libdrgn: embed drgn_debug_info in drgn_program

This will simplify the implementation of the module API (#332).

Signed-off-by: Omar Sandoval <osandov@osandov.com>

libdrgn/debug_info.c

@@ -2086,12 +2086,9 @@ bool drgn_debug_info_is_indexed(struct drgn_debug_info *dbinfo,
 	return c_string_set_search(&dbinfo->module_names, &name).entry != NULL;
 }
 
-struct drgn_error *drgn_debug_info_create(struct drgn_program *prog,
-					  struct drgn_debug_info **ret)
+void drgn_debug_info_init(struct drgn_debug_info *dbinfo,
+			  struct drgn_program *prog)
 {
-	struct drgn_debug_info *dbinfo = malloc(sizeof(*dbinfo));
-	if (!dbinfo)
-		return &drgn_enomem;
 	dbinfo->prog = prog;
 	const Dwfl_Callbacks *dwfl_callbacks;
 	if (prog->flags & DRGN_PROGRAM_IS_LINUX_KERNEL)
@@ -2101,10 +2098,10 @@ struct drgn_error *drgn_debug_info_create(struct drgn_program *prog,
 	else
 		dwfl_callbacks = &drgn_userspace_core_dump_dwfl_callbacks;
 	dbinfo->dwfl = dwfl_begin(dwfl_callbacks);
-	if (!dbinfo->dwfl) {
-		free(dbinfo);
-		return drgn_error_libdwfl();
-	}
+	// This is temporary until we stop using libdwfl, and is extremely
+	// unlikely to fail anwyays, so don't bother propagating an error up.
+	if (!dbinfo->dwfl)
+		abort();
 	drgn_program_add_type_finder_impl(prog, &dbinfo->type_finder,
 					  drgn_debug_info_find_type, dbinfo);
 	drgn_program_add_object_finder_impl(prog, &dbinfo->object_finder,
@@ -2113,21 +2110,16 @@ struct drgn_error *drgn_debug_info_create(struct drgn_program *prog,
 	drgn_module_table_init(&dbinfo->modules);
 	c_string_set_init(&dbinfo->module_names);
 	drgn_dwarf_info_init(dbinfo);
-	*ret = dbinfo;
-	return NULL;
 }
 
-void drgn_debug_info_destroy(struct drgn_debug_info *dbinfo)
+void drgn_debug_info_deinit(struct drgn_debug_info *dbinfo)
 {
-	if (!dbinfo)
-		return;
 	drgn_dwarf_info_deinit(dbinfo);
 	c_string_set_deinit(&dbinfo->module_names);
 	drgn_debug_info_free_modules(dbinfo, false, true);
 	assert(drgn_module_table_empty(&dbinfo->modules));
 	drgn_module_table_deinit(&dbinfo->modules);
 	dwfl_end(dbinfo->dwfl);
-	free(dbinfo);
 }
 
 struct drgn_elf_file *drgn_module_find_dwarf_file(struct drgn_module *module,

libdrgn/debug_info.h

@@ -153,12 +153,12 @@ struct drgn_debug_info {
 	struct drgn_dwarf_info dwarf;
 };
 
-/** Create a @ref drgn_debug_info. */
-struct drgn_error *drgn_debug_info_create(struct drgn_program *prog,
-					  struct drgn_debug_info **ret);
+/** Initialize a @ref drgn_debug_info. */
+void drgn_debug_info_init(struct drgn_debug_info *dbinfo,
+			  struct drgn_program *prog);
 
-/** Destroy a @ref drgn_debug_info. */
-void drgn_debug_info_destroy(struct drgn_debug_info *dbinfo);
+/** Deinitialize a @ref drgn_debug_info. */
+void drgn_debug_info_deinit(struct drgn_debug_info *dbinfo);
 
 DEFINE_VECTOR_TYPE(drgn_module_vector, struct drgn_module *);
 

libdrgn/dwarf_info.c

@@ -4917,7 +4917,7 @@ drgn_dwarf_member_thunk_fn(struct drgn_object *res, void *arg_)
 	struct drgn_dwarf_member_thunk_arg *arg = arg_;
 	if (res) {
 		struct drgn_qualified_type qualified_type;
-		err = drgn_type_from_dwarf_attr(drgn_object_program(res)->dbinfo,
+		err = drgn_type_from_dwarf_attr(&drgn_object_program(res)->dbinfo,
 						arg->file, &arg->die, NULL,
 						false,
 						arg->can_be_incomplete_array,
@@ -5200,7 +5200,7 @@ drgn_dwarf_template_type_parameter_thunk_fn(struct drgn_object *res, void *arg_)
 	struct drgn_dwarf_die_thunk_arg *arg = arg_;
 	if (res) {
 		struct drgn_qualified_type qualified_type;
-		err = drgn_type_from_dwarf_attr(drgn_object_program(res)->dbinfo,
+		err = drgn_type_from_dwarf_attr(&drgn_object_program(res)->dbinfo,
 						arg->file, &arg->die, NULL,
 						true, true, NULL,
 						&qualified_type);
@@ -5222,7 +5222,7 @@ drgn_dwarf_template_value_parameter_thunk_fn(struct drgn_object *res,
 	struct drgn_error *err;
 	struct drgn_dwarf_die_thunk_arg *arg = arg_;
 	if (res) {
-		err = drgn_object_from_dwarf(drgn_object_program(res)->dbinfo,
+		err = drgn_object_from_dwarf(&drgn_object_program(res)->dbinfo,
 					     arg->file, &arg->die, NULL, NULL,
 					     NULL, res);
 		if (err)
@@ -5790,7 +5790,7 @@ drgn_dwarf_formal_parameter_thunk_fn(struct drgn_object *res, void *arg_)
 	struct drgn_dwarf_die_thunk_arg *arg = arg_;
 	if (res) {
 		struct drgn_qualified_type qualified_type;
-		err = drgn_type_from_dwarf_attr(drgn_object_program(res)->dbinfo,
+		err = drgn_type_from_dwarf_attr(&drgn_object_program(res)->dbinfo,
 						arg->file, &arg->die, NULL,
 						false, true, NULL,
 						&qualified_type);

libdrgn/program.c

@@ -100,6 +100,7 @@ void drgn_program_init(struct drgn_program *prog,
 	drgn_memory_reader_init(&prog->reader);
 	drgn_program_init_types(prog);
 	drgn_object_index_init(&prog->oindex);
+	drgn_debug_info_init(&prog->dbinfo, prog);
 	prog->core_fd = -1;
 	if (platform)
 		drgn_program_set_platform(prog, platform);
@@ -147,7 +148,7 @@ void drgn_program_deinit(struct drgn_program *prog)
 	if (prog->core_fd != -1)
 		close(prog->core_fd);
 
-	drgn_debug_info_destroy(prog->dbinfo);
+	drgn_debug_info_deinit(&prog->dbinfo);
 }
 
 LIBDRGN_PUBLIC struct drgn_error *
@@ -695,7 +696,7 @@ static void drgn_program_set_language_from_main(struct drgn_program *prog)
 	if (prog->flags & DRGN_PROGRAM_IS_LINUX_KERNEL)
 		return;
 	const struct drgn_language *lang;
-	err = drgn_debug_info_main_language(prog->dbinfo, &lang);
+	err = drgn_debug_info_main_language(&prog->dbinfo, &lang);
 	if (err) {
 		drgn_error_destroy(err);
 		return;
@@ -734,20 +735,12 @@ drgn_program_load_debug_info(struct drgn_program *prog, const char **paths,
 		return NULL;
 
 	drgn_blocking_guard(prog);
-	struct drgn_debug_info *dbinfo = prog->dbinfo;
-	if (!dbinfo) {
-		err = drgn_debug_info_create(prog, &dbinfo);
-		if (err)
-			return err;
-		prog->dbinfo = dbinfo;
-	}
-
-	err = drgn_debug_info_load(dbinfo, paths, n, load_default, load_main);
+	err = drgn_debug_info_load(&prog->dbinfo, paths, n, load_default, load_main);
 	if ((!err || err->code == DRGN_ERROR_MISSING_DEBUG_INFO)) {
 		if (!prog->lang)
 			drgn_program_set_language_from_main(prog);
 		if (!prog->has_platform) {
-			dwfl_getdwarf(dbinfo->dwfl,
+			dwfl_getdwarf(prog->dbinfo.dwfl,
 				      drgn_set_platform_from_dwarf, prog, 0);
 		}
 	}
@@ -1784,13 +1777,9 @@ bool drgn_program_find_symbol_by_address_internal(struct drgn_program *prog,
 						  struct drgn_symbol *ret)
 {
 	if (!module) {
-		if (prog->dbinfo) {
-			module = dwfl_addrmodule(prog->dbinfo->dwfl, address);
-			if (!module)
-				return false;
-		} else {
+		module = dwfl_addrmodule(prog->dbinfo.dwfl, address);
+		if (!module)
 			return false;
-		}
 	}
 
 	GElf_Off offset;
@@ -1894,11 +1883,6 @@ symbols_search(struct drgn_program *prog, struct symbols_search_arg *arg,
 {
 	struct drgn_error *err;
 
-	if (!prog->dbinfo) {
-		return drgn_error_create(DRGN_ERROR_MISSING_DEBUG_INFO,
-					 "could not find matching symbols");
-	}
-
 	symbolp_vector_init(&arg->results);
 
 	/*
@@ -1907,12 +1891,12 @@ symbols_search(struct drgn_program *prog, struct symbols_search_arg *arg,
 	 */
 	err = NULL;
 	if (arg->flags & SYMBOLS_SEARCH_ADDRESS) {
-		Dwfl_Module *module = dwfl_addrmodule(prog->dbinfo->dwfl,
+		Dwfl_Module *module = dwfl_addrmodule(prog->dbinfo.dwfl,
 						      arg->address);
 		if (module && symbols_search_cb(module, NULL, NULL, 0, arg))
 			err = &drgn_enomem;
 	} else {
-		if (dwfl_getmodules(prog->dbinfo->dwfl, symbols_search_cb, arg,
+		if (dwfl_getmodules(prog->dbinfo.dwfl, symbols_search_cb, arg,
 				    0))
 			err = &drgn_enomem;
 	}
@@ -2015,17 +1999,14 @@ drgn_program_find_symbol_by_name(struct drgn_program *prog,
 	struct find_symbol_by_name_arg arg = {
 		.name = name,
 	};
-	if (prog->dbinfo) {
-		dwfl_getmodules(prog->dbinfo->dwfl, find_symbol_by_name_cb,
-				&arg, 0);
-		if (arg.found) {
-			struct drgn_symbol *sym = malloc(sizeof(*sym));
-			if (!sym)
-				return &drgn_enomem;
-			drgn_symbol_from_elf(name, arg.addr, &arg.sym, sym);
-			*ret = sym;
-			return NULL;
-		}
+	dwfl_getmodules(prog->dbinfo.dwfl, find_symbol_by_name_cb, &arg, 0);
+	if (arg.found) {
+		struct drgn_symbol *sym = malloc(sizeof(*sym));
+		if (!sym)
+			return &drgn_enomem;
+		drgn_symbol_from_elf(name, arg.addr, &arg.sym, sym);
+		*ret = sym;
+		return NULL;
 	}
 	return drgn_error_format(DRGN_ERROR_LOOKUP,
 				 "could not find symbol with name '%s'%s", name,

libdrgn/program.h

@@ -19,6 +19,7 @@
 #include <libkdumpfile/kdumpfile.h>
 #endif
 
+#include "debug_info.h"
 #include "drgn.h"
 #include "hash_table.h"
 #include "language.h"
@@ -107,7 +108,7 @@ struct drgn_program {
 	 * Debugging information.
 	 */
 	struct drgn_object_index oindex;
-	struct drgn_debug_info *dbinfo;
+	struct drgn_debug_info dbinfo;
 
 	/*
 	 * Program information.

libdrgn/register_state.c

@@ -105,15 +105,13 @@ void drgn_register_state_set_pc(struct drgn_program *prog,
 	pc &= drgn_platform_address_mask(&prog->platform);
 	regs->_pc = pc;
 	drgn_register_state_set_known(regs, 0);
-	if (prog->dbinfo) {
-		Dwfl_Module *dwfl_module = dwfl_addrmodule(prog->dbinfo->dwfl,
-							   pc - !regs->interrupted);
-		if (dwfl_module) {
-			void **userdatap;
-			dwfl_module_info(dwfl_module, &userdatap, NULL, NULL,
-					 NULL, NULL, NULL, NULL);
-			regs->module = *userdatap;
-		}
+	Dwfl_Module *dwfl_module = dwfl_addrmodule(prog->dbinfo.dwfl,
+						   pc - !regs->interrupted);
+	if (dwfl_module) {
+		void **userdatap;
+		dwfl_module_info(dwfl_module, &userdatap, NULL, NULL,
+				 NULL, NULL, NULL, NULL);
+		regs->module = *userdatap;
 	}
 }
 

libdrgn/stack_trace.c

@@ -495,7 +495,7 @@ not_found:;
 	if (!drgn_platforms_equal(&file->platform, &trace->prog->platform))
 		regs = NULL;
 	Dwarf_Die function_die = frame->scopes[frame->function_scope];
-	return drgn_object_from_dwarf(trace->prog->dbinfo, file, &die,
+	return drgn_object_from_dwarf(&trace->prog->dbinfo, file, &die,
 				      dwarf_tag(&die) == DW_TAG_enumerator ?
 				      &type_die : NULL,
 				      &function_die, regs, ret);