From: Mark Wielaard Date: Wed, 2 Nov 2016 12:29:26 +0000 (+0100) Subject: Add GCC7 -Wimplicit-fallthrough support/fixes. X-Git-Tag: elfutils-0.168~9 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a3cc8182b2ae05290b0eafa74b70746d7befc0e4;p=thirdparty%2Felfutils.git Add GCC7 -Wimplicit-fallthrough support/fixes. GCC7 will have a new -Wimplicit-fallthrough warning. It did catch one small buglet in elflint option procession. So it seems useful to enable to make sure all swatch case fallthroughs are deliberate. Add configure check to detect whether gcc support -Wimplicit-fallthrough and enable it. Add fixes and explicit fallthrough comments where necessary. Signed-off-by: Mark Wielaard --- diff --git a/ChangeLog b/ChangeLog index 8d6157215..f21421f94 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,4 +1,9 @@ -2015-10-11 Akihiko Odaki +2016-11-02 Mark Wielaard + + * configure.ac: Add check for whether gcc accepts + -Wimplict-fallthrough. + +2016-10-11 Akihiko Odaki * configure.ac: Add memrchr, rawmemchr and powerof2 checks. diff --git a/backends/ChangeLog b/backends/ChangeLog index 53d290811..1c561b501 100644 --- a/backends/ChangeLog +++ b/backends/ChangeLog @@ -1,3 +1,14 @@ +2016-11-02 Mark Wielaard + + * i386_regs.c (i386_register_info): Add fallthrough comment. + * i386_retval.c (i386_return_value_location): Move fallthrough + comment. + * linux-core-note.c (core_note): Adjust fallthrough comment. + * m68k_retval.c (m68k_return_value_location): Move fallthrough + comment. + * ppc_regs.c (ppc_register_info): Add fallthrough comment. + * x86_64_regs.c (x86_64_register_info): Likewise. + 2016-08-09 Jose E. Marchesi * sparc_attrs.c (sparc_check_object_attribute): Fix the diff --git a/backends/i386_regs.c b/backends/i386_regs.c index fb8ded333..fd963a62b 100644 --- a/backends/i386_regs.c +++ b/backends/i386_regs.c @@ -92,6 +92,7 @@ i386_register_info (Ebl *ebl __attribute__ ((unused)), case 5: case 8: *type = DW_ATE_address; + /* Fallthrough */ case 0 ... 3: case 6 ... 7: name[0] = 'e'; diff --git a/backends/i386_retval.c b/backends/i386_retval.c index 9da797d5e..4aa646fe7 100644 --- a/backends/i386_retval.c +++ b/backends/i386_retval.c @@ -122,9 +122,8 @@ i386_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) return nloc_intreg; if (size <= 8) return nloc_intregpair; - - /* Else fall through. */ } + /* Fallthrough */ case DW_TAG_structure_type: case DW_TAG_class_type: diff --git a/backends/linux-core-note.c b/backends/linux-core-note.c index a4ec0be07..67638d700 100644 --- a/backends/linux-core-note.c +++ b/backends/linux-core-note.c @@ -225,8 +225,8 @@ EBLHOOK(core_note) (const GElf_Nhdr *nhdr, const char *name, case sizeof "CORE": if (memcmp (name, "CORE", nhdr->n_namesz) == 0) break; - /* Buggy old Linux kernels didn't terminate "LINUX". - Fall through. */ + /* Buggy old Linux kernels didn't terminate "LINUX". */ + /* Fall through. */ case sizeof "LINUX": if (memcmp (name, "LINUX", nhdr->n_namesz) == 0) diff --git a/backends/m68k_retval.c b/backends/m68k_retval.c index 2dd285a07..c68ed0221 100644 --- a/backends/m68k_retval.c +++ b/backends/m68k_retval.c @@ -134,10 +134,8 @@ m68k_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) return nloc_intreg; if (size <= 8) return nloc_intregpair; - - /* Else fall through. */ } - + /* Fallthrough */ case DW_TAG_structure_type: case DW_TAG_class_type: case DW_TAG_union_type: diff --git a/backends/ppc_regs.c b/backends/ppc_regs.c index 4b92a9aa9..bcf4f7a3e 100644 --- a/backends/ppc_regs.c +++ b/backends/ppc_regs.c @@ -140,7 +140,7 @@ ppc_register_info (Ebl *ebl __attribute__ ((unused)), case 100: if (*bits == 32) return stpcpy (name, "mq") + 1 - name; - + /* Fallthrough */ case 102 ... 107: name[0] = 's'; name[1] = 'p'; diff --git a/backends/x86_64_regs.c b/backends/x86_64_regs.c index 2172d9f1d..843044071 100644 --- a/backends/x86_64_regs.c +++ b/backends/x86_64_regs.c @@ -87,6 +87,7 @@ x86_64_register_info (Ebl *ebl __attribute__ ((unused)), case 6 ... 7: *type = DW_ATE_address; + /* Fallthrough */ case 0 ... 5: name[0] = 'r'; name[1] = baseregs[regno][0]; diff --git a/config/ChangeLog b/config/ChangeLog index 2ca25bc33..a18fa847c 100644 --- a/config/ChangeLog +++ b/config/ChangeLog @@ -1,3 +1,8 @@ +2016-11-02 Mark Wielaard + + * eu.am: Check HAVE_IMPLICIT_FALLTHROUGH_WARNING. + (AM_CFLAGS): Add IMPLICIT_FALLTHROUGH_WARNING. + 2016-08-04 Mark Wielaard * elfutils.spec.in: Update for 0.167. diff --git a/config/eu.am b/config/eu.am index 4998771dc..8fe1e259f 100644 --- a/config/eu.am +++ b/config/eu.am @@ -61,10 +61,16 @@ else NULL_DEREFERENCE_WARNING= endif +if HAVE_IMPLICIT_FALLTHROUGH_WARNING +IMPLICIT_FALLTHROUGH_WARNING=-Wimplicit-fallthrough +else +IMPLICIT_FALLTHROUGH_WARNING= +endif + AM_CFLAGS = -std=gnu99 -Wall -Wshadow -Wformat=2 \ -Wold-style-definition -Wstrict-prototypes \ $(LOGICAL_OP_WARNING) $(DUPLICATED_COND_WARNING) \ - $(NULL_DEREFERENCE_WARNING) \ + $(NULL_DEREFERENCE_WARNING) $(IMPLICIT_FALLTHROUGH_WARNING) \ $(if $($(*F)_no_Werror),,-Werror) \ $(if $($(*F)_no_Wunused),,-Wunused -Wextra) \ $(if $($(*F)_no_Wstack_usage),,$(STACK_USAGE_WARNING)) \ diff --git a/configure.ac b/configure.ac index c02d4c2a9..c55fb9b45 100644 --- a/configure.ac +++ b/configure.ac @@ -311,6 +311,16 @@ CFLAGS="$old_CFLAGS"]) AM_CONDITIONAL(HAVE_NULL_DEREFERENCE_WARNING, [test "x$ac_cv_null_dereference" != "xno"]) +# -Wimplicit-fallthrough was added by GCC7 +AC_CACHE_CHECK([whether gcc accepts -Wimplicit-fallthrough], ac_cv_implicit_fallthrough, [dnl +old_CFLAGS="$CFLAGS" +CFLAGS="$CFLAGS -Wimplicit-fallthrough -Werror" +AC_COMPILE_IFELSE([AC_LANG_SOURCE([])], + ac_cv_implicit_fallthrough=yes, ac_cv_implicit_fallthrough=no) +CFLAGS="$old_CFLAGS"]) +AM_CONDITIONAL(HAVE_IMPLICIT_FALLTHROUGH_WARNING, + [test "x$ac_cv_implicit_fallthrough" != "xno"]) + dnl Check if we have argp available from our libc AC_LINK_IFELSE( [AC_LANG_PROGRAM( diff --git a/libcpu/ChangeLog b/libcpu/ChangeLog index fff1d96a8..79110c221 100644 --- a/libcpu/ChangeLog +++ b/libcpu/ChangeLog @@ -1,4 +1,8 @@ -2015-10-11 Akihiko Odaki +2016-11-02 Mark Wielaard + + * i386_disasm.c (i386_disasm): Add fallthrough comment. + +2016-10-11 Akihiko Odaki * i386_lex.l: Remove system.h include, add libeu.h include. * i386_parse.y: Remove sys/param.h include, add libeu.h include. diff --git a/libcpu/i386_disasm.c b/libcpu/i386_disasm.c index 699dd6199..831afbe20 100644 --- a/libcpu/i386_disasm.c +++ b/libcpu/i386_disasm.c @@ -819,7 +819,7 @@ i386_disasm (Ebl *ebl __attribute__((unused)), ++param_start; break; } - + /* Fallthrough */ default: assert (! "INVALID not handled"); } diff --git a/libdw/ChangeLog b/libdw/ChangeLog index c2f25ea62..cc92f1634 100644 --- a/libdw/ChangeLog +++ b/libdw/ChangeLog @@ -1,4 +1,12 @@ -2015-10-11 Akihiko Odaki +2016-11-02 Mark Wielaard + + * cfi.c (execute_cfi): Add fallthrough comments. + * encoded-value.h (encoded_value_size): Add explicit return instead + of relying on fallthrough. + * dwfl_report_elf.c (__libdwfl_elf_address_range): Add fallthrough + comment. + +2016-10-11 Akihiko Odaki * dwarf_getpubnames.c: Remove sys/param.h include, add system.h. * libdw_alloc.c: Likewise. diff --git a/libdw/cfi.c b/libdw/cfi.c index 1fd668d79..daa845f35 100644 --- a/libdw/cfi.c +++ b/libdw/cfi.c @@ -138,6 +138,7 @@ execute_cfi (Dwarf_CFI *cache, case DW_CFA_advance_loc1: operand = *program++; + /* Fallthrough */ case DW_CFA_advance_loc + 0 ... DW_CFA_advance_loc + CFI_PRIMARY_MAX: advance_loc: loc += operand * cie->code_alignment_factor; @@ -300,6 +301,7 @@ execute_cfi (Dwarf_CFI *cache, case DW_CFA_restore_extended: get_uleb128 (operand, program, end); + /* Fallthrough */ case DW_CFA_restore + 0 ... DW_CFA_restore + CFI_PRIMARY_MAX: if (unlikely (abi_cfi) && likely (opcode == DW_CFA_restore)) diff --git a/libdw/encoded-value.h b/libdw/encoded-value.h index 48d868fb6..f0df4cec3 100644 --- a/libdw/encoded-value.h +++ b/libdw/encoded-value.h @@ -64,6 +64,7 @@ encoded_value_size (const Elf_Data *data, const unsigned char e_ident[], if (*end++ & 0x80u) return end - p; } + return 0; default: return 0; diff --git a/libdwfl/dwfl_report_elf.c b/libdwfl/dwfl_report_elf.c index 1c6e401d1..73a5511a8 100644 --- a/libdwfl/dwfl_report_elf.c +++ b/libdwfl/dwfl_report_elf.c @@ -170,7 +170,7 @@ __libdwfl_elf_address_range (Elf *elf, GElf_Addr base, bool add_p_vaddr, /* An assigned base address is meaningless for these. */ base = 0; add_p_vaddr = true; - + /* Fallthrough. */ case ET_DYN: default:; size_t phnum; diff --git a/src/ChangeLog b/src/ChangeLog index ee67cffcd..b2909b65e 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,11 @@ +2016-11-02 Mark Wielaard + + * addr2line.c (handle_address): Add fallthrough comment. + * elfcompress.c (parse_opt): Adjust fallthrough comment. + * elflint.c (parse_opt): Add missing break after 'd' case. + (check_sections): Add fallthrough comments. + * objdump.c (parse_opt): Add explantion for fallthrough comment. + 2016-10-22 Kevin Cernekee * unstrip.c: Fix "invalid string offset" error caused by using the diff --git a/src/addr2line.c b/src/addr2line.c index 0ce854f6a..bea24aeac 100644 --- a/src/addr2line.c +++ b/src/addr2line.c @@ -632,6 +632,7 @@ handle_address (const char *string, Dwfl *dwfl) case 1: addr = 0; j = i; + /* Fallthrough */ case 2: if (string[j] != '\0') break; diff --git a/src/elfcompress.c b/src/elfcompress.c index 7392cb763..82ab96559 100644 --- a/src/elfcompress.c +++ b/src/elfcompress.c @@ -155,7 +155,8 @@ parse_opt (int key, char *arg __attribute__ ((unused)), argp_error (state, N_("Only one input file allowed together with '-o'")); /* We only use this for checking the number of arguments, we don't - actually want to consume them, so fallthrough. */ + actually want to consume them. */ + /* Fallthrough */ default: return ARGP_ERR_UNKNOWN; } diff --git a/src/elflint.c b/src/elflint.c index 8b52ee2b1..b304a3091 100644 --- a/src/elflint.c +++ b/src/elflint.c @@ -210,6 +210,7 @@ parse_opt (int key, char *arg __attribute__ ((unused)), case 'd': is_debuginfo = true; + break; case ARGP_gnuld: gnuld = true; @@ -3963,6 +3964,7 @@ section [%2zu] '%s': merge flag set but entry size is zero\n"), case SHT_NOBITS: if (is_debuginfo) break; + /* Fallthrough */ default: ERROR (gettext ("\ section [%2zu] '%s' has unexpected type %d for an executable section\n"), @@ -4305,7 +4307,7 @@ section [%2d] '%s': unknown core file note type %" PRIu32 if (nhdr.n_namesz == sizeof "Linux" && !memcmp (data->d_buf + name_offset, "Linux", sizeof "Linux")) break; - + /* Fallthrough */ default: if (shndx == 0) ERROR (gettext ("\ diff --git a/src/objdump.c b/src/objdump.c index 1afcd573b..f84513ca2 100644 --- a/src/objdump.c +++ b/src/objdump.c @@ -234,7 +234,9 @@ parse_opt (int key, char *arg, program_invocation_short_name); exit (EXIT_FAILURE); } - + /* We only use this for checking the number of arguments, we don't + actually want to consume them. */ + /* Fallthrough */ default: return ARGP_ERR_UNKNOWN; } diff --git a/tests/ChangeLog b/tests/ChangeLog index 3d34778bd..5a9d5372a 100644 --- a/tests/ChangeLog +++ b/tests/ChangeLog @@ -1,3 +1,8 @@ +2016-11-02 Mark Wielaard + + * backtrace-data.c (thread_callback): Add explicit break after error. + * backtrace.c (callback_verify): Change PASSTHRU to FALLTHRU. + 2016-10-22 Kevin Cernekee * Makefile.am (TESTS): Add run-unstrip-test4.sh. diff --git a/tests/backtrace-data.c b/tests/backtrace-data.c index bc5ceba0d..b7158dae8 100644 --- a/tests/backtrace-data.c +++ b/tests/backtrace-data.c @@ -250,6 +250,7 @@ thread_callback (Dwfl_Thread *thread, void *thread_arg __attribute__ ((unused))) break; case -1: error (1, 0, "dwfl_thread_getframes: %s", dwfl_errmsg (-1)); + break; default: abort (); } diff --git a/tests/backtrace.c b/tests/backtrace.c index 2440ab34e..1ff6353c2 100644 --- a/tests/backtrace.c +++ b/tests/backtrace.c @@ -123,7 +123,7 @@ callback_verify (pid_t tid, unsigned frameno, Dwarf_Addr pc, assert (symname2 == NULL || strcmp (symname2, "jmp") != 0); break; } - /* PASSTHRU */ + /* FALLTHRU */ case 4: assert (symname != NULL && strcmp (symname, "stdarg") == 0); break;