8 files changed, 8 insertions, 103 deletions
diff --git a/src/backend/jit/llvm/llvmjit_types.c b/src/backend/jit/llvm/llvmjit_types.c
index 4a9e0770145..13efe18e6b0 100644
--- a/src/backend/jit/llvm/llvmjit_types.c
+++ b/src/backend/jit/llvm/llvmjit_types.c
@@ -117,11 +117,9 @@ ExecEvalBoolSubroutineTemplate(ExprState *state,
 }
 
 /*
- * Clang represents stdbool.h style booleans that are returned by functions
- * differently (as i1) than stored ones (as i8). Therefore we do not just need
- * TypeBool (above), but also a way to determine the width of a returned
- * integer. This allows us to keep compatible with non-stdbool using
- * architectures.
+ * Clang represents bool returned by functions differently (as i1) than stored
+ * ones (as i8).  Therefore we do not just need TypeStorageBool (above), but
+ * also a way to determine the width of a returned integer.
  */
 extern bool FunctionReturningBool(void);
 bool
diff --git a/src/backend/utils/fmgr/dfmgr.c b/src/backend/utils/fmgr/dfmgr.c
index c7aa789b51b..8e81ecc7491 100644
--- a/src/backend/utils/fmgr/dfmgr.c
+++ b/src/backend/utils/fmgr/dfmgr.c
@@ -18,16 +18,6 @@
 
 #ifndef WIN32
 #include <dlfcn.h>
-
-/*
- * On macOS, <dlfcn.h> insists on including <stdbool.h>.  If we're not
- * using stdbool, undef bool to undo the damage.
- */
-#ifndef PG_USE_STDBOOL
-#ifdef bool
-#undef bool
-#endif
-#endif
 #endif							/* !WIN32 */
 
 #include "fmgr.h"
diff --git a/src/include/c.h b/src/include/c.h
index fe1ce87882b..304dff27e34 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -450,37 +450,11 @@ typedef void (*pg_funcptr_t) (void);
  * bool
  *		Boolean value, either true or false.
  *
- * We use stdbool.h if bool has size 1 after including it.  That's useful for
- * better compiler and debugger output and for compatibility with third-party
- * libraries.  But PostgreSQL currently cannot deal with bool of other sizes;
- * there are static assertions around the code to prevent that.
- *
- * For C++ compilers, we assume the compiler has a compatible built-in
- * definition of bool.
- *
- * See also the version of this code in src/interfaces/ecpg/include/ecpglib.h.
+ * PostgreSQL currently cannot deal with bool of size other than 1; there are
+ * static assertions around the code to prevent that.
  */
 
-#ifndef __cplusplus
-
-#ifdef PG_USE_STDBOOL
 #include <stdbool.h>
-#else
-
-#ifndef bool
-typedef unsigned char bool;
-#endif
-
-#ifndef true
-#define true	((bool) 1)
-#endif
-
-#ifndef false
-#define false	((bool) 0)
-#endif
-
-#endif							/* not PG_USE_STDBOOL */
-#endif							/* not C++ */
 
 
 /* ----------------------------------------------------------------
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 6e25afc58fd..ab0f8cc2b4a 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -597,9 +597,6 @@
 /* Define to best printf format archetype, usually gnu_printf if available. */
 #undef PG_PRINTF_ATTRIBUTE
 
-/* Define to 1 to use <stdbool.h> to define type bool. */
-#undef PG_USE_STDBOOL
-
 /* PostgreSQL version as a string */
 #undef PG_VERSION
 
@@ -630,9 +627,6 @@
    RELSEG_SIZE requires an initdb. */
 #undef RELSEG_SIZE
 
-/* The size of `bool', as computed by sizeof. */
-#undef SIZEOF_BOOL
-
 /* The size of `long', as computed by sizeof. */
 #undef SIZEOF_LONG
 
diff --git a/src/interfaces/ecpg/include/ecpg_config.h.in b/src/interfaces/ecpg/include/ecpg_config.h.in
index 2b439c1e58d..75f542f263b 100644
--- a/src/interfaces/ecpg/include/ecpg_config.h.in
+++ b/src/interfaces/ecpg/include/ecpg_config.h.in
@@ -6,6 +6,3 @@
 
 /* Define to 1 if `long long int' works and is 64 bits. */
 #undef HAVE_LONG_LONG_INT_64
-
-/* Define to 1 to use <stdbool.h> to define type bool. */
-#undef PG_USE_STDBOOL
diff --git a/src/interfaces/ecpg/include/ecpglib.h b/src/interfaces/ecpg/include/ecpglib.h
index 771761ffe49..dbf3cc3a0c2 100644
--- a/src/interfaces/ecpg/include/ecpglib.h
+++ b/src/interfaces/ecpg/include/ecpglib.h
@@ -7,6 +7,7 @@
 #ifndef _ECPGLIB_H
 #define _ECPGLIB_H
 
+#include <stdbool.h>
 #include <string.h>
 
 #include "ecpg_config.h"
@@ -14,35 +15,6 @@
 #include "libpq-fe.h"
 #include "sqlca.h"
 
-/*
- * This is a small extract from c.h since we don't want to leak all postgres
- * definitions into ecpg programs; but we need to know what bool is.
- */
-#ifndef __cplusplus
-
-#ifdef PG_USE_STDBOOL
-#include <stdbool.h>
-#else
-
-/*
- * We assume bool has been defined if true and false are.  This avoids
- * duplicate-typedef errors if this file is included after c.h.
- */
-#if !(defined(true) && defined(false))
-typedef unsigned char bool;
-#endif
-
-#ifndef true
-#define true	((bool) 1)
-#endif
-
-#ifndef false
-#define false	((bool) 0)
-#endif
-
-#endif							/* not PG_USE_STDBOOL */
-#endif							/* not C++ */
-
 
 #ifdef __cplusplus
 extern "C"
diff --git a/src/interfaces/ecpg/include/meson.build b/src/interfaces/ecpg/include/meson.build
index b4a5aedd51f..a3beb3cc7be 100644
--- a/src/interfaces/ecpg/include/meson.build
+++ b/src/interfaces/ecpg/include/meson.build
@@ -5,7 +5,6 @@ ecpg_inc = include_directories('.')
 ecpg_conf_keys = [
   'HAVE_LONG_INT_64',
   'HAVE_LONG_LONG_INT_64',
-  'PG_USE_STDBOOL',
 ]
 
 ecpg_conf_data = configuration_data()
diff --git a/src/pl/plperl/plperl_system.h b/src/pl/plperl/plperl_system.h
index 48f6575e513..d1b9ea17fca 100644
--- a/src/pl/plperl/plperl_system.h
+++ b/src/pl/plperl/plperl_system.h
@@ -72,16 +72,10 @@
 #endif
 
 /*
- * Regarding bool, both PostgreSQL and Perl might use stdbool.h or not,
- * depending on configuration.  If both agree, things are relatively harmless.
- * If not, things get tricky.  If PostgreSQL does but Perl does not, define
- * HAS_BOOL here so that Perl does not redefine bool; this avoids compiler
- * warnings.  If PostgreSQL does not but Perl does, we need to undefine bool
- * after we include the Perl headers; see below.
+ * Define HAS_BOOL here so that Perl does not redefine bool.  We included
+ * <stdbool.h> in c.h.
  */
-#ifdef PG_USE_STDBOOL
 #define HAS_BOOL 1
-#endif
 
 /*
  * Get the basic Perl API.  We use PERL_NO_GET_CONTEXT mode so that our code
@@ -180,19 +174,6 @@
 /* perl version and platform portability */
 #include "ppport.h"
 
-/*
- * perl might have included stdbool.h.  If we also did that earlier (see c.h),
- * then that's fine.  If not, we probably rejected it for some reason.  In
- * that case, undef bool and proceed with our own bool.  (Note that stdbool.h
- * makes bool a macro, but our own replacement is a typedef, so the undef
- * makes ours visible again).
- */
-#ifndef PG_USE_STDBOOL
-#ifdef bool
-#undef bool
-#endif
-#endif
-
 /* supply HeUTF8 if it's missing - ppport.h doesn't supply it, unfortunately */
 #ifndef HeUTF8
 #define HeUTF8(he)			   ((HeKLEN(he) == HEf_SVKEY) ?			   \