build against sqlite amalgamation

Makefile

@@ -1,11 +1,13 @@
 EXT = .so
 SQLITE_VERSION ?= version-3.46.1
-CFLAGS ?= -I deps/$(SQLITE_VERSION)/ext/fts5 -Os -Wall -Wextra -Werror -Wno-error=type-limits
 
 SQLITE_TARBALL_URL = https://www.sqlite.org/src/tarball/sqlite.tar.gz?r=${SQLITE_VERSION}
 SQLITE_SRC = deps/$(SQLITE_VERSION)/src
+SQLITE_AMALGAMATION_URL = https://sqlite.org/2024/sqlite-amalgamation-3460100.zip
+SQLITE_AMALGAMATION_PATH = deps/sqlite-amalgamation-3460100
 
-CONDITIONAL_CFLAGS =
+CFLAGS ?= -Ideps/$(SQLITE_VERSION)/ext/fts5 -I$(SQLITE_AMALGAMATION_PATH) -Os -Wall -Wextra
+CONDITIONAL_CFLAGS = -lm
 
 ifeq ($(OS),Windows_NT)
 	EXT = .dll
@@ -19,30 +21,37 @@ endif
 
 .PHONY: all clean test
 
-all: $(SQLITE_SRC)/sqlite3ext.h better-trigram$(EXT)
+all: better-trigram$(EXT)
 
 clean:
 	rm -rf deps
 	rm -f better-trigram$(EXT)
 	rm -rf better-trigram$(EXT).dSYM
 	rm -rf fts5$(EXT)
 
-$(SQLITE_SRC)/sqlite3ext.h:
+$(SQLITE_SRC):
 	mkdir -p deps/$(SQLITE_VERSION)
 	curl -LsS $(SQLITE_TARBALL_URL) | tar -xzf - -C deps/$(SQLITE_VERSION)/ --strip-components=1
 
-better-trigram$(EXT): better-trigram.c
-	$(CC) $(CFLAGS) $(CONDITIONAL_CFLAGS) -g -shared -fPIC -o $@ $<
+$(SQLITE_AMALGAMATION_PATH):
+	@echo Downloading SQLite amalgamation...
+	wget -q $(SQLITE_AMALGAMATION_URL) -O sqlite.zip
+	@echo Extracting SQLite amalgamation...
+	unzip sqlite.zip -d deps/
+	rm -f sqlite.zip
+
+better-trigram$(EXT): $(SQLITE_SRC) $(SQLITE_AMALGAMATION_PATH)
+	$(CC) $(CFLAGS) $(CONDITIONAL_CFLAGS) -shared -fPIC -o $@ better-trigram.c
 
 fts5$(EXT): SHELL := /bin/bash -e
-fts5$(EXT): $(SQLITE_SRC)/sqlite3ext.h
+fts5$(EXT): $(SQLITE_SRC) $(SQLITE_AMALGAMATION_PATH)
 	dir=deps/$(SQLITE_VERSION) \
 	cwd=$$(pwd); \
 	lemon $$dir/ext/fts5/fts5parse.y; \
 	cd $$dir/ext/fts5; \
 	tclsh $$cwd/$$dir/ext/fts5/tool/mkfts5c.tcl; \
 	cd $$cwd; \
-	$(CC) $(CONDITIONAL_CFLAGS) -DSQLITE_TEST -g -shared -fPIC $$dir/ext/fts5/fts5.c -o $@; \
+	$(CC) $(CFLAGS) $(CONDITIONAL_CFLAGS) -DSQLITE_TEST -shared -fPIC -o $@ $$dir/ext/fts5/fts5.c; \
 
 test: fts5$(EXT) better-trigram$(EXT)
 	bun test

better-trigram.c

@@ -10,21 +10,16 @@
 **
 */
 
+#include "better-trigram.h"
 #include "tokenizer.c"
 #include <stdio.h>
 #include <string.h>
 
-#ifdef SQLITE_OMIT_LOAD_EXTENSION
-#define SQLITE_OMIT_LOAD_EXTENSION_PREINCLUDE
-#endif
-
+#ifndef SQLITE_CORE
 #include "sqlite3ext.h"
 SQLITE_EXTENSION_INIT1
-
-#if defined(SQLITE_OMIT_LOAD_EXTENSION) &&                                     \
-    !defined(SQLITE_OMIT_LOAD_EXTENSION_PREINCLUDE)
-/* note: if you are on macOS - do not use included SQLite sqlite3ext.h */
-#error "The sqlite3ext.h header defines SQLITE_OMIT_LOAD_EXTENSION"
+#else
+#include "sqlite3.h"
 #endif
 
 #define UNUSED_PARAM(x) (void)(x)
@@ -140,22 +135,17 @@ static int fts5BetterTrigramInit(sqlite3 *db) {
   }
 }
 
-#ifdef _WIN32
-__declspec(dllexport)
-#endif
-
-#ifndef SQLITE_CORE
-#ifdef _WIN32
-__declspec(dllexport)
-#endif
-int sqlite3_bettertrigram_init(sqlite3 *db, char **error, const sqlite3_api_routines *api) {
-  SQLITE_EXTENSION_INIT2(api);
-  UNUSED_PARAM(error);
-
+#ifdef SQLITE_CORE
+SQLITE_PRIVATE int sqlite3Fts5BetterTrigramInit(sqlite3 *db) {
   return fts5BetterTrigramInit(db);
 }
 #else
-SQLITE_PRIVATE int sqlite3Fts5BetterTrigramInit(sqlite3 *db) {
+SQLITE_BETTER_TRIGRAM_API int
+sqlite3_bettertrigram_init(sqlite3 *db, char **error,
+                           const sqlite3_api_routines *api) {
+  SQLITE_EXTENSION_INIT2(api);
+  UNUSED_PARAM(error);
+
   return fts5BetterTrigramInit(db);
 }
-#endif
+#endif

better-trigram.h

@@ -0,0 +1,41 @@
+#ifndef SQLITE_BETTER_TRIGRAM_H
+#define SQLITE_BETTER_TRIGRAM_H
+
+#ifndef SQLITE_CORE
+#include "sqlite3ext.h"
+#else
+#include "sqlite3.h"
+#endif
+
+#ifndef SQLITE_PRIVATE
+#define SQLITE_PRIVATE static
+#endif
+
+#ifdef SQLITE_BETTER_TRIGRAM_STATIC
+#define SQLITE_BETTER_TRIGRAM_API
+#else
+#ifdef _WIN32
+#define SQLITE_BETTER_TRIGRAM_API __declspec(dllexport)
+#else
+#define SQLITE_BETTER_TRIGRAM_API
+#endif
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef SQLITE_CORE
+SQLITE_PRIVATE int sqlite3Fts5BetterTrigramInit(sqlite3 *db);
+#else
+SQLITE_BETTER_TRIGRAM_API int
+sqlite3_bettertrigram_init(sqlite3 *db, char **pzErrMsg,
+                           const sqlite3_api_routines *pApi);
+
+#endif
+
+#ifdef __cplusplus
+} /* end of the 'extern "C"' block */
+#endif
+
+#endif /* ifndef SQLITE_BETTER_TRIGRAM_H */