Don't use TARGET unless the target options are *not* specified

This eliminates the possibility of inlining target failures for ondemand

Also makes it so we always compile common architectures needed by simdjson.cpp in simdjson.h, since amalgamation has no way to reason about whether to include / exclude it.

include/simdjson/arm64.h

@@ -27,10 +27,6 @@ namespace arm64 {
 #include "simdjson/generic/atomparsing.h"
 #include "simdjson/arm64/stringparsing.h"
 #include "simdjson/arm64/numberparsing.h"
-#include "simdjson/generic/implementation_simdjson_result_base.h"
-
-// Inline definitions
-#include "simdjson/generic/implementation_simdjson_result_base-inl.h"
 #include "simdjson/arm64/end.h"
 
 #endif // SIMDJSON_IMPLEMENTATION_ARM64

include/simdjson/builtin.h

@@ -3,6 +3,37 @@
 
 #include "simdjson/implementations.h"
 
+// Determine the best builtin implementation
+#ifndef SIMDJSON_BUILTIN_IMPLEMENTATION
+#if SIMDJSON_CAN_ALWAYS_RUN_HASWELL
+#define SIMDJSON_BUILTIN_IMPLEMENTATION haswell
+#elif SIMDJSON_CAN_ALWAYS_RUN_WESTMERE
+#define SIMDJSON_BUILTIN_IMPLEMENTATION westmere
+#elif SIMDJSON_CAN_ALWAYS_RUN_ARM64
+#define SIMDJSON_BUILTIN_IMPLEMENTATION arm64
+#elif SIMDJSON_CAN_ALWAYS_RUN_PPC64
+#define SIMDJSON_BUILTIN_IMPLEMENTATION ppc64
+#elif SIMDJSON_CAN_ALWAYS_RUN_FALLBACK
+#define SIMDJSON_BUILTIN_IMPLEMENTATION fallback
+#else
+#error "All possible implementations (including fallback) have been disabled! simdjson will not run."
+#endif
+#endif // SIMDJSON_BUILTIN_IMPLEMENTATION
+
+#define SIMDJSON_IMPLEMENTATION SIMDJSON_BUILTIN_IMPLEMENTATION
+
+// ondemand is only compiled as part of the builtin implementation at present
+
+// Interface declarations
+#include "simdjson/generic/implementation_simdjson_result_base.h"
+#include "simdjson/generic/ondemand.h"
+
+// Inline definitions
+#include "simdjson/generic/implementation_simdjson_result_base-inl.h"
+#include "simdjson/generic/ondemand-inl.h"
+
+#undef SIMDJSON_IMPLEMENTATION
+
 namespace simdjson {
   /**
    * Represents the best statically linked simdjson implementation that can be used by the compiling

include/simdjson/fallback.h

@@ -24,13 +24,6 @@ namespace fallback {
 #include "simdjson/generic/atomparsing.h"
 #include "simdjson/fallback/stringparsing.h"
 #include "simdjson/fallback/numberparsing.h"
-#include "simdjson/generic/implementation_simdjson_result_base.h"
-#include "simdjson/generic/ondemand.h"
-
-// Inline definitions
-#include "simdjson/generic/implementation_simdjson_result_base-inl.h"
-#include "simdjson/generic/ondemand-inl.h"
-
 #include "simdjson/fallback/end.h"
 
 #endif // SIMDJSON_IMPLEMENTATION_FALLBACK

include/simdjson/haswell.h

@@ -5,12 +5,12 @@
 
 #if SIMDJSON_IMPLEMENTATION_HASWELL
 
-#ifndef SIMDJSON_CAN_ALWAYS_RUN_HASWELL
-#define SIMDJSON_TARGET_HASWELL SIMDJSON_TARGET_REGION("avx2,bmi,pclmul,lzcnt")
-#define SIMDJSON_UNTARGET_HASWELL SIMDJSON_UNTARGET_REGION
-#else
+#if SIMDJSON_CAN_ALWAYS_RUN_HASWELL
 #define SIMDJSON_TARGET_HASWELL
 #define SIMDJSON_UNTARGET_HASWELL
+#else
+#define SIMDJSON_TARGET_HASWELL SIMDJSON_TARGET_REGION("avx2,bmi,pclmul,lzcnt")
+#define SIMDJSON_UNTARGET_HASWELL SIMDJSON_UNTARGET_REGION
 #endif
 
 namespace simdjson {
@@ -41,13 +41,6 @@ namespace haswell {
 #include "simdjson/generic/atomparsing.h"
 #include "simdjson/haswell/stringparsing.h"
 #include "simdjson/haswell/numberparsing.h"
-#include "simdjson/generic/implementation_simdjson_result_base.h"
-#include "simdjson/generic/ondemand.h"
-
-// Inline definitions
-#include "simdjson/generic/implementation_simdjson_result_base-inl.h"
-#include "simdjson/generic/ondemand-inl.h"
-
 #include "simdjson/haswell/end.h"
 
 #endif // SIMDJSON_IMPLEMENTATION_HASWELL

include/simdjson/implementation-base.h

@@ -51,21 +51,4 @@
 #endif
 #define SIMDJSON_CAN_ALWAYS_RUN_FALLBACK SIMDJSON_IMPLEMENTATION_FALLBACK
 
-// Determine the best builtin implementation
-#ifndef SIMDJSON_BUILTIN_IMPLEMENTATION
-#if SIMDJSON_CAN_ALWAYS_RUN_HASWELL
-#define SIMDJSON_BUILTIN_IMPLEMENTATION haswell
-#elif SIMDJSON_CAN_ALWAYS_RUN_WESTMERE
-#define SIMDJSON_BUILTIN_IMPLEMENTATION westmere
-#elif SIMDJSON_CAN_ALWAYS_RUN_ARM64
-#define SIMDJSON_BUILTIN_IMPLEMENTATION arm64
-#elif SIMDJSON_CAN_ALWAYS_RUN_PPC64
-#define SIMDJSON_BUILTIN_IMPLEMENTATION ppc64
-#elif SIMDJSON_CAN_ALWAYS_RUN_FALLBACK
-#define SIMDJSON_BUILTIN_IMPLEMENTATION fallback
-#else
-#error "All possible implementations (including fallback) have been disabled! simdjson will not run."
-#endif
-#endif // SIMDJSON_BUILTIN_IMPLEMENTATION
-
 #endif // SIMDJSON_IMPLEMENTATION_BASE_H

include/simdjson/implementations.h

@@ -1,6 +1,8 @@
 #ifndef SIMDJSON_IMPLEMENTATIONS_H
 #define SIMDJSON_IMPLEMENTATIONS_H
 
+#include "simdjson/implementation-base.h"
+
 SIMDJSON_PUSH_DISABLE_WARNINGS
 SIMDJSON_DISABLE_UNDESIRED_WARNINGS
 
@@ -10,6 +12,7 @@ SIMDJSON_DISABLE_UNDESIRED_WARNINGS
 #include "simdjson/westmere.h"
 #include "simdjson/ppc64.h"
 #include "simdjson/fallback.h"
+#include "simdjson/builtin.h"
 
 SIMDJSON_POP_DISABLE_WARNINGS
 

include/simdjson/ppc64.h

@@ -27,12 +27,6 @@ namespace ppc64 {
 #include "simdjson/generic/atomparsing.h"
 #include "simdjson/ppc64/stringparsing.h"
 #include "simdjson/ppc64/numberparsing.h"
-#include "simdjson/generic/implementation_simdjson_result_base.h"
-#include "simdjson/generic/ondemand.h"
-
-// Inline definitions
-#include "simdjson/generic/implementation_simdjson_result_base-inl.h"
-#include "simdjson/generic/ondemand-inl.h"
 #include "simdjson/ppc64/end.h"
 
 #endif // SIMDJSON_IMPLEMENTATION_PPC64

include/simdjson/westmere.h

@@ -5,12 +5,12 @@
 
 #if SIMDJSON_IMPLEMENTATION_WESTMERE
 
-#ifndef SIMDJSON_CAN_ALWAYS_RUN_WESTMERE
-#define SIMDJSON_TARGET_WESTMERE SIMDJSON_TARGET_REGION("sse4.2,pclmul")
-#define SIMDJSON_UNTARGET_WESTMERE SIMDJSON_UNTARGET_REGION
-#else
+#if SIMDJSON_CAN_ALWAYS_RUN_WESTMERE
 #define SIMDJSON_TARGET_WESTMERE
 #define SIMDJSON_UNTARGET_WESTMERE
+#else
+#define SIMDJSON_TARGET_WESTMERE SIMDJSON_TARGET_REGION("sse4.2,pclmul")
+#define SIMDJSON_UNTARGET_WESTMERE SIMDJSON_UNTARGET_REGION
 #endif
 
 namespace simdjson {
@@ -41,13 +41,6 @@ namespace westmere {
 #include "simdjson/generic/atomparsing.h"
 #include "simdjson/westmere/stringparsing.h"
 #include "simdjson/westmere/numberparsing.h"
-#include "simdjson/generic/implementation_simdjson_result_base.h"
-#include "simdjson/generic/ondemand.h"
-
-// Inline definitions
-#include "simdjson/generic/implementation_simdjson_result_base-inl.h"
-#include "simdjson/generic/ondemand-inl.h"
-
 #include "simdjson/westmere/end.h"
 
 #endif // SIMDJSON_IMPLEMENTATION_WESTMERE

singleheader/amalgamate.py

@@ -83,7 +83,8 @@ def dofile(fid, prepath, filename):
     # Last lines are always ignored. Files should end by an empty lines.
     print(f"/* begin file {RELFILE} */", file=fid)
     includepattern = re.compile('^#include "(.*)"')
-    redefines_simdjson_implementation = re.compile('^#define SIMDJSON_IMPLEMENTATION (.*)')
+    redefines_simdjson_implementation = re.compile('^#define\s+SIMDJSON_IMPLEMENTATION\s+(.*)')
+    undefines_simdjson_implementation = re.compile('^#undef\s+SIMDJSON_IMPLEMENTATION\s*$')
     uses_simdjson_implementation = re.compile('SIMDJSON_IMPLEMENTATION([^_a-zA-Z0-9]|$)')
     with open(file, 'r') as fid2:
         for line in fid2:
@@ -106,6 +107,9 @@ def dofile(fid, prepath, filename):
                 if s:
                     current_implementation=s.group(1)
                     print(f"// redefining SIMDJSON_IMPLEMENTATION to \"{current_implementation}\"\n// {line}", file=fid)
+                elif undefines_simdjson_implementation.search(line):
+                    # Don't include #undef SIMDJSON_IMPLEMENTATION since we're handling it ourselves
+                    print(f"// {line}")
                 else:
                     # copy the line, with SIMDJSON_IMPLEMENTATION replace to what it is currently defined to
                     print(uses_simdjson_implementation.sub(current_implementation+"\\1",line), file=fid)

src/implementation.cpp

@@ -155,6 +155,7 @@ simdjson_warn_unused bool validate_utf8(const char *buf, size_t len) noexcept {
 
 const implementation * builtin_implementation() {
   static const implementation * builtin_impl = available_implementations[STRINGIFY(SIMDJSON_BUILTIN_IMPLEMENTATION)];
+  assert(builtin_impl);
   return builtin_impl;
 }