Run SpecBAS on macOS and Linux, through SDL2

.gitignore

@@ -29,3 +29,7 @@ src/backup.bat
 specbas_dev_notes.txt
 specbas_log.txt
 *.log
+
+# SDL2 backend build: fetched dependencies and build products.
+/build-sdl2/vendor/
+/build-sdl2/build/

build-sdl2/Makefile

@@ -0,0 +1,135 @@
+# Builds SpecBAS with the SDL2 backend, using Free Pascal on its own. No
+# Lazarus, no lazbuild, no .lpi.
+#
+#   make deps      fetch the outside pieces into vendor/
+#   make           build the executable into build/
+#   make app       macOS only: build build/SpecBAS.app, self-contained
+#   make clean     remove build/
+#   make distclean also remove vendor/
+#
+# Linking against a framework on macOS: SDL2-for-Pascal's sdl2.pas carries
+# {$LINKLIB libSDL2} for Darwin, so fpc always asks the linker for a library
+# named libSDL2 and there is no switch that stops it. build/link/ holds one
+# symlink, libSDL2.dylib, pointing at the framework's binary. The linker
+# follows it, reads that binary's own LC_ID_DYLIB, and records it in the
+# executable - @rpath/SDL2.framework/Versions/A/SDL2, which is the
+# dependency a bundled framework needs. The symlink exists only at link
+# time; nothing is copied and nothing is rewritten, so the framework's
+# signature stays valid.
+#
+# On Linux SDL2 comes from the distribution. sdl2.pas names libSDL2.so, fpc
+# turns that into -lSDL2, and the development package supplies it.
+
+FPC        ?= fpc
+APP_NAME   ?= SpecBAS
+BIN_NAME   ?= specbas
+
+HERE       := $(patsubst %/,%,$(dir $(abspath $(lastword $(MAKEFILE_LIST)))))
+ROOT       := $(dir $(HERE))
+SRC        := $(ROOT)src
+VENDOR     := $(HERE)/vendor
+BUILD      := $(HERE)/build
+UNITS      := $(VENDOR)/SDL2-for-Pascal/units
+FRAMEWORK  := $(VENDOR)/SDL2.framework
+LINKDIR    := $(BUILD)/link
+OBJDIR     := $(BUILD)/obj
+APP        := $(BUILD)/$(APP_NAME).app
+PROGRAM    := $(SRC)/SpecBAS_SDL2.dpr
+
+UNAME_S    := $(shell uname -s)
+
+# -O1, not -O2: Free Pascal 3.2.2 for aarch64 raises internal error
+# 200510011 on SP_FPEditor.pas at -O2.
+#
+# -MDelphi matches the mode every SpecBAS unit selects for itself.
+#
+# -Fi$(OBJDIR) is for the generated version include below.
+FPCFLAGS   := -MDelphi -Sh -O1 -vew -Fu$(SRC) -Fi$(SRC) -Fu$(UNITS) -Fi$(UNITS) \
+              -Fi$(OBJDIR)
+
+# The version SpecBAS shows in Finder, taken from the same file the Windows
+# build's VERSIONINFO resource is written in.
+VERSION_RC := $(SRC)/SpecBAS.rc
+VERSION    := $(shell sed -n 's/^FILEVERSION *[0-9]*,[0-9]*,\([0-9]*\),\([0-9]*\).*/\1.\2/p' $(VERSION_RC))
+BUILDNUM   := $(shell sed -n 's/^FILEVERSION *[0-9]*,[0-9]*,[0-9]*,\([0-9]*\).*/\1/p' $(VERSION_RC))
+
+ifeq ($(UNAME_S),Darwin)
+# -WM11.0 pins the deployment target to the macOS 11 floor the SDL2 release
+# framework carries, so the build is not tied to whatever macOS built it.
+#
+# -undefined dynamic_lookup leaves the BASS imports unresolved at link time.
+# bass.pas declares them "delayed", which Free Pascal honours on Windows
+# only; elsewhere they are ordinary imports and the link fails with no BASS
+# library present. SpecBAS loads BASS by hand at startup and runs silent
+# when that fails, so nothing calls those symbols while the library is
+# absent.
+FPCFLAGS   += -WM11.0 -Fl$(LINKDIR) -k-rpath -k@executable_path/../Frameworks \
+              -k-undefined -kdynamic_lookup
+LINKDEPS   := $(LINKDIR)/libSDL2.dylib
+else
+# The same BASS problem, answered in two pieces because GNU ld fails earlier
+# than Apple's linker does.
+#
+#   1. bass.pas names its library libbass.so, which fpc hands to the linker
+#      as -lbass, so the link dies on a missing library before it reaches
+#      the symbols. build/link/libbass.so is an empty GNU ld linker script:
+#      -lbass finds it, it contributes nothing, and unlike a stub shared
+#      object it leaves no DT_NEEDED behind, so the finished executable does
+#      not ask for a BASS library at run time either.
+#   2. --unresolved-symbols=ignore-all then lets the BASS_ symbols stay
+#      undefined, which is what "delayed" does on Windows.
+FPCFLAGS   += -Fl$(LINKDIR) -k--unresolved-symbols=ignore-all
+LINKDEPS   := $(LINKDIR)/libbass.so
+endif
+
+.PHONY: all deps exe app clean distclean
+
+all: exe
+
+deps:
+	@$(HERE)/fetch-deps.sh
+
+$(LINKDIR)/libSDL2.dylib: $(FRAMEWORK)/Versions/A/SDL2
+	@mkdir -p $(LINKDIR)
+	@ln -sf $(FRAMEWORK)/Versions/A/SDL2 $@
+
+$(LINKDIR)/libbass.so:
+	@mkdir -p $(LINKDIR)
+	@printf '/* Empty linker script. See the BASS note in build-sdl2/Makefile. */\n' > $@
+
+# The version SpecBAS puts in its window title and in BUILDSTR.
+#
+# On Windows it comes from the executable's own VERSIONINFO resource, read
+# back at run time. src/SpecBAS.rc is where that resource is written, so it
+# is the project's one statement of its own version, and this build reads
+# the same file rather than keeping a second copy of the number.
+#
+# Only the last two of the four components are used, because that is what
+# the Windows title bar shows: FILEVERSION 0,0,0,1511 is 0.1511 there and
+# 0.1511 here.
+VERSION_INC := $(OBJDIR)/SpecBAS_Version.inc
+
+$(VERSION_INC): $(VERSION_RC)
+	@mkdir -p $(OBJDIR)
+	@sed -n 's/^FILEVERSION *\([0-9]*\),\([0-9]*\),\([0-9]*\),\([0-9]*\).*/'"'"'\3.\4'"'"'/p' \
+	    $(VERSION_RC) > $@
+	@test -s $@ || { echo "Makefile: no FILEVERSION in $(VERSION_RC)" >&2; rm -f $@; exit 1; }
+
+exe: $(LINKDEPS) $(VERSION_INC)
+	@mkdir -p $(OBJDIR)
+	$(FPC) $(FPCFLAGS) -FU$(OBJDIR) -FE$(OBJDIR) -o$(OBJDIR)/$(BIN_NAME) $(PROGRAM)
+
+app: exe
+ifeq ($(UNAME_S),Darwin)
+	@$(HERE)/bundle.sh $(OBJDIR)/$(BIN_NAME) $(FRAMEWORK) $(APP) $(BIN_NAME) \
+	    $(VERSION) $(BUILDNUM)
+else
+	@echo "make app builds a macOS application bundle; on $(UNAME_S) the"
+	@echo "executable in $(OBJDIR) is the build product."
+endif
+
+clean:
+	rm -rf $(BUILD)
+
+distclean: clean
+	rm -rf $(VENDOR)

build-sdl2/bundle.sh

@@ -0,0 +1,71 @@
+#!/usr/bin/env bash
+# bundle.sh <executable> <SDL2.framework> <out.app> <binname> <version> <build>
+#
+# Assemble a self-contained .app: the executable, an Info.plist, and SDL2
+# inside the bundle. The result runs on a machine with no toolchain and no
+# system SDL2.
+#
+# Three facts have to agree, and none of them is set here:
+#
+#   1. SDL2.framework's own install name is
+#      @rpath/SDL2.framework/Versions/A/SDL2, which is what the release
+#      framework ships with.
+#   2. The executable records that same dependency, picked up at link time
+#      through the symlink the Makefile makes.
+#   3. The executable carries an rpath of @executable_path/../Frameworks,
+#      which from Contents/MacOS is Contents/Frameworks, where the framework
+#      is copied.
+#
+# So nothing needs install_name_tool, and because nothing is rewritten the
+# framework's signature survives the copy.
+
+set -euo pipefail
+
+exe="${1:?executable}"
+framework="${2:?SDL2.framework}"
+app="${3:?out .app}"
+binname="${4:?bin name}"
+version="${5:?version}"
+buildnum="${6:?build number}"
+
+contents="${app}/Contents"
+
+rm -rf "${app}"
+mkdir -p "${contents}/MacOS" "${contents}/Frameworks" "${contents}/Resources"
+
+cp "${exe}" "${contents}/MacOS/${binname}"
+# ditto keeps the framework's symlinks and signature; cp -R does not.
+ditto "${framework}" "${contents}/Frameworks/SDL2.framework"
+
+cat > "${contents}/Info.plist" <<PLIST
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>          <string>en</string>
+	<key>CFBundleExecutable</key>                 <string>${binname}</string>
+	<key>CFBundleIdentifier</key>                 <string>org.specos.SpecBAS</string>
+	<key>CFBundleInfoDictionaryVersion</key>      <string>6.0</string>
+	<key>CFBundleName</key>                       <string>$(basename "${app}" .app)</string>
+	<key>CFBundlePackageType</key>                <string>APPL</string>
+	<key>CFBundleShortVersionString</key>         <string>${version}</string>
+	<key>CFBundleVersion</key>                    <string>${buildnum}</string>
+	<key>LSMinimumSystemVersion</key>             <string>11.0</string>
+	<key>NSHighResolutionCapable</key>            <true/>
+	<key>NSPrincipalClass</key>                   <string>NSApplication</string>
+</dict>
+</plist>
+PLIST
+
+# Ad-hoc signature. Apple Silicon refuses to run an unsigned Mach-O.
+# --deep is deprecated, so each piece is named, innermost first.
+codesign --force --sign - --timestamp=none \
+    "${contents}/Frameworks/SDL2.framework" >/dev/null 2>&1
+codesign --force --sign - --timestamp=none \
+    "${contents}/MacOS/${binname}" >/dev/null 2>&1
+codesign --force --sign - --timestamp=none "${app}" >/dev/null 2>&1
+
+echo "==> ${app}"
+codesign --verify --deep --verbose=1 "${app}" 2>&1 | sed 's/^/    /'
+echo "    executable links:"
+otool -L "${contents}/MacOS/${binname}" | tail -n +2 | sed 's/^/    /'

build-sdl2/fetch-deps.sh

@@ -0,0 +1,120 @@
+#!/usr/bin/env bash
+#
+# Put the outside pieces the SDL2 build needs into vendor/:
+#
+#   vendor/SDL2-for-Pascal/    the Pascal bindings, all platforms
+#   vendor/SDL2.framework      the SDL2 runtime for the bundle, macOS only
+#
+# vendor/ is gitignored. Everything fetched here is pinned and checked, so
+# this script is the tracked half and vendor/ is disposable.
+#
+# On Linux SDL2 comes from the distribution instead: the bindings name
+# libSDL2.so, fpc turns that into -lSDL2, and the development package
+# supplies both. This script checks it is there and says what to install if
+# it is not.
+#
+# On macOS the runtime is the release framework from libsdl.org rather than
+# Homebrew's sdl2, which is sdl2-compat: a shim that reaches SDL3 by dlopen
+# at run time, so copying it into a bundle copies something that then looks
+# for an SDL3 the target machine has no reason to have. Homebrew also builds
+# to the host's own macOS version, so the result refuses to load on anything
+# older. The release framework is built for this job: its LC_ID_DYLIB is
+# already @rpath/SDL2.framework/Versions/A/SDL2, it is universal, and its
+# minimum is macOS 11.
+#
+# The disk image is mounted with hdiutil rather than unpacked with an
+# archiver. A framework is held together by symlinks, and an archiver writes
+# those out as small text files, which gives a directory that looks right,
+# fails to load, and fails codesign.
+
+set -euo pipefail
+
+here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd -P)"
+vendor="${here}/vendor"
+work="${vendor}/.download"
+
+SDL2_VERSION="2.32.8"
+SDL2_DMG_SHA256="de07f71cc85cd8909c977e105c4f2ca419abd09b981c347e003592186caf6fa0"
+SDL2_DMG_URL="https://github.com/libsdl-org/SDL/releases/download/release-${SDL2_VERSION}/SDL2-${SDL2_VERSION}.dmg"
+
+BINDINGS_URL="https://github.com/PascalGameDevelopment/SDL2-for-Pascal.git"
+BINDINGS_COMMIT="a48b83efbfa7c13ce548905ebdc954eb6c8384be"
+
+mkdir -p "${work}"
+
+# --- SDL2 runtime ------------------------------------------------------
+
+case "$(uname -s)" in
+Darwin)
+    if [[ -d "${vendor}/SDL2.framework" ]]; then
+        echo "==> SDL2.framework already present"
+    else
+        dmg="${work}/SDL2-${SDL2_VERSION}.dmg"
+        if [[ ! -f "${dmg}" ]]; then
+            echo "==> downloading SDL2 ${SDL2_VERSION}"
+            curl -fsSL -o "${dmg}" "${SDL2_DMG_URL}"
+        fi
+
+        got="$(shasum -a 256 "${dmg}" | awk '{print $1}')"
+        if [[ "${got}" != "${SDL2_DMG_SHA256}" ]]; then
+            echo "fetch-deps.sh: sha256 mismatch for ${dmg}" >&2
+            echo "  expected ${SDL2_DMG_SHA256}" >&2
+            echo "  got      ${got}" >&2
+            exit 1
+        fi
+
+        # The mount point is hdiutil's own choice, read back out of its
+        # output. Naming one under this directory is refused where the
+        # repository is on a secondary volume.
+        echo "==> mounting ${dmg}"
+        mnt="$(hdiutil attach -nobrowse -readonly "${dmg}" \
+            | sed -n 's#.*\(/Volumes/.*\)$#\1#p' | tail -1)"
+        if [[ -z "${mnt}" || ! -d "${mnt}/SDL2.framework" ]]; then
+            echo "fetch-deps.sh: could not mount ${dmg}" >&2
+            exit 1
+        fi
+        trap 'hdiutil detach -quiet "'"${mnt}"'" >/dev/null 2>&1 || true' EXIT
+
+        echo "==> copying SDL2.framework into vendor/"
+        # ditto, not cp -R: it keeps the symlinks, permissions and extended
+        # attributes that leave the framework's signature intact.
+        ditto "${mnt}/SDL2.framework" "${vendor}/SDL2.framework"
+        cp "${mnt}/License.txt" "${vendor}/SDL2-License.txt"
+
+        hdiutil detach -quiet "${mnt}" || true
+        trap - EXIT
+    fi
+
+    codesign --verify --verbose=1 "${vendor}/SDL2.framework" 2>&1 | sed 's/^/    /'
+    ;;
+Linux)
+    if command -v sdl2-config >/dev/null 2>&1; then
+        echo "==> system SDL2 $(sdl2-config --version)"
+    elif command -v pkg-config >/dev/null 2>&1 && pkg-config --exists sdl2; then
+        echo "==> system SDL2 $(pkg-config --modversion sdl2)"
+    else
+        echo "fetch-deps.sh: SDL2 development files not found." >&2
+        echo "  Debian, Ubuntu, Raspberry Pi OS:  sudo apt install libsdl2-dev" >&2
+        echo "  Fedora:                           sudo dnf install SDL2-devel" >&2
+        echo "  Arch:                             sudo pacman -S sdl2" >&2
+        exit 1
+    fi
+    ;;
+*)
+    echo "==> $(uname -s): assuming SDL2 is supplied by the system"
+    ;;
+esac
+
+# --- SDL2-for-Pascal ---------------------------------------------------
+
+if [[ -d "${vendor}/SDL2-for-Pascal/.git" ]]; then
+    echo "==> SDL2-for-Pascal already present"
+else
+    echo "==> cloning SDL2-for-Pascal"
+    rm -rf "${vendor}/SDL2-for-Pascal"
+    git clone --quiet "${BINDINGS_URL}" "${vendor}/SDL2-for-Pascal"
+fi
+git -C "${vendor}/SDL2-for-Pascal" checkout --quiet "${BINDINGS_COMMIT}"
+echo "    bindings at $(git -C "${vendor}/SDL2-for-Pascal" rev-parse HEAD)"
+
+echo "==> vendor/ ready"

src/RunTimeCompiler.pas

@@ -29,7 +29,9 @@   TPayload = class(TObject)
 implementation
 
 uses
-  SysUtils, ActiveX, SP_Tokenise, SP_Util, SP_BankFiling, SP_SysVars;
+  // ActiveX is a Windows unit and supplies IsEqualGUID there. Off Windows
+  // the same function comes from SysUtils.
+  SysUtils, {$IFNDEF UNIX}ActiveX, {$ENDIF}SP_Tokenise, SP_Util, SP_BankFiling, SP_SysVars;
 
 type
   TPayloadFooter = packed record

src/SP_BankManager.pas

@@ -224,7 +224,7 @@ interface
 
 implementation
 
-Uses MainForm, {$IFNDEF RUNTIMEONLY}SP_FPEditor, SP_BASICEditorHostUnit, SP_ToolTipWindow, {$ENDIF}
+Uses {$IFDEF SDL2}SP_SDL2Host{$ELSE}MainForm{$ENDIF}, {$IFNDEF RUNTIMEONLY}SP_FPEditor, SP_BASICEditorHostUnit, SP_ToolTipWindow, {$ENDIF}
      SP_Graphics, SP_Graphics32, SP_Sound, SP_Main, SP_BaseComponentUnit, SP_3DEngineUnit;
 
 Procedure SP_ChangeBankSize(Index: Integer);

src/SP_CheckBoxUnit.pas

@@ -60,7 +60,7 @@ interface
 
 implementation
 
-Uses {$IFNDEF FPC}Windows{$ELSE}LCLType{$ENDIF}, Types, Classes, Math, SP_Interpret_PostFix, SP_Input, SP_Components, SP_Sound, SP_SysVars;
+Uses {$IFNDEF FPC}Windows, {$ELSE}{$IFNDEF SDL2}LCLType, {$ENDIF}{$ENDIF}Types, Classes, Math, SP_Interpret_PostFix, SP_Input, SP_Components, SP_Sound, SP_SysVars;
 
 // SP_CheckBox
 

src/SP_Components.pas

@@ -23,7 +23,7 @@
 interface
 
 Uses Types, SysUtils, {$IFNDEF FPC}System.Generics.Collections{$ELSE}Generics.Collections{$ENDIF}, Classes, SyncObjs, Math,
-     {$IFNDEF FPC}Vcl.ClipBrd{$ELSE}ClipBrd{$ENDIF}, SP_SysVars, SP_FileIO, SP_Util, SP_ButtonUnit, SP_BaseComponentUnit, SP_Errors;
+     {$IFNDEF FPC}Vcl.ClipBrd, {$ELSE}{$IFNDEF SDL2}ClipBrd, {$ENDIF}{$ENDIF}SP_SysVars, SP_FileIO, SP_Util, SP_ButtonUnit, SP_BaseComponentUnit, SP_Errors;
 
 // A collection of UI elements for building UI apps. Based on Windows controls.
 

src/SP_DebugPanel.pas

@@ -4,7 +4,7 @@
 
 interface
 
-uses Dialogs, Math, Classes, SyncObjs, SysUtils, SP_Util, SP_BaseComponentUnit, SP_ListBoxUnit, SP_ComboBoxUnit, SP_ControlMsgs, SP_ButtonUnit, SP_Input, SP_ContainerUnit, SP_AmigaGuideUnit;
+uses {$IFNDEF SDL2}Dialogs, {$ENDIF}Math, Classes, SyncObjs, SysUtils, SP_Util, SP_BaseComponentUnit, SP_ListBoxUnit, SP_ComboBoxUnit, SP_ControlMsgs, SP_ButtonUnit, SP_Input, SP_ContainerUnit, SP_AmigaGuideUnit;
 
 Type
 
@@ -73,7 +73,7 @@ interface
 
 implementation
 
-Uses {$IFNDEF FPC}Vcl.ClipBrd{$ELSE}ClipBrd{$ENDIF}, SP_FPEditor, SP_Errors, SP_Graphics, SP_BankManager, SP_BankFiling, SP_SysVars, SP_Components, SP_Variables, SP_AnsiStringList,
+Uses {$IFNDEF FPC}Vcl.ClipBrd, {$ELSE}{$IFNDEF SDL2}ClipBrd, {$ENDIF}{$ENDIF}SP_FPEditor, SP_Errors, SP_Graphics, SP_BankManager, SP_BankFiling, SP_SysVars, SP_Components, SP_Variables, SP_AnsiStringList,
      SP_Interpret_PostFix, SP_FileIO, SP_Main, SP_MenuActions, SP_BASICEditorHostUnit, SP_MemoUnit, SP_Debugging, SP_Execute;
 
 Procedure SP_UpdateAfterDebug;