exception handling. There are now two layers an error or warning goes
through before it hits the user: first an error is logged via
yasm_error_set() (or yasm_warn_set() for a warning). Only one error may
be set, whereas multiple warnings can be set (yasm_warn_set maintains a
linked list). Then, calling yasm_errwarn_propagate() propagates any error
and/or warning(s) to an errwarns structure and associates the
errors/warnings with a line number at that time; this call also clears the
pending errors/warnings and allows new ones to be set. The propagate
function can safely be called when there are no pending error/warnings.
In addition, there are some helper errwarn functions that allow clearing of
an error/warning without propagating, getting it separately, etc.
Still yet to be done: changing most/all uses of yasm_internal_error() into
yasm_error_set(YASM_ERROR_ASSERTION).
The main advantage this change has is making libyasm functions feel much
more library like, and separating the user code line numbers from the inner
function error handling (e.g. intnum create functions only needed the line
number to trigger errors; this is no longer required).
The set/propagate/etc functions use global data structures to avoid passing
around a pointer to every function. This would need to be made thread-local
data in a threaded app. Errwarns containers (that keep associated line
numbers) are no longer global, so multiple source streams can be processed
separately with no conflict (at least if there's only a single thread of
execution).
svn path=/trunk/yasm/; revision=1521
groundwork for further features and possible cleanups.
Note: this commit changes the way in which relocations in the
COFF/Win32/Win64 target can be forced to reference a different symbol than
is being pointed to; instead of the ambiguous "trap+(trap.end-trap)" to get
the reloc to point at trap.end but reference the trap symbol, after this
commit "trap.end wrt trap" is the way to say this. This also reads a lot
more clearly and is not ambiguous. This should really only affect people
who write .pdata sections for Win64. See the
objfmts/win64/tests/win64-dataref.asm testcase for an example of usage.
This cleanup adds a new data structure, yasm_value, which is used for all
expressions that can be potentially relocatable. This data structure
splits the absolute portion of the expression away from the relative
portion and any modifications to the relative portion (SEG, WRT,
PC-relative, etc). A large amount of code in the new value module breaks
a general expression into its absolute and relative parts
(yasm_value_finalize_expr) and provides a common set of code for writing
out non-relocated values (yasm_value_output_basic).
All bytecode handling in both libyasm and the architecture modules was
rewritten to use yasm_values when appropriate (e.g. data values,
immediates, and effective addresses). The yasm_output_expr_func is now
yasm_output_value_func and all users and implementors (mainly in object
formats) have been updated to handle yasm_values.
Simultaneously with this change, yasm_effaddr and yasm_immval full
structure definitions have been moved from bc-int.h to bytecode.h.
The data hiding provided by bc-int.h was relatively minimal and probably
overkill. Also, great simplifications have been made to x86 effective
address expression handling.
svn path=/trunk/yasm/; revision=1419
correct detection of absolute section reference loops (fixing a crash case).
This is also needed for an ongoing rewrite of reloc/value handling.
* expr.c (expr_xform_bc_dist): Remove transformation of absolute section
references; move in changed form into...
(yasm_expr__level_tree): Here. The new code doesn't immediately calculate
the distance from the start of the absolute section to the referenced symbol;
rather it generates an expression for this quantity. As this actually adds
new absolute section refs to the tree, we can't expand with YASM_EXPR_SYMs,
otherwise we would expand multiple times. Thus we need a new
YASM_EXPR_SYMEXP type that thus does not get expanded. Unfortunately this
ripples changes a bit because everywhere *else* we look for YASM_EXPR_SYM,
we now need to look for YASM_EXPR_SYMEXP as well...
(expr_xform_bc_dist): Here.
(yasm_expr__copy_except): Here.
(yasm_expr_extract_symrec): Here.
(yasm_expr_get_symrec): Here.
(yasm_expr_print): Here.
* bin-objfmt.c (bin_objfmt_expr_xform): And here.
* expr-int.h (yasm_expr__type): Define new YASM_EXPR_SYMEXP.
* section.h (yasm_section_abs_get_sym): To implement above, we need to get
a symbol referencing the first bytecode in the absolute section. To avoid
creating redundant symrecs, one is generated for us now. This function
lets us get it in yasm_expr__level_tree().
* section.c (yasm_section_abs_get_sym): Implement.
(yasm_section): Add necessary SECTION_ABSOLUTE data.
(yasm_section_create_absolute): Create the symrec here.
* absloop-err.asm: New test for absolute section reference loops.
svn path=/trunk/yasm/; revision=1417
