..d9b433be 100644
--- a/src/vtestream-file.h
+++ b/src/vtestream-file.h
@@ -83,16 +83,18 @@
 #include <unistd.h>
 #include <zlib.h>
 
-#ifdef WITH_GNUTLS
+#include "vteutils.h"
+
+#if WITH_GNUTLS
 # include <gnutls/gnutls.h>
 # include <gnutls/crypto.h>
+#else
+#undef WITH_GNUTLS
 #endif
 
-#include "vteutils.h"
-
 G_BEGIN_DECLS
 
-#ifdef WITH_GNUTLS
+#if WITH_GNUTLS
 /* Currently the code requires that a stream cipher (e.g. GCM) is used
  * which can encrypt any amount of data without need for padding. */
 # define VTE_CIPHER_ALGORITHM    GNUTLS_CIPHER_AES_256_GCM
@@ -126,11 +128,11 @@ typedef guint8 _vte_overwrite_counter_t;
 
 /******************************************************************************************/
 
-#ifndef HAVE_EXPLICIT_BZERO
+#if !HAVE_EXPLICIT_BZERO
 #define explicit_bzero(s, n) memset((s), 0, (n))
 #endif
 
-#ifndef HAVE_PREAD
+#if !HAVE_PREAD
 #define pread _pread
 static inline gsize
 pread (int fd, char *data, gsize len, gsize offset)
@@ -141,7 +143,7 @@ pread (int fd, char *data, gsize len, gsize offset)
 }
 #endif
 
-#ifndef HAVE_PWRITE
+#if !HAVE_PWRITE
 #define pwrite _pwrite
 static inline gsize
 pwrite (int fd, char *data, gsize len, gsize offset)
diff --git a/src/vtetypes.cc b/src/vtetypes.cc
index f25cc0b6..eb5c3c70 100644
--- a/src/vtetypes.cc
+++ b/src/vtetypes.cc
@@ -76,7 +76,7 @@ vte::color::rgb::parse(char const* spec)
 	return retval;
 }
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 
 #define DEBUG_STRING_SIZE (256)
 #define DEBUG_STRING_SLICES (64)
@@ -204,7 +204,7 @@ test_grid_coords (void)
         g_assert_false(coords(42, 42) >= coords(43, 160));
         g_assert_false(coords(42, 42) >  coords(43, 160));
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         /* to_string() */
         g_assert_cmpstr(vte::grid::coords(17, 42).to_string(), ==, "grid[17,42]");
 #endif
@@ -257,7 +257,7 @@ test_grid_halfcoords (void)
         g_assert_false(d >  e);
         g_assert_false(d >= e);
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         /* to_string() */
         g_assert_cmpstr(halfcoords(16, 32, 0).to_string(), ==, "halfgrid[16,32L]");
         g_assert_cmpstr(halfcoords(16, 32, 1).to_string(), ==, "halfgrid[16,32R]");
@@ -363,7 +363,7 @@ test_grid_span (void)
         span s10(16, 16, 32, 1);
         g_assert_cmpint(s10.last_row(), ==, 32);
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         /* to_string() */
         g_assert_cmpstr(vte::grid::span(17, 42, 18, 3).to_string(), ==, "grid[(17,42), (18,3))");
 #endif
@@ -395,7 +395,7 @@ test_view_coords (void)
         g_assert_true(p3 == p4);
         g_assert_true(p5 == p2);
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
         /* to_string() */
         g_assert_cmpstr(vte::view::coords(256, 512).to_string(), ==, "view[256,512]");
 #endif
diff --git a/src/vtetypes.hh b/src/vtetypes.hh
index cf93b723..6083930c 100644
--- a/src/vtetypes.hh
+++ b/src/vtetypes.hh
@@ -25,7 +25,7 @@
 #include <cstdint>
 #include <memory>
 
-#ifdef VTE_DEBUG
+#if VTE_DEBUG
 #define IFDEF_DEBUG(str) str
 #else
 #define IFDEF_DEBUG(str)
diff --git a/src/widget.cc b/src/widget.cc
index 49e02049..84704275 100644
--- a/src/widget.cc
+++ b/src/widget.cc
@@ -758,7 +758,7 @@ Widget::direction_changed(GtkTextDirection old_direction) noexcept
 void
 Widget::dispose() noexcept
 {
-#ifdef WITH_A11Y
+#if WITH_A11Y && VTE_GTK == 3
         m_terminal->set_accessible(nullptr);
 #endif