linux/tools/objtool/include/objtool/warn.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
 */

#ifndef _WARN_H
#define _WARN_H

#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <objtool/builtin.h>
#include <objtool/elf.h>

extern const char *objname;

static inline char *offstr(struct section *sec, unsigned long offset)
{
	bool is_text = (sec->sh.sh_flags & SHF_EXECINSTR);
	struct symbol *sym = NULL;
	char *str;
	int len;

	if (is_text)
		sym = find_func_containing(sec, offset);
	if (!sym)
		sym = find_symbol_containing(sec, offset);

	if (sym) {
		str = malloc(strlen(sym->name) + strlen(sec->name) + 40);
		len = sprintf(str, "%s+0x%lx", sym->name, offset - sym->offset);
		if (opts.sec_address)
			sprintf(str+len, " (%s+0x%lx)", sec->name, offset);
	} else {
		str = malloc(strlen(sec->name) + 20);
		sprintf(str, "%s+0x%lx", sec->name, offset);
	}

	return str;
}

#define ___WARN(severity, extra, format, ...)				\
	fprintf(stderr,							\
		"%s%s%s: objtool" extra ": " format "\n",		\
		objname ?: "",						\
		objname ? ": " : "",					\
		severity,						\
		##__VA_ARGS__)

#define __WARN(severity, format, ...)					\
	___WARN(severity, "", format, ##__VA_ARGS__)

#define __WARN_LINE(severity, format, ...)				\
	___WARN(severity, " [%s:%d]", format, __FILE__, __LINE__, ##__VA_ARGS__)

#define __WARN_ELF(severity, format, ...)				\
	__WARN_LINE(severity, "%s: " format " failed: %s", __func__, ##__VA_ARGS__, elf_errmsg(-1))

#define __WARN_GLIBC(severity, format, ...)				\
	__WARN_LINE(severity, "%s: " format " failed: %s", __func__, ##__VA_ARGS__, strerror(errno))

#define __WARN_FUNC(severity, sec, offset, format, ...)			\
({									\
	char *_str = offstr(sec, offset);				\
	__WARN(severity, "%s: " format, _str, ##__VA_ARGS__);		\
	free(_str);							\
})

#define WARN_STR (opts.werror ? "error" : "warning")

#define WARN(format, ...) __WARN(WARN_STR, format, ##__VA_ARGS__)
#define WARN_FUNC(sec, offset, format, ...) __WARN_FUNC(WARN_STR, sec, offset, format, ##__VA_ARGS__)

#define WARN_INSN(insn, format, ...)					\
({									\
	struct instruction *_insn = (insn);				\
	if (!insn_sym(_insn) || !insn_sym(_insn)->warned)	{	\
		WARN_FUNC(_insn->sec, _insn->offset, format,		\
			  ##__VA_ARGS__);				\
		BT_INSN(_insn, "");					\
	}								\
	if (insn_sym(_insn))						\
		insn_sym(_insn)->warned = 1;				\
})

#define BT_INSN(insn, format, ...)				\
({								\
	if (opts.verbose || opts.backtrace) {			\
		struct instruction *__insn = (insn);		\
		char *_str = offstr(__insn->sec, __insn->offset); \
		const char *_istr = objtool_disas_insn(__insn);	\
		int _len;					\
		_len = snprintf(NULL, 0, "  %s: " format,  _str, ##__VA_ARGS__);	\
		_len = (_len < 50) ? 50 - _len : 0;		\
		WARN("  %s: " format "  %*s%s", _str, ##__VA_ARGS__, _len, "", _istr); \
		free(_str);						\
		__insn->trace = 1;				\
	}							\
})

#define ERROR_STR "error"

#define ERROR(format, ...) __WARN(ERROR_STR, format, ##__VA_ARGS__)
#define ERROR_ELF(format, ...) __WARN_ELF(ERROR_STR, format, ##__VA_ARGS__)
#define ERROR_GLIBC(format, ...) __WARN_GLIBC(ERROR_STR, format, ##__VA_ARGS__)
#define ERROR_FUNC(sec, offset, format, ...) __WARN_FUNC(ERROR_STR, sec, offset, format, ##__VA_ARGS__)
#define ERROR_INSN(insn, format, ...) ERROR_FUNC(insn->sec, insn->offset, format, ##__VA_ARGS__)

extern bool debug, debug_correlate, debug_clone;
extern int indent;

static inline void unindent(int *unused) { indent--; }

/*
 * Clang prior to 17 is being silly and considers many __cleanup() variables
 * as unused (because they are, their sole purpose is to go out of scope).
 *
 * https://github.com/llvm/llvm-project/commit/877210faa447f4cc7db87812f8ed80e398fedd61
 */
#undef __cleanup
#define __cleanup(func) __maybe_unused __attribute__((__cleanup__(func)))

#define __dbg(format, ...)						\
	fprintf(stderr,							\
		"DEBUG: %s%s" format "\n",				\
		objname ?: "",						\
		objname ? ": " : "",					\
		##__VA_ARGS__)

#define dbg_checksum_insn(func, insn, checksum)				\
({									\
	if (unlikely(func->debug_checksum)) {				\
		char *insn_off = offstr(insn->sec, insn->offset);	\
		__dbg("checksum: %s(): %s %016llx",			\
		      func->name, insn_off, (unsigned long long)checksum);\
		free(insn_off);						\
	}								\
})

#define dbg_checksum_object(sym, offset, what, checksum)		\
({									\
	if (unlikely(sym->debug_checksum))				\
		__dbg("checksum: %s+0x%lx: %s %016llx",			\
		      sym->name, offset, what,				\
		      (unsigned long long)checksum);			\
})

#define dbg_correlate(args...)						\
({									\
	if (unlikely(debug_correlate))					\
		__dbg(args);						\
})

#define __dbg_clone(format, ...)					\
({									\
	if (unlikely(debug_clone))					\
		__dbg("%*s" format, indent * 8, "", ##__VA_ARGS__);	\
})

#define dbg_clone(args...)						\
	int __cleanup(unindent) __dummy_##__COUNTER__;			\
	__dbg_clone(args);						\
	indent++

#endif /* _WARN_H */