Module Name: src
Committed By: rillig
Date: Sun Mar 13 15:20:50 UTC 2022
Modified Files:
src/usr.bin/xlint/lint1: lex.c
Log Message:
lint: clean up comments, explain assertion in inssym
To generate a diff of this commit:
cvs rdiff -u -r1.112 -r1.113 src/usr.bin/xlint/lint1/lex.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/xlint/lint1/lex.c
diff -u src/usr.bin/xlint/lint1/lex.c:1.112 src/usr.bin/xlint/lint1/lex.c:1.113
--- src/usr.bin/xlint/lint1/lex.c:1.112 Sun Mar 13 15:17:08 2022
+++ src/usr.bin/xlint/lint1/lex.c Sun Mar 13 15:20:50 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: lex.c,v 1.112 2022/03/13 15:17:08 rillig Exp $ */
+/* $NetBSD: lex.c,v 1.113 2022/03/13 15:20:50 rillig Exp $ */
/*
* Copyright (c) 1996 Christopher G. Demetriou. All Rights Reserved.
@@ -38,7 +38,7 @@
#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(lint)
-__RCSID("$NetBSD: lex.c,v 1.112 2022/03/13 15:17:08 rillig Exp $");
+__RCSID("$NetBSD: lex.c,v 1.113 2022/03/13 15:20:50 rillig Exp $");
#endif
#include <ctype.h>
@@ -775,9 +775,7 @@ lex_operator(int t, op_t o)
return t;
}
-/*
- * Called if lex found a leading \'.
- */
+/* Called if lex found a leading "'". */
int
lex_character_constant(void)
{
@@ -1368,17 +1366,16 @@ lex_unknown_character(int c)
}
/*
- * As noted above, the scanner does not create new symbol table entries
- * for symbols it cannot find in the symbol table. This is to avoid
- * putting undeclared symbols into the symbol table if a syntax error
- * occurs.
+ * The scanner does not create new symbol table entries for symbols it cannot
+ * find in the symbol table. This is to avoid putting undeclared symbols into
+ * the symbol table if a syntax error occurs.
*
- * getsym() is called as soon as it is probably ok to put the symbol in the
+ * getsym is called as soon as it is probably ok to put the symbol in the
* symbol table. It is still possible that symbols are put in the symbol
* table that are not completely declared due to syntax errors. To avoid too
- * many problems in this case, symbols get type 'int' in getsym().
+ * many problems in this case, symbols get type 'int' in getsym.
*
- * XXX calls to getsym() should be delayed until decl1*() is called.
+ * XXX calls to getsym should be delayed until declare_1_* is called.
*/
sym_t *
getsym(sbuf_t *sb)
@@ -1490,14 +1487,15 @@ rmsym(sym_t *sym)
}
/*
- * Remove a list of symbols declared at one level from the symbol
- * table.
+ * Remove all symbols from the symbol table that have the same level as the
+ * given symbol.
*/
void
rmsyms(sym_t *syms)
{
sym_t *sym;
+ /* Note the use of s_level_next instead of s_symtab_next. */
for (sym = syms; sym != NULL; sym = sym->s_level_next) {
if (sym->s_block_level != -1) {
debug_step("rmsyms '%s' %s '%s'",
@@ -1513,15 +1511,22 @@ rmsyms(sym_t *syms)
* Put a symbol into the symbol table.
*/
void
-inssym(int bl, sym_t *sym)
+inssym(int level, sym_t *sym)
{
debug_step("inssym '%s' %s '%s'",
sym->s_name, symt_name(sym->s_kind), type_name(sym->s_type));
symtab_add(sym);
- sym->s_block_level = bl;
- lint_assert(sym->s_symtab_next == NULL ||
- sym->s_block_level >= sym->s_symtab_next->s_block_level);
+ sym->s_block_level = level;
+
+ /*
+ * Placing the inner symbols to the beginning of the list ensures
+ * that these symbols are preferred over symbols from the outer
+ * blocks that happen to have the same name.
+ */
+ lint_assert(sym->s_symtab_next != NULL
+ ? sym->s_block_level >= sym->s_symtab_next->s_block_level
+ : true);
}
/*
@@ -1541,9 +1546,7 @@ clean_up_after_error(void)
level_free_all(i);
}
-/*
- * Create a new symbol with the name of an existing symbol.
- */
+/* Create a new symbol with the same name as an existing symbol. */
sym_t *
pushdown(const sym_t *sym)
{
