[hackers] [scc] Add basic error recovery in identifier() || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Fri, 21 Aug 2015 00:17:08 +0200 (CEST)

X-DEBUG-UPD: ff5758a151b905af1f39827d8b755c7fccd11961
commit ff5758a151b905af1f39827d8b755c7fccd11961
Author: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
AuthorDate: Fri Aug 21 00:10:04 2015 +0200
Commit: Roberto E. Vargas Caballero <k0ga_AT_shike2.com>
CommitDate: Fri Aug 21 00:10:04 2015 +0200

    Add basic error recovery in identifier()
    
    The idea is very simple: Don't raise error recovery when you
    only have semantic errors, when it is not needed a character
    synchronization

diff --git a/cc1/decl.c b/cc1/decl.c
index 581a146..2bd6a0f 100644
--- a/cc1/decl.c
+++ b/cc1/decl.c
_AT_@ -128,7 +128,8 @@ parameter(struct decl *dcl)
         case STATIC:
         case EXTERN:
         case AUTO:
- error("bad storage class in function parameter");
+ errorp("bad storage class in function parameter");
+ break;
         case REGISTER:
                 sym->flags |= ISREGISTER;
                 break;
_AT_@ -266,7 +267,7 @@ specifier(int *sclass)
                         break;
                 case TQUALIFIER:
                         if (qlf && qlf != RESTRICT)
- goto invalid_type;
+ errorp("invalid type specification");
                         qlf |= yylval.token;
                         next();
                         continue;
_AT_@ -314,11 +315,11 @@ specifier(int *sclass)
                         goto return_type;
                 }
                 if (*p)
- goto invalid_type;
+ errorp("invalid type specification");
                 *p = yylval.token;
                 if (dcl) {
                         if (size || sign)
- goto invalid_type;
+ errorp("invalid type specification");
                         tp = (*dcl)();
                         goto return_type;
                 } else {
_AT_@ -341,9 +342,6 @@ return_type:
                 }
         }
         return tp;
-
-invalid_type:
- error("invalid type specification");
 }
 
 /* TODO: check correctness of the initializator */
_AT_@ -514,6 +512,14 @@ field(struct decl *dcl)
         return sym;
 }
 
+static void
+bad_storage(Type *tp, char *name)
+{
+ if (tp->op != FTN)
+ errorp("incorrect storage class for file-scope declaration");
+ errorp("invalid storage class for function '%s'", name);
+}
+
 static Symbol *
 identifier(struct decl *dcl)
 {
_AT_@ -557,7 +563,6 @@ identifier(struct decl *dcl)
 
         if (sym == NULL) {
                 sym = dcl->sym;
- flags = sym->flags;
                 if (!eqtype(sym->type, tp))
                         error("conflicting types for '%s'", name);
                 if (sym->token == TYPEIDEN && sclass != TYPEDEF ||
_AT_@ -568,32 +573,49 @@ identifier(struct decl *dcl)
                         if (!(sym->flags & ISEXTERN) || sclass != EXTERN)
                                 goto redeclaration;
                 } else {
+ sym->u.pars = dcl->pars;
+ flags = sym->flags;
+
                         switch (sclass) {
                         case REGISTER:
                         case AUTO:
- goto bad_storage;
+ bad_storage(tp, name);
+ break;
                         case NOSCLASS:
- if (flags & ISPRIVATE)
- goto non_after_static;
- flags &= ~ISEXTERN;
- flags |= ISGLOBAL;
+ if ((flags & ISPRIVATE) == 0) {
+ flags &= ~ISEXTERN;
+ flags |= ISGLOBAL;
+ break;
+ }
+ errorp("non-static declaration of '%s' follows static declaration",
+ name);
+ break;
                         case TYPEDEF:
                         case EXTERN:
                                 break;
                         case STATIC:
- if (flags & (ISGLOBAL|ISEXTERN))
- goto static_after_non;
- flags |= ISPRIVATE;
+ if ((flags & (ISGLOBAL|ISEXTERN)) == 0) {
+ flags |= ISPRIVATE;
+ break;
+ }
+ errorp("static declaration of '%s' follows non-static declaration",
+ name);
                                 break;
                         }
                 }
+ sym->flags = flags;
         } else {
+ sym->type = tp;
+ sym->u.pars = dcl->pars;
                 flags = sym->flags;
+
                 switch (sclass) {
                 case REGISTER:
                 case AUTO:
- if (curctx == GLOBALCTX || tp->op == FTN)
- goto bad_storage;
+ if (curctx == GLOBALCTX || tp->op == FTN) {
+ bad_storage(tp, name);
+ break;
+ }
                         flags |= (sclass == REGISTER) ? ISREGISTER : ISAUTO;
                         break;
                 case NOSCLASS:
_AT_@ -609,12 +631,9 @@ identifier(struct decl *dcl)
                         sym->token = TYPEIDEN;
                         break;
                 }
+ sym->flags = flags;
         }
 
- sym->u.pars = dcl->pars;
- sym->flags = flags;
- sym->type = tp;
-
         if (accept('='))
                 initializer(sym);
         /* TODO: disallow initializators in functions */
_AT_@ -625,21 +644,8 @@ identifier(struct decl *dcl)
         return sym;
 
 redeclaration:
- error("redeclaration of '%s'", name);
-
-bad_storage:
- if (tp->op != FTN)
- error("incorrect storage class for file-scope declaration");
-bad_function:
- error("invalid storage class for function '%s'", name);
-
-non_after_static:
- error("non-static declaration of '%s' follows static declaration",
- name);
-
-static_after_non:
- error("static declaration of '%s' follows non-static declaration",
- name);
+ errorp("redeclaration of '%s'", name);
+ return sym;
 }
 
 static Symbol *
_AT_@ -714,6 +720,7 @@ decl(void)
                 prototype:
                         emit(ODECL, sym);
                         free(sym->u.pars);
+ sym->u.pars = NULL;
                         popctx();
                 }
         }
Received on Fri Aug 21 2015 - 00:17:08 CEST