dissect: introduce dissect_ctx

Commit Message

Oleg Nesterov Feb. 6, 2020, 5:01 p.m. UTC

Points to the current function or to the global variable in case of
compound initializer.

Kill the ugly test-dissect.c:storage() and change print_usage() to
report dissect_ctx->ident instead.

Signed-off-by: Oleg Nesterov <[e-mail]>
---
 dissect.c      | 17 +++++++++++++++--
 dissect.h      |  2 ++
 test-dissect.c | 21 ++++++++-------------
 3 files changed, 25 insertions(+), 15 deletions(-)

Comments

Luc Van Oostenryck Feb. 6, 2020, 8:45 p.m. UTC | #1

On Thu, Feb 06, 2020 at 06:01:32PM +0100, Oleg Nesterov wrote:
> Points to the current function or to the global variable in case of
> compound initializer.
> 
> Kill the ugly test-dissect.c:storage() and change print_usage() to
> report dissect_ctx->ident instead.

Having the ful ident will be good, I think, but the cost is to have
to maintain this context. I suppose it would be too painful to 
propgate this context via an additional argument to all involved
functions?

-- Luc

Oleg Nesterov Feb. 7, 2020, 10:01 a.m. UTC | #2

On 02/06, Luc Van Oostenryck wrote:
>
> On Thu, Feb 06, 2020 at 06:01:32PM +0100, Oleg Nesterov wrote:
> > Points to the current function or to the global variable in case of
> > compound initializer.
> >
> > Kill the ugly test-dissect.c:storage() and change print_usage() to
> > report dissect_ctx->ident instead.
>
> Having the ful ident will be good, I think, but the cost is to have
> to maintain this context. I suppose it would be too painful to
> propgate this context via an additional argument to all involved
> functions?

Oh, I'd prefer to not do this. This needs to add the additional "ctx"
arg to every do_.*() function in dissect.c, and for what? IMHO, this
will just complicate the code for no reason.

I can unexport the global "struct symbol *dissect_ctx" introduced by
this patch and pass it as the additional (new) argument to every to
every callback, but I'd like to do this later, along with other
"incompatible" changes for the new tool Alexey is working on.

Thanks,

Oleg.

Luc Van Oostenryck Feb. 7, 2020, 11:21 a.m. UTC | #3

On Fri, Feb 07, 2020 at 11:01:50AM +0100, Oleg Nesterov wrote:
> On 02/06, Luc Van Oostenryck wrote:
> >
> > On Thu, Feb 06, 2020 at 06:01:32PM +0100, Oleg Nesterov wrote:
> > > Points to the current function or to the global variable in case of
> > > compound initializer.
> > >
> > > Kill the ugly test-dissect.c:storage() and change print_usage() to
> > > report dissect_ctx->ident instead.
> >
> > Having the ful ident will be good, I think, but the cost is to have
> > to maintain this context. I suppose it would be too painful to
> > propgate this context via an additional argument to all involved
> > functions?
> 
> Oh, I'd prefer to not do this. This needs to add the additional "ctx"
> arg to every do_.*() function in dissect.c, and for what? IMHO, this
> will just complicate the code for no reason.

Yes, I guessed so. No problem.

-- Luc

Patch

diff --git a/dissect.c b/dissect.c
index 60fccbd..54e11d2 100644
--- a/dissect.c
+++ b/dissect.c
@@ -51,6 +51,8 @@ 
 
 typedef unsigned usage_t;
 
+struct symbol *dissect_ctx;
+
 static struct reporter *reporter;
 static struct symbol *return_type;
 
@@ -211,7 +213,7 @@  static void report_memdef(struct symbol *sym, struct symbol *mem)
 
 static void examine_sym_node(struct symbol *node, struct symbol *parent)
 {
-	struct symbol *base;
+	struct symbol *base, *dctx;
 	struct ident *name;
 
 	if (node->examined)
@@ -240,6 +242,9 @@  static void examine_sym_node(struct symbol *node, struct symbol *parent)
 				return;
 			base->evaluated = 1;
 
+			dctx = dissect_ctx;
+			dissect_ctx = NULL;
+
 			if (base->ident || deanon(base, name, parent))
 				reporter->r_symdef(base);
 
@@ -248,6 +253,7 @@  static void examine_sym_node(struct symbol *node, struct symbol *parent)
 			DO_LIST(base->symbol_list, mem,
 				examine_sym_node(mem, parent);
 				report_memdef(parent, mem));
+			dissect_ctx = dctx;
 		default:
 			return;
 		}
@@ -582,6 +588,7 @@  static struct symbol *do_initializer(struct symbol *type, struct expression *exp
 static inline struct symbol *do_symbol(struct symbol *sym)
 {
 	struct symbol *type = base_type(sym);
+	struct symbol *dctx = dissect_ctx;
 
 	reporter->r_symdef(sym);
 
@@ -590,14 +597,20 @@  static inline struct symbol *do_symbol(struct symbol *sym)
 		if (!sym->initializer)
 			break;
 		reporter->r_symbol(U_W_VAL, &sym->pos, sym);
+		if (!dctx)
+			dissect_ctx = sym;
 		do_initializer(type, sym->initializer);
+		dissect_ctx = dctx;
 
 	break; case SYM_FN:
-		do_sym_list(type->arguments);
+		dissect_ctx = sym;
 		return_type = base_type(type);
+		do_sym_list(type->arguments);
 		do_statement(U_VOID, sym->ctype.modifiers & MOD_INLINE
 					? type->inline_stmt
 					: type->stmt);
+		dissect_ctx = dctx;
+		return_type = NULL;
 	}
 
 	return type;
diff --git a/dissect.h b/dissect.h
index 1f5b1d9..efe2c0b 100644
--- a/dissect.h
+++ b/dissect.h
@@ -25,6 +25,8 @@  struct reporter
 	void (*r_member)(unsigned, struct position *, struct symbol *, struct symbol *);
 };
 
+extern struct symbol *dissect_ctx;
+
 extern void dissect(struct symbol_list *, struct reporter *);
 
 #endif
diff --git a/test-dissect.c b/test-dissect.c
index e725eec..d93a2a0 100644
--- a/test-dissect.c
+++ b/test-dissect.c
@@ -2,17 +2,6 @@ 
 
 static unsigned dotc_stream;
 
-static inline char storage(struct symbol *sym)
-{
-	int t = sym->type;
-	unsigned m = sym->ctype.modifiers;
-
-	if (m & MOD_INLINE || t == SYM_STRUCT || t == SYM_UNION /*|| t == SYM_ENUM*/)
-		return sym->pos.stream == dotc_stream ? 's' : 'g';
-
-	return (m & MOD_STATIC) ? 's' : (m & MOD_NONLOCAL) ? 'g' : 'l';
-}
-
 static inline const char *show_mode(unsigned mode)
 {
 	static char str[3];
@@ -32,14 +21,20 @@  static inline const char *show_mode(unsigned mode)
 static void print_usage(struct position *pos, struct symbol *sym, unsigned mode)
 {
 	static unsigned curr_stream = -1;
+	static struct ident null;
+	struct ident *ctx = &null;
 
 	if (curr_stream != pos->stream) {
 		curr_stream = pos->stream;
 		printf("\nFILE: %s\n\n", stream_name(curr_stream));
 	}
 
-	printf("%4d:%-3d %c %-5.3s",
-		pos->line, pos->pos, storage(sym), show_mode(mode));
+	if (dissect_ctx)
+		ctx = dissect_ctx->ident;
+
+	printf("%4d:%-3d %-16.*s %-5.3s",
+		pos->line, pos->pos, ctx->len, ctx->name, show_mode(mode));
+
 }
 
 static void r_symbol(unsigned mode, struct position *pos, struct symbol *sym)