1 files changed, 194 insertions, 0 deletions
diff --git a/ext/wasm/fiddle.make b/ext/wasm/fiddle.make
new file mode 100644
index 0000000..43e6941
--- /dev/null
+++ b/ext/wasm/fiddle.make
@@ -0,0 +1,194 @@
+#!/do/not/make
+#^^^ help emacs select edit mode
+#
+# Intended to include'd by ./GNUmakefile.
+#######################################################################
+MAKEFILE.fiddle := $(lastword $(MAKEFILE_LIST))
+
+########################################################################
+# shell.c and its build flags...
+make-np-0 := make -C  $(dir.top) -n -p
+make-np-1 := sed -e 's/(TOP)/(dir.top)/g'
+$(eval $(shell $(make-np-0) | grep -e '^SHELL_OPT ' | $(make-np-1)))
+$(eval $(shell $(make-np-0) | grep -e '^SHELL_SRC ' | $(make-np-1)))
+# ^^^ can't do that in 1 invocation b/c newlines get stripped
+ifeq (,$(SHELL_OPT))
+$(error Could not parse SHELL_OPT from $(dir.top)/Makefile.)
+endif
+ifeq (,$(SHELL_SRC))
+$(error Could not parse SHELL_SRC from $(dir.top)/Makefile.)
+endif
+$(dir.top)/shell.c: $(SHELL_SRC) $(dir.top)/tool/mkshellc.tcl
+	$(MAKE) -C $(dir.top) shell.c
+# /shell.c
+########################################################################
+
+EXPORTED_FUNCTIONS.fiddle := $(dir.tmp)/EXPORTED_FUNCTIONS.fiddle
+fiddle.emcc-flags = \
+  $(emcc.cflags) $(emcc_opt_full) \
+  --minify 0 \
+  -sALLOW_TABLE_GROWTH \
+  -sABORTING_MALLOC \
+  -sSTRICT_JS \
+  -sENVIRONMENT=web,worker \
+  -sMODULARIZE \
+  -sDYNAMIC_EXECUTION=0 \
+  -sWASM_BIGINT=$(emcc.WASM_BIGINT) \
+  -sEXPORT_NAME=$(sqlite3.js.init-func) \
+  -Wno-limited-postlink-optimizations \
+  $(sqlite3.js.flags.--post-js) \
+  $(emcc.exportedRuntimeMethods) \
+  -sEXPORTED_FUNCTIONS=@$(abspath $(EXPORTED_FUNCTIONS.fiddle)) \
+  $(SQLITE_OPT) $(SHELL_OPT) \
+  -DSQLITE_SHELL_FIDDLE
+# -D_POSIX_C_SOURCE is needed for strdup() with emcc
+
+fiddle.EXPORTED_FUNCTIONS.in := \
+    EXPORTED_FUNCTIONS.fiddle.in \
+    $(EXPORTED_FUNCTIONS.api)
+
+$(EXPORTED_FUNCTIONS.fiddle): $(fiddle.EXPORTED_FUNCTIONS.in) $(MAKEFILE.fiddle)
+	sort -u $(fiddle.EXPORTED_FUNCTIONS.in) > $@
+
+fiddle-module.js := $(dir.fiddle)/fiddle-module.js
+fiddle-module.wasm := $(subst .js,.wasm,$(fiddle-module.js))
+fiddle.cses := $(dir.top)/shell.c $(sqlite3-wasm.c)
+
+fiddle.SOAP.js := $(dir.fiddle)/$(notdir $(SOAP.js))
+$(fiddle.SOAP.js): $(SOAP.js)
+	cp $< $@
+
+$(eval $(call call-make-pre-js,fiddle-module))
+$(fiddle-module.js): $(MAKEFILE) $(MAKEFILE.fiddle) \
+    $(EXPORTED_FUNCTIONS.fiddle) \
+    $(fiddle.cses) $(pre-post-fiddle-module.deps) $(fiddle.SOAP.js)
+	$(emcc.bin) -o $@ $(fiddle.emcc-flags) \
+    $(pre-post-common.flags) $(pre-post-fiddle-module.flags) \
+    $(fiddle.cses)
+	$(maybe-wasm-strip) $(fiddle-module.wasm)
+	gzip < $@ > $@.gz
+	gzip < $(fiddle-module.wasm) > $(fiddle-module.wasm).gz
+
+$(dir.fiddle)/fiddle.js.gz: $(dir.fiddle)/fiddle.js
+	gzip < $< > $@
+
+clean: clean-fiddle
+clean-fiddle:
+	rm -f $(fiddle-module.js) $(fiddle-module.js).gz \
+        $(fiddle-module.wasm) $(fiddle-module.wasm).gz \
+        $(dir.fiddle)/$(SOAP.js) \
+        $(dir.fiddle)/fiddle-module.worker.js \
+        EXPORTED_FUNCTIONS.fiddle
+.PHONY: fiddle
+fiddle: $(fiddle-module.js) $(dir.fiddle)/fiddle.js.gz
+all: fiddle
+
+########################################################################
+# fiddle_remote is the remote destination for the fiddle app. It
+# must be a [user@]HOST:/path for rsync.
+# Note that the target "should probably" contain a symlink of
+# index.html -> fiddle.html.
+fiddle_remote ?=
+ifeq (,$(fiddle_remote))
+ifneq (,$(wildcard /home/stephan))
+  fiddle_remote = wh:www/wh/sqlite3/.
+else ifneq (,$(wildcard /home/drh))
+  #fiddle_remote = if appropriate, add that user@host:/path here
+endif
+endif
+push-fiddle: fiddle
+	@if [ x = "x$(fiddle_remote)" ]; then \
+		echo "fiddle_remote must be a [user@]HOST:/path for rsync"; \
+		exit 1; \
+	fi
+	rsync -va fiddle/ $(fiddle_remote)
+# end fiddle remote push
+########################################################################
+
+
+########################################################################
+# Explanation of the emcc build flags follows. Full docs for these can
+# be found at:
+#
+#  https://github.com/emscripten-core/emscripten/blob/main/src/settings.js
+#
+# -sENVIRONMENT=web: elides bootstrap code related to non-web JS
+#  environments like node.js. Removing this makes the output a tiny
+#  tick larger but hypothetically makes it more portable to
+#  non-browser JS environments.
+#
+# -sMODULARIZE: changes how the generated code is structured to avoid
+#  declaring a global Module object and instead installing a function
+#  which loads and initializes the module. The function is named...
+#
+# -sEXPORT_NAME=jsFunctionName (see -sMODULARIZE)
+#
+# -sEXPORTED_RUNTIME_METHODS=@/absolute/path/to/file: a file
+#  containing a list of emscripten-supplied APIs, one per line, which
+#  must be exported into the generated JS. Must be an absolute path!
+#
+# -sEXPORTED_FUNCTIONS=@/absolute/path/to/file: a file containing a
+#  list of C functions, one per line, which must be exported via wasm
+#  so they're visible to JS. C symbols names in that file must all
+#  start with an underscore for reasons known only to the emcc
+#  developers. e.g., _sqlite3_open_v2 and _sqlite3_finalize. Must be
+#  an absolute path!
+#
+# -sSTRICT_JS ensures that the emitted JS code includes the 'use
+#  strict' option. Note that -sSTRICT is more broadly-scoped and
+#  results in build errors.
+#
+# -sALLOW_TABLE_GROWTH is required for (at a minimum) the UDF-binding
+#  feature. Without it, JS functions cannot be made to proxy C-side
+#  callbacks.
+#
+# -sABORTING_MALLOC causes the JS-bound _malloc() to abort rather than
+#  return 0 on OOM. If set to 0 then all code which uses _malloc()
+#  must, just like in C, check the result before using it, else
+#  they're likely to corrupt the JS/WASM heap by writing to its
+#  address of 0. It is, as of this writing, enabled in Emscripten by
+#  default but we enable it explicitly in case that default changes.
+#
+# -sDYNAMIC_EXECUTION=0 disables eval() and the Function constructor.
+#  If the build runs without these, it's preferable to use this flag
+#  because certain execution environments disallow those constructs.
+#  This flag is not strictly necessary, however.
+#
+# -sWASM_BIGINT is UNTESTED but "should" allow the int64-using C APIs
+#  to work with JS/wasm, insofar as the JS environment supports the
+#  BigInt type. That support requires an extremely recent browser:
+#  Safari didn't get that support until late 2020.
+#
+# --no-entry: for compiling library code with no main(). If this is
+#  not supplied and the code has a main(), it is called as part of the
+#  module init process. Note that main() is #if'd out of shell.c
+#  (renamed) when building in wasm mode.
+#
+# --pre-js/--post-js=FILE relative or absolute paths to JS files to
+#  prepend/append to the emcc-generated bootstrapping JS. It's
+#  easier/faster to develop with separate JS files (reduces rebuilding
+#  requirements) but certain configurations, namely -sMODULARIZE, may
+#  require using at least a --pre-js file. They can be used
+#  individually and need not be paired.
+#
+# -O0..-O3 and -Oz: optimization levels affect not only C-style
+#  optimization but whether or not the resulting generated JS code
+#  gets minified. -O0 compiles _much_ more quickly than -O3 or -Oz,
+#  and doesn't minimize any JS code, so is recommended for
+#  development. -O3 or -Oz are recommended for deployment, but
+#  primarily because -Oz will shrink the wasm file notably. JS-side
+#  minification makes little difference in terms of overall
+#  distributable size.
+#
+# --minify 0: disables minification of the generated JS code,
+#  regardless of optimization level. Minification of the JS has
+#  minimal overall effect in the larger scheme of things and results
+#  in JS files which can neither be edited nor viewed as text files in
+#  Fossil (which flags them as binary because of their extreme line
+#  lengths). Interestingly, whether or not the comments in the
+#  generated JS file get stripped is unaffected by this setting and
+#  depends entirely on the optimization level. Higher optimization
+#  levels reduce the size of the JS considerably even without
+#  minification.
+#
+########################################################################