some newer systems have debug sections compressed by default, which
includes those in the crt[1in].o startup files. These can't simply
be concatenated like all others (which leads to invalid section contents
ultimately making gdb fail) but need special handling.
Instead of that special handling (decompressing, which in turn requires
linking against zlib) let's just ignore such sections, even though that
means to also ignore all other debug sections from that particular input
file. Our own generated files of course don't have the problem.
introduce common_section (SHN_COMMON), factorize some handling
in decl_initializer_alloc, add section_add and use it to factorize
some code that allocates stuff in sections (at the same time also fixing
harmless bugs re section alignment), use init_putv to emit float consts
into .data from gv() (fixing an XXX).
Don't emit useless section headers and also sort them in allocated
order. Doesn't change behaviour except makes the resulting files
a tiny bit smaller (though at the expense of some very tiny compile
time and code size increase of tcc itself; not 100% it's worth it).
The O(xxx) stuff in i386-asm.c had me scratching my head. Extracting
the macro and trying it out in a separate program doesn't give
me any warnings, so I'm confused about what could be going on there.
Any cast will make things happy. I used a uint64_t to catch actual
cases of overflow, which will still cause a -Wconstant-conversion
warning.
Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com>
since configure supports only native configuration
a file 'cross-tcc.mak' needs to be created manually.
It is included in the Makefile if present.
# ----------------------------------------------------
# Example config-cross.mak:
#
# windows -> i386-linux cross-compiler
# (it expects the linux files in <prefix>/i386-linux)
ROOT-i386 = {B}/i386-linux
CRT-i386 = $(ROOT-i386)/usr/lib
LIB-i386 = $(ROOT-i386)/lib:$(ROOT-i386)/usr/lib
INC-i386 = {B}/lib/include:$(ROOT-i386)/usr/include
DEF-i386 += -D__linux__
# ----------------------------------------------------
Also:
- use libtcc1-<target>.a instead of directories
- add dummy arm assembler
- remove include dependencies from armeabi.c/lib-arm64.c
- tccelf/ld_add_file: add SYSROOT (when defined) to absolute
filenames coming from ld-scripts
Today by accident i had to deal with linker problems of some
software and found an issue that mentioned DT_RUNPATH, which
mentioned that DT_RPATH is legacy and searched for
$LD_LIBRARY_PATH, whereas the newer DT_RUNPATH is searched
thereafter. Completely unencrypted! Well. For what's it worth,
i for one am astonished because of course i want to override
$LD_LIBRARY_PATH, but it surely has its merites, smart people came
to the conclusion, did they.
The attached diff below seems to be sufficient to support
DT_RUNPATH instead of DT_RPATH with tcc(1). But i have no insight
in what --enable-new-dtags is supposed to change in addition, so
i wonder.
Ciao!
--steffen
libtcc.c | 2 ++
tcc-doc.texi | 4 ++++
tcc.h | 1 +
tccelf.c | 3 ++-
4 files changed, 9 insertions(+), 1 deletion(-)
- tccgen.c/tcc.h: allow function declaration after use:
int f() { return g(); }
int g() { return 1; }
may be a warning but not an error
see also 76cb1144ef
- tccgen.c: redundant code related to inline functions removed
(functions used anywhere have sym->c set automatically)
- tccgen.c: make 32bit llop non-equal test portable
(probably not on C67)
- dynarray_add: change prototype to possibly avoid aliasing
problems or at least warnings
- lib/alloca*.S: ".section .note.GNU-stack,"",%progbits" removed
(has no effect)
- tccpe: set SizeOfCode field (for correct upx decompression)
- libtcc.c: fixed alternative -run invocation
tcc "-run -lxxx ..." file.c
(meant to load the library after file).
Also supported now:
tcc files ... options ... -run @ arguments ...
When intializing members where the initializer needs relocations
and the member is initialized multiple times we can't allow
that to lead to multiple relocations to the same place. The last
one must win.
- generate and use SYM@PLT for plt addresses
- get rid of patch_dynsym_undef hack (no idea what it did on FreeBSD)
- use sym_attrs instead of symtab_to_dynsym
- special case for function pointers into .so on i386
- libtcc_test: test tcc_add_symbol with data object
- move target specicic code to *-link.c files
- add R_XXX_RELATIVE (needed for PE)
MSVC does not support array designator so cannot compile source using
relocs_info. This commit replace the relocs_info array into a set of
functions, each returning the value given by a given field of the struct
reloc_info.
i386 target does not have PC relative loads. Its ABI therefore require
ebx register to points to the GOT when executing a PLT entry. This means
that PLT entry cannot be used transparently, the compiler needs to
expect execution of a PLT entry to be able to use one, that is a PLT
entry should only be created if the relocation explicitely asks for it
(eg. R_386_PLT32).
This patch creates a new target macro PCRELATIVE_DLLPLT to indicate
whether a target can do a PC relative load in PLT entry when building a
dynamic library. Executable do not normally pose a problem because they
are loaded at a fixed address and thus the absolute address of GOT can
be used.
Note that in such a case, if the compiler does not use a PLT aware
relocation for external access then the code relocation will fall on the
dynamic loader since there is no PLT entry to relocate too.
Static relocation of functions in dynamic libraries must use the PLT
entry as the target. Before this commit, it used to be done in 2 parts
for ARM, with the offset of the PLT entry from the beginning of the PLT
being put in the relocated place in build_got_entries () and then the
address of the PLT being added in relocate_section.
This led to code dealing with reading the offset of a bl instruction in
build_got_entries. Furthermore, the addition of the address of the start
of the PLT was done based on the relocation type which does not convey
whether a PLT entry should be used to reach the symbol.
This commit moves the decision to use the PLT as the target in
relocate_section, therefore having the instruction aware code contained
to the target-specific bit of that function (in <target>-link.c).
Note that relocate_syms is *not* the right place to do this because two
different relocations for the same symbol can make different decision.
This is the case in tcc -run mode where the static and dynamic
relocation are done by tcc.
Storing the PLT entry address in the symbol's st_value field and relying
on the specific relocation type being used for dynamic relocation would
work but the PLT entry address would then appear in the static symbol
table (symtab). This would also make the static symbol table entry
differ from the dynamic symbol table entry.
Change alloc_sym_attr into get_sym_attr and add a parameter to control
whether to allocate a new symattr structure or return NULL if symbol is
not found;
Currently GOT/PLT creation happens in two locations depending on whether
the GOT/PLT [entry] is required by the symbol or the relocation:
- bind_exe_dynsym for relocations to undefined symbol
- build_got_entries/put_got_entry for relocations that require a GOT/PLT
entry
This commit consolidate GOT/PLT creation in build_got_entries by
reducing bind_exe_dynsym's job to create a dynamic symbol for undefined
symbols. build_got_entries then invoke put_got_entry if the symbol being
relocated is undefined or the relocation asks for a PLT or GOT [entry].
put_got_entry is also modified to only export a symbol in the dynamic
symbol table when we are in the case of PLT/GOT [entry] required by the
relocation (since undefined symbol are already exported by
bind_exe_dynsym).
Currently we always build a GOT when we recognize a relocation in
build_got_entries even if the relocation does not require one. In the
same spirit, when the relocation does require one we always create a GOT
entry even if not entry is necessary. This patch restricts the creation
of a GOT and a GOT entry to relocations that needs it, ie:
- do not create a GOT if relocation is not related to GOT and symbol is
not UNDEF
- do not create a GOT entry if relocation only relates to beginning of
GOT
On ARM targets, the jump to ld.so resolution routine is done in PLT0 by
loading the offset to the GOT found in PLT+16 and from there loading the
address in GOT+8 and jumping to it.
Currently tcc starts the first regular PLT entry at PLT+16 which thus
does not contain the offset to the GOT. This commit fixes that.
Note that calls via PLT still worked nonetheless because of some missing
dynamic tag which makes ld.so behaves as if RTLD_BIND_NOW was specified
in the environment for all executable created by tcc.
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.
