From 5010de0779d0a7de02426cfe63727bd9a84af7c3 Mon Sep 17 00:00:00 2001
From: Michael Adams <mdadams@ece.uvic.ca>
Date: Sat, 4 Nov 2023 21:39:06 -0700
Subject: [PATCH] Made a few improvements to the WebAssembly support.

---
 CMakeLists.txt                  |  1 +
 build/build_wasi_jasper         | 12 ++++++------
 src/libjasper/base/jas_malloc.c | 10 +++++++++-
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 17ffcf30..ba6f1173 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -197,6 +197,7 @@ if(JAS_WASM)
 	set(JAS_STDC_VERSION "201112L")
 	set(JAS_ENABLE_MULTITHREADING_SUPPORT 0)
 	set(JAS_ENABLE_SHARED 0)
+	set(JAS_USE_JAS_INIT 0)
 	add_compile_definitions(JAS_WASI_LIBC)
 endif()
 
diff --git a/build/build_wasi_jasper b/build/build_wasi_jasper
index e5aad739..5594410f 100755
--- a/build/build_wasi_jasper
+++ b/build/build_wasi_jasper
@@ -111,15 +111,15 @@ configure_options=(
 	-DCMAKE_INSTALL_PREFIX="$install_dir"
 	-DCMAKE_BUILD_TYPE=Release
 	-DCMAKE_VERBOSE_MAKEFILE=1
-	-DJAS_CROSSCOMPILING=1
-	-DJAS_STDC_VERSION=201112L
-	-DJAS_ENABLE_MULTITHREADING_SUPPORT=0
-	-DJAS_ENABLE_SHARED=0
+	-DJAS_WASM=1
 	-DJAS_ENABLE_CXX=0
-	-DJAS_USE_JAS_INIT=1
 	-DJAS_STRICT=0
-	-DJAS_WASM=1
 	-DJAS_ENABLE_DOC=0
+	#-DJAS_CROSSCOMPILING=1
+	#-DJAS_STDC_VERSION=201112L
+	#-DJAS_ENABLE_MULTITHREADING_SUPPORT=0
+	#-DJAS_ENABLE_SHARED=0
+	#-DJAS_USE_JAS_INIT=0
 )
 
 cmake -H"$source_dir" -B"$build_dir" "${configure_options[@]}" || \
diff --git a/src/libjasper/base/jas_malloc.c b/src/libjasper/base/jas_malloc.c
index 7eb3e6a2..9b540008 100644
--- a/src/libjasper/base/jas_malloc.c
+++ b/src/libjasper/base/jas_malloc.c
@@ -626,7 +626,15 @@ void jas_basic_free(jas_allocator_t *allocator, void *ptr)
 
 size_t jas_get_total_mem_size()
 {
-#if defined(__linux__)
+#if defined(JAS_WASI_LIBC)
+	/*
+	NOTE: On the 32-bit WebAssembly platform, the unsigned integral type
+	size_t is likely to have a size of 32 bits.  So, choose the maximum
+	memory to be less than 2 ^ 32 in order to avoid overflow.
+	*/
+	return JAS_CAST(size_t, 4096) * JAS_CAST(size_t, 1024) *
+	  JAS_CAST(size_t, 1024) - 1;
+#elif defined(__linux__)
 	struct sysinfo buf;
 	if (sysinfo(&buf)) {
 		return 0;