Replace use of cpp with the fit-to-purpose c-pp to avoid cpp's C-centric/JS-unfriendly quirks.

FossilOrigin-Name: 49d70f071e918d5d095c807575bb7ce2b287a123261e789e938521b3b409429a

ext/wasm/GNUmakefile

@@ -235,8 +235,8 @@ $(foreach X,$(SOAP.js) $(sqlite3-worker1.js) $(sqlite3-worker1-promiser.js),\
 all: $(sqlite3-api.ext.jses)
 
 sqlite3-api.js := $(dir.tmp)/sqlite3-api.js
-sqlite3-api.pre-cpp.js := $(dir.tmp)/sqlite3-api.pre-cpp.js
+sqlite3-api.c-pp.js := $(dir.tmp)/sqlite3-api.c-pp.js
-$(sqlite3-api.pre-cpp.js): $(sqlite3-api.jses) $(MAKEFILE)
+$(sqlite3-api.c-pp.js): $(sqlite3-api.jses) $(MAKEFILE)
 	@echo "Making $@..."
 	@for i in $(sqlite3-api.jses); do \
 		echo "/* BEGIN FILE: $$i */"; \
@@ -257,7 +257,6 @@ $(sqlite3-api-build-version.js): $(bin.version-info) $(MAKEFILE)
 ########################################################################
 # --post-js and --pre-js are emcc flags we use to append/prepend JS to
 # the generated emscripten module file.
-pre-js.pre-cpp.js := $(dir.api)/pre-js.pre-cpp.js
 pre-js.js := $(dir.tmp)/pre-js.js
 post-js.js := $(dir.tmp)/post-js.js
 post-jses := \
@@ -291,47 +290,47 @@ $(sqlite3-license-version.js): $(sqlite3.h) $(sqlite3-license-version-header.js)
    } > $@
 
 ########################################################################
-# Transform $(1) to $(2) via cpp -E -CC $(1) ...
+# Transform $(1) to $(2) via ./c-pp -f $(1) ...
 #
-# DO NOT use gcc as the preprocessor because it will emit its own
+# Historical notes:
-# license header to our output because that's a comment in its
-# stdc-predef.h, which we cannot tell it to _not_ include. The only
-# workaround to that is to allow gcc -E to strip all comments. The
-# wasm build uses clang behind emcc, anyway, so we already have a
-# clang dependency. However, the clang cpp refuses to read empty
-# strings in the form '', so we have to be sure to use "" in JS code
-# for those.
 #
-# It's tempting to build a custom mini-cpp-like binary for this
+# - We first attempted to use gcc and/or clang to preprocess JS files
-# purpose to avoid these dependencies and quirks. Maybe we could use
+#   in the same way we would normally do C files, but C-specific quirks
-# lemon to do the heavy lifting for that, noting that we'd still need
+#   of each makes that untennable.
-# to tokenize it by hand (but only lines which start with "#" or
-# backslash-continued lines, and we could treat all other lines as
-# opaque content).
 #
-# In this build we may have #ifdef's (and the like) in arbitrary input
+# - We implemented c-pp.c (the C-Minus Pre-processor) as a custom
-# JS files and we need to preprocess those before Emscripten gets
+#   generic/file-format-agnostic preprocessor to enable us to pack
-# ahold of them. We cannot simply preprocess the resulting
+#   code for different target builds into the same JS files. Most
-# Emscripten-generated sqlite3.js because (A) Emscripten may choke on
+#   notably, some ES6 module (a.k.a. ESM) features cannot legally be
-# C preprocessor directives in the input and (B) Emscripten's output
+#   referenced at all in non-ESM code, e.g.  the "import" and "export"
-# may contain things which cpp cannot read (like single-quoted empty
+#   keywords. This preprocessing step permits us to swap out sections
-# strings: '').
+#   of code where necessary for ESM and non-ESM (a.k.a. vanilla JS)
-bin.cpp ?= clang
+#   require different implementations. The alternative to such
-ifneq (,$(filter ems,$(MAKECMDGOALS)))
+#   preprocessing, would be to have separate source files for ES6
+#   builds, which would have a higher maintenance burden than c-pp.c
+#   seems likely to.
+#
+# c-pp.c was written specifically for the sqlite project's JavaScript
+# builds but is maintained as a standalone project:
+# https://fossil.wanderinghorse.net/r/c-pp
+bin.c-pp := ./c-pp
+$(bin.c-pp): c-pp.c $(sqlite3.c) $(MAKEFILE)
+	$(CC) -O0 -o $@ c-pp.c $(sqlite3.c) '-DCMPP_DEFAULT_DELIM="//#"' -I$(dir.top)
+ifneq (,$(filter esm,$(MAKECMDGOALS)))
 js.cpp.defines ?= -DSQLITE_JS_ESM
-ems: $(filter-out ems,$(MAKECMDGOALS))
+esm: $(filter-out esm,$(MAKECMDGOALS))
 else
 js.cpp.defines ?=
 endif
-define CPP_JS
+define C-PP_JS
 # $1 = X.js. $2 = output file to generate by filtering $(1) through
 # $(bin.cpp) -E -CC.
-$(2): $(1) $$(MAKEFILE)
+$(2): $(1) $$(MAKEFILE) $$(bin.c-pp)
-	$$(bin.cpp) -E -CC -undef $(js.cpp.defines) -x c $(1) | sed -e '/^#/d' > $$@
+	$$(bin.c-pp) $(js.cpp.defines) -f $(1) -o $$@
 CLEAN_FILES += $(2)
 endef
-$(eval $(call CPP_JS,$(dir.tmp)/sqlite3-api.pre-cpp.js,$(dir.tmp)/sqlite3-api.js))
+$(eval $(call C-PP_JS,$(dir.tmp)/sqlite3-api.c-pp.js,$(dir.tmp)/sqlite3-api.js))
-$(eval $(call CPP_JS,$(dir.api)/pre-js.js,$(dir.tmp)/pre-js.js))
+$(eval $(call C-PP_JS,$(dir.api)/pre-js.js,$(dir.tmp)/pre-js.js))
 # /end CPP-of-JS bits
 ########################################################################
 

ext/wasm/api/pre-js.js

@@ -29,9 +29,9 @@ sqlite3InitModuleState.debugModule('self.location =',self.location);
    4) If none of the above apply, (prefix+path) is returned.
 */
 Module['locateFile'] = function(path, prefix) {
-#ifdef SQLITE_JS_ESM
+//#if SQLITE_JS_ESM
   return new URL(path, import.meta.url).href;
-#else
+//#else
   'use strict';
   let theFile;
   const up = this.urlParams;
@@ -51,7 +51,7 @@ Module['locateFile'] = function(path, prefix) {
     "result =", theFile
   );
   return theFile;
-#endif /* SQLITE_JS_EMS */
+//#endif /* SQLITE_JS_EMS */
 }.bind(sqlite3InitModuleState);
 
 /**

ext/wasm/api/sqlite3-api-opfs.js

@@ -167,11 +167,11 @@ const installOpfsVfs = function callee(options){
       return promiseReject_(err);
     };
     const W =
-#ifdef SQLITE_JS_ESM
+//#if SQLITE_JS_ESM
     new Worker(new URL(options.proxyUri, import.meta.url));
-#else
+//#else
     new Worker(options.proxyUri);
-#endif
+//#endif
     W._originalOnError = W.onerror /* will be restored later */;
     W.onerror = function(err){
       // The error object doesn't contain any useful info when the

manifest

@@ -1,5 +1,5 @@
-C Merge\strunk\sinto\sjs-cpp\sbranch.
+C Replace\suse\sof\scpp\swith\sthe\sfit-to-purpose\sc-pp\sto\savoid\scpp's\sC-centric/JS-unfriendly\squirks.
-D 2022-11-17T15:21:49.967
+D 2022-11-18T02:29:59.533
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -488,7 +488,7 @@ F ext/userauth/sqlite3userauth.h 7f3ea8c4686db8e40b0a0e7a8e0b00fac13aa7a3
 F ext/userauth/user-auth.txt e6641021a9210364665fe625d067617d03f27b04
 F ext/userauth/userauth.c 7f00cded7dcaa5d47f54539b290a43d2e59f4b1eb5f447545fa865f002fc80cb
 F ext/wasm/EXPORTED_FUNCTIONS.fiddle.in 27450c8b8c70875a260aca55435ec927068b34cef801a96205adb81bdcefc65c
-F ext/wasm/GNUmakefile 5034e5c0ebbf15479887d7253dcb2efb292906fb78d3e69701191c6257c45a9c
+F ext/wasm/GNUmakefile 3c97824ce76c7678344844e581a07ba75901a06def4d0046a2a410d9dd635a83
 F ext/wasm/README-dist.txt 2d670b426fc7c613b90a7d2f2b05b433088fe65181abead970980f0a4a75ea20
 F ext/wasm/README.md ef39861aa21632fdbca0bdd469f78f0096f6449a720f3f39642594af503030e9
 F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api 9120c2f8f51fa85f46dcf4dcb6b12f4a807d428f6089b99cdb08d8ddfcfd88b2
@@ -498,11 +498,11 @@ F ext/wasm/api/extern-post-js.js c197b7567496fc27766842f8c4f4963054bf8c667926ab3
 F ext/wasm/api/extern-pre-js.js cc61c09c7a24a07dbecb4c352453c3985170cec12b4e7e7e7a4d11d43c5c8f41
 F ext/wasm/api/post-js-footer.js cd0a8ec768501d9bd45d325ab0442037fb0e33d1f3b4f08902f15c34720ee4a1
 F ext/wasm/api/post-js-header.js d6ab3dfef4a06960d28a7eaa338d4e2a1a5981e9b38718168bbde8fdb2a439b8
-F ext/wasm/api/pre-js.js 9620327120abb15b3af96f72ef9efbcf69e78d90e501328521108b93547a8eb8
+F ext/wasm/api/pre-js.js 749bbbac2f1a2192eaba80cf5e00a3219da78b3c0a84e3019b5eef30e0bc9b88
 F ext/wasm/api/sqlite3-api-cleanup.js ecdc69dbfccfe26146f04799fcfd4a6f5790d46e7e3b9b6e9b0491f92ed8ae34
 F ext/wasm/api/sqlite3-api-glue.js 056f44b82c126358a0175e08a892d56fadfce177b0d7a0012502a6acf67ea6d5
 F ext/wasm/api/sqlite3-api-oo1.js e9a83489bbb4838ce0aee46eaaa9350e0e25a5b926b565e4f5ae8e840e4fbaed
-F ext/wasm/api/sqlite3-api-opfs.js 1def5fd676142ebe69594c77c5cf8523be1ca0880846a441bf5f981ff529672b
+F ext/wasm/api/sqlite3-api-opfs.js 4368a30586df3e11339a72082c77bdef670d619c6185c2dd1ebf5208c3ab0a5c
 F ext/wasm/api/sqlite3-api-prologue.js fd526fa017fa2578673ca18158354515c719e719a5d93f2f6d0e43f39170430e
 F ext/wasm/api/sqlite3-api-worker1.js e94ba98e44afccfa482874cd9acb325883ade50ed1f9f9526beb9de1711f182f
 F ext/wasm/api/sqlite3-license-version-header.js a661182fc93fc2cf212dfd0b987f8e138a3ac98f850b1112e29b5fbdaecc87c3
@@ -513,6 +513,7 @@ F ext/wasm/api/sqlite3-worker1-promiser.js 0c7a9826dbf82a5ed4e4f7bf7816e825a52af
 F ext/wasm/api/sqlite3-worker1.js 1e54ea3d540161bcfb2100368a2fc0cad871a207b8336afee1c445715851ec54
 F ext/wasm/batch-runner.html 4deeed44fe41496dc6898d9fb17938ea3291f40f4bfb977e29d0cef96fbbe4c8
 F ext/wasm/batch-runner.js 49609e89aaac9989d6c1ad3fae268e4878e1ad7bc5fd3e5c2f44959660780b2e
+F ext/wasm/c-pp.c 92285f7bce67ed7b7020b40fde8ed0982c442b63dc33df9dfd4b658d4a6c0779
 F ext/wasm/common/SqliteTestUtil.js d8bf97ecb0705a2299765c8fc9e11b1a5ac7f10988bbf375a6558b7ca287067b
 F ext/wasm/common/emscripten.css 3d253a6fdb8983a2ac983855bfbdd4b6fa1ff267c28d69513dd6ef1f289ada3f
 F ext/wasm/common/testing.css 35889709547d89a6109ff83b25c11bbc91d8dd43aab8722e428655ca98880a06
@@ -2055,8 +2056,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 718a6d371e61359d73c8f80afdb248e3d9b4d8df4c4e5c122ac884344e31035b 7c572d02e60a83b36543ba4d9d45f61e9fc111b61fee085410c2d87558c732d6
+P e047b33d1fb7d6a32e967f03f9952249cd2da4d21dc301fe92bd7baa0da5d6a9
-R dcd3d37cda21e5021973ee2a87f95321
+R f08c58c3d67343dbb1484f5dc6d0d557
 U stephan
-Z 83259d3e3081896d2aa5795af34840f7
+Z df00239aed9bf555d5579b7e3a06d443
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-e047b33d1fb7d6a32e967f03f9952249cd2da4d21dc301fe92bd7baa0da5d6a9
+49d70f071e918d5d095c807575bb7ce2b287a123261e789e938521b3b409429a