From 305ccfe74676a371e3f69b560dbaf0b81a6a4094 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 21 Apr 2022 13:07:15 +0200
Subject: [PATCH] constant: Make const.allow_constexpr default to true.

---
 docs.md                                       |  2 +-
 src/bindgen/config.rs                         |  2 +-
 tests/expectations/assoc_const_conflict.cpp   |  2 +-
 tests/expectations/assoc_constant.cpp         |  4 +--
 tests/expectations/cfg_2.cpp                  |  4 +--
 tests/expectations/const_conflict.cpp         |  2 +-
 tests/expectations/const_transparent.cpp      |  2 +-
 tests/expectations/constant.cpp               | 34 +++++++++----------
 tests/expectations/constant_big.cpp           |  8 ++---
 tests/expectations/constant_constexpr.cpp     | 12 +++----
 tests/expectations/constant_sort_name.cpp     |  4 +--
 tests/expectations/constant_sort_none.cpp     |  4 +--
 .../constant_user_defined_type.cpp            |  6 ++--
 tests/expectations/enum_discriminant.cpp      |  2 +-
 tests/expectations/mod_2015.cpp               |  2 +-
 tests/expectations/mod_2018.cpp               |  2 +-
 tests/expectations/mod_attr.cpp               |  4 +--
 tests/expectations/mod_path.cpp               |  2 +-
 tests/expectations/namespace_constant.cpp     |  4 +--
 tests/expectations/namespaces_constant.cpp    |  4 +--
 tests/expectations/prefix.cpp                 |  6 ++--
 .../expectations/prefixed_struct_literal.cpp  |  4 +--
 .../prefixed_struct_literal_deep.cpp          |  2 +-
 tests/expectations/rename.cpp                 |  2 +-
 tests/expectations/struct_literal.cpp         |  8 ++---
 tests/expectations/struct_literal_order.cpp   | 12 +++----
 tests/expectations/transparent.cpp            |  6 ++--
 tests/expectations/workspace.cpp              |  2 +-
 tests/rust/constant_constexpr.toml            |  2 +-
 29 files changed, 75 insertions(+), 75 deletions(-)

diff --git a/docs.md b/docs.md
index e97e16f..9a434aa 100644
--- a/docs.md
+++ b/docs.md
@@ -913,7 +913,7 @@ allow_static_const = true
 
 # Whether a generated constant can be constexpr in C++ mode.
 #
-# default: false
+# default: true
 allow_constexpr = false
 
 # This rule specifies the order in which constants will be sorted.
diff --git a/src/bindgen/config.rs b/src/bindgen/config.rs
index d0dbf22..b4a0cb7 100644
--- a/src/bindgen/config.rs
+++ b/src/bindgen/config.rs
@@ -706,7 +706,7 @@ impl Default for ConstantConfig {
     fn default() -> ConstantConfig {
         ConstantConfig {
             allow_static_const: true,
-            allow_constexpr: false,
+            allow_constexpr: true,
             sort_by: None,
         }
     }
diff --git a/tests/expectations/assoc_const_conflict.cpp b/tests/expectations/assoc_const_conflict.cpp
index a342401..f031e27 100644
--- a/tests/expectations/assoc_const_conflict.cpp
+++ b/tests/expectations/assoc_const_conflict.cpp
@@ -4,4 +4,4 @@
 #include <ostream>
 #include <new>
 
-static const uint32_t Foo_FOO = 42;
+constexpr static const uint32_t Foo_FOO = 42;
diff --git a/tests/expectations/assoc_constant.cpp b/tests/expectations/assoc_constant.cpp
index 4a9f51b..07a0dbd 100644
--- a/tests/expectations/assoc_constant.cpp
+++ b/tests/expectations/assoc_constant.cpp
@@ -7,8 +7,8 @@
 struct Foo {
 
 };
-static const int32_t Foo_GA = 10;
-static const float Foo_ZO = 3.14;
+constexpr static const int32_t Foo_GA = 10;
+constexpr static const float Foo_ZO = 3.14;
 
 extern "C" {
 
diff --git a/tests/expectations/cfg_2.cpp b/tests/expectations/cfg_2.cpp
index cddb7a4..40aee48 100644
--- a/tests/expectations/cfg_2.cpp
+++ b/tests/expectations/cfg_2.cpp
@@ -11,11 +11,11 @@ DEF NOT_DEFINED = 0
 #include <new>
 
 #if defined(NOT_DEFINED)
-static const int32_t DEFAULT_X = 8;
+constexpr static const int32_t DEFAULT_X = 8;
 #endif
 
 #if defined(DEFINED)
-static const int32_t DEFAULT_X = 42;
+constexpr static const int32_t DEFAULT_X = 42;
 #endif
 
 #if (defined(NOT_DEFINED) || defined(DEFINED))
diff --git a/tests/expectations/const_conflict.cpp b/tests/expectations/const_conflict.cpp
index a342401..f031e27 100644
--- a/tests/expectations/const_conflict.cpp
+++ b/tests/expectations/const_conflict.cpp
@@ -4,4 +4,4 @@
 #include <ostream>
 #include <new>
 
-static const uint32_t Foo_FOO = 42;
+constexpr static const uint32_t Foo_FOO = 42;
diff --git a/tests/expectations/const_transparent.cpp b/tests/expectations/const_transparent.cpp
index d536dd9..920af50 100644
--- a/tests/expectations/const_transparent.cpp
+++ b/tests/expectations/const_transparent.cpp
@@ -6,4 +6,4 @@
 
 using Transparent = uint8_t;
 
-static const Transparent FOO = 0;
+constexpr static const Transparent FOO = 0;
diff --git a/tests/expectations/constant.cpp b/tests/expectations/constant.cpp
index c8196d3..a43099d 100644
--- a/tests/expectations/constant.cpp
+++ b/tests/expectations/constant.cpp
@@ -4,44 +4,44 @@
 #include <ostream>
 #include <new>
 
-static const int32_t FOO = 10;
+constexpr static const int32_t FOO = 10;
 
-static const uint32_t DELIMITER = ':';
+constexpr static const uint32_t DELIMITER = ':';
 
-static const uint32_t LEFTCURLY = '{';
+constexpr static const uint32_t LEFTCURLY = '{';
 
-static const uint32_t QUOTE = '\'';
+constexpr static const uint32_t QUOTE = '\'';
 
-static const uint32_t TAB = '\t';
+constexpr static const uint32_t TAB = '\t';
 
-static const uint32_t NEWLINE = '\n';
+constexpr static const uint32_t NEWLINE = '\n';
 
-static const uint32_t HEART = U'\U00002764';
+constexpr static const uint32_t HEART = U'\U00002764';
 
-static const uint32_t EQUID = U'\U00010083';
+constexpr static const uint32_t EQUID = U'\U00010083';
 
-static const float ZOM = 3.14;
+constexpr static const float ZOM = 3.14;
 
 /// A single-line doc comment.
-static const int8_t POS_ONE = 1;
+constexpr static const int8_t POS_ONE = 1;
 
 /// A
 /// multi-line
 /// doc
 /// comment.
-static const int8_t NEG_ONE = -1;
+constexpr static const int8_t NEG_ONE = -1;
 
-static const int64_t SHIFT = 3;
+constexpr static const int64_t SHIFT = 3;
 
-static const int64_t XBOOL = 1;
+constexpr static const int64_t XBOOL = 1;
 
-static const int64_t XFALSE = ((0 << SHIFT) | XBOOL);
+constexpr static const int64_t XFALSE = ((0 << SHIFT) | XBOOL);
 
-static const int64_t XTRUE = (1 << (SHIFT | XBOOL));
+constexpr static const int64_t XTRUE = (1 << (SHIFT | XBOOL));
 
-static const uint8_t CAST = (uint8_t)'A';
+constexpr static const uint8_t CAST = (uint8_t)'A';
 
-static const uint32_t DOUBLE_CAST = (uint32_t)(float)1;
+constexpr static const uint32_t DOUBLE_CAST = (uint32_t)(float)1;
 
 struct Foo {
   int32_t x[FOO];
diff --git a/tests/expectations/constant_big.cpp b/tests/expectations/constant_big.cpp
index 2b5b87a..d86c3e7 100644
--- a/tests/expectations/constant_big.cpp
+++ b/tests/expectations/constant_big.cpp
@@ -4,10 +4,10 @@
 #include <ostream>
 #include <new>
 
-static const uint64_t UNSIGNED_NEEDS_ULL_SUFFIX = 9223372036854775808ULL;
+constexpr static const uint64_t UNSIGNED_NEEDS_ULL_SUFFIX = 9223372036854775808ULL;
 
-static const uint64_t UNSIGNED_DOESNT_NEED_ULL_SUFFIX = 8070450532247928832;
+constexpr static const uint64_t UNSIGNED_DOESNT_NEED_ULL_SUFFIX = 8070450532247928832;
 
-static const int64_t SIGNED_NEEDS_ULL_SUFFIX = -9223372036854775808ULL;
+constexpr static const int64_t SIGNED_NEEDS_ULL_SUFFIX = -9223372036854775808ULL;
 
-static const int64_t SIGNED_DOESNT_NEED_ULL_SUFFIX = -9223372036854775807;
+constexpr static const int64_t SIGNED_DOESNT_NEED_ULL_SUFFIX = -9223372036854775807;
diff --git a/tests/expectations/constant_constexpr.cpp b/tests/expectations/constant_constexpr.cpp
index dab7437..f600980 100644
--- a/tests/expectations/constant_constexpr.cpp
+++ b/tests/expectations/constant_constexpr.cpp
@@ -4,18 +4,18 @@
 #include <ostream>
 #include <new>
 
-constexpr static const int64_t CONSTANT_I64 = 216;
+static const int64_t CONSTANT_I64 = 216;
 
-constexpr static const float CONSTANT_FLOAT32 = 312.292;
+static const float CONSTANT_FLOAT32 = 312.292;
 
-constexpr static const uint32_t DELIMITER = ':';
+static const uint32_t DELIMITER = ':';
 
-constexpr static const uint32_t LEFTCURLY = '{';
+static const uint32_t LEFTCURLY = '{';
 
 struct Foo {
   int32_t x;
   static const int64_t CONSTANT_I64_BODY;
 };
-constexpr inline const int64_t Foo::CONSTANT_I64_BODY = 216;
+inline const int64_t Foo::CONSTANT_I64_BODY = 216;
 
-constexpr static const Foo SomeFoo = Foo{ /* .x = */ 99 };
+static const Foo SomeFoo = Foo{ /* .x = */ 99 };
diff --git a/tests/expectations/constant_sort_name.cpp b/tests/expectations/constant_sort_name.cpp
index 6de3dda..1a7dd50 100644
--- a/tests/expectations/constant_sort_name.cpp
+++ b/tests/expectations/constant_sort_name.cpp
@@ -4,9 +4,9 @@
 #include <ostream>
 #include <new>
 
-static const uint8_t A = 0;
+constexpr static const uint8_t A = 0;
 
-static const uint8_t B = 0;
+constexpr static const uint8_t B = 0;
 
 extern "C" {
 
diff --git a/tests/expectations/constant_sort_none.cpp b/tests/expectations/constant_sort_none.cpp
index 6e7360b..c5571e9 100644
--- a/tests/expectations/constant_sort_none.cpp
+++ b/tests/expectations/constant_sort_none.cpp
@@ -4,9 +4,9 @@
 #include <ostream>
 #include <new>
 
-static const uint8_t B = 0;
+constexpr static const uint8_t B = 0;
 
-static const uint8_t A = 0;
+constexpr static const uint8_t A = 0;
 
 extern "C" {
 
diff --git a/tests/expectations/constant_user_defined_type.cpp b/tests/expectations/constant_user_defined_type.cpp
index c00e83f..f127292 100644
--- a/tests/expectations/constant_user_defined_type.cpp
+++ b/tests/expectations/constant_user_defined_type.cpp
@@ -14,8 +14,8 @@ struct S {
 
 using A = uint8_t;
 
-static const S C1 = S{ /* .field = */ 0 };
+constexpr static const S C1 = S{ /* .field = */ 0 };
 
-static const E C2 = V;
+constexpr static const E C2 = V;
 
-static const A C3 = 0;
+constexpr static const A C3 = 0;
diff --git a/tests/expectations/enum_discriminant.cpp b/tests/expectations/enum_discriminant.cpp
index 30b383f..8183823 100644
--- a/tests/expectations/enum_discriminant.cpp
+++ b/tests/expectations/enum_discriminant.cpp
@@ -4,7 +4,7 @@
 #include <ostream>
 #include <new>
 
-static const int8_t FOURTY_FOUR = 4;
+constexpr static const int8_t FOURTY_FOUR = 4;
 
 enum class E : int8_t {
   A = 1,
diff --git a/tests/expectations/mod_2015.cpp b/tests/expectations/mod_2015.cpp
index 0259968..b3caaed 100644
--- a/tests/expectations/mod_2015.cpp
+++ b/tests/expectations/mod_2015.cpp
@@ -4,7 +4,7 @@
 #include <ostream>
 #include <new>
 
-static const uint8_t EXPORT_ME_TOO = 42;
+constexpr static const uint8_t EXPORT_ME_TOO = 42;
 
 struct ExportMe {
   uint64_t val;
diff --git a/tests/expectations/mod_2018.cpp b/tests/expectations/mod_2018.cpp
index 4d195ac..cd3ca85 100644
--- a/tests/expectations/mod_2018.cpp
+++ b/tests/expectations/mod_2018.cpp
@@ -4,7 +4,7 @@
 #include <ostream>
 #include <new>
 
-static const uint8_t EXPORT_ME_TOO = 42;
+constexpr static const uint8_t EXPORT_ME_TOO = 42;
 
 struct ExportMe {
   uint64_t val;
diff --git a/tests/expectations/mod_attr.cpp b/tests/expectations/mod_attr.cpp
index dd8a63d..10d0fe8 100644
--- a/tests/expectations/mod_attr.cpp
+++ b/tests/expectations/mod_attr.cpp
@@ -11,11 +11,11 @@ DEF BAR = 0
 #include <new>
 
 #if defined(FOO)
-static const int32_t FOO = 1;
+constexpr static const int32_t FOO = 1;
 #endif
 
 #if defined(BAR)
-static const int32_t BAR = 2;
+constexpr static const int32_t BAR = 2;
 #endif
 
 #if defined(FOO)
diff --git a/tests/expectations/mod_path.cpp b/tests/expectations/mod_path.cpp
index 22b3f70..0cda2e6 100644
--- a/tests/expectations/mod_path.cpp
+++ b/tests/expectations/mod_path.cpp
@@ -4,7 +4,7 @@
 #include <ostream>
 #include <new>
 
-static const uint8_t EXPORT_ME_TOO = 42;
+constexpr static const uint8_t EXPORT_ME_TOO = 42;
 
 struct ExportMe {
   uint64_t val;
diff --git a/tests/expectations/namespace_constant.cpp b/tests/expectations/namespace_constant.cpp
index 7f405f0..889472c 100644
--- a/tests/expectations/namespace_constant.cpp
+++ b/tests/expectations/namespace_constant.cpp
@@ -6,9 +6,9 @@
 
 namespace constants {
 
-static const int32_t FOO = 10;
+constexpr static const int32_t FOO = 10;
 
-static const float ZOM = 3.14;
+constexpr static const float ZOM = 3.14;
 
 struct Foo {
   int32_t x[FOO];
diff --git a/tests/expectations/namespaces_constant.cpp b/tests/expectations/namespaces_constant.cpp
index 2167fa9..2da55d7 100644
--- a/tests/expectations/namespaces_constant.cpp
+++ b/tests/expectations/namespaces_constant.cpp
@@ -7,9 +7,9 @@
 namespace constants {
 namespace test {
 
-static const int32_t FOO = 10;
+constexpr static const int32_t FOO = 10;
 
-static const float ZOM = 3.14;
+constexpr static const float ZOM = 3.14;
 
 struct Foo {
   int32_t x[FOO];
diff --git a/tests/expectations/prefix.cpp b/tests/expectations/prefix.cpp
index abde339..7f2c8ba 100644
--- a/tests/expectations/prefix.cpp
+++ b/tests/expectations/prefix.cpp
@@ -4,11 +4,11 @@
 #include <ostream>
 #include <new>
 
-static const int32_t PREFIX_LEN = 22;
+constexpr static const int32_t PREFIX_LEN = 22;
 
-static const int64_t PREFIX_X = (22 << 22);
+constexpr static const int64_t PREFIX_X = (22 << 22);
 
-static const int64_t PREFIX_Y = (PREFIX_X + PREFIX_X);
+constexpr static const int64_t PREFIX_Y = (PREFIX_X + PREFIX_X);
 
 using PREFIX_NamedLenArray = int32_t[PREFIX_LEN];
 
diff --git a/tests/expectations/prefixed_struct_literal.cpp b/tests/expectations/prefixed_struct_literal.cpp
index d18fe77..218d1c8 100644
--- a/tests/expectations/prefixed_struct_literal.cpp
+++ b/tests/expectations/prefixed_struct_literal.cpp
@@ -8,9 +8,9 @@ struct PREFIXFoo {
   int32_t a;
   uint32_t b;
 };
-static const PREFIXFoo PREFIXFoo_FOO = PREFIXFoo{ /* .a = */ 42, /* .b = */ 47 };
+constexpr static const PREFIXFoo PREFIXFoo_FOO = PREFIXFoo{ /* .a = */ 42, /* .b = */ 47 };
 
-static const PREFIXFoo PREFIXBAR = PREFIXFoo{ /* .a = */ 42, /* .b = */ 1337 };
+constexpr static const PREFIXFoo PREFIXBAR = PREFIXFoo{ /* .a = */ 42, /* .b = */ 1337 };
 
 extern "C" {
 
diff --git a/tests/expectations/prefixed_struct_literal_deep.cpp b/tests/expectations/prefixed_struct_literal_deep.cpp
index 7749e3e..4dbfb7b 100644
--- a/tests/expectations/prefixed_struct_literal_deep.cpp
+++ b/tests/expectations/prefixed_struct_literal_deep.cpp
@@ -14,7 +14,7 @@ struct PREFIXFoo {
   PREFIXBar bar;
 };
 
-static const PREFIXFoo PREFIXVAL = PREFIXFoo{ /* .a = */ 42, /* .b = */ 1337, /* .bar = */ PREFIXBar{ /* .a = */ 323 } };
+constexpr static const PREFIXFoo PREFIXVAL = PREFIXFoo{ /* .a = */ 42, /* .b = */ 1337, /* .bar = */ PREFIXBar{ /* .a = */ 323 } };
 
 extern "C" {
 
diff --git a/tests/expectations/rename.cpp b/tests/expectations/rename.cpp
index 59862a7..cfa3285 100644
--- a/tests/expectations/rename.cpp
+++ b/tests/expectations/rename.cpp
@@ -4,7 +4,7 @@
 #include <ostream>
 #include <new>
 
-static const int32_t C_H = 10;
+constexpr static const int32_t C_H = 10;
 
 enum class C_E : uint8_t {
   x = 0,
diff --git a/tests/expectations/struct_literal.cpp b/tests/expectations/struct_literal.cpp
index a751b75..68fa0f5 100644
--- a/tests/expectations/struct_literal.cpp
+++ b/tests/expectations/struct_literal.cpp
@@ -10,12 +10,12 @@ struct Foo {
   int32_t a;
   uint32_t b;
 };
-static const Foo Foo_FOO = Foo{ /* .a = */ 42, /* .b = */ 47 };
-static const Foo Foo_FOO2 = Foo{ /* .a = */ 42, /* .b = */ 47 };
-static const Foo Foo_FOO3 = Foo{ /* .a = */ 42, /* .b = */ 47 };
+constexpr static const Foo Foo_FOO = Foo{ /* .a = */ 42, /* .b = */ 47 };
+constexpr static const Foo Foo_FOO2 = Foo{ /* .a = */ 42, /* .b = */ 47 };
+constexpr static const Foo Foo_FOO3 = Foo{ /* .a = */ 42, /* .b = */ 47 };
 
 
-static const Foo BAR = Foo{ /* .a = */ 42, /* .b = */ 1337 };
+constexpr static const Foo BAR = Foo{ /* .a = */ 42, /* .b = */ 1337 };
 
 
 
diff --git a/tests/expectations/struct_literal_order.cpp b/tests/expectations/struct_literal_order.cpp
index e73339a..9f4021c 100644
--- a/tests/expectations/struct_literal_order.cpp
+++ b/tests/expectations/struct_literal_order.cpp
@@ -9,18 +9,18 @@ struct ABC {
   uint32_t b;
   uint32_t c;
 };
-static const ABC ABC_abc = ABC{ /* .a = */ 1.0, /* .b = */ 2, /* .c = */ 3 };
-static const ABC ABC_bac = ABC{ /* .a = */ 1.0, /* .b = */ 2, /* .c = */ 3 };
-static const ABC ABC_cba = ABC{ /* .a = */ 1.0, /* .b = */ 2, /* .c = */ 3 };
+constexpr static const ABC ABC_abc = ABC{ /* .a = */ 1.0, /* .b = */ 2, /* .c = */ 3 };
+constexpr static const ABC ABC_bac = ABC{ /* .a = */ 1.0, /* .b = */ 2, /* .c = */ 3 };
+constexpr static const ABC ABC_cba = ABC{ /* .a = */ 1.0, /* .b = */ 2, /* .c = */ 3 };
 
 struct BAC {
   uint32_t b;
   float a;
   int32_t c;
 };
-static const BAC BAC_abc = BAC{ /* .b = */ 1, /* .a = */ 2.0, /* .c = */ 3 };
-static const BAC BAC_bac = BAC{ /* .b = */ 1, /* .a = */ 2.0, /* .c = */ 3 };
-static const BAC BAC_cba = BAC{ /* .b = */ 1, /* .a = */ 2.0, /* .c = */ 3 };
+constexpr static const BAC BAC_abc = BAC{ /* .b = */ 1, /* .a = */ 2.0, /* .c = */ 3 };
+constexpr static const BAC BAC_bac = BAC{ /* .b = */ 1, /* .a = */ 2.0, /* .c = */ 3 };
+constexpr static const BAC BAC_cba = BAC{ /* .b = */ 1, /* .a = */ 2.0, /* .c = */ 3 };
 
 extern "C" {
 
diff --git a/tests/expectations/transparent.cpp b/tests/expectations/transparent.cpp
index f51491a..4c06739 100644
--- a/tests/expectations/transparent.cpp
+++ b/tests/expectations/transparent.cpp
@@ -23,10 +23,10 @@ template<typename T>
 using TransparentPrimitiveWrapper = uint32_t;
 
 using TransparentPrimitiveWithAssociatedConstants = uint32_t;
-static const TransparentPrimitiveWithAssociatedConstants TransparentPrimitiveWithAssociatedConstants_ZERO = 0;
-static const TransparentPrimitiveWithAssociatedConstants TransparentPrimitiveWithAssociatedConstants_ONE = 1;
+constexpr static const TransparentPrimitiveWithAssociatedConstants TransparentPrimitiveWithAssociatedConstants_ZERO = 0;
+constexpr static const TransparentPrimitiveWithAssociatedConstants TransparentPrimitiveWithAssociatedConstants_ONE = 1;
 
-static const TransparentPrimitiveWrappingStructure EnumWithAssociatedConstantInImpl_TEN = 10;
+constexpr static const TransparentPrimitiveWrappingStructure EnumWithAssociatedConstantInImpl_TEN = 10;
 
 extern "C" {
 
diff --git a/tests/expectations/workspace.cpp b/tests/expectations/workspace.cpp
index 1077bbd..b7b31a1 100644
--- a/tests/expectations/workspace.cpp
+++ b/tests/expectations/workspace.cpp
@@ -4,7 +4,7 @@
 #include <ostream>
 #include <new>
 
-static const int32_t EXT_CONST = 0;
+constexpr static const int32_t EXT_CONST = 0;
 
 struct ExtType {
   uint32_t data;
diff --git a/tests/rust/constant_constexpr.toml b/tests/rust/constant_constexpr.toml
index bc413fd..5deb0ed 100644
--- a/tests/rust/constant_constexpr.toml
+++ b/tests/rust/constant_constexpr.toml
@@ -1,5 +1,5 @@
 [const]
-allow_constexpr = true
+allow_constexpr = false
 
 [struct]
 associated_constants_in_body = true