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Rangi42Rangi42
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Avoid treating labels and macros differently in column 1 (#1515)
Fixes #1512
1 parent 15919e5 commit 6b89938

9 files changed

+75
-39
lines changed

‎man/rgbasm.5

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Original file line numberDiff line numberDiff line change
@@ -41,7 +41,6 @@ or
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Labels tie a name to a specific location within a section (see
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.Sx Labels
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below).
44-
They must come first in the line.
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.Pp
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Instructions are assembled into Game Boy opcodes.
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Multiple instructions on one line can be separated by double colons

‎src/asm/lexer.cpp

Lines changed: 13 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1849,7 +1849,19 @@ static Token yylex_NORMAL() {
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}
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}
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1852-
if (token.type == T_(ID) && (lexerState->atLineStart || peek() == ':'))
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// This is a "lexer hack"! We need it to distinguish between label definitions
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// (which start with `LABEL`) and macro invocations (which start with `ID`).
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//
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// If we had one `IDENTIFIER` token, the parser would need to perform "lookahead"
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// to determine which rule applies. But since macros need to enter "raw" mode to
1857+
// parse their arguments, which may not even be valid tokens in "normal" mode, we
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// cannot use lookahead to check for the presence of a `COLON`.
1859+
//
1860+
// Instead, we have separate `ID` and `LABEL` tokens, lexing as a `LABEL` if a ':'
1861+
// character *immediately* follows the identifier. Thus, at the beginning of a line,
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// "Label:" and "mac:" are treated as label definitions, but "Label :" and "mac :"
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// are treated as macro invocations.
1864+
if (token.type == T_(ID) && peek() == ':')
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token.type = T_(LABEL);
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18551867
return token;

‎src/asm/parser.y

Lines changed: 0 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -433,22 +433,6 @@ line:
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fstk_StopRept();
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yyerrok;
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}
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// Hint about unindented macros parsed as labels
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| LABEL error {
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lexer_SetMode(LEXER_NORMAL);
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lexer_ToggleStringExpansion(true);
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} endofline {
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Symbol *macro = sym_FindExactSymbol($1);
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443-
if (macro && macro->type == SYM_MACRO)
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fprintf(
445-
stderr,
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" To invoke `%s` as a macro it must be indented\n",
447-
$1.c_str()
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);
449-
fstk_StopRept();
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yyerrok;
451-
}
452436
;
453437

454438
endofline: NEWLINE | EOB;

‎test/asm/lexer-hack.asm

Lines changed: 28 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,28 @@
1+
MACRO mac
2+
println "got {d:_NARG} args: \#"
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ENDM
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5+
; indented, these were always macro invocations
6+
mac
7+
mac ro
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mac : ld a, 1
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; in column 1, we historically treated these as labels
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mac
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mac ro
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mac : ld b, 2
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SECTION "test", ROM0
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17+
; a colon makes these into labels
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Label1: ld c, 3
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Label2: ld d, 4
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; a macro invocation when already defined as a label
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Label1 args
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; and a label definition when already defined as a macro
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mac: ld e, 5
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; the space before the colon matters!
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undef :
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undef :

‎test/asm/lexer-hack.err

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,9 @@
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error: lexer-hack.asm(22):
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"Label1" is not a macro
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error: lexer-hack.asm(24):
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'mac' already defined at lexer-hack.asm(1)
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error: lexer-hack.asm(27):
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Macro "undef" not defined
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error: lexer-hack.asm(28):
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Macro "undef" not defined
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error: Assembly aborted (4 errors)!

‎test/asm/lexer-hack.out

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,6 @@
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got 0 args:
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got 1 args: ro
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got 2 args: : ld a,1
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got 0 args:
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got 1 args: ro
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got 2 args: : ld b,2

‎test/asm/syntax-error-after-syntax-error.asm

Lines changed: 11 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -1,10 +1,11 @@
1-
MACRO mac
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println "got {d:_NARG} args"
3-
ENDM
4-
mac
5-
mac 42
6-
notmac
7-
mac
8-
mac 42
9-
mac::
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mac ::
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def x = 1 ; so far so good...
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def n equ 2 + * / ^ 3 ; oops
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def s equs "no closing quote, lol
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section "test", rom0 ; good again
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ld a, 42 ; keep going...
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ld xor, ret ; oh no :(
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label1: ; yes...
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label2:: ; yes...
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label3::: ; no!
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halt stop abort ; please
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println "finally!"

‎test/asm/syntax-error-after-syntax-error.err

Lines changed: 7 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -1,13 +1,11 @@
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error: syntax-error-after-syntax-error.asm(2):
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syntax error, unexpected *
3+
error: syntax-error-after-syntax-error.asm(3):
4+
Unterminated string
15
error: syntax-error-after-syntax-error.asm(6):
2-
syntax error, unexpected newline, expecting : or ::
3-
error: syntax-error-after-syntax-error.asm(7):
4-
syntax error, unexpected newline, expecting : or ::
5-
To invoke `mac` as a macro it must be indented
6-
error: syntax-error-after-syntax-error.asm(8):
7-
syntax error, unexpected number, expecting : or ::
8-
To invoke `mac` as a macro it must be indented
6+
syntax error, unexpected xor
97
error: syntax-error-after-syntax-error.asm(9):
10-
'mac' already defined at syntax-error-after-syntax-error.asm(1)
8+
syntax error, unexpected :
119
error: syntax-error-after-syntax-error.asm(10):
12-
'mac' already defined at syntax-error-after-syntax-error.asm(1)
10+
syntax error, unexpected stop, expecting newline or end of buffer or ::
1311
error: Assembly aborted (5 errors)!

‎test/asm/syntax-error-after-syntax-error.out

Lines changed: 1 addition & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1,2 +1 @@
1-
got 0 args
2-
got 1 args
1+
finally!

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