Clang.jl generated bindings and internal refactor (#296)

* Refactor
1. Use Clang.jl to generate C bindings automatically
2. Use JuliaFormatter.jl to format all the code
3. Use WeakKeyDict to record prepared statements of a DB
4. Upgrade Julia version requirement to 1.6

* Recover SQlite.isready for statemaent

* Remove extra return

* Bump Clang.jl version and regenerate bindings

Author: metab0t

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.3'
+          - '1.6'
           - '1' # automatically expands to the latest stable 1.x release of Julia
           - 'nightly'
         os:

Project.toml

@@ -5,18 +5,15 @@ version = "1.4.2"
 
 [deps]
 DBInterface = "a10d1c49-ce27-4219-8d33-6db1a4562965"
-Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
-Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 SQLite_jll = "76ed43ae-9a5d-5a62-8c75-30186b810ce8"
 Serialization = "9e88b42a-f829-5b0c-bbe9-9e923198166b"
 Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
-Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 WeakRefStrings = "ea10d353-3f73-51f8-a26c-33c1cb351aa5"
 
 [compat]
 DBInterface = "2.5"
 SQLite_jll = "3"
 Tables = "1"
 WeakRefStrings = "0.4,0.5,0.6,1"
-julia = "1.3"
+julia = "1.6"

gen/Project.toml

@@ -0,0 +1,7 @@
+[deps]
+Clang = "40e3b903-d033-50b4-a0cc-940c62c95e31"
+SQLite_jll = "76ed43ae-9a5d-5a62-8c75-30186b810ce8"
+
+[compat]
+Clang = "0.16"
+SQLite_jll = "3"

gen/generate_wrapper.jl

@@ -0,0 +1,18 @@
+using Clang.Generators
+using SQLite_jll
+
+cd(@__DIR__)
+
+include_dir = normpath(SQLite_jll.artifact_dir, "include")
+
+options = load_options(joinpath(@__DIR__, "generator.toml"))
+
+args = get_default_args()
+
+headers = [joinpath(include_dir, "sqlite3.h")]
+
+# create context
+ctx = create_context(headers, args, options)
+
+# run generator
+build!(ctx)

gen/generator.toml

@@ -0,0 +1,14 @@
+[general]
+library_name = "libsqlite"
+output_file_path = "../src/capi.jl"
+module_name = "C"
+jll_pkg_name = "SQLite_jll"
+print_using_CEnum = false
+output_ignorelist = [
+    "SQLITE_STDCALL"
+]
+
+[codegen]
+use_julia_bool = true
+use_ccall_macro = true
+opaque_func_arg_as_PtrCvoid = true