correct returning from procedure with arguments

- ec: first working return from a procedure with parameters
- asm-i386: needed a ret imm16 to clean up stack when returning from call with parameters
- asm-i386: introduced min and max operands constraints (better than arbitrary expections
  by opcode, for instance dd)

8 files changed, 120 insertions, 52 deletions

diff --git a/ecomp-c/asm-i386.c b/ecomp-c/asm-i386.c
index c9de15a..584c631 100644
--- a/ecomp-c/asm-i386.c
+++ b/ecomp-c/asm-i386.c
@@ -32,6 +32,7 @@
  * E9 XX XX XX XX      jmp  rel32
  * E8 XX XX XX XX      call rel32
  * C3                  ret
+ * C2 XX XX            ret  imm16
  * F4                  hlt
  * CD XX               int  nnn
  * 90                  nop
@@ -52,6 +53,9 @@
  * rel32
  * relative address offset (8/32 bits)
  * 
+ * imm16
+ * little endian 16-bit constant
+ * 
  * format binary
  * use32
  * org 0x00000000
@@ -68,7 +72,8 @@ enum {
 	MAX_NUMBER_LEN = 10,
 	MAX_HEXNUMBER_LEN = 8,
 	MAX_STRING_LEN = 64,	
-	MAX_PASSES = 10
+	MAX_PASSES = 10,
+	MAX_NOF_OPERANDS = 64
 };
 
 static int DEBUG_GETCHAR = 0;
@@ -842,7 +847,8 @@ typedef struct OpcodeInfo {
 	Symbol *label;
 	int addr;
 	Opcode opcode;
-	int nof_operands;
+	int min_operands;
+	int max_operands;
 	OperandInfo *operand;
 	struct OpcodeInfo *next;
 	int size;
@@ -866,51 +872,60 @@ static OpcodeInfo *parseOpcode( void )
 			case 'a':
 				if( strcmp( ident, "add" ) == 0 ) {
 					opcode_info->opcode = OPCODE_ADD;
-					opcode_info->nof_operands = 2;
+					opcode_info->min_operands = 2;
+					opcode_info->max_operands = 2;
 					opcode_info->size = 2;
 				}
 				break;
 			case 'c':
 				if( strcmp( ident, "cmp" ) == 0 ) {
 					opcode_info->opcode = OPCODE_CMP;
-					opcode_info->nof_operands = 2;
+					opcode_info->min_operands = 2;
+					opcode_info->max_operands = 2;
 					opcode_info->size = 2;
 				} else if( strcmp( ident, "call" ) == 0 ) {
 					opcode_info->opcode = OPCODE_CALL;
-					opcode_info->nof_operands = 1;
+					opcode_info->min_operands = 1;
+					opcode_info->max_operands = 1;
 					opcode_info->size = 5;
 				}
 				break;
 			case 'd':
 				if( strcmp( ident, "dd" ) == 0 ) {
 					opcode_info->opcode = OPCODE_PSEUDO_DD;
-					opcode_info->nof_operands = 1;
+					opcode_info->min_operands = 1;
+					opcode_info->max_operands = MAX_NOF_OPERANDS;
 					opcode_info->size = 4;
 				} else if( strcmp( ident, "db" ) == 0 ) {
 					opcode_info->opcode = OPCODE_PSEUDO_DB;
-					opcode_info->nof_operands = 1;
+					opcode_info->min_operands = 1;
+					opcode_info->max_operands = MAX_NOF_OPERANDS;
 					opcode_info->size = 1;
 				} else if( strcmp( ident, "dw" ) == 0 ) {
 					opcode_info->opcode = OPCODE_PSEUDO_DW;
-					opcode_info->nof_operands = 1;
+					opcode_info->min_operands = 1;
+					opcode_info->max_operands = MAX_NOF_OPERANDS;
 					opcode_info->size = 2;
 				} else if( strcmp( ident, "div" ) == 0 ) {
 					opcode_info->opcode = OPCODE_DIV;
-					opcode_info->nof_operands = 1;
+					opcode_info->min_operands = 1;
+					opcode_info->max_operands = 1;
 					opcode_info->size = 2;
 				}
 				break;
 			case 'h':
 				if( strcmp( ident, "hlt" ) == 0 ) {
 					opcode_info->opcode = OPCODE_HLT;
-					opcode_info->nof_operands = 0;
+					opcode_info->min_operands = 0;
+					opcode_info->max_operands = 0;
 					opcode_info->size = 1;
 				}
 				break;
 			case 'i':
 				if( strcmp( ident, "int" ) == 0 ) {
 					opcode_info->opcode = OPCODE_INT;
-					opcode_info->nof_operands = 1;
+					opcode_info->min_operands = 1;
+					opcode_info->max_operands = 1;
 					opcode_info->size = 2;
 				}
 				break;
@@ -919,43 +934,50 @@ static OpcodeInfo *parseOpcode( void )
 					case 'm':
 						if( strcmp( ident, "jmp" ) == 0 ) {
 							opcode_info->opcode = OPCODE_JMP;
-							opcode_info->nof_operands = 1;
+							opcode_info->min_operands = 1;
+							opcode_info->max_operands = 1;
 							opcode_info->size = 2;
 						}
 						break;
 					case 'e':
 						if( strcmp( ident, "je" ) == 0 ) {
 							opcode_info->opcode = OPCODE_JE;
-							opcode_info->nof_operands = 1;
+							opcode_info->min_operands = 1;
+							opcode_info->max_operands = 1;
 							opcode_info->size = 2;
 						}
 						break;
 					case 'n':
 						if( strcmp( ident, "jne" ) == 0 ) {
 							opcode_info->opcode = OPCODE_JNE;
-							opcode_info->nof_operands = 1;
+							opcode_info->min_operands = 1;
+							opcode_info->max_operands = 1;
 							opcode_info->size = 2;
 						}
 						break;
 					case 'b':
 						if( strcmp( ident, "jb" ) == 0 ) {
 							opcode_info->opcode = OPCODE_JB;
-							opcode_info->nof_operands = 1;
+							opcode_info->min_operands = 1;
+							opcode_info->max_operands = 1;
 							opcode_info->size = 2;
 						} else if( strcmp( ident, "jbe" ) == 0 ) {
 							opcode_info->opcode = OPCODE_JBE;
-							opcode_info->nof_operands = 1;
+							opcode_info->min_operands = 1;
+							opcode_info->max_operands = 1;
 							opcode_info->size = 2;
 						}
 						break;
 					case 'a':
 						if( strcmp( ident, "ja" ) == 0 ) {
 							opcode_info->opcode = OPCODE_JA;
-							opcode_info->nof_operands = 1;
+							opcode_info->min_operands = 1;
+							opcode_info->max_operands = 1;
 							opcode_info->size = 2;
 						} else if( strcmp( ident, "jae" ) == 0 ) {
 							opcode_info->opcode = OPCODE_JAE;
-							opcode_info->nof_operands = 1;
+							opcode_info->min_operands = 1;
+							opcode_info->max_operands = 1;
 							opcode_info->size = 2;
 						}
 						break;
@@ -964,43 +986,50 @@ static OpcodeInfo *parseOpcode( void )
 			case 'm':
 				if( strcmp( ident, "mov" ) == 0 ) {
 					opcode_info->opcode = OPCODE_MOV;
-					opcode_info->nof_operands = 2;
+					opcode_info->min_operands = 2;
+					opcode_info->max_operands = 2;
 					opcode_info->size = 5;
 				} else if( strcmp( ident, "mul" ) == 0 ) {
 					opcode_info->opcode = OPCODE_MUL;
-					opcode_info->nof_operands = 1;
+					opcode_info->min_operands = 1;
+					opcode_info->max_operands = 1;
 					opcode_info->size = 2;
 				}
 				break;
 			case 'n':
 				if( strcmp( ident, "nop" ) == 0 ) {
 					opcode_info->opcode = OPCODE_NOP;
-					opcode_info->nof_operands = 0;
+					opcode_info->min_operands = 0;
+					opcode_info->max_operands = 0;
 					opcode_info->size = 1;
 				}
 				break;
 			case 'p':
 				if( strcmp( ident, "push" ) == 0 ) {
 					opcode_info->opcode = OPCODE_PUSH;
-					opcode_info->nof_operands = 1;
+					opcode_info->min_operands = 1;
+					opcode_info->max_operands = 1;
 					opcode_info->size = 1;
 				} else if( strcmp( ident, "pop" ) == 0 ) {
 					opcode_info->opcode = OPCODE_POP;
-					opcode_info->nof_operands = 1;
+					opcode_info->min_operands = 1;
+					opcode_info->max_operands = 1;
 					opcode_info->size = 1;
 				}
 				break;
 			case 'r':
 				if( strcmp( ident, "ret" ) == 0 ) {
 					opcode_info->opcode = OPCODE_RET;
-					opcode_info->nof_operands = 0;
+					opcode_info->min_operands = 0;
+					opcode_info->max_operands = 1;
 					opcode_info->size = 1;
 				}
 				break;
 			case 's':
 				if( strcmp( ident, "sub" ) == 0 ) {
 					opcode_info->opcode = OPCODE_SUB;
-					opcode_info->nof_operands = 2;
+					opcode_info->min_operands = 2;
+					opcode_info->max_operands = 2;
 					opcode_info->size = 2;
 				}
 				break;
@@ -1317,17 +1346,16 @@ static void parseOperands( OpcodeInfo *opcode_info )
 		}
 	}
 	
-	if( opcode_info->opcode != OPCODE_PSEUDO_DB &&
-		opcode_info->opcode != OPCODE_PSEUDO_DW &&
-		opcode_info->opcode != OPCODE_PSEUDO_DD &&
-		nof_operands != opcode_info->nof_operands ) {
-		Abort( "'%s' expects %d operand(s), %d given", opcodename[opcode_info->opcode], opcode_info->nof_operands, nof_operands );
+	if( nof_operands < opcode_info->min_operands ) {
+		Abort( "'%s' expects at least %d operand(s), only %d given", opcodename[opcode_info->opcode], opcode_info->min_operands, nof_operands );
+	}
+	if( nof_operands > opcode_info->max_operands ) {
+		Abort( "'%s' expects at most %d operand(s), but %d given", opcodename[opcode_info->opcode], opcode_info->max_operands, nof_operands );
 	}
 
 	switch( opcode_info->opcode ) {
 		case OPCODE_HLT:
 		case OPCODE_NOP:
-		case OPCODE_RET:
 			break;
 		case OPCODE_PSEUDO_DD:
 		case OPCODE_PSEUDO_DW: {
@@ -1349,7 +1377,7 @@ static void parseOperands( OpcodeInfo *opcode_info )
 				i++;
 				operand_info = operand_info->next;
 			}
-			opcode_info->nof_operands = i;
+			opcode_info->max_operands = i;
 			opcode_info->size = size;
 			} break;
 		case OPCODE_PSEUDO_DB: {
@@ -1367,7 +1395,7 @@ static void parseOperands( OpcodeInfo *opcode_info )
 				i++;
 				operand_info = operand_info->next;
 			}
-			opcode_info->nof_operands = i;
+			opcode_info->max_operands = i;
 			opcode_info->size = size;
 			} break;
 		case OPCODE_MOV:
@@ -1434,9 +1462,19 @@ static void parseOperands( OpcodeInfo *opcode_info )
 			}
 			break;
 		case OPCODE_INT:
-			if( opcode_info->operand->next->type != OPERAND_ABSOLUTE ) {
+			if( opcode_info->operand->type == OPERAND_ABSOLUTE ) {
 				/* int $80, jump to interrupt vector number */
 			}
+		case OPCODE_RET:
+			if( opcode_info->operand == NULL ) {
+				/* ok, no parameter return */
+				opcode_info->size = 1;
+			} else if( opcode_info->operand->type == OPERAND_ABSOLUTE ) {
+				/* return, pop N bytes from stack */
+				opcode_info->size = 3;
+			} else {
+				Abort( "'%s' expects either no operand or a number of bytes to remove from the stack", opcodename[opcode_info->opcode] );
+			}			
 			break;
 		default:
 			Abort( "Unhandled opcode '%s' when checking operand validity", opcodename[opcode_info->opcode] );			
@@ -2169,7 +2207,12 @@ static void emit_opcode( OpcodeInfo *opcode_info )
 			}
 			break;
 		case OPCODE_RET:
-			Emit( "%c", 0xC3 );
+			if( opcode_info->operand == NULL ) {
+				Emit( "%c", 0xC3 );
+			} else if( opcode_info->operand->type == OPERAND_ABSOLUTE ) {
+				Emit( "%c", 0xC2 );
+				Emit_word_little_endian( opcode_info->operand->num );
+			}
 			break;
 		case OPCODE_PSEUDO_ASSIGN:
 			break;
diff --git a/ecomp-c/ec.c b/ecomp-c/ec.c
index 5d42355..f6e1926 100644
--- a/ecomp-c/ec.c
+++ b/ecomp-c/ec.c
@@ -1548,15 +1548,34 @@ static void parseParameterList( Scope *scope )
 	ExpressionNode *node;
 	
 	Expect( S_lparen );
+	Emit( "( " );
 	do {
 		node = parseExpression( scope );
+		generate_expression_comment( node );
 		if( sym == S_comma ) {
 			sym = getSym( );
 		}
 	} while( sym != S_rparen );
 	Expect( S_rparen );
-	
-	(void)node;
+
+	Emit( ")\n" );
+
+	emit_expression_code( node, scope );
+}
+
+static void parseProcedureCall( Scope *scope )
+{
+	Symbol *symbol;
+
+	symbol = get_symbol( scope, ident );
+
+	Emit( "; CALL %s", symbol->label );
+	if( sym == S_lparen ) {
+		parseParameterList( scope );
+	} else {
+		Emit( "\n" );
+	}
+	Emit( "call %s\n", symbol->label );
 }
 
 static void parseStatement( Scope *scope )
@@ -1576,10 +1595,7 @@ static void parseStatement( Scope *scope )
 			Abort( "Unknown indentifier '%s'", ident );
 		}
 		if( symbol->class == SYMBOL_CLASS_PROCEDURE_TYPE ) {
-			if( sym == S_lparen ) {
-				parseParameterList( scope );
-			}
-			Emit( "call %s\n", symbol->label );
+			parseProcedureCall( scope );
 		} else {
 			parseAssignment( scope );
 		}
@@ -2082,7 +2098,7 @@ static void parseProcedureDeclaration( Scope *scope )
 		param = symbol->scope->symbol;
 		
 		size_params = 0;
-		offset = 0;
+		offset = -4;
 		while( param != NULL ) {
 			if( param->class == SYMBOL_CLASS_VARIABLE ) {
 				int size = get_size( param );
@@ -2143,7 +2159,7 @@ static void parseProcedureDeclaration( Scope *scope )
 		 * at runtime (every time the stack is created for that procedure) */
 		param_or_local = symbol->scope->symbol;
 		while( param_or_local != NULL ) {
-			if( param_or_local->class == SYMBOL_CLASS_VARIABLE ) {
+			if( param_or_local->class == SYMBOL_CLASS_VARIABLE && param_or_local->offset >= 0 ) {
 				/* TODO: use type here! */
 				int size = get_size( param_or_local );
 				if( param_or_local->type == integer_type || param_or_local->type == boolean_type ) {
@@ -2187,15 +2203,17 @@ static void parseProcedureDeclaration( Scope *scope )
 
 		parseStatementBlock( symbol->scope );
 				
-		/* discard locals, discard params, reset base pointer */
-		if( size_locals + size_params > 0 ) {
-			Emit( "mov eax, %d\n", size_locals + size_params );
+		/* discard locals, restore base pointer, discard params */
+		if( size_locals > 0 ) {
+			Emit( "mov eax, %d\n", size_locals );
 			Emit( "add esp, eax\n" );
 		}
-
 		Emit( "pop ebp\n" );
-		
-		Emit( "ret\n" );
+		if( size_params > 0 ) {	
+			Emit( "ret %d\n", size_params );
+		} else {
+			Emit( "ret\n" );
+		}
 	}
 
 	free_scope( symbol->scope );
diff --git a/ecomp-c/test.sh b/ecomp-c/test.sh
index 014eb98..6030462 100755
--- a/ecomp-c/test.sh
+++ b/ecomp-c/test.sh
@@ -26,6 +26,7 @@ procedure_call
 procedure_forward_declaration
 procedure_local_variables
 procedure_scoping
+procedure_call_value_parameters
 example_divisors
 example_divisors_array_result
 example_reverse_array
diff --git a/ecomp-c/tests/procedure_call.easm b/ecomp-c/tests/procedure_call.easm
index 09daf38..013f8b2 100644
--- a/ecomp-c/tests/procedure_call.easm
+++ b/ecomp-c/tests/procedure_call.easm
@@ -16,6 +16,7 @@ mov [i], eax
 pop ebp
 ret
 __global_0:
+; CALL __global_proc
 call __global_proc
 hlt
 i: dd $00000000
diff --git a/ecomp-c/tests/procedure_call_value_parameters.e b/ecomp-c/tests/procedure_call_value_parameters.e
index 3b100ed..f0d6372 100644
--- a/ecomp-c/tests/procedure_call_value_parameters.e
+++ b/ecomp-c/tests/procedure_call_value_parameters.e
@@ -5,14 +5,14 @@
 module procedure_call_value_parameters;
 
 var
-	i : integer := 0;
-	
+	i : integer := 1;
+
 procedure proc( x : integer );
 var
 	l : integer;
 begin
 	l := x;
-	i := x;
+	i := l;
 end
 
 begin
diff --git a/ecomp-c/tests/procedure_forward_declaration.easm b/ecomp-c/tests/procedure_forward_declaration.easm
index 79ad4a4..23440e3 100644
--- a/ecomp-c/tests/procedure_forward_declaration.easm
+++ b/ecomp-c/tests/procedure_forward_declaration.easm
@@ -8,6 +8,7 @@ __global_proc1:
 push ebp
 push esp
 pop ebp
+; CALL __global_proc2
 call __global_proc2
 pop ebp
 ret
@@ -24,6 +25,7 @@ mov [i], eax
 pop ebp
 ret
 __global_0:
+; CALL __global_proc1
 call __global_proc1
 hlt
 i: dd $00000000
diff --git a/ecomp-c/tests/procedure_local_variables.easm b/ecomp-c/tests/procedure_local_variables.easm
index 88312af..1979c0c 100644
--- a/ecomp-c/tests/procedure_local_variables.easm
+++ b/ecomp-c/tests/procedure_local_variables.easm
@@ -50,6 +50,7 @@ add esp, eax
 pop ebp
 ret
 __global_0:
+; CALL __global_proc
 call __global_proc
 hlt
 i: dd $00000001
diff --git a/ecomp-c/tests/procedure_scoping.easm b/ecomp-c/tests/procedure_scoping.easm
index 07106a7..64a9d31 100644
--- a/ecomp-c/tests/procedure_scoping.easm
+++ b/ecomp-c/tests/procedure_scoping.easm
@@ -93,7 +93,9 @@ push eax
 pop eax
 pop ebx
 mov [ebx], eax
+; CALL __global_A
 call __global_A
+; CALL __global_B
 call __global_B
 hlt
 y: dd $00000000