***********************************************
For _tmain:

findstr /s /n /r /c:"[^a-zA-Z][w]*main[^a-zA-Z]" *.c

-----------------------------------------------
arm-gen.c:902:   See the comment for the main loop in copy_params() for the reason. */

-----------------------------------------------
conftest.c:44:int main(int argc, char *argv[])

-----------------------------------------------
il-gen.c:434:    if (!strcmp(funcname, "main"))
    if (!strcmp(funcname, "main"))
        fprintf(il_outfile, " .entrypoint\n");

??? who/where/which platform uses this?

-----------------------------------------------
lib\bcheck.c:421:void __bound_main_arg(void **p)

-----------------------------------------------
libtcc.c:1047:    s->runtime_main = "main";

for tcc_new() ... add a flag "unicode_mode"
......
tcc.h
..............................................
#ifdef TCC_TARGET_PE
    /* PE info */
    int pe_subsystem;
    unsigned pe_file_align;
    unsigned pe_stack_size;
# ifdef TCC_TARGET_X86_64
    Section *uw_pdata;
    int uw_sym;
    unsigned uw_offs;
# endif
    int unicode_mode; /* _tmain, _tWinMain */
#endif
..............................................
#ifdef TCC_IS_NATIVE
    s->runtime_main = "main";
#endif
#ifdef TCC_TARGET_PE
    s->unicode_mode = 0;
#endif
    return s;
..............................................

-----------------------------------------------
tcc.c:244:int main(int argc, char **argv)

-----------------------------------------------
*** not for TCC_TARGET_COFF
tcccoff.c:46:int C67_main_entry_point;
tcccoff.c:108:    o_filehdr.entrypt = C67_main_entry_point;	/* entry pt.                          */
tcccoff.c:931:	    // strip off any leading underscore (except for other main routine)

-----------------------------------------------
tcccoff.c:933:	    if (name[0] == '_' && strcmp(name, "_main") != 0)
?
ST_FUNC int tcc_load_coff(TCCState * s1, int fd)
{
xxx-unknown
..............................................
	    // strip off any leading underscore (except for other main routine)

	    if (name[0] == '_'
            && (strcmp(name, s1->unicode_mode == 0 ? "_main" : "_wmain") != 0))
		name++;

            /* skip unused (undefined) */ /* Need or not? */
            if ((s1->unicode_mode == 0 && strcmp(name, "wmain") != 0)
                || (s1->unicode_mode && strcmp(name, "main") != 0))
	    tcc_add_symbol(s1, name, (void*)(uintptr_t)csym.n_value);
	}
..............................................
tcc_add_symbol [---> (TCC_TARGET_PE) pe_putimport] --->| add_elf_sym

-----------------------------------------------
tccgen.c:5827:        && !strcmp(get_tok_str(sym->v, NULL), "main")) {
??? compilation stage
..............................................
#ifdef CONFIG_TCC_BCHECK
    if (tcc_state->do_bounds_check
        && (!strcmp(get_tok_str(sym->v, NULL),
#ifdef TCC_TARGET_PE
        tcc_state->unicode_entry == 3 /*PE_EXE*/ ? "wmain" :
        //tcc_state->unicode_entry == 2 /*PE_GUI*/ ? PE_STDSYM("wWinMain","@16") :
        //tcc_state->pe_subsystem == 2 /*PE_GUI*/ ? PE_STDSYM("WinMain","@16") :
#endif
        "main"))) {
        int i;

        sym = local_stack;
        for (i = 0, sym = local_stack; i < 2; i++, sym = sym->prev) {
            if (sym->v & SYM_FIELD || sym->prev->v & SYM_FIELD)
                break;
            vpush_global_sym(&func_old_type, TOK___bound_main_arg);
            vset(&sym->type, sym->r, sym->c);
            gfunc_call(1);
        }
    }
#endif
..............................................

-----------------------------------------------
tccgen.c:5834:            vpush_global_sym(&func_old_type, TOK___bound_main_arg);

-----------------------------------------------
tccpe.c:1759:        ? PE_GUI == pe_type ? "__runwinmain" : wconsole == 0 ? "_main" : "_wmain"
tccpe.c:1793:        s1->runtime_main = start_symbol;
static void pe_add_runtime(TCCState *s1, struct pe_info *pe)
{
..............................................
    else {
        pe_type = PE_EXE;
        if (find_elf_sym(symtab_section, "wmain"))
            s1->unicode_mode = 1;
    }
..............................................
    if (TCC_OUTPUT_MEMORY == s1->output_type) {
        pe_type = PE_RUN;
#ifdef TCC_IS_NATIVE
        s1->runtime_main = start_symbol;
#endif
    } else {
        pe->start_addr = (DWORD)(uintptr_t)tcc_get_symbol_err(s1, start_symbol);
    }
..............................................
    start_symbol =
        TCC_OUTPUT_MEMORY == s1->output_type
        ? PE_GUI == pe_type ? "__runwinmain" : s1->unicode_mode ? "_wmain" : "_main"
        : PE_DLL == pe_type ? PE_STDSYM("__dllstart","@12")
        : PE_GUI == pe_type ? "__winstart" : s1->unicode_mode ? "__wstart" : "__start"
        ;
..............................................
(tccpe.c) pe_add_runtime --->
(libtcc.c) tcc_add_library ---> tcc_add_library_internal ---> tcc_add_file_internal --->
(tccelf.c) [tcc_load_archive --->] tcc_load_object_file --->| add_elf_sym

++ tccelf.c
..............................................
#ifdef TCC_TARGET_PE
#ifdef TCC_TARGET_X86_64
#define PE_STDSYM(n,s) n
#else
#define PE_STDSYM(n,s) "_" n s
#endif
#endif
..............................................
ST_FUNC int tcc_load_object_file(TCCState *s1,
                                int fd, unsigned long file_offset)
{
..............................................
        /* add symbol */
        name = (char *) strtab + sym->st_name;
#ifdef TCC_TARGET_PE
        /* skip unused (undefined) */
        int unicode_mode = s1->unicode_mode;
        if ((unicode_mode && strcmp(name, "main") != 0)
            || (unicode_mode == 0 && strcmp(name, "wmain") != 0))
#endif
        sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
                                sym->st_info, sym->st_other,
                                sym->st_shndx, name);
        old_to_new_syms[i] = sym_index;
..............................................

-----------------------------------------------
tccrun.c:29:ST_DATA void *rt_prog_main;
tccrun.c:94:    int (*prog_main)(int, char **);
tccrun.c:100:    prog_main = tcc_get_symbol_err(s1, s1->runtime_main);

-----------------------------------------------
tccrun.c:105:        rt_prog_main = prog_main;
tccrun.c:130:        ret = (*prog_main)(argc, argv);
tccrun.c:140:        ret = (*prog_main)(argc, argv);
tccrun.c:406:        if (pc == (addr_t)rt_prog_main && pc)

-----------------------------------------------
win32\lib\crt1.c:19:int main(int argc, char **argv, char **env);
win32\lib\crt1.c:33:        ret = main(argc, argv, env);
+++
For ExitProcess, Add "#include <windows.h>".

===============================================
"add_elf_sym" is used in many other cases!
So, the skipping judgement placed out of it and only for win.
===============================================

-----------------------------------------------
win32\tools\tiny_impdef.c:47:int main(int argc, char **argv)
win32\tools\tiny_libmaker.c:74:int main(int argc, char **argv)

examples\ex1.c:4:int main()
examples\ex2.c:67:int main(int argc, char **argv)
examples\ex3.c:12:int main(int argc, char **argv)
examples\ex4.c:8:int main(int argc, char **argv)
examples\ex5.c:4:int main()

tests\abitest.c:422:int main(int argc, char **argv) {
tests\boundtest.c:208:int main(int argc, char **argv)
tests\libtcc_test.c:35:int main(int argc, char **argv)
tests\tcctest.c:636:int main(int argc, char **argv)
tests\tests2\00_assignment.c:3:int main() 
tests\tests2\01_comment.c:3:int main() 
tests\tests2\02_printf.c:3:int main() 
tests\tests2\03_struct.c:9:int main()
tests\tests2\04_for.c:3:int main() 
tests\tests2\05_array.c:3:int main() 
tests\tests2\06_case.c:3:int main()
tests\tests2\07_function.c:18:int main()
tests\tests2\08_while.c:3:int main()
tests\tests2\09_do_while.c:3:int main()
tests\tests2\10_pointer.c:10:int main()
tests\tests2\11_precedence.c:3:int main()
tests\tests2\12_hashdefine.c:6:int main()
tests\tests2\13_integer_literals.c:3:int main()
tests\tests2\14_if.c:3:int main()
tests\tests2\15_recursion.c:11:int main()
tests\tests2\16_nesting.c:3:int main()
tests\tests2\17_enum.c:15:int main()
tests\tests2\18_include.c:3:int main()
tests\tests2\19_pointer_arithmetic.c:3:int main()
tests\tests2\20_pointer_comparison.c:3:int main()
tests\tests2\21_char_array.c:3:int main()
tests\tests2\22_floating_point.c:4:int main()
tests\tests2\23_type_coercion.c:18:int main()
tests\tests2\24_math_library.c:4:int main()
tests\tests2\25_quicksort.c:47:int main()
tests\tests2\26_character_constants.c:3:int main()
tests\tests2\27_sizeof.c:3:int main()
tests\tests2\28_strings.c:5:int main()
tests\tests2\29_array_address.c:4:int main()
tests\tests2\30_hanoi.c:100:int main()
tests\tests2\31_args.c:3:int main(int argc, char **argv)
tests\tests2\32_led.c:224:int main()
tests\tests2\32_led.c:234:int main(int argc, char **argv)
tests\tests2\33_ternary_op.c:3:int main()
tests\tests2\34_array_assignment.c:3:int main()
tests\tests2\35_sizeof.c:3:int main()
tests\tests2\36_array_initialisers.c:3:int main()
tests\tests2\37_sprintf.c:3:int main()
tests\tests2\38_multiple_array_index.c:3:int main()
tests\tests2\39_typedef.c:15:int main()
tests\tests2\40_stdio.c:3:int main()
tests\tests2\41_hashif.c:3:int main()
tests\tests2\42_function_pointer.c:11:int main()
tests\tests2\43_void_param.c:8:int main()
tests\tests2\44_scoped_declarations.c:3:int main()
tests\tests2\45_empty_for.c:3:int main()
tests\tests2\46_grep.c:481:int main(int argc, char **argv)
tests\tests2\47_switch_return.c:15:int main()
tests\tests2\48_nested_break.c:3:int main()
tests\tests2\49_bracket_evaluation.c:11:int main()
tests\tests2\50_logical_second_arg.c:15:int main()
tests\tests2\51_static.c:14:int main()
tests\tests2\52_unnamed_enum.c:5:int main()
tests\tests2\54_goto.c:47:int main()
tests\tests2\55_lshift_type.c:45:int main (int argc, char **argv)
tests\tests2\63_local_enumerator_redefinition.c:6:int main(void)
tests\tests2\64_macro_nesting.c:5:int main(void)
tests\tests2\67_macro_concat.c:6:int main(void)
tests\tests2\68_macro_param_list_err_1.c:4:int main(void)
tests\tests2\69_macro_param_list_err_2.c:4:int main(void)
tests\vla_test.c:75:int main(int argc, char **argv) {

win32\examples\fib.c:11:int main(int argc, char **argv) 
win32\examples\hello_dll.c:3://  HELLO_DLL.C - Windows DLL example - main application part
win32\examples\hello_win.c:95:    // the main window.
win32\examples\libtcc_test.c:35:int main(int argc, char **argv)

+++++++++++++++++++++++++++++++++++++++++++++++
***********************************************
For _tWinMain:
findstr /s /n /r /c:"winstart" *.c

-----------------------------------------------
tccpe.c:1764:        : PE_GUI == pe_type ? "__winstart" : s1->unicode_mode ? "__wstart" : "__start"

static void pe_add_runtime(TCCState *s1, struct pe_info *pe)
{
..............................................
    if (find_elf_sym(symtab_section, PE_STDSYM("WinMain","@16")))
        pe_type = PE_GUI;
    else
    if (find_elf_sym(symtab_section, PE_STDSYM("wWinMain","@16"))) {
        pe_type = PE_GUI;
        s1->unicode_mode = PE_GUI;
    } else
..............................................
and
..............................................
    unicode_mode = s1->unicode_mode;
    start_symbol =
        TCC_OUTPUT_MEMORY == s1->output_type
        ? PE_GUI == pe_type ? (unicode_mode ? "__wrunwinmain" : "__runwinmain")
            : (unicode_mode ? "_wmain" : "_main")
        : PE_DLL == pe_type ? PE_STDSYM("__dllstart","@12")
            : PE_GUI == pe_type ? (unicode_mode ? "__wwinstart": "__winstart")
                : (unicode_mode ? "__wstart" : "__start")
        ;
..............................................

==>
tccelf.c
ST_FUNC int tcc_load_object_file(TCCState *s1,
                                int fd, unsigned long file_offset)
{
..............................................
        /* add symbol */
        name = (char *) strtab + sym->st_name;
#ifdef TCC_TARGET_PE
        /* skip unused (undefined) */
        int unicode_mode = s1->unicode_mode;
        if ((unicode_mode == 3 /*PE_EXE*/ && strcmp(name, "main") != 0)
            || (unicode_mode == 2 /*PE_GUI*/
                && strcmp(name, PE_STDSYM("WinMain","@16")) != 0)
            || (unicode_mode == 0
                && strcmp(name, "wmain") != 0
                && strcmp(name, PE_STDSYM("wWinMain","@16")) != 0)
        )
#endif
        sym_index = add_elf_sym(symtab_section, sym->st_value, sym->st_size,
                                sym->st_info, sym->st_other,
                                sym->st_shndx, name);
        old_to_new_syms[i] = sym_index;
    }
..............................................

-----------------------------------------------
win32\lib\wincrt1.c:12:int _winstart(void)
+++
-----------------------------------------------

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
More:

1. unknown codes?
findstr /s /n il- *
-------------------
Changelog:206:  462: Use LGPL with bcheck.c and il-gen.c
il-gen.c:81:#include "il-opcodes.h"
il-gen.c:87:#include "il-opcodes.h"

2. Does unix/linux platform always use main as program's entry? And what about
"C67/coff" (TMS320C67xx target) environment?
ref:
http://en.wikipedia.org/wiki/TMS320C67xx#Software_support
http://en.wikipedia.org/wiki/DSP/BIOS

3. Some stub thing.
Useless functions are also added when linking the executable file.
If the size of crt1.c and wincrt1.c increases, the size of the compiled file increases.

Maybe the Unicode and ASCII entry functions should be placed in seperate files,
for example: "crt1.c/crt1_w.c" and "wincrt1.c/wincrt1_w.c".

My tests confirmed it. TCC adds the whole codes in c a file or  a file's o file,
as there is no optimization for the "defined but not used" codes.

So, shall we split the  start_entry
(_winstart/_runwinmain and _wwinstart/_wrunwinmain)
for
PE_GUI/TCC_OUTPUT_MEMORY
into seperate files? Then, it can reduce the linked file size.