From d510bfa2df52e6ec6e78c59fe7a2855f3344665e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Morten=20S=C3=B8rvig?= <morten.sorvig@qt.io>
Date: Mon, 23 Oct 2023 22:29:44 +0200
Subject: [PATCH] wasm: set MAXIMUM_MEMORY to 4GB
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This increases the maximum available memory from 2GB
(Emscritpten default) to 4GB, which is the 32-bit wasm
max.

Add QT_WASM_MAXIMUM_MEMORY qmake/cmake option for overriding.

Change-Id: I6257fc919a749412c4ba1e0f939996c6057ce314
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
(cherry picked from commit c6d3b91549ceaafa81cbcedf243f798f1114a467)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 mkspecs/features/wasm/wasm.prf                |  6 +++++
 src/corelib/Qt6WasmMacros.cmake               |  9 ++++++++
 .../doc/src/cmake/cmake-properties.qdoc       | 23 +++++++++++++++++++
 3 files changed, 38 insertions(+)

diff --git a/mkspecs/features/wasm/wasm.prf b/mkspecs/features/wasm/wasm.prf
index 4e969aaf5ff..fb9f757ce26 100644
--- a/mkspecs/features/wasm/wasm.prf
+++ b/mkspecs/features/wasm/wasm.prf
@@ -48,6 +48,12 @@ exists($$QMAKE_QT_CONFIG) {
         INITIAL_MEMORY = $$QT_WASM_INITIAL_MEMORY
     }
     EMCC_LFLAGS += -s INITIAL_MEMORY=$$INITIAL_MEMORY
+    isEmpty(QT_WASM_MAXIMUM_MEMORY) {
+        MAXIMUM_MEMORY = 4GB # 32-bit max
+    } else {
+        MAXIMUM_MEMORY = $$QT_WASM_MAXIMUM_MEMORY
+    }
+    EMCC_LFLAGS += -s MAXIMUM_MEMORY=$$MAXIMUM_MEMORY
 
     qtConfig(sse2) {
         QMAKE_CFLAGS += -O2 -msimd128 -msse -msse2
diff --git a/src/corelib/Qt6WasmMacros.cmake b/src/corelib/Qt6WasmMacros.cmake
index 147c02e36df..0d851e0e481 100644
--- a/src/corelib/Qt6WasmMacros.cmake
+++ b/src/corelib/Qt6WasmMacros.cmake
@@ -91,6 +91,15 @@ function(_qt_internal_wasm_add_target_helpers target)
         endif()
         target_link_options("${target}" PRIVATE "SHELL:-s INITIAL_MEMORY=${QT_WASM_INITIAL_MEMORY}")
 
+        # Set maximum memory size, either from user setting or to 4GB (the 32-bit maximum)
+        get_target_property(_tmp_maximumMemory "${target}" QT_WASM_MAXIMUM_MEMORY)
+        if(_tmp_maximumMemory)
+            set(QT_WASM_MAXIMUM_MEMORY "${_tmp_maximumMemory}")
+        elseif(NOT DEFINED QT_WASM_MAXIMUM_MEMORY)
+            set(QT_WASM_MAXIMUM_MEMORY "4GB")
+        endif()
+        target_link_options("${target}" PRIVATE "SHELL:-s MAXIMUM_MEMORY=${QT_WASM_MAXIMUM_MEMORY}")
+
     endif()
 endfunction()
 
diff --git a/src/corelib/doc/src/cmake/cmake-properties.qdoc b/src/corelib/doc/src/cmake/cmake-properties.qdoc
index 91b2259eafd..f228cea1019 100644
--- a/src/corelib/doc/src/cmake/cmake-properties.qdoc
+++ b/src/corelib/doc/src/cmake/cmake-properties.qdoc
@@ -591,6 +591,29 @@ QT_WASM_INITIAL_MEMORY must be a multiple of 65536 bytes.
 For more information, see \l{https://github.com/emscripten-core/emscripten/blob/main/src/settings.js}{Emscripten compiler settings}.
 */
 
+/*!
+\page cmake-target-property-qt-wasm-maximum-memory.html
+\ingroup cmake-properties-qtcore
+\ingroup cmake-target-properties-qtcore
+
+\title QT_WASM_MAXIMUM_MEMORY
+\target cmake-target-property-QT_WASM_MAXIMUM_MEMORY
+
+\summary {Internal WebAssembly maximum memory.}
+
+\cmakepropertysince 6.7
+\preliminarycmakeproperty
+\cmakepropertywebassemblyonly
+
+Specifies the maximum amount of memory the applicataion can use. Translates into
+the Emscripten compiler setting of MAXIMUM_MEMORY. The default value
+is 4GB, which is the maximum for 32-bit WebAssembly.
+
+For more information, see \l{https://github.com/emscripten-core/emscripten/blob/main/src/settings.js}{Emscripten compiler settings}.
+*/
+
+
+
 /*!
 \page cmake-target-property-qt-ios-launch-screen.html
 \ingroup cmake-properties-qtcore