More work on variables and parameters

7 files changed, 53 insertions, 4 deletions

diff --git a/src/GCodes/GCodeBuffer/ExpressionParser.cpp b/src/GCodes/GCodeBuffer/ExpressionParser.cpp
index 344810e3..48f5c027 100644
--- a/src/GCodes/GCodeBuffer/ExpressionParser.cpp
+++ b/src/GCodes/GCodeBuffer/ExpressionParser.cpp
@@ -1031,6 +1031,23 @@ ExpressionValue ExpressionParser::ParseIdentifierExpression(bool evaluate, bool
 	// If we are not evaluating then the object expression doesn't have to exist, so don't retrieve it because that might throw an error
 	if (evaluate)
 	{
+		// Check for a parameter, local or global variable
+		if (StringStartsWith(id.c_str(), "param."))
+		{
+			return GetVariableValue(gb.GetVariables(), id.c_str() + strlen("param."), true);
+		}
+
+		if (StringStartsWith(id.c_str(), "global."))
+		{
+			return GetVariableValue(gb.GetVariables(), id.c_str() + strlen("global."), false);
+		}
+
+		if (StringStartsWith(id.c_str(), "user."))
+		{
+			return GetVariableValue(reprap.globalVariables, id.c_str() + strlen("user."), false);
+		}
+
+		// Else assume an object model value
 		ExpressionValue value = reprap.GetObjectValue(context, nullptr, id.c_str());
 		if (context.ObsoleteFieldQueried() && obsoleteField.IsEmpty())
 		{
@@ -1041,6 +1058,18 @@ ExpressionValue ExpressionParser::ParseIdentifierExpression(bool evaluate, bool
 	return ExpressionValue(nullptr);
 }
 
+// Get the value of a variable
+ExpressionValue ExpressionParser::GetVariableValue(VariableSet& vars, const char *name, bool parameter) THROWS(GCodeException)
+{
+	const Variable* var = vars.Lookup(name);
+	if (var != nullptr && (!parameter || var->GetScope() < 0))
+	{
+		return var->GetValue();
+	}
+
+	throw ConstructParseException("Unknown variable");
+}
+
 // Parse a quoted string, given that the current character is double-quote
 // This is almost a copy of InternalGetQuotedString in class StringParser
 ExpressionValue ExpressionParser::ParseQuotedString() THROWS(GCodeException)
diff --git a/src/GCodes/GCodeBuffer/ExpressionParser.h b/src/GCodes/GCodeBuffer/ExpressionParser.h
index f48679fc..3dd5f236 100644
--- a/src/GCodes/GCodeBuffer/ExpressionParser.h
+++ b/src/GCodes/GCodeBuffer/ExpressionParser.h
@@ -13,6 +13,8 @@
 #include <ObjectModel/ObjectModel.h>
 #include <GCodes/GCodeException.h>
 
+class VariableSet;
+
 class ExpressionParser
 {
 public:
@@ -41,6 +43,7 @@ private:
 	ExpressionValue ParseIdentifierExpression(bool evaluate, bool applyLengthOperator) THROWS(GCodeException)
 		pre(readPointer >= 0; isalpha(gb.buffer[readPointer]));
 	ExpressionValue ParseQuotedString() THROWS(GCodeException);
+	ExpressionValue GetVariableValue(VariableSet& vars, const char *name, bool parameter) THROWS(GCodeException);
 
 	void ConvertToFloat(ExpressionValue& val, bool evaluate) const THROWS(GCodeException);
 	void ConvertToBool(ExpressionValue& val, bool evaluate) const THROWS(GCodeException);
diff --git a/src/GCodes/GCodeBuffer/GCodeBuffer.cpp b/src/GCodes/GCodeBuffer/GCodeBuffer.cpp
index 21e6c1f2..1feac192 100644
--- a/src/GCodes/GCodeBuffer/GCodeBuffer.cpp
+++ b/src/GCodes/GCodeBuffer/GCodeBuffer.cpp
@@ -1016,4 +1016,14 @@ void GCodeBuffer::SetParameters(int codeRunning) noexcept
 	PARSER_OPERATION(SetParameters(machineState, codeRunning));
 }
 
+VariableSet& GCodeBuffer::GetVariables() const noexcept
+{
+	GCodeMachineState *mc = machineState;
+	while (mc->localPush && mc->GetPrevious() != nullptr)
+	{
+		mc = mc->GetPrevious();
+	}
+	return mc->variables;
+}
+
 // End
diff --git a/src/GCodes/GCodeBuffer/GCodeBuffer.h b/src/GCodes/GCodeBuffer/GCodeBuffer.h
index 25931cc4..65acf25f 100644
--- a/src/GCodes/GCodeBuffer/GCodeBuffer.h
+++ b/src/GCodes/GCodeBuffer/GCodeBuffer.h
@@ -49,7 +49,7 @@ public:
 	void Init() noexcept;														// Set it up to parse another G-code
 	void Diagnostics(MessageType mtype) noexcept;								// Write some debug info
 
-	bool Put(char c) noexcept SPEED_CRITICAL;								// Add a character to the end
+	bool Put(char c) noexcept SPEED_CRITICAL;									// Add a character to the end
 #if HAS_LINUX_INTERFACE
 	void PutBinary(const uint32_t *data, size_t len) noexcept;					// Add an entire binary G-Code, overwriting any existing content
 #endif
@@ -224,6 +224,7 @@ public:
 	bool WasMotionCommanded() const noexcept { return motionCommanded; }
 
 	void SetParameters(int codeRunning) noexcept;
+	VariableSet& GetVariables() const noexcept;
 
 	Mutex mutex;
 
diff --git a/src/GCodes/GCodeMachineState.cpp b/src/GCodes/GCodeMachineState.cpp
index e0868f08..bae9873b 100644
--- a/src/GCodes/GCodeMachineState.cpp
+++ b/src/GCodes/GCodeMachineState.cpp
@@ -20,7 +20,7 @@ GCodeMachineState::GCodeMachineState() noexcept
 	  selectedPlane(0), drivesRelative(false), axesRelative(false),
 	  doingFileMacro(false), waitWhileCooling(false), runningM501(false), runningM502(false),
 	  volumetricExtrusion(false), g53Active(false), runningSystemMacro(false), usingInches(false),
-	  waitingForAcknowledgement(false), messageAcknowledged(false),
+	  waitingForAcknowledgement(false), messageAcknowledged(false), localPush(false),
 #if HAS_LINUX_INTERFACE
 	  lastCodeFromSbc(false), macroStartedByCode(false), fileFinished(false),
 #endif
@@ -45,7 +45,7 @@ GCodeMachineState::GCodeMachineState(GCodeMachineState& prev, bool withinSameFil
 	  selectedPlane(prev.selectedPlane), drivesRelative(prev.drivesRelative), axesRelative(prev.axesRelative),
 	  doingFileMacro(prev.doingFileMacro), waitWhileCooling(prev.waitWhileCooling), runningM501(prev.runningM501), runningM502(prev.runningM502),
 	  volumetricExtrusion(false), g53Active(false), runningSystemMacro(prev.runningSystemMacro), usingInches(prev.usingInches),
-	  waitingForAcknowledgement(false), messageAcknowledged(false),
+	  waitingForAcknowledgement(false), messageAcknowledged(false), localPush(withinSameFile),
 #if HAS_LINUX_INTERFACE
 	  lastCodeFromSbc(prev.lastCodeFromSbc), macroStartedByCode(prev.macroStartedByCode), fileFinished(prev.fileFinished),
 #endif
diff --git a/src/GCodes/Variable.h b/src/GCodes/Variable.h
index d6074f52..9054514e 100644
--- a/src/GCodes/Variable.h
+++ b/src/GCodes/Variable.h
@@ -25,6 +25,9 @@ public:
 	Variable(const char *str, ExpressionValue pVal, int8_t pScope) noexcept;
 	~Variable();
 
+	ExpressionValue GetValue() const { return val; }
+	int8_t GetScope() const { return scope; }
+
 private:
 	Variable *next;
 	StringHandle name;
diff --git a/src/Platform/RepRap.h b/src/Platform/RepRap.h
index b3227255..9e07bf3a 100644
--- a/src/Platform/RepRap.h
+++ b/src/Platform/RepRap.h
@@ -27,6 +27,7 @@ Licence: GPL
 #include "RTOSIface/RTOSIface.h"
 #include "GCodes/GCodeResult.h"
 #include <General/inplace_function.h>
+#include <GCodes/Variable.h>
 
 #if SUPPORT_CAN_EXPANSION
 # include <CAN/ExpansionManager.h>
@@ -177,7 +178,7 @@ public:
 	static uint32_t DoDivide(uint32_t a, uint32_t b) noexcept;			// helper function for diagnostic tests
 	static void GenerateBusFault() noexcept;							// helper function for diagnostic tests
 	static float SinfCosf(float angle) noexcept;						// helper function for diagnostic tests
-	static float FastSqrtf(float f) noexcept;								// helper function for diagnostic tests
+	static float FastSqrtf(float f) noexcept;							// helper function for diagnostic tests
 
 	void KickHeatTaskWatchdog() noexcept { heatTaskIdleTicks = 0; }
 
@@ -196,6 +197,8 @@ public:
 	void ToolsUpdated() noexcept { ++toolsSeq; }
 	void VolumesUpdated() noexcept { ++volumesSeq; }
 
+	VariableSet globalVariables;
+
 protected:
 	DECLARE_OBJECT_MODEL
 	OBJECT_MODEL_ARRAY(boards)