Improve inline assembler parser

README.md

@@ -49,7 +49,6 @@ After four weeks, the compiler has now matured significantly.  There are still s
 
 * Simple loop opmtimization
 * Partial block domination analysis
-* No register use for arguments
 * Auto variables placed on fixed stack for known call sequence
 
 ### Intermediate code generation
@@ -77,7 +76,98 @@ The compiler is command line driven, and creates an executable .prg file.
 
 A list of source files can be provided.
 
+## Inline Assembler
 
+Inline assembler can be embedded inside of any functions, regardles of their compilation target of byte code or native.  
+
+### Accessing variables in assembler
+
+Access to local variables and parameters is done with zero page registers, global variables are accessed using absolute addressing.
+
+    void putchar(char c)
+    {
+        __asm {
+            lda c
+            bne w1
+            lda #13
+        w1:
+            jsr 0xffd2
+        }
+    }
+
+A function return value can be provided in the zero page addresses ACCU (+0..+3).
+
+    char getchar(void)
+    {
+        __asm {
+            jsr 0xffcf
+            sta accu
+            lda #0
+            sta accu + 1
+            }
+    }
+
+Labels are defined with a colon after the name.  Pure assembler functions can be defined outside of the scope of a function and accessed using their name inside of other assembler function.  One can e.g. set up an interrupt
+
+### Interrupt routines
+
+The C compiler will not generate good interrupt code, it is simply too greedy with the zero page registers.  Interrupt code should therefore be written in assembler.
+
+
+	#include <math.h>
+
+    // Next line for interrupt
+    char npos;
+
+    // Interrupt routine
+    __asm irq
+    {   
+        lda $d019   // Check if it is raster IRQ
+        and #$01
+        beq w1
+        
+        inc $d020   // Start colored section
+        inc $d021
+        
+        ldx #20     // Wait for 2/3 lines
+    l1: dex
+        bne l1
+        
+        dec $d020   // End colored section
+        dec $d021
+        
+        lda npos    // Setup next interrupt
+        sta $d012
+    w1:
+        asl $d019   // Ack interrupt
+        
+        jmp $ea31   // System IRQ routine
+    }
+
+    int main(void)
+    {
+        __asm { sei }   // Disable interrupt
+        
+        
+        *(void **)0x0314 = irq;     // Install interrupt routine
+        *(char *)0xd01a = 1;        // Enable raster interrupt
+        *(char *)0xd011 &= 0x7f;    // Set raster line for IRQ
+        *(char *)0xd012 = 100;
+
+        npos = 100;
+        
+        __asm { cli }   // Re-enable interrupt
+        
+        // Move the interrupt raster line up/down
+        float f = 0;
+        while (true)
+        {
+            npos = 130 + (int)(100 * sin(f));
+            f += 0.1;
+        }
+        
+        return 0;
+    }
 
 ## Implementation Details
 

oscar64/InterCodeGenerator.cpp

@@ -668,6 +668,23 @@ InterCodeGenerator::ExValue InterCodeGenerator::TranslateExpression(Declaration*
 
 			} break;
 
+			case DT_CONST_ASSEMBLER:
+			{
+				if (!dec->mLinkerObject)
+					TranslateAssembler(proc->mModule, dec->mValue, nullptr);
+
+				InterInstruction* ins = new InterInstruction();
+				ins->mCode = IC_CONSTANT;
+				ins->mDst.mType = IT_POINTER;
+				ins->mDst.mTemp = proc->AddTemporary(ins->mDst.mType);
+				ins->mConst.mVarIndex = dec->mVarIndex;
+				ins->mConst.mLinkerObject = dec->mLinkerObject;
+				ins->mConst.mMemory = IM_PROCEDURE;
+				ins->mConst.mIntConst = 0;
+				block->Append(ins);
+				return ExValue(TheVoidPointerTypeDeclaration, ins->mDst.mTemp);
+			}
+
 			case DT_CONST_POINTER:
 			{
 				vl = TranslateExpression(procType, proc, block, dec->mValue, breakBlock, continueBlock, inlineMapper);

oscar64/Parser.cpp

@@ -1991,6 +1991,17 @@ Expression* Parser::ParseAssemblerBaseOperand(void)
 			else
 				mErrors->Error(mScanner->mLocation, EERR_INCOMPATIBLE_OPERATOR, "Identifier for qualification expected");
 		}
+
+		if (exp->mDecValue->mType == DT_CONST_ASSEMBLER)
+		{
+			Declaration* ndec = new Declaration(mScanner->mLocation, DT_LABEL);
+			ndec->mIdent = exp->mDecValue->mIdent;
+			ndec->mBase = exp->mDecValue;
+			ndec->mInteger = 0;
+			exp->mDecValue = ndec;
+			exp->mDecType = TheUnsignedIntTypeDeclaration;
+		}
+
 		break;
 	default:
 		mErrors->Error(mScanner->mLocation, EERR_ASM_INVALD_OPERAND, "Invalid assembler operand");
@@ -2286,7 +2297,7 @@ Expression* Parser::ParseAssembler(void)
 			{
 				ilast->mAsmInsType = ins;
 				mScanner->NextToken();
-				if (mScanner->mToken == TK_EOL)
+				if (mScanner->mToken == TK_EOL || mScanner->mToken == TK_CLOSE_BRACE)
 					ilast->mAsmInsMode = ASMIM_IMPLIED;
 				else if (mScanner->mToken == TK_HASH)
 				{
@@ -2382,12 +2393,12 @@ Expression* Parser::ParseAssembler(void)
 				if (ilast->mAsmInsType == ASMIT_BYTE)
 					ilast->mAsmInsMode = ASMIM_IMMEDIATE;
 
-				if (mScanner->mToken != TK_EOL)
+				if (mScanner->mToken != TK_EOL && mScanner->mToken != TK_CLOSE_BRACE)
 				{
 					mErrors->Error(mScanner->mLocation, EERR_SYNTAX, "End of line expected");
 				}
 
-				while (mScanner->mToken != TK_EOL && mScanner->mToken != TK_EOF)
+				while (mScanner->mToken != TK_EOL && mScanner->mToken != TK_EOF && mScanner->mToken != TK_CLOSE_BRACE)
 					mScanner->NextToken();
 
 				offset += AsmInsSize(ilast->mAsmInsType, ilast->mAsmInsMode);