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dissect: don't set ->ident = '?' in no_member()

PATCH New Oleg Nesterov 1 participant 2 messages Feb 12, 2020 Sparse checker

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Oleg Nesterov

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#0 lore raw

PATCH 1/2 dissect: don't set ->ident = '?' in no_member()

no_member() sets ->ident = built_in_ident("?") for the case when dissect() can't figure out the name of initialized member. For example:

	struct EMPTY {} var = { 10 };

the output:

1:25 var -w- m EMPTY.? bad type

This is useful, but dissect should not dictate the policy. Let r_member() decide how this case should be reported.

Signed-off-by Oleg Nesterov <[email protected]>
---
 dissect.c      | 6 +++---
 test-dissect.c | 7 ++++---
 2 files changed, 7 insertions(+), 6 deletions(-)
dissect.c +3 -3
index 6706690..05bddc8 100644
@@ -123,11 +123,11 @@ static inline struct symbol *no_member(struct ident *name)
 {
 	static struct symbol sym = {
 		.type = SYM_BAD,
+		.ctype.base_type = &bad_ctype,
 		.kind = 'm',
 	};
 
-	sym.ctype.base_type = &bad_ctype;
-	sym.ident = name ?: built_in_ident("?");
+	sym.ident = name;
 
 	return &sym;
 }

@@ -137,7 +137,7 @@ static struct symbol *report_member(usage_t mode, struct position *pos,
 {
 	struct symbol *ret = mem->ctype.base_type;
 
-	if (mem->ident)
+	if (mem->ident || mem->type == SYM_BAD)
 		reporter->r_member(fix_mode(ret, mode), pos, type, mem);
 
 	return ret;
test-dissect.c +4 -3
index 4b2d3be..58b3e63 100644
@@ -80,13 +80,14 @@ err:
 
 static void r_member(unsigned mode, struct position *pos, struct symbol *sym, struct symbol *mem)
 {
-	struct ident *si, *mi;
+	struct ident *ni, *si, *mi;
 
 	print_usage(pos, sym, mode);
 
-	si = sym->ident ?: built_in_ident("?");
+	ni = built_in_ident("?");
+	si = sym->ident ?: ni;
 	/* mem == NULL means entire struct accessed */
-	mi = mem ? mem->ident : built_in_ident("*");
+	mi = mem ? (mem->ident ?: ni) : built_in_ident("*");
 
 	printf("%c m %.*s.%-*.*s %s\n",
 		symscope(sym), si->len, si->name,
Signature · 1 line
2.5.0
author
#1 lore raw

PATCH 2/2 dissect: kill no_member()

It is trivial and has a single caller, lookup_member().

Signed-off-by Oleg Nesterov <[email protected]>
---
 dissect.c | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)
dissect.c +14 -15
index 05bddc8..40baf64 100644
@@ -119,19 +119,6 @@ static usage_t fix_mode(struct symbol *type, usage_t mode)
 	return mode;
 }
 
-static inline struct symbol *no_member(struct ident *name)
-{
-	static struct symbol sym = {
-		.type = SYM_BAD,
-		.ctype.base_type = &bad_ctype,
-		.kind = 'm',
-	};
-
-	sym.ident = name;
-
-	return &sym;
-}
-
 static struct symbol *report_member(usage_t mode, struct position *pos,
 					struct symbol *type, struct symbol *mem)
 {

@@ -308,8 +295,20 @@ found:
 
 static struct symbol *lookup_member(struct symbol *type, struct ident *name, int *addr)
 {
-	return __lookup_member(type, name, addr)
-		?: no_member(name);
+	struct symbol *mem = __lookup_member(type, name, addr);
+
+	if (!mem) {
+		static struct symbol bad_member = {
+			.type = SYM_BAD,
+			.ctype.base_type = &bad_ctype,
+			.kind = 'm',
+		};
+
+		mem = &bad_member;
+		mem->ident = name;
+	}
+
+	return mem;
 }
 
 static struct expression *peek_preop(struct expression *expr, int op)
Signature · 1 line
2.5.0