scc

Simple C99 Compiler
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commit 5cc0256ea7e075ec951904e3cfcfcd30e0df31d4
parent eb12bd70592fe92197ceec3bbfd8d064ad273a33
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Wed,  9 Jul 2014 12:25:34 +0200

Simplify stmt

We can use a function pointer for this function, but then we need
to pass the state to all the possible statements. This is not a
problem, because we can ignore the parameters we are not using,
and the code of stmt will be smaller because we have only one
function call.

Diffstat:
cc1/stmt.c | 61+++++++++++++++++++++++++++++++------------------------------
1 file changed, 31 insertions(+), 30 deletions(-)

diff --git a/cc1/stmt.c b/cc1/stmt.c @@ -43,7 +43,7 @@ label(char *s, char define) } static void -stmtexp(void) +stmtexp(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { if (yytoken != ';') emitexp(expr()); @@ -62,7 +62,7 @@ condition(void) } static void -While(Caselist *lswitch) +While(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { Symbol *begin, *cond, *end; Node *np; @@ -84,7 +84,7 @@ While(Caselist *lswitch) } static void -For(Caselist *lswitch) +For(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { Symbol *begin, *cond, *end; Node *econd = NULL, *einc = NULL; @@ -117,7 +117,7 @@ For(Caselist *lswitch) } static void -Dowhile(Caselist *lswitch) +Dowhile(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { Symbol *begin = label("", 1), *end = label("", 1); @@ -132,7 +132,7 @@ Dowhile(Caselist *lswitch) } static void -Return(void) +Return(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { Node *np; Type *tp = curfun->type->type; @@ -155,7 +155,7 @@ Return(void) } static void -Break(Symbol *lbreak) +Break(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { expect(BREAK); if (!lbreak) @@ -164,17 +164,20 @@ Break(Symbol *lbreak) expect(';'); } +static void stmt(Symbol *lbreak, Symbol *lcont, Caselist *lswitch); + static void -Label(void) +Label(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { emitlabel(label(yytext, 1)); expect(IDEN); expect(':'); + stmt(lbreak, lcont, lswitch); } static void -Continue(Symbol *lcont) +Continue(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { expect(CONTINUE); if (!lcont) @@ -184,7 +187,7 @@ Continue(Symbol *lcont) } static void -Goto(void) +Goto(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { expect(GOTO); @@ -196,13 +199,14 @@ Goto(void) } static void -Switch(Symbol *lcont) +Switch(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { Caselist lcase = {.nr = 0, .head = NULL, .deflabel = NULL}; struct scase *p; - Symbol *lbreak = label("", 1), *lcond = label("", 1); Node *cond; + Symbol *lcond = label("", 1); + lbreak = label("", 1); expect(SWITCH); expect ('('); cond = eval(expr()); @@ -298,27 +302,24 @@ compound(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) static void stmt(Symbol *lbreak, Symbol *lcont, Caselist *lswitch) { + void (*fun)(Symbol *lbreak, Symbol *lcont, Caselist *lswitch); -repeat: switch (yytoken) { - case '{': context(lbreak, lcont, lswitch); break; - case RETURN: Return(); break; - case WHILE: While(lswitch); break; - case FOR: For(lswitch); break; - case DO: Dowhile(lswitch); break; - case IF: If(lbreak, lcont, lswitch); break; - case BREAK: Break(lbreak); break; - case CONTINUE: Continue(lcont); break; - case GOTO: Goto(); break; - case SWITCH: Switch(lcont); break; - case CASE: Case(lbreak, lcont, lswitch); break; - case DEFAULT: Default(lbreak, lcont, lswitch); break; - case IDEN: - if (ahead() == ':') { - Label(); - goto repeat; - } - default: stmtexp(); break; + case '{': fun = context; break; + case RETURN: fun = Return; break; + case WHILE: fun = While; break; + case FOR: fun = For; break; + case DO: fun = Dowhile; break; + case IF: fun = If; break; + case BREAK: fun = Break; break; + case CONTINUE: fun = Continue; break; + case GOTO: fun = Goto; break; + case SWITCH: fun = Switch; break; + case CASE: fun = Case; break; + case DEFAULT: fun = Default; break; + default: fun = stmtexp; break; + case IDEN: fun = (ahead() == ':') ? Label : stmtexp; break; } + (*fun)(lbreak, lcont, lswitch); }