tccelf: cleanup sort_sections() & etc. fixes

with -Wl,-oformat=binary, executable code should come first.
(for linux kernel image for example)

Also:
- simplify RELRO sections: create them as readonly, but add
  SHF_WRITE flag later when needed (i.e. relocations do exist)
- tcc.h etc: exclude eh_frames on non-elf platforms
- tccelf.c:tcc_load_object_file(): don't load debug sections when
  linking without -g (special dwarf case in relocate_section()
  wont work when dwlo/hi were not initialized).
- tcc.c: avoid loop if something fails (ret < 0) without message
  (while failing without message should not happen either)
- tccelf.c:tcc_load_alacarte: give message
- tccpp.c: treat '# 123xyz' in asm file as comment
- lib/Makefile: cleanup
- libtcc.c: tcc_add_library(): fallback to try filename as is
  (also remove tcc_add_library_err())

lib/Makefile

@@ -7,6 +7,8 @@ include $(TOP)/Makefile
 VPATH = $(TOPSRC)/lib $(TOPSRC)/win32/lib
 T = $(or $(CROSS_TARGET),$(NATIVE_TARGET),unknown)
 X = $(if $(CROSS_TARGET),$(CROSS_TARGET)-)
+XCFG = $(or $(findstring -win,$T),-unx)
+S = $(if $(findstring yes,$(SILENT)),@$(info * $@))
 
 TCC = $(TOP)/$(X)tcc$(EXESUF)
 XTCC ?= $(TOP)/$(X)tcc$(EXESUF)
@@ -16,8 +18,6 @@ XFLAGS-unx = -B$(TOPSRC)
 XFLAGS-win = -B$(TOPSRC)/win32 -I$(TOPSRC)/include
 XFLAGS = $(XFLAGS$(XCFG)) -I$(TOP)
 BFLAGS = -bt
-XCFG = $(or $(findstring -win,$T),-unx)
-S = $(if $(findstring yes,$(SILENT)),@$(info * $@))
 
 # in order to use gcc, type: make <target>-libtcc1-usegcc=yes
 arm-libtcc1-usegcc ?= no
@@ -29,47 +29,48 @@ arm-libtcc1-usegcc ?= no
 ifeq "$($(T)-libtcc1-usegcc)" "yes"
  XCC = $(CC)
  XAR = $(AR)
- XFLAGS = $(CFLAGS) -fPIC -gdwarf -fno-omit-frame-pointer -Wno-unused-function -Wno-unused-variable
- BFLAGS = -g
+ XFLAGS = $(CFLAGS) -fPIC -fno-omit-frame-pointer -Wno-unused-function -Wno-unused-variable
+ BFLAGS = $(if $(CONFIG_dwarf),-gdwarf,-gstabs)
 endif
 
-ifneq ($(CONFIG_backtrace),no)
-# only for native compiler
-ifneq ($(CONFIG_bcheck),no)
-$(X)BCHECK_O = bcheck.o
-endif
-$(X)BT_O = bt-exe.o bt-log.o
-$(X)B_O = $(BCHECK_O) bt-exe.o bt-log.o bt-dll.o
-endif
-$(X)BT_O += runmain.o tcov.o
+I386_O = libtcc1.o alloca.o alloca-bt.o $(COMMON_O)
+X86_64_O = libtcc1.o alloca.o alloca-bt.o $(COMMON_O)
+ARM_O = libtcc1.o armeabi.o alloca.o armflush.o $(COMMON_O)
+ARM64_O = lib-arm64.o $(COMMON_O)
+RISCV64_O = lib-arm64.o $(COMMON_O)
+COMMON_O = stdatomic.o atomic.o builtin.o
+WIN_O = crt1.o crt1w.o wincrt1.o wincrt1w.o dllcrt1.o dllmain.o
+LIN_O = dsohandle.o
+OSX_O =
+
+# backtrace/bcheck/run only for native compiler
+Nat = $(if $X,no,)
+Cbt = $(Nat)$(subst yes,,$(CONFIG_backtrace))
+Cbc = $(Cbt)$(subst yes,,$(CONFIG_bcheck))
 
-DSO_O = dsohandle.o
+$(Nat)COMMON_O += runmain.o tcov.o
+$(Cbt)COMMON_O += bt-exe.o bt-log.o
+$(Cbt)WIN_O += bt-dll.o
+$(Cbc)COMMON_O += bcheck.o
 
 # not in libtcc1.a
 EXTRA_O = runmain.o bt-exe.o bt-dll.o bt-log.o bcheck.o
 
-I386_O = libtcc1.o alloca.o alloca-bt.o stdatomic.o atomic.o builtin.o $(BT_O)
-X86_64_O = libtcc1.o alloca.o alloca-bt.o stdatomic.o atomic.o builtin.o $(BT_O)
-ARM_O = libtcc1.o armeabi.o alloca.o armflush.o stdatomic.o atomic.o builtin.o $(BT_O)
-ARM64_O = lib-arm64.o stdatomic.o atomic.o builtin.o $(BT_O)
-RISCV64_O = lib-arm64.o stdatomic.o atomic.o builtin.o $(BT_O)
-WIN_O = crt1.o crt1w.o wincrt1.o wincrt1w.o dllcrt1.o dllmain.o
-
-OBJ-i386 = $(I386_O) $(BCHECK_O) $(DSO_O)
-OBJ-x86_64 = $(X86_64_O) va_list.o $(BCHECK_O) $(DSO_O)
-OBJ-x86_64-osx = $(X86_64_O) va_list.o $(BCHECK_O)
-OBJ-i386-win32 = $(I386_O) chkstk.o $(B_O) $(WIN_O)
-OBJ-x86_64-win32 = $(X86_64_O) chkstk.o $(B_O) $(WIN_O)
-OBJ-arm64 = $(ARM64_O) $(BCHECK_O) $(DSO_O)
-OBJ-arm64-osx = $(ARM64_O) $(BCHECK_O)
-OBJ-arm = $(ARM_O) $(BCHECK_O) $(DSO_O)
-OBJ-arm-fpa = $(ARM_O) $(DSO_O)
-OBJ-arm-fpa-ld = $(ARM_O) $(DSO_O)
-OBJ-arm-vfp = $(ARM_O) $(DSO_O)
-OBJ-arm-eabi = $(ARM_O) $(DSO_O)
-OBJ-arm-eabihf = $(ARM_O) $(DSO_O)
+OBJ-i386 = $(I386_O) $(LIN_O)
+OBJ-x86_64 = $(X86_64_O) va_list.o $(LIN_O)
+OBJ-x86_64-osx = $(X86_64_O) va_list.o $(OSX_O)
+OBJ-i386-win32 = $(I386_O) chkstk.o $(WIN_O)
+OBJ-x86_64-win32 = $(X86_64_O) chkstk.o $(WIN_O)
+OBJ-arm64 = $(ARM64_O) $(LIN_O)
+OBJ-arm64-osx = $(ARM64_O) $(OSX_O)
+OBJ-arm = $(ARM_O) $(LIN_O)
+OBJ-arm-fpa = $(OBJ-arm)
+OBJ-arm-fpa-ld = $(OBJ-arm)
+OBJ-arm-vfp = $(OBJ-arm)
+OBJ-arm-eabi = $(OBJ-arm)
+OBJ-arm-eabihf = $(OBJ-arm)
 OBJ-arm-wince = $(ARM_O) $(WIN_O)
-OBJ-riscv64 = $(RISCV64_O) $(BCHECK_O) $(DSO_O)
+OBJ-riscv64 = $(RISCV64_O) $(LIN_O)
 
 OBJ-extra = $(filter $(EXTRA_O),$(OBJ-$T))
 OBJ-libtcc1 = $(addprefix $(X),$(filter-out $(OBJ-extra),$(OBJ-$T)))

libtcc.c

@@ -1004,6 +1004,8 @@ static int tcc_glob_so(TCCState *s1, const char *pattern, char *buf, int size)
 }
 #endif
 
+static int guess_filetype(const char *filename);
+
 ST_FUNC int tcc_add_file_internal(TCCState *s1, const char *filename, int flags)
 {
     int fd, ret = -1;
@@ -1014,6 +1016,9 @@ ST_FUNC int tcc_add_file_internal(TCCState *s1, const char *filename, int flags)
         filename = buf;
 #endif
 
+    if (0 == (flags & AFF_TYPE_MASK))
+        flags |= guess_filetype(filename);
+
     /* ignore binary files with -E */
     if (s1->output_type == TCC_OUTPUT_PREPROCESS
         && (flags & AFF_TYPE_BIN))
@@ -1123,10 +1128,10 @@ ST_FUNC int tcc_add_file_internal(TCCState *s1, const char *filename, int flags)
     return ret;
 }
 
-LIBTCCAPI int tcc_add_file(TCCState *s, const char *filename)
+static int guess_filetype(const char *filename)
 {
-    int filetype = s->filetype;
-    if (0 == (filetype & AFF_TYPE_MASK)) {
+    int filetype = 0;
+    if (1) {
         /* use a file extension to detect a filetype */
         const char *ext = tcc_fileextension(filename);
         if (ext[0]) {
@@ -1145,7 +1150,12 @@ LIBTCCAPI int tcc_add_file(TCCState *s, const char *filename)
             filetype = AFF_TYPE_C;
         }
     }
-    return tcc_add_file_internal(s, filename, filetype | AFF_PRINT_ERROR);
+    return filetype;
+}
+
+LIBTCCAPI int tcc_add_file(TCCState *s, const char *filename)
+{
+    return tcc_add_file_internal(s, filename, s->filetype | AFF_PRINT_ERROR);
 }
 
 LIBTCCAPI int tcc_add_library_path(TCCState *s, const char *pathname)
@@ -1162,12 +1172,12 @@ static int tcc_add_library_internal(TCCState *s1, const char *fmt,
 
     for(i = 0; i < nb_paths; i++) {
         snprintf(buf, sizeof(buf), fmt, paths[i], filename);
-        ret = tcc_add_file_internal(s1, buf, (flags & ~AFF_PRINT_ERROR) | AFF_TYPE_BIN);
+        ret = tcc_add_file_internal(s1, buf, flags & ~AFF_PRINT_ERROR);
         if (ret != FILE_NOT_FOUND)
             return ret;
     }
     if (flags & AFF_PRINT_ERROR)
-        tcc_error_noabort("file '%s' not found", filename);
+        tcc_error_noabort("library '%s' not found", filename);
     return FILE_NOT_FOUND;
 }
 
@@ -1219,23 +1229,15 @@ LIBTCCAPI int tcc_add_library(TCCState *s, const char *libraryname)
             return ret;
         ++pp;
     }
-    return FILE_NOT_FOUND;
-}
-
-PUB_FUNC int tcc_add_library_err(TCCState *s1, const char *libname)
-{
-    int ret = tcc_add_library(s1, libname);
-    if (ret == FILE_NOT_FOUND)
-        tcc_error_noabort("library '%s' not found", libname);
-    return ret;
+    return tcc_add_dll(s, libraryname, AFF_PRINT_ERROR);
 }
 
 /* handle #pragma comment(lib,) */
 ST_FUNC void tcc_add_pragma_libs(TCCState *s1)
 {
     int i;
     for (i = 0; i < s1->nb_pragma_libs; i++)
-        tcc_add_library_err(s1, s1->pragma_libs[i]);
+        tcc_add_library(s1, s1->pragma_libs[i]);
 }
 
 LIBTCCAPI int tcc_add_symbol(TCCState *s1, const char *name, const void *val)

tcc.c

@@ -366,7 +366,7 @@ int main(int argc0, char **argv0)
         struct filespec *f = s->files[n];
         s->filetype = f->type;
         if (f->type & AFF_TYPE_LIB) {
-            ret = tcc_add_library_err(s, f->name);
+            ret = tcc_add_library(s, f->name);
         } else {
             if (1 == s->verbose)
                 printf("-> %s\n", f->name);
@@ -392,17 +392,17 @@ int main(int argc0, char **argv0)
         } else {
             if (!s->outfile)
                 s->outfile = default_outputfile(s, first_file);
-            if (!s->just_deps && tcc_output_file(s, s->outfile))
-                ;
-            else if (s->gen_deps)
+            if (!s->just_deps)
+                ret = tcc_output_file(s, s->outfile);
+            if (!ret && s->gen_deps)
                 gen_makedeps(s, s->outfile, s->deps_outfile);
         }
     }
 
     done = 1;
     if (t)
         done = 0; /* run more tests with -dt -run */
-    else if (s->nb_errors)
+    else if (ret)
         ret = 1;
     else if (n < s->nb_files)
         done = 0; /* compile more files with -c */

tcc.h

@@ -974,8 +974,6 @@ struct TCCState {
     int uw_sym;
     unsigned uw_offs;
 # endif
-#else
-    unsigned shf_RELRO; /* section flags for RELRO sections */
 #endif
 
 #if defined TCC_TARGET_MACHO
@@ -1874,10 +1872,6 @@ ST_FUNC int gen_makedeps(TCCState *s, const char *target, const char *filename);
 
 /* ------------ tccdbg.c ------------ */
 
-ST_FUNC void tcc_eh_frame_start(TCCState *s1);
-ST_FUNC void tcc_eh_frame_end(TCCState *s1);
-ST_FUNC void tcc_eh_frame_hdr(TCCState *s1, int final);
-
 ST_FUNC void tcc_debug_new(TCCState *s);
 
 ST_FUNC void tcc_debug_start(TCCState *s1);
@@ -1896,6 +1890,13 @@ ST_FUNC void tcc_debug_typedef(TCCState *s1, Sym *sym);
 ST_FUNC void tcc_debug_stabn(TCCState *s1, int type, int value);
 ST_FUNC void tcc_debug_fix_anon(TCCState *s1, CType *t);
 
+#if !(defined ELF_OBJ_ONLY || defined TCC_TARGET_ARM || defined TARGETOS_BSD)
+ST_FUNC void tcc_eh_frame_start(TCCState *s1);
+ST_FUNC void tcc_eh_frame_end(TCCState *s1);
+ST_FUNC void tcc_eh_frame_hdr(TCCState *s1, int final);
+#define TCC_EH_FRAME 1
+#endif
+
 ST_FUNC void tcc_tcov_start(TCCState *s1);
 ST_FUNC void tcc_tcov_end(TCCState *s1);
 ST_FUNC void tcc_tcov_check_line(TCCState *s1, int start);

tccdbg.c

@@ -424,7 +424,7 @@ ST_FUNC void tcc_debug_new(TCCState *s1)
     if (s1->do_debug && s1->output_type == TCC_OUTPUT_MEMORY)
         s1->do_backtrace = 1;
     if (s1->do_backtrace)
-        shf = SHF_ALLOC | SHF_WRITE; // SHF_WRITE needed for musl/SELINUX
+        shf = SHF_ALLOC; /* have debug data available at runtime */
 #endif
 
     if (s1->dwarf) {
@@ -511,7 +511,7 @@ static void put_stabn(TCCState *s1, int type, int other, int desc, int value)
 
 /* ------------------------------------------------------------------------- */
 #define	dwarf_data1(s,data) \
-	{ unsigned char *p = section_ptr_add((s), 1); *p = (data); }
+	(*(uint8_t*)section_ptr_add((s), 1) = (data))
 #define	dwarf_data2(s,data) \
 	write16le(section_ptr_add((s), 2), (data))
 #define	dwarf_data4(s,data) \
@@ -712,10 +712,9 @@ static void dwarf_sleb128_op (TCCState *s1, long long value)
     } while (more);
 }
 
+#if TCC_EH_FRAME
 ST_FUNC void tcc_eh_frame_start(TCCState *s1)
 {
-#if !(defined _WIN32 || defined __APPLE__ || defined TCC_TARGET_ARM || \
-      defined TARGETOS_BSD)
     if (!s1->unwind_tables)
         return;
     eh_frame_section = new_section(s1, ".eh_frame", SHT_PROGBITS, SHF_ALLOC);
@@ -784,7 +783,6 @@ ST_FUNC void tcc_eh_frame_start(TCCState *s1)
 	dwarf_data1(eh_frame_section, DW_CFA_nop);
     write32le(eh_frame_section->data + s1->eh_start, // length
 	      eh_frame_section->data_offset - s1->eh_start - 4);
-#endif
 }
 
 static void tcc_debug_frame_end(TCCState *s1, int size)
@@ -1006,6 +1004,7 @@ ST_FUNC void tcc_eh_frame_hdr(TCCState *s1, int final)
     qsort(eh_frame_hdr_section->data + tab_offset, count,
 	  sizeof(struct eh_search_table), sort_eh_table);
 }
+#endif
 
 /* start of translation unit info */
 ST_FUNC void tcc_debug_start(TCCState *s1)
@@ -2172,7 +2171,9 @@ ST_FUNC void tcc_debug_funcend(TCCState *s1, int size)
     /* lldb does not like function end and next function start at same pc */
     int min_instr_len;
 
+#if TCC_EH_FRAME
     tcc_debug_frame_end(s1, size);
+#endif
     if (!s1->do_debug)
         return;
     min_instr_len = dwarf_line.last_pc == ind ? 0 : DWARF_MIN_INSTR_LEN;