tccgen.c:
- fix ldouble asm hack
- fix a VLA problem on Win64 (also x86_64-gen.c)
- patch_type(): make sure that no symbol ever changes
from global to static
tcc.c:
- tcc -vv: print libtcc1.a path also on win32
tccpe.c, tcctools.c:
- use unix LF mode to for .def output files (that is for
creating reproducible output trees)
Makefile:
- suppress some warnings when makeinfo is missing
- call 'which install' only on win32
tests/Makefile:
- change PATH only on WINNT systems (i.e. not if cross-compiling
on linux for win32)
- asm-c-connect.test: slim output and do diff
tccrun.c tccpe.c *-link.c:
- integrate former 'pe_relocate_rva()' into normal relocation
This also fixes linkage of the unwind data on WIN64 for -run
(reported by Janus Lynggaard Thorborg)
tccasm.c, tests/tcctest.c:
- fix dot (sym_index of -1 crashed in put_elf_reloc)
- massage .set a bit (see test)
other:
- #define SECTION_ABS removed
- ST_DATA Section *strtab_section: removed
- put_extern_sym2(): take int section number
Conflicts:
tccelf.c
tccpe.c
Conflicts:
tccelf.c
This is supposed to make compilation and linking with
multiple source files (tcc f1.c f2.S ...) behave just
the same as linking object files.
tccgen.c:put_extern_sym2():
- use put_elf_sym to enter new symbols unconditionally
tccelf.c:
- save section state before compilation
- disable symbol hashing during compilation
- merge symbols and update relocations after compilation
tccpe.c:
- re-create s1->uw_sym for each compilation (because it
may change)
tccgen.c:
- improved function patch_storage() and added new function
patch_type() for more consistent type redefinition and
instance redefinition checks.
* removed asm_label stack
* removed asm_free_labels() post-processing
* using "impossible C type" for asm labels (VT_ASM)
* tccgen.c:update_storage(): use it to refresh symbol attributes
* tccelf.c:find_elf_sym(): ignore STB_LOCAL symbols
* tccgen.c:unary(): asm symbols are supposed to be undeclared in C
This makes the asm symbols use the same members as the C symbols
for global decls, e.g. using the ELF symbol to hold offset and
section. That allows us to use only one symbol table for C and
asm symbols and to get rid of hacks to synch between them.
We still need some special handling for symbols that come purely
from asm sources.
See testcase. The C and asm symtab are still separate,
but integrated tighter: the asm labels are only synched at file
end, not after each asm snippet (this fixes references from one
to another asm block), the C and asm syms are synched both ways,
so defining things in asm and refering from C, or the other way
around works. In effect this model reflects what happens with
GCC better.
For this the asm labels aren't using the C label namespace anymore,
but their own, which increases the size of each TokenSym by a pointer.
win32/Makefile ("for cygwin") removed
- On cygwin, the normal ./configure && make can be used with either
cygwin's "GCC for Win32 Toolchain"
./configure --cross-prefix=i686-w64-mingw32-
or with an existing tcc:
./configure --cc=<old-tccdir>/tcc.exe
tcctest.c:
- exclude test_high_clobbers() on _WIN64 (does not work)
tests2/95_bitfield.c:
- use 'signed char' for ARM (where default 'char' is unsigned)
tests:
- remove -I "expr" diff option to allow tests with
busybox-diff.
libtcc.c, tcc.c:
- removed -iwithprefix option. It is supposed to be
combined with -iprefix which we don't have either.
tccgen.c:
- fix assignments and return of 'void', as in
void f() {
void *p, *q;
*p = *q:
return *p;
}
This appears to be allowed but should do nothing.
tcc.h, libtcc.c, tccpp.c:
- Revert "Introduce VIP sysinclude paths which are always searched first"
This reverts commit 1d5e386b0a.
The patch was giving tcc's system includes priority over -I which
is not how it should be.
tccelf.c:
- add DT_TEXTREL tag only if text relocations are actually
used (which is likely not the case on x86_64)
- prepare_dynamic_rel(): avoid relocation of unresolved
(weak) symbols
tccrun.c:
- for HAVE_SELINUX, use two mappings to the same (real) file.
(it was so once except the RX mapping wasn't used at all).
tccpe.c:
- fix relocation constant used for x86_64 (by Andrei E. Warentin)
- #ifndef _WIN32 do "chmod 755 ..." to get runnable exes on cygwin.
tccasm.c:
- keep forward asm labels static, otherwise they will endup
in dynsym eventually.
configure, Makefile:
- mingw32: respect ./configure options --bindir --docdir --libdir
- allow overriding tcc when building libtcc1.a and libtcc.def with
make XTCC=<tcc program to use>
- use $(wildcard ...) for install to allow installing just
a cross compiler for example
make cross-arm
make install
- use name <target>-libtcc1.a
build-tcc.bat:
- add options: -clean, -b bindir
add some features for more complete 'long' support
tcc.h:
- use LONG_SIZE=4/8 instead of TCC_LONG_ARE_64_BIT
tccgen.c:
- add ptrdiff_type, update size_type
- support shift and ?: operations
- support long enum types
- display 'long' from type_to_str
- nwchar_t is unsigned short on windows
- unrelated: use memcpy in init_putv for long doubles to avoid
random bytes in the image (if tcc was compiled by gcc) for
diff purposes.
tccpp.c:
- make parse_number return correct types
- improve multi-character-constants 'XX' 'abcd'
Changelog:
- update
Too simple long parsion.
Take me a long long long time to see my mistake,
Sorry
(long long long wasn't see as an error)
This reverts commit a4cd2805f9.
tccgen.c:
doubles need to be aligned, on ARM. The section_reserve()
in init_putv does not do that.
-D ONE_SOURCE: is now the default and not longer needed. Also,
tcc.h now sets the default native target. These both make
compiling tcc simple as "gcc tcc.c -o tcc -ldl" again.
arm-asm.c:
enable pseudo asm also for inline asm
tests/tests2/Makefile:
disable bitfield tests except on windows and x86_64
and don't generate-always
tcc.c:
fix a loop with -dt on errors
configure:
print compiler version (as recognized)
tccpp.c:
actually define symbols for tcc -dt
clear static variables (needed for -dt or libtcc usage)
96_nodata_wanted.c:
use __label__ instead of asm
lib/files:
use native symbols (__i386__ etc.) instead of TCC_TARGET_...
* check that _Generic don't match unsigned char * with char *
this case is usefull as with -funsigned-char, 'char *' are unsigned
* change VT_LONG so it's now a qualifier
VT_LONG are never use for code generation, but only durring parsing state,
in _Generic we need to be able to make diference between
'long' and 'long long'
So VT_LONG is now use as a type qualifier, it's old behaviour is still
here, but we can keep trace of what was a long and what wasn't
* add TOK_CLONG and TOK_CULONG
tcc was directly converting value like '7171L' into TOK_CLLONG or
TOK_CINT depending of the machine architecture.
because of that, we was unable to make diference between a long and a
long long, which doesn't work with _Generic.
So now 7171L is a TOK_CLONG, and we can handle _Generic properly
* check that _Generic can make diference between long and long long
* uncomment "type match twice" as it should now pass tests on any platforms
* add inside_generic global
the point of this variable is to use VT_LONG in comparaison only
when we are evaluating a _Generic.
problem is with my lastest patchs tcc can now make the diference between
a 'long long' and a 'long', but in 64 bit stddef.h typedef uint64_t as
typedef signed long long int int64_t and stdint.h as unsigned long int, so tcc
break when stdint.h and stddef.h are include together.
Another solution woud be to modifie include/stddef.h so it define uint64_t as
unsigned long int when processor is 64 bit, but this could break some
legacy code, so for now, VT_LONG are use only inside generc.
* check that _Generic parse first argument correctly
* check that _Generic evaluate correctly exresion like "f() / 2"
* -dt now with lowercase t
* test snippets now separated by real preprocessor statements
which is valid C also for other compilers
#if defined test_xxx
< test snippet x >
#elif defined test_yyy
< test snippet y >
#elif ...
#endif
* simpler implementation, behaves like -run if no 'test_...' macros
are seen, works with -E too
* for demonstration I combined some of the small tests for errors
and warnings (56..63,74) in "60_errors_and_warnings.c"
Also:
* libtcc.c:
put tcc_preprocess() and tcc_assemble() under the setjmp clause
to let them return to caller after errors. This is for -dt -E.
* tccgen.c:
- get rid of save/restore_parse_state(), macro_ptr is saved
by begin_macro anyway, now line_num too.
- use expr_eq for parsing _Generic's controlling_type
- set nocode_wanted with const_wanted. too, This is to keep
VT_JMP on vtop when parsing preprocessor expressions.
* tccpp.c: tcc -E: suppress trailing whitespace from lines with
comments (that -E removes) such as
NO_GOTPLT_ENTRY,\t /* never generate ... */
The existing variable 'nocode_wanted' is now used to control
output of static data too. So...
(nocode_wanted == 0)
code and data (normal within functions)
(nocode_wanted < 0)
means: no code, but data (global or static data)
(nocode_wanted > 0)
means: no code and no data (code and data suppressed)
(nocode_wanted & 0xC0000000)
means: we're in declaration of static data
Also: new option '-dT' to be used with -run
tcc -dT -run file.c
This will look in file.c for certain comment-boundaries:
/*-* test-xxx: ...some description */
and then for each test below run it from memory. This way
various features and error messages can be tested with one
single file. See 96_nodata_wanted.c for an example.
Also: tccgen.c: one more bitfield fix
tccpp.c:
* #pragma comment(option,"-some-option")
to set commandline option from C code. May work only
for some options.
libtcc.c:
* option "-d1..9": sets a 'g_debug' global variable.
(for development)
tests2/Makefile:
* new make targets: tests2.37 / tests2.37+
run single test from tests2, optionally update .expect
* new variable GEN-ALWAYS to always generate certain .expects
* bitfields test
tccgen.c:
* bitfields: fix a bug and improve slightly more
* _Generic: ignore "type match twice"
The assembler uses the ->sym_scope member to walk up the symbols
until finding a non-automatic symbol. Since reordering the
members of Sym the sym_scope member contains a scope even for local
statics. Formerly the use of asm_label for statics was implicitely
clearing sym_scope, now we have to do that explicitely.
Add a testcase for that, and one I encountered when moving the
clearing of sym_scope too deep into the call chain (into put_extern_sym).
Like returned local variables also labels local to a statement expression
can be returned, and so their symbols must not be immediately freed
(though they need to be removed from the symbol table).
Use 2 level strategy to access packed bitfields cleanly:
1) Allow to override the original declaration type with
an auxilary "access type". This solves cases such as
struct {
...
unsigned f1:1;
};
by using VT_BYTE to access f1.
2) Allow byte-wise split accesses using two new functions
load/store_packed_bf. This solves any cases, also ones
such as
struct __attribute((packed)) _s {
unsigned x : 12;
unsigned char y : 7;
unsigned z : 28;
unsigned a: 3;
unsigned b: 3;
unsigned c: 3;
};
where for field 'z':
- VT_INT access from offset 2 would be unaligned
- VT_LLONG from offset 0 would go past the total
struct size (7)
and for field 'a' because it is in two bytes and
aligned access with VT_SHORT/INT is not possible.
Also, static bitfield initializers are stored byte-wise always.
Also, cleanup the struct_layout function a bit.
tcc.h:
* cleanup struct 'Sym'
* include some 'Attributes' into 'Sym'
* in turn get rid of VT_IM/EXPORT, VT_WEAK
* re-number VT_XXX flags
* replace some 'long' function args by 'int'
tccgen.c:
* refactor parse_btype()
- configure
* use aarch64 instead of arm64
- Makefile
* rename the custom include file to "config-extra.mak"
* Also avoid "rm -r /*" if $(tccdir) is empty
- pp/Makefile
* fix .expect generation with gcc
- tcc.h
* cleanup #defines for _MSC_VER
- tccgen.c:
* fix const-propagation for &,|
* fix anonymous named struct (ms-extension) and enable
-fms-extension by default
- i386-gen.c
* clear VT_DEFSIGN
- x86_64-gen.c/win64:
* fix passing structs in registers
* fix alloca (need to keep "func_scratch" below each alloca area on stack)
(This allows to compile a working gnu-make on win64)
- tccpp.c
* alternative approach to 37999a4fbf
This is to avoid some slowdown with ## token pasting.
* get_tok_str() : return <eof> for TOK_EOF
* -funsigned-char: apply to "string" literals as well
- tccpe/tools.c: -impdef: support both 32 and 64 bit dlls anyway
Simple implementation, I'm not even sure to respect C standart here,
but it should work with most use case.
This add an case in unary(), and generate TokString depending of _Generic
controlling exression, use begin_macro to "push"
the generated TokString, then call unary() again before exiting the switch
so the just add token are reevaluate again.
This reverts commit d4fe9aba3f.
I was confused by the fact that string literals aren't writable.
Nevertheless the type isn't const. As extension in GCC it's const
with -Wwrite-string, which is exactly what we had before.
GCC also wonders in a comment if it's really a good idea to change
expression types based on warning flags (IMHO it's not), but let's
be compatible. So restore the state from before.
Don't make the standard mandated types of string literals
depends on warning options. Instead make them always const,
but limit the emission of the warning by that option.
Only warn if the struct has a non-zero size. You can't create objects
of zero-sized structs, but they can be used inside sizeof (e.g.
"sizeof (struct {int :0;})". The warning would always trigger for these,
but as no objects can be created no accesses can ever happen.
- configure:
- add --config-uClibc,-musl switch and suggest to use
it if uClibc/musl is detected
- make warning options magic clang compatible
- simplify (use $confvars instead of individual options)
- Revert "Remove some unused-parameter lint"
7443db0d5f
rather use -Wno-unused-parameter (or just not -Wextra)
- #ifdef functions that are unused on some targets
- tccgen.c: use PTR_SIZE==8 instead of (X86_64 || ARM64)
- tccpe.c: fix some warnings
- integrate dummy arm-asm better
For integer promotion with for example arithmetics or
expr_cond (x ? y : z), integral types need to be promoted
to signed if they fit.
According to latest standards, this also applies to bit-field
types taking into account their specific width.
In tcc, VT_BITFIELD set means width < original type width
Field-widths between 33 and 63 are promoted to signed long long
accordingly.
struct { unsigned long long ullb:35; } s = { 1 };
#define X (s.ullb - 2)
int main (void)
{
long long Y = X;
printf("%d %016llx %016llx\n", X < 0, -X, -Y);
return 0;
}
Results:
GCC 4.7 : 0 0000000000000001 FFFFFFF800000001
MSVC : 1 0000000000000001 0000000000000001
TCC : 1 0000000000000001 0000000000000001
Also, gcc would promote long long bitfields of size < 32
to int as well. Example:
struct { unsigned long long x:20; } t = { 123 };
/* with gcc: */ printf("%d %d\n", t.x, 456);
/* with tcc: */ printf("%lld %d\n", t.x, 456);
bit_pos + bit_size > type_size * 8
must NEVER happen because the code generator can read/write
only the basic integral types.
Warn if tcc has to break GCC compatibility for that reason
and if -Wgcc-compat is given.
Example:
struct __attribute__((packed)) _s
{
unsigned int x : 12;
unsigned char y : 7;
unsigned int z : 28;
};
Expected (GCC) layout (sizeof struct = 6)
.xxxxxxxx.xxxxyyyy.yyyzzzzz.zzzzzzzz.zzzzzzzz.zzzzzzz0.
But we cannot read/write 'char y'from 2 bytes in memory.
So we have to adjust:
.xxxxxxxx.xxxx0000.yyyyyyyz.zzzzzzzz.zzzzzzzz.zzzzzzzz.zzz00000
Now 'int z' cannot be accessed from 5 bytes. So we arrive
at this (sizeof struct = 7):
.xxxxxxxx.xxxx0000.yyyyyyy0.zzzzzzzz.zzzzzzzz.zzzzzzzz.zzzz0000
Otherwise the bitfield load/store generator needs to be
changed to allow byte-wise accesses.
Also we may touch memory past the struct in some cases
currently. The patch adds a warning for that too.
0: 55 push %ebp
1: 89 e5 mov %esp,%ebp
3: 81 ec 04 00 00 00 sub $0x4,%esp
9: 90 nop
struct __attribute__((packed)) { unsigned x : 5; } b = {0} ;
a: 8b 45 ff mov -0x1(%ebp),%eax
d: 83 e0 e0 and $0xffffffe0,%eax
10: 89 45 ff mov %eax,-0x1(%ebp)
This touches -0x1 ... +0x3(%ebp), hence 3 bytes beyond
stack space. Since the data is not changed, nothing
else happens here.
* tccgen: re-allow long double constants for x87 cross
sizeof (long double) may be 12 or 16 depending on host platform
(i386/x86_64 on unix/windows).
Except that it's 8 if the host is on windows and not gcc
was used to compile tcc.
* win64: fix builtin_va_start after VT_REF removal
See also a8b83ce43a
* tcctest.c: remove outdated limitation for ll-bitfield test
It always worked, there is no reason why it should not work
in future.
* libtcc1.c: exclude long double conversion on ARM
* Makefile: remove CFLAGS from link recipes
* lib/Makefile: use target DEFINES as passed from main Makefile
* lib/armflush.c lib/va_list.c: factor out from libtcc1.c
* arm-gen.c: disable "depreciated" warnings for now
'extern int i = 42;' at file scope (but not in function scope!) is
allowed and is a proper definition, even though questionable style;
some compilers warn about this.
See the added testcase. When one used designators like .a.x to initialize
sub-members of members, and didn't then initialize all of them the
required zero-initialization of the other sub-members wasn't done.
The fix also enables tiny code cleanups.
See testcase. If an enum has only positive values, fits N bits,
and is placed in a N-bit bit-field that bit-fields must be treated
as unsigned, not signed.
This invalid function definition:
int f()[] {}
was tried to be handled but there was no testcase if it actually worked.
This fixes it and adds a TCC only testcase.
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).
factor code a bit for transforming tokens into SValues. This revealed
a bug in TOK_GET (see testcase), which happened to be harmless before.
So fix that as well.
The canonical way to describe a local variable that actually holds
the address of an lvalue is VT_LLOCAL. Remove the last user of VT_REF,
and handling of it, thereby freeing a flag for SValue.r.
VT_LLOCAL is a flag on .r, not on type.t. Fixing this requires
minor surgery for compound literals which accidentally happened
to be subsumed by the bogus test.
the second argument can be an arbitrary expression (including
side-effects), not just a constant. This removes the last user
of expr_lor_const and hence also that function (and expr_land_const).
Also the argument to __builtin_constant_p can be only a non-comma
expression (like all functions arguments).
Our code generation assumes that it can load/store with the
bit-fields base type, so bit_pos/bit_size must be in range for this.
We could change the fields type or adjust offset/bit_pos; we do the
latter.
Checked the lcc testsuite for bitfield stuff (in cq.c and fields.c),
fixed one more error in initializing unnamed members (which have
to be skipped), removed the TODO.
- configure/Makefiles: minor adjustments
- build-tcc.bat: add -static to gcc options
(avoids libgcc_s*.dll dependency with some mingw versions)
- tccpe.c/tcctools.c: eliminate MAX_PATH
(not available for cross compilers)
- tccasm.c: use uint64_t/strtoull in unary()
(unsigned long sometimes is only uint32_t, as always on windows)
- tccgen.c: Revert (f077d16c) "tccgen: gen_cast: cast FLOAT to DOUBLE"
Was a rather experimental, tentative commit, not really necessary
and somewhat ugly too.
- cleanup recent osx support:
- Makefile/libtcc.c: cleanup copy&paste code
- tccpp.c: restore deleted function
Also, retain storage qualifiers in type_decl, in particular
also for function pointers. This allows to get rid of this
very early hack in decl()
type.t |= (btype.t & VT_STATIC); /* Retain "static". */
which was to fix the case of
int main() { static int (*foo)(); ...
Also:
- missing __declspec(dllimport) is an error now
- except if the symbol is "_imp__symbol"
- demonstrate export/import of data in the dll example (while
'extern' isn't strictly required with dllimport anymore)
- new function 'patch_storage()' replaces 'weaken_symbol()'
and 'apply_visibility()'
- new function 'update_storage()' applies storage attributes
to Elf symbols.
- put_extern_sym/2 accepts new pseudo section SECTION_COMMON
- add -Wl,-export-all-symbols as alias for -rdynamic
- add -Wl,-subsystem=windows for mingw compatibility
- redefinition of 'sym' error for initialized global data
Forgot about it. It allows to compile several
sources (and other .o's) to one single .o file;
tcc -r -o all.o f1.c f2.c f3.S o4.o ...
Also:
- option -fold-struct-init-code removed, no effect anymore
- (tcc_)set_environment() moved to tcc.c
- win32/lib/(win)crt1 minor fix & add dependency
- debug line output for asm (tcc -c -g xxx.S) enabled
- configure/Makefiles: x86-64 -> x86_64 changes
- README: cleanup
- 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 ...
Some code in gen_opl was depending on a gvtst label
which in nocode_wanted mode is not set.
This was causing vstack leaks and crashes with for example
long long ll;
if (0)
return ll - 10 < 0;
Also:
- on windows i386 and x86-64, structures of size <= 8 are
NOT returned in registers if size is not one of 1,2,4,8.
- cleanup: put all tv-push/pop/swap/rot into one place
Some more subtle issues with code suppression:
- outputting asms but not their operand setup is broken
- but global asms must always be output
- statement expressions are transparent to code suppression
- vtop can't be transformed from VT_CMP/VT_JMP when nocode_wanted
Also remove .exe files from tests2 if they don't fail.
Restore ebx from *ebp because alloca might change esp.
Also disable USE_EBX for upcoming release.
Actually the benefit is less than one would expect, it
appears that tcc can't do much with more than 3 registers
except with extensive use of long longs where the disassembly
looks much prettier (and shorter also).
Also: tccgen/expr_cond() : fix wrong gv/save_regs order
Also ...
tcctest.c:
- exclude stuff that gcc doesn't compile on windows.
libtcc.c/tccpp.c:
- use unsigned for memory sizes to avoid printf format warnings
- use "file:line: message" to make IDE error parsers happy.
tccgen.c: fix typo
tccgen.c: remove any 'nocode_wanted' checks, except in
- greloca(), disables output elf symbols and relocs
- get_reg(), will return just the first suitable reg)
- save_regs(), will do nothing
Some minor adjustments were made where nocode_wanted is set.
xxx-gen.c: disable code output directly where it happens
in functions:
- g(), output disabled
- gjmp(), will do nothing
- gtst(), dto.
when an alignment is explicitely given on the member itself,
or on its types attributes then respect it always. Was only
allowed to increase before, but GCC is allowing it.
The linux kernel has some structures that are page aligned,
i.e. 4096. Instead of enlarging the bit fields to specify this,
use the fact that alignment is always power of two, and store only
the log2 minus 1 of it. The 5 bits are enough to specify an alignment
of 1 << 30.
Another corner case:
struct foo6_1
{
char x;
short p:8;
short :0;
short :0;
short p2:8;
char y;
};
In MS layout the second anon :0 bit-field does _not_ adjust size or
alignment of the struct again. The first one does, though.
Bit-fields are layed out differently in visual C, this implements
a compatible mode. Checked against Visual C/C++ 2016.
Unfortunately the GCC implementation of MS layout (behind
-mms-bitfields) actually is different, and hence not compatible
with MS in all cases :-/
Such struct decl:
struct S { char a; int i;} __attribute__((packed));
should be accepted and cause S to be five bytes long (i.e.
the packed attribute should matter). So we can't layout
the members during parsing already. Split off the offset
and alignment calculation for this.
See testcases. We now support 64bit case constants. At the same time
also 64bit enum constants on L64 platforms (otherwise the Sym struct
isn't large enough for now). The testcase also checks for various
cases where sign/zero extension was confused.
In certain very specific situations (involving switches
with asms inside dead statement expressions) we could generate
invalid code (clobbering the buffer so much that we generated
invalid instructions). Don't emit the decision table if the
switch itself is dead.
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.
Similar to GCC a local asm register variable enforces the use of a
specified register in asm operands (and doesn't otherwise
matter). Works only if the variable is directly mentioned as
operand. For that we now generally store a backpointer from
an SValue to a Sym when the SValue was the result of unary()
parsing a symbol identifier.
If a condition is always zero/non-zero we can omit the
then or else code. This is complicated a bit by having to
deal with labels that might make such code reachable without
us yet knowing during parsing.
Not fully thought out. You can't jump inside stmt exprs,
but you can jump out of them. So there's a difference
between undefined but declared labels at the end of stmt
exprs and those defined inside. Additionally it should
also be checked if a label defined inside a stmt expr
was tentatively created as declared from outside.
I'm not prepared doing that right now, so simply revert.
This reverts commit 9160e4cab9147d77840cc44a285031fdb4640cf9.
One can't jump into statement expressions from outside
them, like the following:
int i = ({ label: foo(); 42; });
goto label;
We reject this by making the labels simply not available
outside (GCC has a nicer error message about jumping into
a statement expression).
In statement expression we really mustn't emit backward jumps
under nocode_wanted (they will form infinte loops as no expressions
are evaluated). Do-while and explicit loop with gotos weren't
handled.
