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Simplify parser and rewrite error printing.
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With new parser, we can print multiple alternative errors on the same
spot.
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@dmsc
dmsc committed Oct 27, 2018
1 parent 300c3b5 commit 41f3293
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Showing 3 changed files with 79 additions and 70 deletions.
84 changes: 40 additions & 44 deletions src/basic.syn
View file
Original file line number Diff line number Diff line change
Expand Up @@ -90,20 +90,20 @@ EXTERN {

# Floating point expressions
#@if FASTBASIC_FP
FP_EXPR: floating point expression
FP_EXPR:
FP_T_EXPR FP_E_EXPR_MORE FP_M_EXPR_MORE FP_EXPR_MORE

FP_EXPR_MORE:
FP_EXPR_MORE: '+', '-'
"+" FP_T_EXPR FP_E_EXPR_MORE FP_M_EXPR_MORE emit TOK_FP_ADD FP_EXPR_MORE
"-" FP_T_EXPR FP_E_EXPR_MORE FP_M_EXPR_MORE emit TOK_FP_SUB FP_EXPR_MORE
pass

FP_M_EXPR_MORE:
FP_M_EXPR_MORE: '*', '/'
"*" FP_T_EXPR FP_E_EXPR_MORE emit TOK_FP_MUL FP_M_EXPR_MORE
"/" FP_T_EXPR FP_E_EXPR_MORE emit TOK_FP_DIV FP_M_EXPR_MORE
pass

FP_E_EXPR_MORE:
FP_E_EXPR_MORE: '^'
"^" T_EXPR emit TOK_FP_IPOW FP_E_EXPR_MORE
"^" emit TOK_FP_LOG10 FP_T_EXPR emit TOK_FP_MUL emit TOK_FP_EXP10 FP_E_EXPR_MORE
pass
Expand Down Expand Up @@ -137,18 +137,18 @@ FP_PAR_EXPR: left parenthesis
INT_EXPR: integer expression
T_EXPR BIT_EXPR_MORE M_EXPR_MORE INT_EXPR_MORE

INT_EXPR_MORE:
INT_EXPR_MORE: '+', '-'
"+" T_EXPR BIT_EXPR_MORE M_EXPR_MORE emit TOK_ADD INT_EXPR_MORE
"-" T_EXPR BIT_EXPR_MORE M_EXPR_MORE emit TOK_SUB INT_EXPR_MORE
pass

M_EXPR_MORE:
M_EXPR_MORE: '*', '/', 'MOD'
"*" T_EXPR BIT_EXPR_MORE emit TOK_MUL M_EXPR_MORE
"/" T_EXPR BIT_EXPR_MORE emit TOK_DIV M_EXPR_MORE
"MOD" T_EXPR BIT_EXPR_MORE emit TOK_MOD M_EXPR_MORE
pass

BIT_EXPR_MORE:
BIT_EXPR_MORE: '&', '!', 'EXOR'
"&" T_EXPR emit TOK_BIT_AND BIT_EXPR_MORE
"!" T_EXPR emit TOK_BIT_OR BIT_EXPR_MORE
"EXOR" T_EXPR emit TOK_BIT_EXOR BIT_EXPR_MORE
Expand All @@ -168,7 +168,7 @@ ADR_EXPR: string or variable
emit TOK_VAR_LOAD E_VAR_ARRAY_STRING

USR_EXPR_MORE:
"," EXPR emit TOK_USR_PARAM USR_EXPR_MORE
C_EXPR emit TOK_USR_PARAM USR_EXPR_MORE
pass

T_EXPR: integer constant, variable or function
Expand Down Expand Up @@ -242,14 +242,14 @@ EXPR:
FORCE_BOOL_EXPR:
NOT_EXPR AND_EXPR_MORE OR_EXPR_MORE

OR_EXPR_RIGHT:
OR_EXPR_RIGHT: 'OR'
"OR" NOT_EXPR AND_EXPR_MORE emit TOK_L_OR OR_EXPR_MORE

OR_EXPR_MORE:
OR_EXPR_RIGHT
pass

AND_EXPR_RIGHT:
AND_EXPR_RIGHT: 'AND'
"AND" NOT_EXPR emit TOK_L_AND AND_EXPR_MORE

AND_EXPR_MORE:
Expand All @@ -271,7 +271,7 @@ COMP_OR_BOOL:
#@endif FASTBASIC_FP
emit TOK_COMP_0

COMP_EXPR_RIGHT:
COMP_EXPR_RIGHT: integer comparison operator
"<=" INT_EXPR emit TOK_GT emit TOK_L_NOT
">=" INT_EXPR emit TOK_LT emit TOK_L_NOT
"<>" INT_EXPR emit TOK_NEQ
Expand All @@ -281,7 +281,7 @@ COMP_EXPR_RIGHT:

#@if FASTBASIC_FP
# FP Comparisons:
COMP_FP_RIGHT: integer expression
COMP_FP_RIGHT: floating-point comparison operator
"=" FP_EXPR emit TOK_FP_CMP emit TOK_EQ
">" FP_EXPR emit TOK_FP_CMP emit TOK_GT
">=" FP_EXPR emit TOK_FP_CMP emit TOK_LT emit TOK_L_NOT
Expand All @@ -290,7 +290,7 @@ COMP_FP_RIGHT: integer expression
"<" FP_EXPR emit TOK_FP_CMP emit TOK_LT
#@endif FASTBASIC_FP

COMP_STR_RIGHT: integer expression
COMP_STR_RIGHT: comparison operator
"=" STR_EXPR emit TOK_CMP_STR emit TOK_EQ
">" STR_EXPR emit TOK_CMP_STR emit TOK_GT
">=" STR_EXPR emit TOK_CMP_STR emit TOK_LT emit TOK_L_NOT
Expand All @@ -307,7 +307,7 @@ STR_EXPR: string expression
STR_EXPR_BASE OPT_STR_INDEX

OPT_STR_INDEX:
"[" EXPR_2 "]" emit TOK_STR_IDX OPT_STR_INDEX
"[" EXPR C_EXPR "]" emit TOK_STR_IDX OPT_STR_INDEX
"[" EXPR "]" emit TOK_BYTE emit 255 emit TOK_STR_IDX OPT_STR_INDEX
pass

Expand Down Expand Up @@ -412,14 +412,14 @@ NEXT_VARNAME:

# POSITION arguments, used also in PLOT, DRAWTO, LOCATE and FILLTO
POSITION:
emit TOK_BYTE emit COLCRS EXPR "," emit TOK_DPOKE emit TOK_BYTE emit ROWCRS EXPR emit TOK_POKE
emit TOK_BYTE emit COLCRS EXPR emit TOK_DPOKE emit TOK_BYTE emit ROWCRS C_EXPR emit TOK_POKE

# SOUND arguments, three possibilities:
# SOUND voice, freq, distort, vol
# SOUND voice
# SOUND
SOUND:
EXPR emit TOK_USHL emit TOK_NUM word AUDF1 emit TOK_ADD "," EXPR "," EXPR_AB emit TOK_SHL8 emit TOK_ADD emit TOK_DPOKE emit TOK_NUM word AUDCTL emit TOK_0 emit TOK_POKE emit TOK_NUM word SKCTL emit TOK_BYTE emit 3 emit TOK_POKE
EXPR emit TOK_USHL emit TOK_NUM word AUDF1 emit TOK_ADD C_EXPR EXPR_AB emit TOK_SHL8 emit TOK_ADD emit TOK_DPOKE emit TOK_NUM word AUDCTL emit TOK_0 emit TOK_POKE emit TOK_NUM word SKCTL emit TOK_BYTE emit 3 emit TOK_POKE
EXPR emit TOK_USHL emit TOK_NUM word AUDF1 emit TOK_ADD emit TOK_0 emit TOK_DPOKE
emit TOK_SOUND_OFF

Expand All @@ -442,7 +442,7 @@ DIM_MORE: comma
# INPUT
INPUT_STR:
IO_CHAN_COMMA # I/O channel, don't print prompt
IO_CHAN "," # I/O channel, don't print prompt
"\"" emit TOK_CSTRING E_CONST_STRING emit TOK_PRINT_STR PRINT_SEP # Prints a given string
PRINT_SEP # If starts with ',' or ';', don't print anyting
emit TOK_BYTE emit 63 emit TOK_PUT # Prints a '?' by default
Expand Down Expand Up @@ -480,12 +480,8 @@ DIM_VAR: new variable name
IO_CHAN: I/O channel number
"#" emit TOK_BYTE emit IOCHN EXPR emit TOK_USHL emit TOK_USHL emit TOK_USHL emit TOK_USHL emit TOK_POKE

# Note: we need the version without comma for "CLOSE #*"
IO_CHAN_COMMA:
IO_CHAN ","

IO_CHAN_OPT:
IO_CHAN_COMMA
IO_CHAN ","
pass

# Used only for CLS
Expand All @@ -500,24 +496,24 @@ GETK_EXPR: variable name

# Get expression
GET_EXPR: variable name
VAR_BYTE_LVALUE emit TOK_GET emit TOK_POKE GET_EXPR_MORE
VAR_WORD_LVALUE emit TOK_GET emit TOK_DPOKE GET_EXPR_MORE
"," VAR_BYTE_LVALUE emit TOK_GET emit TOK_POKE GET_EXPR_MORE
"," VAR_WORD_LVALUE emit TOK_GET emit TOK_DPOKE GET_EXPR_MORE

GET_EXPR_MORE:
"," GET_EXPR
GET_EXPR
emit TOK_IOCHN0

# Get two comma separated expressions "A,B" and returns "A*16+B"
EXPR_AB:
EXPR emit TOK_USHL emit TOK_USHL emit TOK_USHL emit TOK_USHL "," EXPR emit TOK_ADD
# A comma followed by an expression
C_EXPR: comma followed by an expression
"," EXPR

# 2 expressions separated by comma
EXPR_2:
EXPR "," EXPR
# Get two comma separated expressions ",A,B" and returns "A*16+B"
EXPR_AB:
C_EXPR emit TOK_USHL emit TOK_USHL emit TOK_USHL emit TOK_USHL C_EXPR emit TOK_ADD

# Parses a XIO AUX1/AUX2/STRING expression
XIO_EXPR:
EXPR_2 emit TOK_SHL8 emit TOK_ADD "," STR_EXPR emit TOK_XIO
C_EXPR C_EXPR emit TOK_SHL8 emit TOK_ADD "," STR_EXPR emit TOK_XIO

# Parses a "DATA" expression, get's binary data in memory
DATA_WORDS: data word
Expand Down Expand Up @@ -548,14 +544,14 @@ PARSE_LINE_COMMAND:
"PRint" IO_CHAN_OPT PRINT_EXPR
"INput" INPUT_STR INPUT_VAR_LIST emit TOK_IOCHN0
"GEt" GETK_EXPR
"GEt" IO_CHAN_COMMA GET_EXPR
"GEt" IO_CHAN GET_EXPR
"PUt" IO_CHAN_OPT EXPR emit TOK_PUT
"CLS" IO_CHAN_OPT_NOCOMMA emit TOK_BYTE emit CLS emit TOK_PUT
"Poke" EXPR_2 emit TOK_POKE
"Dpoke" EXPR_2 emit TOK_DPOKE
"MSet" EXPR_2 "," EXPR emit TOK_MSET
"Move" EXPR_2 "," EXPR emit TOK_MOVE
"-move" EXPR_2 "," EXPR emit TOK_NMOVE
"Poke" EXPR C_EXPR emit TOK_POKE
"Dpoke" EXPR C_EXPR emit TOK_DPOKE
"MSet" EXPR C_EXPR C_EXPR emit TOK_MSET
"Move" EXPR C_EXPR C_EXPR emit TOK_MOVE
"-move" EXPR C_EXPR C_EXPR emit TOK_NMOVE
"DO" emit LT_DO_LOOP E_PUSH_LT
"Loop" emit TOK_JUMP E_POP_LOOP
"Repeat" emit LT_REPEAT E_PUSH_LT
Expand All @@ -576,14 +572,14 @@ PARSE_LINE_COMMAND:
"PLot" POSITION emit TOK_BYTE emit COLOR emit TOK_PEEK emit TOK_PLOT
"DRawto" POSITION emit TOK_BYTE emit DRAWLN emit TOK_DRAWTO
"FIllto" POSITION emit TOK_BYTE emit FILLIN emit TOK_DRAWTO
"SEtcolor" EXPR emit TOK_NUM word COLOR0 emit TOK_ADD "," EXPR_AB emit TOK_POKE
"SEtcolor" EXPR emit TOK_NUM word COLOR0 emit TOK_ADD EXPR_AB emit TOK_POKE
"Sound" SOUND
"DIm" DIM_VAR DIM_MORE
"CLose" IO_CHAN emit TOK_CLOSE
"Open" IO_CHAN_COMMA emit TOK_BYTE emit OPEN XIO_EXPR
"Xio" IO_CHAN_COMMA EXPR "," XIO_EXPR
"BPut" IO_CHAN_COMMA EXPR_2 emit TOK_BPUT
"BGet" IO_CHAN_COMMA EXPR_2 emit TOK_BGET
"Open" IO_CHAN emit TOK_BYTE emit OPEN XIO_EXPR
"Xio" IO_CHAN C_EXPR XIO_EXPR
"BPut" IO_CHAN C_EXPR C_EXPR emit TOK_BPUT
"BGet" IO_CHAN C_EXPR C_EXPR emit TOK_BGET
"PAuse" EXPR emit TOK_PAUSE
"INC" VAR_WORD_LVALUE emit TOK_INC
"DEc" VAR_WORD_LVALUE emit TOK_DEC
Expand All @@ -597,7 +593,7 @@ PARSE_LINE_COMMAND:
"RAd" emit TOK_BYTE emit DEGFLAG emit TOK_0 emit TOK_POKE
#@endif FASTBASIC_FP

PARSE_LINE_ASSIGN: &LOW_ERROR
PARSE_LINE_ASSIGN:
VAR_WORD_LVALUE EQUAL EXPR emit TOK_DPOKE
VAR_BYTE_LVALUE EQUAL EXPR emit TOK_POKE
VAR_STR_LVALUE EQUAL STR_EXPR emit TOK_COPY_STR
Expand Down
14 changes: 12 additions & 2 deletions src/compiler/main.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -180,8 +180,18 @@ int main(int argc, char **argv)
if( !SMB_PARSE_START(s) || ( s.pos != line.length() && !s.peek(':') ) )
{
std::cerr << iname << ":" << ln << ":" << s.max_pos << ": parse error";
if( !s.saved_error.empty() )
std::cerr << ", " << s.saved_error;
if( !s.saved_errors.empty() )
{
std::cerr << ", expected: ";
bool first = true;
for(const auto &i: s.saved_errors)
{
if( !first )
std::cerr << ", ";
std::cerr << i;
first = false;
}
}
std::cerr << "\n";
size_t min = 0, max = s.str.length();
if( s.max_pos > 40 ) min = s.max_pos - 40;
Expand Down
51 changes: 27 additions & 24 deletions src/compiler/parser.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@
// parser.cc: C++ parser

#include <string>
#include <algorithm>

#include "codew.h"

Expand All @@ -38,9 +39,7 @@ class parse {
std::string str;
size_t pos;
size_t max_pos;
bool low_error;
std::string current_error;
std::string saved_error;
std::vector<std::string> saved_errors;
int linenum;
std::map<std::string, std::vector<codew>> procs;
std::map<std::string, int> vars;
Expand All @@ -52,7 +51,7 @@ class parse {

parse():
lvl(0), maxlvl(0), pos(0),
max_pos(0), low_error(false), label_num(0),
max_pos(0), label_num(0),
finalized(false),
code(&procs[std::string()]) { }

Expand Down Expand Up @@ -117,6 +116,7 @@ class parse {
{
pos = max_pos = 0;
str = l;
saved_errors.clear();
linenum = ln;
}

Expand All @@ -127,33 +127,41 @@ class parse {

void error(std::string str)
{
if( str == "&LOW_ERROR" )
low_error = true;
else if( !str.empty() )
if( !str.empty() )
{
current_error = "expected " + str;
debug( "Set error='" + current_error + "'" );
if( pos >= max_pos )
{
debug( "Set error='" + str + "' "
"at pos='" + std::to_string(pos) + "' "
"mp='" + std::to_string(max_pos) + "'" );
if( pos > max_pos )
{
debug( "ERROR SAVED" );
saved_errors.clear();
}
else
debug( "ERROR ADDED" );
if( saved_errors.end() == std::find(saved_errors.begin(), saved_errors.end(), str) )
saved_errors.push_back(str);
max_pos = pos;
}
}
}

bool loop_error(std::string str)
{
current_error = str;
saved_error = current_error;
debug( "Set loop error='" + current_error + "'" );
// Loop error takes precedence over all other errors
saved_errors.clear();
saved_errors.push_back(str);
debug( "Set loop error='" + str + "'" );
return false;
}

void restore(saved_pos s)
{
if( pos >= max_pos )
if( pos > max_pos )
{
if( !current_error.empty() &&
( !low_error || pos > max_pos || saved_error.empty() ) )
{
debug("save error='" + current_error + "'");
saved_error = current_error;
}
debug("error, pos > max_pos ?!?!?");
max_pos = pos;
}
pos = s.pos;
Expand Down Expand Up @@ -262,11 +270,6 @@ class parse {
return true;
}
}
if( c == ',' )
{
current_error = "comma";
debug( "Set error='" + current_error + "'" );
}
return false;
}
bool eol()
Expand Down

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