genksyms: track symbol checksum changes
Sometimes it is preferable to avoid changes of exported symbol checksums (to avoid breaking externally provided modules). When a checksum change occurs, it can be hard to figure out what caused this change: underlying types may have changed, or additional type information may simply have become available at the point where a symbol is exported. Add a new --reference option to genksyms which allows it to report why checksums change, based on the type information dumps it creates with the --dump-types flag. Genksyms will read in such a dump from a previous run, and report which symbols have changed (and why). The behavior can be controlled for an entire build as follows: If KBUILD_SYMTYPES is set, genksyms uses --dump-types to produce *.symtypes dump files. If any *.symref files exist, those will be used as the reference to check against. If KBUILD_PRESERVE is set, checksum changes will fail the build. Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
This commit is contained in:
Andreas Gruenbacher
Sam Ravnborg
parent
a680eedc6c
commit
64e6c1e123
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@ -153,12 +153,18 @@ $(obj)/%.i: $(src)/%.c FORCE
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quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
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cmd_cc_symtypes_c = \
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set -e; \
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$(CPP) -D__GENKSYMS__ $(c_flags) $< \
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| $(GENKSYMS) -T $@ >/dev/null; \
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| $(GENKSYMS) -T $@ \
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-r $(firstword $(wildcard \
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$(@:.symtypes=.symref) /dev/null)) \
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$(if $(KBUILD_PRESERVE),-p) \
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-a $(ARCH) \
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>/dev/null; \
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test -s $@ || rm -f $@
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$(obj)/%.symtypes : $(src)/%.c FORCE
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$(call if_changed_dep,cc_symtypes_c)
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$(call cmd,cc_symtypes_c)
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# C (.c) files
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# The C file is compiled and updated dependency information is generated.
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@ -187,7 +193,11 @@ cmd_modversions = \
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if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
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$(CPP) -D__GENKSYMS__ $(c_flags) $< \
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| $(GENKSYMS) $(if $(KBUILD_SYMTYPES), \
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-T $(@D)/$(@F:.o=.symtypes)) -a $(ARCH) \
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-T $(@:.o=.symtypes)) \
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-r $(firstword $(wildcard \
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$(@:.o=.symref) /dev/null)) \
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$(if $(KBUILD_PRESERVE),-p) \
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-a $(ARCH) \
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> $(@D)/.tmp_$(@F:.o=.ver); \
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\
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$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
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@ -42,7 +42,8 @@ static FILE *debugfile;
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int cur_line = 1;
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char *cur_filename;
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static int flag_debug, flag_dump_defs, flag_dump_types, flag_warnings;
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static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types,
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flag_preserve, flag_warnings;
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static const char *arch = "";
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static const char *mod_prefix = "";
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@ -58,6 +59,8 @@ static const char *const symbol_type_name[] = {
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static int equal_list(struct string_list *a, struct string_list *b);
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static void print_list(FILE * f, struct string_list *list);
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static void print_location(void);
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static void print_type_name(enum symbol_type type, const char *name);
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/*----------------------------------------------------------------------*/
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@ -151,27 +154,68 @@ struct symbol *find_symbol(const char *name, enum symbol_type ns)
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for (sym = symtab[h]; sym; sym = sym->hash_next)
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if (map_to_ns(sym->type) == map_to_ns(ns) &&
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strcmp(name, sym->name) == 0)
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strcmp(name, sym->name) == 0 &&
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sym->is_declared)
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break;
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return sym;
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}
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struct symbol *add_symbol(const char *name, enum symbol_type type,
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struct string_list *defn, int is_extern)
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static int is_unknown_symbol(struct symbol *sym)
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{
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struct string_list *defn;
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return ((sym->type == SYM_STRUCT ||
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sym->type == SYM_UNION ||
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sym->type == SYM_ENUM) &&
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(defn = sym->defn) && defn->tag == SYM_NORMAL &&
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strcmp(defn->string, "}") == 0 &&
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(defn = defn->next) && defn->tag == SYM_NORMAL &&
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strcmp(defn->string, "UNKNOWN") == 0 &&
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(defn = defn->next) && defn->tag == SYM_NORMAL &&
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strcmp(defn->string, "{") == 0);
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}
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struct symbol *__add_symbol(const char *name, enum symbol_type type,
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struct string_list *defn, int is_extern,
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int is_reference)
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{
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unsigned long h = crc32(name) % HASH_BUCKETS;
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struct symbol *sym;
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enum symbol_status status = STATUS_UNCHANGED;
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for (sym = symtab[h]; sym; sym = sym->hash_next) {
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if (map_to_ns(sym->type) == map_to_ns(type)
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&& strcmp(name, sym->name) == 0) {
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if (!equal_list(sym->defn, defn))
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if (map_to_ns(sym->type) == map_to_ns(type) &&
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strcmp(name, sym->name) == 0) {
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if (is_reference)
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/* fall through */ ;
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else if (sym->type == type &&
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equal_list(sym->defn, defn)) {
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sym->is_declared = 1;
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return sym;
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} else if (!sym->is_declared) {
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status = is_unknown_symbol(sym) ?
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STATUS_DEFINED : STATUS_MODIFIED;
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} else {
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error_with_pos("redefinition of %s", name);
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return sym;
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return sym;
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}
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break;
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}
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}
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if (sym) {
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struct symbol **psym;
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for (psym = &symtab[h]; *psym; psym = &(*psym)->hash_next) {
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if (*psym == sym) {
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*psym = sym->hash_next;
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break;
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}
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}
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--nsyms;
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}
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sym = xmalloc(sizeof(*sym));
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sym->name = name;
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sym->type = type;
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@ -183,6 +227,9 @@ struct symbol *add_symbol(const char *name, enum symbol_type type,
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sym->hash_next = symtab[h];
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symtab[h] = sym;
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sym->is_declared = !is_reference;
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sym->status = status;
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if (flag_debug) {
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fprintf(debugfile, "Defn for %s %s == <",
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symbol_type_name[type], name);
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@ -196,6 +243,18 @@ struct symbol *add_symbol(const char *name, enum symbol_type type,
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return sym;
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}
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struct symbol *add_symbol(const char *name, enum symbol_type type,
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struct string_list *defn, int is_extern)
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{
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return __add_symbol(name, type, defn, is_extern, 0);
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}
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struct symbol *add_reference_symbol(const char *name, enum symbol_type type,
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struct string_list *defn, int is_extern)
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{
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return __add_symbol(name, type, defn, is_extern, 1);
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}
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/*----------------------------------------------------------------------*/
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void free_node(struct string_list *node)
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@ -236,6 +295,82 @@ static int equal_list(struct string_list *a, struct string_list *b)
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return !a && !b;
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}
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#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
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struct string_list *read_node(FILE *f)
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{
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char buffer[256];
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struct string_list node = {
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.string = buffer,
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.tag = SYM_NORMAL };
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int c;
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while ((c = fgetc(f)) != EOF) {
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if (c == ' ') {
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if (node.string == buffer)
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continue;
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break;
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} else if (c == '\n') {
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if (node.string == buffer)
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return NULL;
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ungetc(c, f);
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break;
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}
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if (node.string >= buffer + sizeof(buffer) - 1) {
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fprintf(stderr, "Token too long\n");
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exit(1);
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}
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*node.string++ = c;
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}
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if (node.string == buffer)
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return NULL;
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*node.string = 0;
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node.string = buffer;
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if (node.string[1] == '#') {
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int n;
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for (n = 0; n < ARRAY_SIZE(symbol_type_name); n++) {
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if (node.string[0] == symbol_type_name[n][0]) {
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node.tag = n;
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node.string += 2;
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return copy_node(&node);
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}
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}
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fprintf(stderr, "Unknown type %c\n", node.string[0]);
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exit(1);
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}
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return copy_node(&node);
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}
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static void read_reference(FILE *f)
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{
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while (!feof(f)) {
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struct string_list *defn = NULL;
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struct string_list *sym, *def;
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int is_extern = 0;
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sym = read_node(f);
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if (!sym)
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continue;
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def = read_node(f);
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if (def && def->tag == SYM_NORMAL &&
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!strcmp(def->string, "extern")) {
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is_extern = 1;
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free_node(def);
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def = read_node(f);
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}
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while (def) {
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def->next = defn;
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defn = def;
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def = read_node(f);
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}
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add_reference_symbol(xstrdup(sym->string), sym->tag,
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defn, is_extern);
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free_node(sym);
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}
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}
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static void print_node(FILE * f, struct string_list *list)
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{
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if (list->tag != SYM_NORMAL) {
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@ -311,6 +446,7 @@ static unsigned long expand_and_crc_sym(struct symbol *sym, unsigned long crc)
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case SYM_TYPEDEF:
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subsym = find_symbol(cur->string, cur->tag);
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/* FIXME: Bad reference files can segfault here. */
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if (subsym->expansion_trail) {
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if (flag_dump_defs)
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fprintf(debugfile, "%s ", cur->string);
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@ -347,9 +483,22 @@ static unsigned long expand_and_crc_sym(struct symbol *sym, unsigned long crc)
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t = n;
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n = xmalloc(sizeof(*n));
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n->string = xstrdup("{ UNKNOWN }");
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n->string = xstrdup("{");
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n->tag = SYM_NORMAL;
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n->next = t;
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t = n;
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n = xmalloc(sizeof(*n));
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n->string = xstrdup("UNKNOWN");
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n->tag = SYM_NORMAL;
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n->next = t;
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t = n;
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n = xmalloc(sizeof(*n));
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n->string = xstrdup("}");
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n->tag = SYM_NORMAL;
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n->next = t;
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t = n;
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subsym =
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add_symbol(cur->string, cur->tag, n, 0);
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@ -397,20 +546,42 @@ void export_symbol(const char *name)
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error_with_pos("export undefined symbol %s", name);
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else {
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unsigned long crc;
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int has_changed = 0;
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if (flag_dump_defs)
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fprintf(debugfile, "Export %s == <", name);
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expansion_trail = (struct symbol *)-1L;
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sym->expansion_trail = expansion_trail;
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expansion_trail = sym;
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crc = expand_and_crc_sym(sym, 0xffffffff) ^ 0xffffffff;
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sym = expansion_trail;
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while (sym != (struct symbol *)-1L) {
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struct symbol *n = sym->expansion_trail;
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if (sym->status != STATUS_UNCHANGED) {
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if (!has_changed) {
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print_location();
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fprintf(stderr, "%s: %s: modversion "
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"changed because of changes "
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"in ", flag_preserve ? "error" :
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"warning", name);
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} else
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fprintf(stderr, ", ");
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print_type_name(sym->type, sym->name);
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if (sym->status == STATUS_DEFINED)
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fprintf(stderr, " (became defined)");
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has_changed = 1;
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if (flag_preserve)
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errors++;
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}
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sym->expansion_trail = 0;
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sym = n;
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}
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if (has_changed)
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fprintf(stderr, "\n");
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if (flag_dump_defs)
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fputs(">\n", debugfile);
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@ -421,13 +592,26 @@ void export_symbol(const char *name)
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}
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/*----------------------------------------------------------------------*/
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static void print_location(void)
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{
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fprintf(stderr, "%s:%d: ", cur_filename ? : "<stdin>", cur_line);
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}
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static void print_type_name(enum symbol_type type, const char *name)
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{
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if (type != SYM_NORMAL)
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fprintf(stderr, "%s %s", symbol_type_name[type], name);
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else
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fprintf(stderr, "%s", name);
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}
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void error_with_pos(const char *fmt, ...)
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{
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va_list args;
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if (flag_warnings) {
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fprintf(stderr, "%s:%d: ", cur_filename ? : "<stdin>",
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cur_line);
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print_location();
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va_start(args, fmt);
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vfprintf(stderr, fmt, args);
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@ -445,7 +629,9 @@ static void genksyms_usage(void)
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" -a, --arch Select architecture\n"
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" -d, --debug Increment the debug level (repeatable)\n"
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" -D, --dump Dump expanded symbol defs (for debugging only)\n"
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" -T, --dump-types file Dump expanded types into file (for debugging only)\n"
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" -r, --reference file Read reference symbols from a file\n"
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" -T, --dump-types file Dump expanded types into file\n"
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" -p, --preserve Preserve reference modversions or fail\n"
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" -w, --warnings Enable warnings\n"
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" -q, --quiet Disable warnings (default)\n"
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" -h, --help Print this message\n"
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@ -454,7 +640,9 @@ static void genksyms_usage(void)
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" -a Select architecture\n"
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" -d Increment the debug level (repeatable)\n"
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" -D Dump expanded symbol defs (for debugging only)\n"
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" -T file Dump expanded types into file (for debugging only)\n"
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" -r file Read reference symbols from a file\n"
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" -T file Dump expanded types into file\n"
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" -p Preserve reference modversions or fail\n"
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" -w Enable warnings\n"
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" -q Disable warnings (default)\n"
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" -h Print this message\n"
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@ -465,7 +653,7 @@ static void genksyms_usage(void)
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int main(int argc, char **argv)
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{
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FILE *dumpfile = NULL;
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FILE *dumpfile = NULL, *ref_file = NULL;
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int o;
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#ifdef __GNU_LIBRARY__
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@ -475,16 +663,18 @@ int main(int argc, char **argv)
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{"warnings", 0, 0, 'w'},
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{"quiet", 0, 0, 'q'},
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{"dump", 0, 0, 'D'},
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{"reference", 1, 0, 'r'},
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{"dump-types", 1, 0, 'T'},
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{"preserve", 0, 0, 'p'},
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{"version", 0, 0, 'V'},
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{"help", 0, 0, 'h'},
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{0, 0, 0, 0}
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};
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while ((o = getopt_long(argc, argv, "a:dwqVDT:h",
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while ((o = getopt_long(argc, argv, "a:dwqVDr:T:ph",
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&long_opts[0], NULL)) != EOF)
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#else /* __GNU_LIBRARY__ */
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while ((o = getopt(argc, argv, "a:dwqVDT:h")) != EOF)
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while ((o = getopt(argc, argv, "a:dwqVDr:T:ph")) != EOF)
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#endif /* __GNU_LIBRARY__ */
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switch (o) {
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case 'a':
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@ -505,6 +695,14 @@ int main(int argc, char **argv)
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case 'D':
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flag_dump_defs = 1;
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break;
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case 'r':
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flag_reference = 1;
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ref_file = fopen(optarg, "r");
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if (!ref_file) {
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perror(optarg);
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return 1;
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}
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break;
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case 'T':
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flag_dump_types = 1;
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dumpfile = fopen(optarg, "w");
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|
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@ -513,6 +711,9 @@ int main(int argc, char **argv)
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return 1;
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}
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break;
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case 'p':
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flag_preserve = 1;
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break;
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case 'h':
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genksyms_usage();
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return 0;
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@ -533,6 +734,9 @@ int main(int argc, char **argv)
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/* setlinebuf(debugfile); */
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}
|
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if (flag_reference)
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read_reference(ref_file);
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|
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yyparse();
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|
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if (flag_dump_types && visited_symbols) {
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|
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|
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@ -29,6 +29,10 @@ enum symbol_type {
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SYM_NORMAL, SYM_TYPEDEF, SYM_ENUM, SYM_STRUCT, SYM_UNION
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};
|
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|
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enum symbol_status {
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STATUS_UNCHANGED, STATUS_DEFINED, STATUS_MODIFIED
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};
|
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|
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struct string_list {
|
||||
struct string_list *next;
|
||||
enum symbol_type tag;
|
||||
|
|
@ -43,6 +47,8 @@ struct symbol {
|
|||
struct symbol *expansion_trail;
|
||||
struct symbol *visited;
|
||||
int is_extern;
|
||||
int is_declared;
|
||||
enum symbol_status status;
|
||||
};
|
||||
|
||||
typedef struct string_list **yystype;
|
||||
|
|
|
|||
Loading…
Reference in New Issue