add_elf_sym is a confusing name because it is not clear what the
function does compared to put_elf_sym. As a matter of fact, put_elf_sym
also adds a symbol in a symbol table. Besides, "add_elf_sym" fails to
convey that the function can be used to update a symbol (for instance
its value). "set_elf_sym" seems like a more appropriate name: it will
set a symbol to a given set of properties (value, size, etc.) and create
a new one if non exist for that name as one would expect.
Do not create a new symbol in add_elf_sym if a symbol with same properties
(value, size, info, etc.) already exists. This prevents symbols from
being exported twice in the dynamic symbol table.
Prior to this patch, an error would only be given when a library has an
unresolved undefined symbol if there is no undefined reference for the
same symbol in the executable itself. This patch changes the logic to
check both that the executable has the symbol in its static symbol table
*and* that it is defined to decide if the error path should be followed.
SHF_GROUP flag set on a section indicates that it is part of a section
group and that if the section is removed, the other sections in the same
group should be removed as well [1]. Since section group are guide for
the linking process, they do not have any meaning after linking has
occured. TCC rightfully [2] discard such sections (by not recognizing the
section type) but keeps the SHF_GROUP flag set on sections that were
part of a section group which confuses binutils (objdump and gdb at
least). Clearing that bit makes objdump and gdb accept binaries created
by TCC.
[1] https://docs.oracle.com/cd/E19683-01/816-1386/chapter7-26/index.html
[2] GNU ld does the same
- call RtlDeleteFunctionTable
(important for multiple compilations)
- the RUNTIME_FUNCTION* is now at the beginning of the
runtime memory. Therefor when tcc_relocate is called
with user memory, this should be done manually before
it is free'd:
RtlDeleteFunctionTable(*(void**)user_mem);
[ free(user_mem); ]
- x86_64-gen.c: expand char/short return values to int
With -run the call instruction and a defined function can be
far away, if the function is defined in the executable itself,
not in the to be compiled code. So we always need PLT slots
for -run, not just for undefined symbols.
Makefile :
- do not 'uninstall' peoples /usr/local/doc entirely
libtcc.c :
- MEM_DEBUG : IDE-friendly output "file:line: ..."
- always ELF for objects
tccgen.c :
- fix memory leak in new switch code
- move static 'in_sizeof' out of function
profiling :
- define 'static' to empty
resolve_sym() :
- replace by dlsym()
win32/64: fix R_XXX_RELATIVE fixme
- was fixed for i386 already in
8e4d64be2f
- do not -Lsystemdir if compiling to .o
Except
- that libtcc1.a is now installed in subdirs i386/ etc.
- the support for arm and arm64
- some of the "Darwin" fixes
- tests are mosly unchanged
Also
- removed the "legacy links for cross compilers" (was total mess)
- removed "out-of-tree" build support (was broken anyway)
-- Not a fix
This reverts commit 089ce6235c.
Revert "handle a -s option by executing sstrip/strip program"
-- related, not a fix.
This reverts commit 5cd4393a54.
- would parse linker args in two different places
- would mess up "tcc -v ..." output:
tcc -v test.c
-> test.c
+> test.c
- would use function "tcc_load_alacarte()" to do the contrary of
what its name suggests.
This reverts commit 19a169ceb8.
A patch is implemented as suggested in tinycc-devel mail list.
From: Reuben Thomas
Date: Thu, 31 Jul 2014 16:52:53 +0100
Subject: [PATCH] Add --{no,}-whole-archive support
I resurrected the patch supplied to the mailing list in 2009
Since --whole-archive is a useful flag to get tcc working with
autotools, and of course in its own right, I suggest you have a look
at the patch and see if it is acceptable. I cannot see any suggestion
that it was actively rejected last time round, just no evidence that
it was ever added.
Traditional behaviour on x86-64 is to encode the relocation
addend in r_addend, not in the relocated field (after all,
that's the reason to use RELA relocs to begin with). Our
linker can deal with both, other linkers as well. But using
e.g. the GNU assembler one can detect differences (equivalent
code in the end, but still a difference).
Now there's only a trivial difference in tests/asmtest.S
(having to do with ordering of prefixes).
This reloction must copy initialized data from the library
to the program .bss segment. Currently made like for ARM
(to remove noise of defaukt case). Is this true?
R_386_GOT32X can occur in object files assembled by new binutils, and in
particular do appear in glibc startup code (crt*.o). This patch is
modeled after the x86_64 one, handling the new relocation in the same
trivial way.
The introduction of read32le everywhere created a subtle issue, going
from
x = *(int*)p;
to
x = read32le(p);
is not equivalent if x is a larger than 32bit quantity, like an
address on x86_64, because read32le returns an unsigned int. The first
sign extends, the latter zero extends. This broke shared library
creation for gawk. It's enough to amend the case of the above
situation, cases like "write32le(p, read32le(p) +- something)" are okay,
no extensions happen or matter.
R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX can occur in object files
comiled by new binutils. They are not dynamic relocations, so normally
wouldn't be a problem for tcc (one doesn't normally mix object files
created by different compiler/binutils, static archives are so out :)).
If it weren't for the glibc startup code, crt*.o, of course. They now
do contain such relocs --> boom. Handle them in the trivial way.
gcc-3.4.6 don't give such error by default
example file1
char __version_303_xxxxxxxx;
void func1() {}
example file2
char __version_303_xxxxxxxx;
void func2() {}
int main() { return 0; }
The call to build_got can cause symtab_section->data to be reallocated
(build_got -> add_elf_sym -> put_elf_sym -> section_ptr_add ->
section_realloc -> tcc_realloc). This is not obvious on a cursory
inspection, but fortunately Valgrind spotted it immediately.
Are there other, similar bugs that Valgrind did not detect?
* Documentation is now in "docs".
* Source code is now in "src".
* Misc. fixes here and there so that everything still works.
I think I got everything in this commit, but I only tested this
on Linux (Make) and Windows (CMake), so I might've messed
something up on other platforms...
* fix some macro expansion issues
* add some pp tests in tests/pp
* improved tcc -E output for better diff'ability
* remove -dD feature (quirky code, exotic feature,
didn't work well)
Based partially on ideas / researches from PipCet
Some issues remain with VA_ARGS macros (if used in a
rather tricky way).
Also, to keep it simple, the pp doesn't automtically
add any extra spaces to separate tokens which otherwise
would form wrong tokens if re-read from tcc -E output
(such as '+' '=') GCC does that, other compilers don't.
* cleanups
- #line 01 "file" / # 01 "file" processing
- #pragma comment(lib,"foo")
- tcc -E: forward some pragmas to output (pack, comment(lib))
- fix macro parameter list parsing mess from
a3fc543459a715d7143d
(some coffee might help, next time ;)
- introduce TOK_PPSTR - to have character constants as
written in the file (similar to TOK_PPNUM)
- allow '\' appear in macros
- new functions begin/end_macro to:
- fix switching macro levels during expansion
- allow unget_tok to unget more than one tok
- slight speedup by using bitflags in isidnum_table
Also:
- x86_64.c : fix decl after statements
- i386-gen,c : fix a vstack leak with VLA on windows
- configure/Makefile : build on windows (MSYS) was broken
- tcc_warning: fflush stderr to keep output order (win32)
Prior to this commit TinyCC was exporting symbols defined in programs
only when they resolve an undefined symbol of a library. However, the
expected behavior (see --export-dynamic in GNU ld manpage) is that all
symbols used by libraries and defined by a program should be exported in
dynsym section. This is because symbol resolution search first in
program and then in libraries, thus allowing program symbol to interpose
symbol defined in a library.
Usage example: tcc -xc ex5.cgi
From a gcc docs:
You can specify the input language explicitly with the -x option:
-x language
Specify explicitly the language for the following input files
(rather than letting the compiler choose a default based on the file
name suffix). This option applies to all following input files until
the next -x option. Possible values for language are:
c c-header c-cpp-output
c++ c++-header c++-cpp-output
objective-c objective-c-header objective-c-cpp-output
objective-c++ objective-c++-header objective-c++-cpp-output
assembler assembler-with-cpp
ada
f77 f77-cpp-input f95 f95-cpp-input
java
-x none
Turn off any specification of a language, so that subsequent files
are handled according to their file name suffixes (as they are if -x
has not been used at all)
* define targetos=Windows when --enable-tcc32-mingw, --enable-cygwin, ...
* use TARGETOS insteed HOST_OS when selecting PROGS
* use "$(tccdir)" insteed $(tccdir) on install (spaces in path)
* install tcc.exe too
* produce bcheck.o when cross-compiling too (lib/Makefile)
* force bcheck.o linking by compiling inside tcc_set_output_type()
a dummy program with local array. Otherwise bcheck.o may be not linked.
* replace %xz format specifier with %p in bcheck (don't supported on
Windows)
* call a __bound_init when __bound_ptr_add, __bound_ptr_indir,
__bound_new_region, __bound_delete_region called.
This is because a __bound_init inside ".init" section is not called
on Windows for unknown reason.
* print on stderr a message when an illegal pointer is returned:
there is no segmentation violation on Windows for a program
compiled with "tcc -b"
* remove "C:" subdir on clean if $HOST_OS = "Linux"
* default CFLAGS="-Wall -g -O0" insteed CFLAGS="-Wall -g -O2"
to speed up compilation and more precise debugging.
tcc w/o -g option generate an executable file which format
is not recognized by binutils. It is like stripped one but
binutils don't think so. Solution: generate not stripped
file which can be correctly stripped by external utils.
may be there is a need to handle a -s option and call
a sstrip/strip program to do a job.
- care about __attribute__ redefinition in the system headers
- an invalid pointer must be returned when (addr >= e->size),
and not (addr > e->size)
A test program:
#include <stdio.h>
#include <stdlib.h>
int main ()
{
int v[10];
fprintf(stderr, "&v[0] = %p\n", &v[0]);
fprintf(stderr, "&v[10] = %p\n", &v[10]);
exit(1);
return 0;
}
// tcc -b test.c
The output before a patch:
&v[0] = 0xbf929d8c
&v[10] = 0xbf929db4
The output after a patch:
&v[0] = 0xbff6e33c
&v[10] = 0xfffffffe
On Linux 32: sizeof(long)=32 == sizeof(void *)=32
on Linux 64: sizeof(long)=64 == sizeof(void *)=64
on Windows 64: sizeof(long)=32 != sizeof(void *)=64
A test program (must be compiled by the above version of the tcc):
/* Tickle a bug in TinyC on 64-bit systems:
* the LSB of the top word or ARGP gets set
* for no obvious reason.
*
* Source: a legacy language interpreter which
* has a little stack / stack pointer for arguments.
*
* Output is: 0x8049620 0x10804961c
* Should be: 0x8049620 0x804961c
*/
#include <stdio.h>
#define NARGS 20000
int ARG[NARGS];
int *ARGSPACE = ARG;
int *ARGP = ARG - 1;
main() { printf("%p %p\n", ARGSPACE, ARGP); }
Don't use /usr/local/lib/tcc/libtcc1.a for i386 and x86_64
A $(tccdir)/i386 directory was used to install a libtcc1.a
but only when cross compiling. And no x86_64 directory.
And this directory location was unknown inside tccelf.c
It is a strange patch because before this commit a gdb is working well
and after this commit there is exactly the same problem on Linux:
gdb refuses to know "main"
Author: grischka <grischka>
Date: Tue Feb 5 21:18:29 2013 +0100
tccelf: fix debug section relocation
With:
tcc -g hello.c
gdb a.out
b main
gdb refused to know "main" because of broken dwarf info.
This adds some more support for properly transfering some
offsets over the different stages of a relocations life.
Still not at all psABI compliant and DSOs can't yet be generated.
But it runs the testsuite in qemu-arm64.
libtcc.c: Add greloca, a generalisation of greloc that takes an addend.
tcc.h: Add greloca and put_elf_reloca.
tccelf.c: Add put_elf_reloca, a generalisation of put_elf_reloc.
tccgen.c: On x86_64, use greloca instead of greloc in init_putv.
- revert to R_X86_64_PC32 for near calls on PE
- revert to s1->section_align set to zero by default
Untested. Compared to release_0_9_26 the pe-image looks back to
normal. There are some differences in dissassembly (r10/r11 usage)
but maybe that's ok.
Same as with x86_64, disable the runtime_plt_and_got hack
for -run on arm as well. For that we need to handle several
relocations as (potentially) generating PLT slots as well.
Tested with mpfr-3.1.2 and gawk (both using --disable-shared),
there are two resp. five pre-existing problems, so no regressions.
This also works toward enabling real shared libs for arm,
but it's not there yet.
This makes us use the normal PLT/GOT codepaths also for -run,
which formerly used an on-the-side blob for the jump tables.
For x86_64 only for now, arm coming up.
These relocations are used to express a dependency on a certain
symbol (e.g. for EABIs exception handling to the
__aeabi_unwind_cpp_pr{0,1,2} routines). Just ignore them in
reloc processing.
When output is memory we applied the correct GOT offset for certain
relocations (e.g. _GOT32), but we forgot to actually fill the got
entries with the final symbol values, so unconditionally create relocs
against .got as well.
This makes it so that the first PT_LOAD segment covers
ELF and program header and .interp (contained in the same page anyway,
right before the start of the first loaded section). binutils
strip creates invalid output otherwise (which strictly is a binutils
bug, but let's be nice anyway).
This correctly resolves local references to global functions from
shared libs to their PLT slot (instead of directly to the target
symbol), so that interposition works.
This is still not 100% conforming (executables don't export symbols
that are also defined in linked shared libs, as they must), but
normal shared lib situations work.
Introduce a new attribute to check the existence of a PLT entry for a
given symbol has the presence of an entry for that symbol in the dynsym
section is not proof that a PLT entry exists.
This fixes commit dc8ea93b13.
Some symbol (such as __gmon_start__ but this one does not matter to tcc)
can have both a R_386_GOT32 and R_386_PLT32 relocation. It is thus not
enough to test if a GOT reloc was already done when deciding whether to
return early from put_got_entry.
When bound check is enabled, tcc tries to relocate a call to
__bound_init in _init. This means that relocation (in tcc_add_bcheck)
must be done after libtcc1.a (which countains __bound_init) is loaded
but before crtn.o is loaded as this finalize _init.
Call fill_got_entry unconditionally from fill_got so as to avoid
warnings on !x86-64 architectures. This can be done since this code path
is only followed by x86-64 architecture anyway.
