scc

Simple C99 Compiler
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commit d092be22d3220430733d7fb532d72d6a2348e9d1
parent f6df05343dbc81b5f3f8f1fa129007b3dd4a47fc
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Tue, 11 Aug 2015 11:53:31 +0200

Keep hash order in lookup() too

The order was not preserved in lookup(), which was
inserting always in the head.

Diffstat:
cc1/symbol.c | 89+++++++++++++++++++++++++++++++++++++++++++++++--------------------------------
1 file changed, 53 insertions(+), 36 deletions(-)

diff --git a/cc1/symbol.c b/cc1/symbol.c @@ -53,6 +53,44 @@ hash(const char *s) return h & NR_SYM_HASH-1; } +static Symbol * +linkhash(Symbol *sym, char *name) +{ + Symbol **h, *p, *prev; + + sym->name = xstrdup(name); + h = &htab[hash(name)]; + + for (prev = p = *h; p; prev = p, p = p->hash) { + if (p->ctx <= sym->ctx) + break; + } + if (p == prev) { + sym->hash = *h; + *h = sym; + } else { + p = prev->hash; + prev->hash = sym; + sym->hash = p; + } + + return sym; +} + +static void +unlinkhash(Symbol *sym) +{ + Symbol **h, *p, *prev; + + h = &htab[hash(sym->name)]; + for (prev = p = *h; p != sym; prev = p, p = p->hash) + /* nothing */; + if (prev == p) + *h = sym->hash; + else + prev->hash = sym->hash; +} + void pushctx(void) { @@ -94,7 +132,7 @@ popctx(void) } if (sym->name) { short f = sym->flags; - htab[hash(sym->name)] = sym->hash; + unlinkhash(sym); if ((f & (ISUSED|ISGLOBAL|ISDECLARED)) == ISDECLARED) warn("'%s' defined but not used", sym->name); } @@ -119,7 +157,7 @@ duptype(Type *base) Symbol * newsym(unsigned ns) { - Symbol *sym; + Symbol *sym, *p, *prev; sym = malloc(sizeof(*sym)); sym->id = 0; @@ -129,22 +167,24 @@ newsym(unsigned ns) sym->flags = ISDECLARED; sym->name = NULL; sym->type = NULL; - sym->hash = NULL; + sym->next = sym->hash = NULL; + + if (ns == NS_CPP) + return sym; - if (!head || head->ctx <= curctx) { + for (prev = p = head; p; prev = p, p = p->next) { + if (p->ctx <= sym->ctx) + break; + } + if (p == prev) { sym->next = head; head = sym; } else { - Symbol *p, *prev; - - for (prev = p = head; p; prev = p, p = p->next) { - if (p->ctx <= sym->ctx) - break; - } p = prev->next; prev->next = sym; sym->next = p; } + return sym; } @@ -168,12 +208,9 @@ lookup(unsigned ns) continue; return sym; } - - sym = newsym(ns); - sym->name = xstrdup(yytext); + sym = linkhash(newsym(ns), yytext); sym->flags &= ~ISDECLARED; - sym->hash = *h; - *h = sym; + return sym; } @@ -213,27 +250,7 @@ install(unsigned ns, Symbol *sym) return NULL; sym->flags |= ISDECLARED; } else { - char *name = sym->name; - Symbol **h; - - sym = newsym(ns); - sym->name = xstrdup(name); - h = &htab[hash(name)]; - - if (!*h || (*h)->ctx <= curctx) { - sym->hash = *h; - *h = sym; - } else { - Symbol *p, *prev; - - for (prev = p = *h; p; prev = p, p = p->hash) { - if (p->ctx <= sym->ctx) - break; - } - p = prev->hash; - prev->hash = sym; - sym->hash = p; - } + sym = linkhash(newsym(ns), sym->name); } if (sym->ns != NS_CPP)