Commit Graph

2316 Commits

Author SHA1 Message Date
Michael Matz
d042e71e9f Fix miscompile with dead switches
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.
2016-12-15 17:49:55 +01:00
Michael Matz
7ae35bf1bb Handle multiple -O options
the last one wins, i.e. "-O2 -O0" does _not_ set __OPTIMIZ__.
2016-12-15 17:49:55 +01:00
Michael Matz
a158260e84 build: Respect CPPFLAGS override
so that e.g. make CPPFLAGS=-DSOMETHING works.
2016-12-15 17:49:55 +01:00
Michael Matz
235711f3d3 64bit: Fix addends > 32 bits
If a symbolic reference is offsetted by a constant > 32bit
the backends can't deal with that, so don't construct such
values.
2016-12-15 17:49:55 +01:00
Michael Matz
a2a596e767 x86-64-asm: Accept high register in clobbers
The callee saved registers (among them r12-r15) really need
saving/restoring if mentioned in asm clobbers, even if TCC
itself doesn't use them.  E.g. the linux kernel relies on that
in its switch_to() implementation.
2016-12-15 17:49:55 +01:00
Michael Matz
ddd461dcc8 Fix initializing members multiple times
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.
2016-12-15 17:49:53 +01:00
Michael Matz
f081acbfba Support local register variables
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.
2016-12-15 17:47:13 +01:00
Michael Matz
3bc9c325c5 Fix const folding of 64bit pointer constants
See testcase.
2016-12-15 17:47:12 +01:00
Michael Matz
0b0e64c2c9 x86-asm: Correct register size for pointer ops
A pointer is 64 bit as well, so it needs a full
register for register operands.
2016-12-15 17:47:12 +01:00
Michael Matz
7ab35c6265 struct-init: Copy relocs for compound literals
When copying the content of compound literals we must
include relocations as well.
2016-12-15 17:47:12 +01:00
Michael Matz
0bca6cab06 x86_64-asm: fix copy-out registers
If the destination is an indirect pointer access (which ends up
as VT_LLOCAL) the intermediate pointer must be loaded as VT_PTR,
not as whatever the pointed to type is.
2016-12-15 17:47:12 +01:00
Michael Matz
ad723a419f x86_64: Add -mno-sse option
This disables generation of any SSE instructions (in particular
in stdarg function prologues).  Necessary for kernel compiles.
2016-12-15 17:47:12 +01:00
Michael Matz
b5669a952b x86-64: relocation addend is 64bit
Some routines were using the wrong type (int) in passing addends,
truncating it.  This matters when bit 31 isn't set and the high
32 bits are set: the truncation would make it unsigned where in
reality it's signed (happen e.g. on the x86-64 with it's load
address at top-2GB).
2016-12-15 17:47:12 +01:00
Michael Matz
975c74c1f5 x86-64: Prefer 32S relocations
This target has _32 and _32S relocs (the latter being for signed
32 bit entities).  All instruction displacements have to use
the 32S variants.  Normal references like
  .long s
normally would use the _32 variant.  For normal executables this
doesn't matter.  For shared libraries neither (which use PC-relative
relocs).  But it matters for things like the kernel that are linked
to high addresses (signed ones).  There the GNU linker would error
out on overflow for the _32 variant.

To keep life simple we simply switch from _32 to _32S altogether.
Strictly speaking it's still wrong, but in practice using _32 is
more often wrong than using _32S ;)
2016-12-15 17:47:12 +01:00
Michael Matz
ad8e14b740 opt: Don't emit inline functions from dead code
Inside dead code don't regard inline functions as being
referenced.
2016-12-15 17:47:12 +01:00
Michael Matz
ce55d03eef Handle __builtin_extract_return_addr
Our architectures don't need anything special for this
builtin, just pass through the argument.
2016-12-15 17:47:12 +01:00
Michael Matz
fb933ae0eb opt: constprop also 'cond && 0'
We didn't handle constants in logical expressions when they weren't
the first operand.  Some reordering in the loop structure is enough
to handle them.
2016-12-15 17:47:12 +01:00
Michael Matz
ca435dc2e3 opt: Make break and goto not fallthrough
As we can optimize dead code a bit already it's fitting
to disable code emission after break and goto.
2016-12-15 17:47:12 +01:00
Michael Matz
31c7ea0165 opt: Start optimizing dead code a bit
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.
2016-12-15 17:47:12 +01:00
Michael Matz
b303a00ce0 Revert "Reject jumping inside stmtexprs"
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.
2016-12-15 17:47:11 +01:00
Michael Matz
d4d3144e75 Factor out const condition detection
Creating condition_3way for this.
2016-12-15 17:47:11 +01:00
Michael Matz
892c3d996f Reject jumping inside stmtexprs
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).
2016-12-15 17:47:11 +01:00
Michael Matz
1602998751 Fix more nocode_wanted jump problems
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.
2016-12-15 17:47:11 +01:00
Michael Matz
f2a071e808 Fix aliases on 64 bit
Use correct width ELF structure.
2016-12-15 17:47:11 +01:00
Michael Matz
9656560f14 Fix sizeof(char[a])
The sizes of VLAs need to be evaluated even inside sizeof,
i.e. when nocode_wanted is set.
2016-12-15 17:47:11 +01:00
Michael Matz
49bb5a7e06 Fix __builtin_constant_p(1000/x)
was incorrectly treated as constant because the vpop removed
all traces of non-constness.
2016-12-15 17:47:11 +01:00
Michael Matz
5bd8aeb917 tccasm: Support refs to anon symbols from asm
This happens when e.g. string constants (or other static data)
are passed as operands to inline asm as immediates.  The produced
symbol ref wouldn't be found.  So tighten the connection between
C and asm-local symbol table even more.
2016-12-15 17:47:11 +01:00
Michael Matz
dd57a34866 tccasm: Don't ignore # in preprocessor directives
Our preprocessor throws away # line-comments in asm mode.
It did so also inside preprocessor directives, thereby
removing stringification.  Parse defines in non-asm mode (but
retain '.' as identifier character inside macro definitions).
2016-12-15 17:47:11 +01:00
Michael Matz
e7ef087598 x86-asm: Accept all 32bit immediates
In particular don't care if they're signed or unsigned, they're all
acceptable as immediates.
2016-12-15 17:47:11 +01:00
Michael Matz
372f4b6a4e Fix enum bitfields passed to stdarg functions
VT_ENUM types use the .ref member and can be VT_BITFIELD,
so we need to copy it as well.  Simply do it always.
2016-12-15 17:47:11 +01:00
Michael Matz
d720865fb6 Addresses of non-weak symbols are non-zero
Use this fact in some foldings of comparisons.  See testcase.
2016-12-15 17:47:10 +01:00
Michael Matz
be6d8ffc10 Fix access-after-free with statement expressions
The return value of statement expressions might refer to local
symbols, so those can't be popped.  The old error message always
was just a band-aid, and since disabling it for pointer types it
wasn't effective anyway.  It also never considered that also the
vtop->sym member might have referred to such symbols (see the
testcase with the local static, that used to segfault).

For fixing this (can be seen better with valgrind and SYM_DEBUG)
simply leave local symbols of stmt exprs on the stack.
2016-12-15 17:47:10 +01:00
Michael Matz
d0d25ec7df tccpp: Allow computed include like 42.h
The include directive needs to be parsed as pp-tokens, not
as token (i.e. no conversion to TOK_STR or TOK_NUM).  Also fix
parsing computed includes using quoted strings.
2016-12-15 17:47:10 +01:00
Michael Matz
0381387640 x86-asm: Correctly infer register size for bools
Register operands of type _Bool weren't correctly getting
the 8-bit sized registers (but rather used the default 32-bit
ones).
2016-12-15 17:47:10 +01:00
Michael Matz
9e0af6d2b5 x86-64-asm: Implement cmpxchg16b 2016-12-15 17:47:10 +01:00
Michael Matz
ca8c1cd643 x86-64: Allow loads from some structs/unions
GCC allows register loads for asms based on type mode,
and correctly sized structs/union have an allowed mode
(basically 1,2,4,8 sized aggregates).
2016-12-15 17:47:10 +01:00
Michael Matz
9ae10cad1f tccasm: Lookup C symbols from ASM blocks
It's now possible to use symbols defined in C code to be used
from later inline asm blocks.  See testcase.
2016-12-15 17:47:10 +01:00
Michael Matz
c4edfb4e08 tccasm: Implement .set sym, expr
That, as well as "sym = expr", if expr contains symbols.
Slightly tricky because a definition from .set is overridable,
whereas proper definitions aren't.

This doesn't yet allow using this for override tricks from C
and global asm blocks because the symbol tables from C and asm
are separate.
2016-12-15 17:47:10 +01:00
Michael Matz
34fc6435ee enums and ints are compatible
But like GCC do warn about changes in signedness.  The latter
leads to some changes in gen_assign_cast to not also warn about
  unsigned* = int*
(where GCC warns, but only with extra warnings).
2016-12-15 17:47:10 +01:00
Michael Matz
b1a906b970 enums and ints are compatible 2016-12-15 17:47:10 +01:00
Michael Matz
c0368604e1 x86-64-asm: Fix ltr/str and push/pop operands
str accepts rm16/r32/r64, and push/pop defaults to 64 when given
memory operands (to 32 on i386).
2016-12-15 17:47:10 +01:00
Michael Matz
45b24c37a0 x86-64-asm: Implement high %cr registers 2016-12-15 17:47:09 +01:00
Michael Matz
4e46c22d5c struct-init: Support range inits for local vars
Implement missing support for range init for local variables.
2016-12-15 17:47:09 +01:00
Michael Matz
4cb7047f0f x86-64-asm: Support high registers %r8 - %r15
This requires correctly handling the REX prefix.
As bonus we now also support the four 8bit registers
spl,bpl,sil,dil, which are decoded as ah,ch,dh,bh in non-long-mode
(and require a REX prefix as well).
2016-12-15 17:47:09 +01:00
Michael Matz
8765826465 inline-asm: Accept "flags" clobber 2016-12-15 17:47:09 +01:00
Michael Matz
b7ca74577b struct-init: Allow member initialization from qualified lvalues
See testcase.
2016-12-15 17:47:09 +01:00
Michael Matz
9e86ebee94 struct-init: Correctly parse unnamed member initializers
For
  union U { struct {int a,b}; int c; };
  union U u = {{ 1, 2, }};
The unnamed first member of union U needs to actually exist in the
structure so initializer parsing isn't confused about the double braces.
That means also the a and b members must be part of _that_, not of
union U directly.  Which in turn means we need to do a bit more work
for field lookup.

See the testcase extension for more things that need to work.
2016-12-15 17:47:09 +01:00
Michael Matz
21da73c383 struct-init: Cleanup some more
Some parameters aren't actually necessary.  Also join the
two parsing loops for the initializer list of arrays and structs.
2016-12-15 17:47:09 +01:00
Michael Matz
7bf323843e struct-init: Cleanup
Remove dead code and variables.  Properly check for unions when
skipping fields in initializers.  Make tests2/*.expect depend
on the .c files so they are automatically rebuilt when the latter
change.
2016-12-15 17:47:09 +01:00
Michael Matz
ed7d54651d struct-init: Implement initializing subaggregates
E.g. "struct { struct S s; int a;} = { others, 42 };"
if 'others' is also a 'struct S'.  Also when the value is a
compound literal.  See added testcases.
2016-12-15 17:47:09 +01:00