gcc/gcc
J"orn Rennecke 7f0ea82ec0 Re-apply this patch:
2002-05-16  Dale Johannesen  <dalej@apple.com>
	  * combine.c (cant_combine_insn_p):  Reenable combinations
	  involving hard regs unless CLASS_LIKELY_SPILLED_P.

From-SVN: r65689
2003-04-16 18:41:10 +01:00
..
ada tree.c (build_constructor): New function. 2003-04-13 01:45:35 +00:00
config pa-protos.h (function_arg): Remove last argument. 2003-04-16 17:06:50 +00:00
cp re PR c++/10381 (Accepts call to inexistent function) 2003-04-15 20:23:36 +00:00
doc varasm.c (output_constant_def): Do not consult CONSTANT_AFTER_FUNCTION_P. 2003-04-15 20:57:12 +00:00
f builtin-types.def (BT_FN_STRING_CONST_STRING): New builtin type. 2003-04-14 02:55:31 +00:00
fixinc re PR target/10338 ([3.3 regression?] [Cygwin -> tic4x | avr] cross target compilation error) 2003-04-15 14:24:26 +00:00
ginclude float.h, [...]: GCC, not GNU CC. 2003-03-13 02:58:40 +00:00
intl Makefile.in (.y.c): Only enable production rule when maintaining. 2003-03-14 21:36:28 +00:00
java * gjavah.c (print_c_decl): Indentation fix. 2003-04-14 04:42:21 +00:00
objc tree.c (build_constructor): New function. 2003-04-13 01:45:35 +00:00
po c-common.c: Include intl.h. 2003-03-22 03:28:39 +00:00
testsuite * lib/prune.exp: Ignore more messages. 2003-04-15 20:24:48 +00:00
treelang treetree.c (cpp_create_reader): Follow prototype change in cpplib.h. 2003-03-21 08:27:42 +01:00
.cvsignore Add more cscope data files 2002-06-10 02:36:06 +00:00
ABOUT-GCC-NLS ABOUT-GCC-NLS: Remove reference to enquire... 2002-09-18 05:07:02 +00:00
ABOUT-NLS ABOUT-NLS: Follow spelling conventions. 2002-09-16 11:42:00 +00:00
COPYING
COPYING.LIB
ChangeLog Re-apply this patch: 2003-04-16 18:41:10 +01:00
ChangeLog.0 ChangeLog: Follow spelling conventions. 2002-09-22 02:03:17 +00:00
ChangeLog.1 ChangeLog.1: Fix typos. 2002-10-28 14:07:45 +00:00
ChangeLog.2 ChangeLog: Follow spelling conventions. 2002-12-19 05:18:13 +00:00
ChangeLog.3 ChangeLog: Follow spelling conventions. 2002-09-22 02:03:17 +00:00
ChangeLog.4 ChangeLog: Follow spelling conventions. 2002-12-19 05:18:13 +00:00
ChangeLog.5 ChangeLog: Follow spelling conventions. 2002-12-19 05:18:13 +00:00
ChangeLog.6 ChangeLog.4: Fix typos. 2002-09-28 15:29:45 +00:00
ChangeLog.7 Fix typos. 2002-11-15 14:53:41 +01:00
ChangeLog.8 ChangeLog: Rotated last year's entries to... 2003-03-13 19:20:26 +00:00
ChangeLog.lib
FSFChangeLog
FSFChangeLog.10 ChangeLog.4: Fix typos. 2002-09-28 15:29:45 +00:00
FSFChangeLog.11 ChangeLog.1: Follow spelling conventions. 2002-09-26 12:29:45 +00:00
LANGUAGES LANGUAGES: Follow spelling conventions. 2002-09-27 12:48:07 +00:00
Makefile.in * Makefile.in (c-opts.o): Use custom action. 2003-04-14 22:25:10 +00:00
ONEWS re PR other/895 (top of ONEWS needs to be merged into EGCS release notes) 2003-03-29 11:35:07 +00:00
README-fixinc
README.Portability * README.Portability: Fix typos. 2002-07-02 09:45:42 +09:30
SERVICE
acconfig.h
aclocal.m4 aclocal.m4 (gcc_AC_EXAMINE_OBJECT, [...]): Delete. 2003-03-21 17:19:34 +00:00
alias.c alias.c (find_base_term): Export. 2003-04-05 15:57:40 +00:00
alloc-pool.c Warning fixes: 2003-01-05 05:27:45 +00:00
alloc-pool.h Makefile.in (OBJS): Add alloc-pool.o 2002-12-19 15:53:46 +00:00
attribs.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
basic-block.h cfg.c (unchecked_make_edge): New. 2003-03-10 12:59:12 +00:00
bb-reorder.c * bb-reorder.c (find_traces_1_round): Fix comment typo. 2003-02-20 08:44:08 +00:00
bitmap.c hashtable.c (gcc_obstack_init): Delete this function and everything related to it. 2003-04-06 21:44:09 +00:00
bitmap.h bitmap.h (BITMAP_WORD): New typedef: fundamental storage type for bitmaps. 2003-01-25 10:21:22 -08:00
builtin-attrs.def re PR c++/9367 (error: nonnull argument with extern "C" snprintf prototype) 2003-03-02 01:34:34 +00:00
builtin-types.def builtin-types.def (BT_FN_STRING_CONST_STRING): New builtin type. 2003-04-14 02:55:31 +00:00
builtins.c builtins.c (expand_builtin_strlen): Evaluate the lengths of string literals at compile-time. 2003-04-14 20:23:27 +00:00
builtins.def builtin-types.def (BT_FN_STRING_CONST_STRING): New builtin type. 2003-04-14 02:55:31 +00:00
c-aux-info.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
c-common.c tree.h (DECL_BUILT_IN_NONANSI): Remove. 2003-04-14 03:13:07 +00:00
c-common.def tree.c (tree_size): For all 'c' and 'x' nodes... 2003-04-07 06:03:17 +00:00
c-common.h c-decl.c (struct binding_level): Add shadowed_tags and function_body... 2003-04-11 04:26:55 +00:00
c-config-lang.in Make gengtype.c language independent. 2002-07-14 01:59:15 +00:00
c-convert.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
c-cppbuiltin.c c-cppbuiltin.c (builtin_define_with_value_n): Fix whitespace. 2003-03-15 13:43:33 +00:00
c-decl.c c-decl.c (implicitly_declare): Copy declarations that are going to be placed in a local scope. 2003-04-15 16:35:52 +00:00
c-dump.c c-common.h (c_dump_tree), [...]): Change return type from 'int' to 'bool'. 2003-03-19 20:34:10 +00:00
c-errors.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
c-format.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
c-incpath.c c-incpath.c (add_standard_paths): Add both "translated" and non-translated header paths. 2003-03-26 09:53:23 +10:30
c-incpath.h c-incpath.c (remove_component_p, [...]): Move back to cppfiles.c. 2003-03-02 17:44:18 +00:00
c-lang.c Makefile.in (CRTSTUFF_CFLAGS): Add -fno-unit-at-a-time 2003-02-12 21:48:59 +00:00
c-lex.c Makefile.in: Update. 2003-03-15 12:18:47 +00:00
c-objc-common.c c-common.h (lang_statement_code_p): Remove declaration. 2003-04-10 08:07:13 +00:00
c-opts.c Various cleanups to help compile server. 2003-03-20 08:46:18 -08:00
c-parse.in * c-parse.in: Remove '%expect 32' directive in objc mode 2003-01-28 01:56:32 +00:00
c-pch.c c-pch.c: Include flags.h. 2003-04-12 01:58:33 +00:00
c-ppoutput.c Makefile.in: Update. 2003-03-15 12:18:47 +00:00
c-pragma.c alias.c: Fix comment typos. 2003-01-18 02:26:43 +00:00
c-pragma.h coretypes.h (cpp_reader): Forward declare struct. 2003-01-28 23:26:28 +00:00
c-pretty-print.c tree.c (tree_size): For all 'c' and 'x' nodes... 2003-04-07 06:03:17 +00:00
c-pretty-print.h alias.c: Fix comment typos. 2003-01-18 02:26:43 +00:00
c-semantics.c i386.c (builtin_description): Add __builtin_ia32_paddq and __builtin_ia32_psubq. 2003-02-22 00:32:09 +00:00
c-tree.h c-decl.c (struct binding_level): Add shadowed_tags and function_body... 2003-04-11 04:26:55 +00:00
c-typeck.c * c-typeck.c (digest_init, push_init_level): Use CONSTRUCTOR_ELTS. 2003-04-13 03:31:09 +00:00
caller-save.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
calls.c builtin-types.def (BT_FN_STRING_CONST_STRING): New builtin type. 2003-04-14 02:55:31 +00:00
cfg.c cfg.c (unchecked_make_edge): New. 2003-03-10 12:59:12 +00:00
cfganal.c alias.c: Fix comment typos. 2003-01-18 02:26:43 +00:00
cfgbuild.c cfgbuild.c (make_edges): Use tablejump_p. 2003-03-30 12:46:57 -08:00
cfgcleanup.c cfgbuild.c (make_edges): Use tablejump_p. 2003-03-30 12:46:57 -08:00
cfglayout.c c-decl.c (struct binding_level): Add shadowed_tags and function_body... 2003-04-11 04:26:55 +00:00
cfglayout.h cfgloopanal.c: New file. 2003-01-24 20:27:02 +00:00
cfgloop.c basic-block.h (EDGE_IRREDUCIBLE_LOOP, [...]): New. 2003-03-05 22:05:18 +00:00
cfgloop.h basic-block.h (EDGE_IRREDUCIBLE_LOOP, [...]): New. 2003-03-05 22:05:18 +00:00
cfgloopanal.c calls.c: Fix comment formatting. 2003-03-08 01:38:27 +00:00
cfgloopmanip.c calls.c: Fix comment formatting. 2003-03-08 01:38:27 +00:00
cfgrtl.c re PR rtl-optimization/10024 ([HP-PA] inline optimization ICE) 2003-04-14 14:19:12 +00:00
cgraph.c Makefile.in (cgraph.o): Depend on gt-cgraph.h and varray.h. 2003-03-08 18:24:22 +00:00
cgraph.h inline-3.c: New test. 2003-03-08 13:26:37 +00:00
cgraphunit.c c-cppbuiltin.c (builtin_define_with_value_n): Fix whitespace. 2003-03-15 13:43:33 +00:00
collect2.c re PR other/6955 (collect2 says "core dumped" when there is no core) 2003-03-30 19:01:58 +00:00
collect2.h Index: ChangeLog 2002-08-04 22:45:31 +00:00
combine.c Re-apply this patch: 2003-04-16 18:41:10 +01:00
conditions.h
config.gcc config-ml.in: Remove support for --disable-aix removing call-aix multilibs. 2003-04-13 16:59:45 +00:00
config.guess
config.in configure.in: Check for wchar.h, mbstowcs, and wcswidth. 2003-04-12 18:07:06 +00:00
configure configure.in: Unify the code which creates symlinks to a just-built as... 2003-04-16 06:51:20 +00:00
configure.frag
configure.in configure.in: Unify the code which creates symlinks to a just-built as... 2003-04-16 06:51:20 +00:00
conflict.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
convert.c convert.c (convert_to_real): Also optimize (float)log(x) into logf(x) where x is a float, i.e. 2003-02-19 03:39:30 +00:00
convert.h
coretypes.h coretypes.h (cpp_reader): Forward declare struct. 2003-01-28 23:26:28 +00:00
cppdefault.c Makefile.in (C_AND_OBJC_OBJS, [...]): Update. 2003-03-01 14:31:21 +00:00
cppdefault.h Makefile.in (C_AND_OBJC_OBJS, [...]): Update. 2003-03-01 14:31:21 +00:00
cpperror.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
cppexp.c cppexp.c (cpp_classify_number): Accept '.' after "0x". 2003-03-31 15:50:53 +00:00
cppfiles.c Various cleanups to help compile server. 2003-03-20 08:46:18 -08:00
cpphash.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
cpphash.h /home/neil/diffs/include.log 2003-03-14 21:47:50 +00:00
cppinit.c Various cleanups to help compile server. 2003-03-20 08:46:18 -08:00
cpplex.c c-opts.c: Default TARGET_EBCDIC to 0 if not defined. 2003-03-17 06:41:06 +00:00
cpplib.c /home/neil/diffs/include.log 2003-03-14 21:47:50 +00:00
cpplib.h Various cleanups to help compile server. 2003-03-20 08:46:18 -08:00
cppmacro.c /home/neil/diffs/include.log 2003-03-14 21:47:50 +00:00
cpppch.c cpppch.c (reset_ht): Remove. 2003-04-03 21:00:56 +00:00
cppspec.c Makefile.in: Update. 2003-03-11 06:42:21 +00:00
cpptrad.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
crtstuff.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
cse.c regrename.c (struct du_chain): Use a bitfield for reg_class. 2003-04-10 05:24:26 +00:00
cselib.c cselib.c (clear_table): Do not take argument; always clear just used slots. 2003-03-14 20:15:13 +00:00
cselib.h cselib.c (cselib_invalidate_mem_1): Move too ... 2003-03-11 21:52:42 +00:00
cstamp-h.in
dbxout.c dbxout.c (print_int_cst_bounds_in_octal_p): New function, extracted from dbxout_type. 2003-04-14 18:06:07 -04:00
dbxout.h
dbxstclass.h
debug.c dbxout.c (scope_labelno): Add GTY. 2003-04-05 07:01:51 +00:00
debug.h dbxout.c (scope_labelno): Add GTY. 2003-04-05 07:01:51 +00:00
defaults.h hashtable.c (gcc_obstack_init): Delete this function and everything related to it. 2003-04-06 21:44:09 +00:00
df.c Makefile.in (df.o): Depend on alloc-pool.h, not obstack.h. 2003-04-05 20:13:20 +00:00
df.h 2003-03-20 Daniel Berlin <dberlin@dberlin.org> 2003-03-20 23:02:54 +00:00
diagnostic.c diagnostic.c (real_abort): New. 2003-02-12 01:05:47 +00:00
diagnostic.def diagnostic.h (output_formatted_scalar): Rename from output_formatted_integer. 2002-08-12 18:34:51 +00:00
diagnostic.h diagnostic.c (real_abort): New. 2003-02-12 01:05:47 +00:00
dojump.c * dojump.c (do_jump): Copy SUBREGs into a pseudo for comparison. 2003-03-30 23:07:27 +00:00
doloop.c cfgloopanal.c: New file. 2003-01-24 20:27:02 +00:00
dominance.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
doschk.c dbxout.c: Fix formatting. 2002-05-11 10:47:05 +00:00
dummy-conditions.c c-pch.c, [...]: Replace "GNU CC" with "GCC". 2003-03-13 03:48:31 +00:00
dwarf.h
dwarf2.h alias.c: Fix comment typos. 2003-01-18 02:26:43 +00:00
dwarf2asm.c Merge from pch-branch. 2003-01-10 02:22:34 +00:00
dwarf2asm.h ansidecl.h (ATTRIBUTE_NONNULL, [...]): New. 2003-03-17 22:57:27 +00:00
dwarf2out.c dwarf2out.c (gen_compile_unit_die): Emit DW_LANG_Ada95 instead of DW_LANG_Ada83 for Ada units. 2003-04-14 17:12:45 -04:00
dwarf2out.h function.h (struct function): Rename profile_label_no. 2002-06-17 10:47:22 -07:00
dwarfout.c dbxout.c (scope_labelno): Add GTY. 2003-04-05 07:01:51 +00:00
emit-rtl.c expr.c (highest_pow2_factor): Return unsigned. 2003-04-14 17:07:12 -04:00
errors.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
errors.h emit-rtl.c: Likewise. 2002-06-03 01:13:17 +00:00
et-forest.c et-forest.c: Fix comment typos. 2003-01-17 14:24:24 +00:00
et-forest.h et-forest.c: Fix comment typos. 2003-01-17 14:24:24 +00:00
except.c except.c (resolve_fixup_regions): Avoid dereferencing null pointer to region... 2003-04-15 08:37:58 -04:00
except.h * except.h: Remove definition of varray_type. 2003-03-31 05:14:54 +00:00
explow.c explow.c (round_push): Use HOST_WIDE_INT instead of int for the temporary used to round CONST_INT sizes. 2003-04-14 18:08:51 -04:00
expmed.c expmed.c (expand_divmod): Undo sign extensions for unsigned operands 2003-02-22 10:02:31 +00:00
expr.c expr.c (highest_pow2_factor): Return unsigned. 2003-04-14 17:07:12 -04:00
expr.h expr.c (highest_pow2_factor): Return unsigned. 2003-04-14 17:07:12 -04:00
final.c final.c (shorten_branches): Align the address of code label when computing initial lengths and addresses. 2003-01-25 23:32:20 +00:00
fix-header.c * fix-header.c (read_scan_file): Defer switch processing. 2003-04-03 22:01:21 +00:00
fixproto fixproto: Define NULL and size_t in generated stdlib.h and unistd.h. 2003-03-22 00:15:53 +00:00
flags.h re PR c++/9393 (Anonymous namespaces and compiling the same file twice) 2003-04-12 02:16:46 +00:00
flow.c combine.c (gen_lowpart_for_combine): Update handling of subregs_of_mode 2003-02-28 10:11:47 +00:00
fold-const.c * fold-const.c (fold): Reorder tests for conditional expressions. 2003-04-14 17:09:44 -04:00
fp-test.c
function.c libfuncs.h (LTI_setbits, [...]): New. 2003-04-11 12:45:32 -07:00
function.h Makefile.in (calls.o, [...]): Depend on cgraph.h 2003-03-05 22:19:33 +00:00
future.options
gbl-ctors.h gbl-ctors.h: Fix formatting. 2002-06-04 11:30:46 +00:00
gcc.c Makefile.in: Update. 2003-03-11 06:42:21 +00:00
gcc.h gcc.c (DEFAULT_SWITCH_TAKES_ARG): Remove. 2003-03-10 15:41:42 -08:00
gccbug.in * gccbug.in: Update. 2003-01-02 05:10:27 +00:00
gccspec.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gcov-dump.c Makefile.in (loop-init.o): Do not depend on gcov-io.h, gcov-iov.h. 2003-04-11 10:38:57 +00:00
gcov-io.h Makefile.in (loop-init.o): Do not depend on gcov-io.h, gcov-iov.h. 2003-04-11 10:38:57 +00:00
gcov-iov.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gcov.c Makefile.in (loop-init.o): Do not depend on gcov-io.h, gcov-iov.h. 2003-04-11 10:38:57 +00:00
gcse.c * gcse.c (replace_store_insn): Use single_set. 2003-04-07 21:00:08 +01:00
gdbinit.in * gdbinit.in (pct): New macro. 2002-08-02 05:25:46 -04:00
gen-protos.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
genattr.c genattrtab.h (INSN_ALTS_FUNC_NAME): Move it from genautomata.c. 2003-01-20 22:49:33 +00:00
genattrtab.c [multiple changes] 2003-02-01 11:00:02 -08:00
genattrtab.h genattrtab.h, [...]: Replace "GNU CC" with "GCC". 2003-03-13 03:51:01 +00:00
genautomata.c genautomata.c (output_translate_vect): Fix a typo in loop condition. 2003-04-14 15:50:08 +00:00
gencheck.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gencodes.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
genconditions.c c-pch.c, [...]: Replace "GNU CC" with "GCC". 2003-03-13 03:48:31 +00:00
genconfig.c genconfig.c (main): Generate CC0_P. 2003-02-05 00:56:40 +00:00
genconstants.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
genemit.c dbxout.c (lastfile, cwd): Fix `unused' warning. 2003-01-16 15:37:57 +00:00
genextract.c c-cppbuiltin.c (builtin_define_with_value_n): Fix whitespace. 2003-03-15 13:43:33 +00:00
genflags.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gengenrtl.c * gengenrtl.c (gencode): Delete unnecessary rtl_obstack declaration. 2002-12-18 22:37:49 +00:00
gengtype-lex.l gengtype-lex.l (IWORD): Add CHAR_BITFIELD. 2003-04-03 15:42:16 +00:00
gengtype-yacc.y Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gengtype.c rtl.def (SYMBOL_REF): Add two 0 fields. 2003-04-11 14:15:36 -07:00
gengtype.h Index: gcc/ChangeLog 2002-09-16 18:33:23 +00:00
genmultilib * genmultilib: Use 'cd ./foo'. 2002-12-17 16:17:35 -05:00
genopinit.c optabs.h (enum optab_index): Add new OTI_pow and OTI_atan2. 2003-02-11 19:34:11 +00:00
genoutput.c * genoutput.c (output_get_insn_name): Handle NOOP_MOVE_INSN_CODE. 2003-02-07 14:39:49 -08:00
genpeep.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
genpreds.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
genrecog.c et-forest.c: Fix comment typos. 2003-01-17 14:24:24 +00:00
gensupport.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gensupport.h gensupport.c: Include hashtab.h. 2002-07-29 18:02:47 +00:00
ggc-common.c cpppch.c (reset_ht): Remove. 2003-04-03 21:00:56 +00:00
ggc-none.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
ggc-page.c Update comment for ggc_alloc - to match API change made 2000-6-9. 2003-03-17 10:42:23 -08:00
ggc-simple.c * ggc-simple.c (debug_ggc_tree): Add PTR cast. 2003-01-25 10:25:14 -08:00
ggc.h cpppch.c (reset_ht): Remove. 2003-04-03 21:00:56 +00:00
glimits.h c-common.c (builtin_define_type_max): New. 2002-06-11 20:06:30 -07:00
global.c global.c (global_conflicts): Prevent allocation of call clobbered hard regs to pseudos live across abnormal... 2003-04-14 17:51:07 -04:00
gmon.c
graph.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
graph.h gbl-ctors.h: Fix formatting. 2002-06-04 11:30:46 +00:00
gstab.h
gsyms.h
gsyslimits.h
gthr-aix.h
gthr-dce.h Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gthr-posix.h Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gthr-rtems.h re PR bootstrap/9296 ([*-rtems] gthr-rtems regression) 2003-01-29 15:06:59 +00:00
gthr-single.h * gthr-single.h: Fix formatting. 2002-11-15 04:53:19 +00:00
gthr-solaris.h Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gthr-vxworks.h Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gthr-win32.h Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
gthr.h Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
haifa-sched.c c-cppbuiltin.c (builtin_define_with_value_n): Fix whitespace. 2003-03-15 13:43:33 +00:00
hard-reg-set.h loop.c (emit_prefetch_instructions): Do conversion at right place in RTL chain. 2003-01-31 23:34:17 +00:00
hashtable.c hashtable.c (gcc_obstack_init): Delete this function and everything related to it. 2003-04-06 21:44:09 +00:00
hashtable.h hashtable.c (gcc_obstack_init): Delete this function and everything related to it. 2003-04-06 21:44:09 +00:00
hooks.c tm.texi: Document TARGET_DWARF_REGISTER_SPAN. 2003-03-05 22:37:52 +00:00
hooks.h tm.texi: Document TARGET_DWARF_REGISTER_SPAN. 2003-03-05 22:37:52 +00:00
host-default.c Makefile.in (host_hook_obj): New. 2003-02-06 01:47:56 +00:00
hosthooks-def.h genattrtab.h, [...]: Replace "GNU CC" with "GCC". 2003-03-13 03:51:01 +00:00
hosthooks.h genattrtab.h, [...]: Replace "GNU CC" with "GCC". 2003-03-13 03:51:01 +00:00
hwint.h hwint.h: If the current compiler has no 64-bit type at all, make HOST_WIDEST_INT 32 bits. 2003-01-06 20:31:16 +00:00
ifcvt.c * ifcvt.c (noce_process_if_block): Fail on BLKmode move. 2003-04-14 17:44:36 -04:00
input.h c-lex.c (indent_level): Remove. 2002-05-23 12:05:38 +00:00
insn-addr.h Merge from pch-branch up to tag pch-commit-20020603. 2002-06-04 07:11:05 +00:00
integrate.c integrate.c (expand_inline_function): Don't inline if would lose /u on a BLKmode TARGET. 2003-04-14 17:33:05 -04:00
integrate.h Merge from pch-branch up to tag pch-commit-20020603. 2002-06-04 07:11:05 +00:00
intl.c configure.in: Check for wchar.h, mbstowcs, and wcswidth. 2003-04-12 18:07:06 +00:00
intl.h * intl.h: #define gcc_gettext_width to strlen when !ENABLE_NLS. 2003-04-12 23:07:34 +00:00
jump.c PR middle-end/10336, c++/10401 2003-04-15 12:13:14 -04:00
langhooks-def.h tree.c (tree_size): For all 'c' and 'x' nodes... 2003-04-07 06:03:17 +00:00
langhooks.c tree.c (tree_size): For all 'c' and 'x' nodes... 2003-04-07 06:03:17 +00:00
langhooks.h tree.c (tree_size): For all 'c' and 'x' nodes... 2003-04-07 06:03:17 +00:00
lcm.c c-cppbuiltin.c (builtin_define_with_value_n): Fix whitespace. 2003-03-15 13:43:33 +00:00
libfuncs.h libfuncs.h (LTI_setbits, [...]): New. 2003-04-11 12:45:32 -07:00
libgcc-std.ver unwind.inc (_Unwind_Backtrace): New function. 2003-04-15 16:24:18 +00:00
libgcc2.c libgcc-std.ver (__clztf2): New. 2003-02-09 10:35:22 -08:00
libgcc2.h libgcc-std.ver (__clztf2): New. 2003-02-09 10:35:22 -08:00
libgcov.c Makefile.in (loop-init.o): Do not depend on gcov-io.h, gcov-iov.h. 2003-04-11 10:38:57 +00:00
limitx.h
limity.h
line-map.c Various cleanups to help compile server. 2003-03-20 08:43:19 -08:00
line-map.h dbxout.c: Follow spelling conventions. 2002-09-22 14:09:34 +00:00
lists.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
local-alloc.c ifcvt.c: Fix comment typos. 2003-01-17 03:28:11 +00:00
location.h diagnostic.h: #include location.h 2002-07-10 10:36:27 +00:00
longlong.h * longlong.h (umul_ppmm) [alpha]: Use __builtin_alpha_umulh. 2003-04-02 11:33:22 -08:00
loop-init.c Change gcov file interface to single file at a time. 2003-04-07 19:37:12 +00:00
loop-unroll.c loop-unroll.c (decide_peel_completely, [...]): Set loop->has_desc. 2003-03-17 20:24:59 +00:00
loop-unswitch.c basic-block.h (EDGE_IRREDUCIBLE_LOOP, [...]): New. 2003-03-05 22:05:18 +00:00
loop.c re PR rtl-optimization/10157 ([Sparc] internal compiler error: in extract_insn, at recog.c:2188) 2003-04-03 19:20:06 +00:00
loop.h loop.h (REGNO_FIRST_LUID, [...]): Provide defaults for insns without luid. 2003-04-07 23:34:25 +00:00
machmode.def Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
machmode.h expr.c (emit_move_insn): Use SCALAR_FLOAT_MODE_P 2002-11-01 09:35:24 +00:00
main.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
mbchar.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
mbchar.h
mips-tdump.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
mips-tfile.c PR bootstrap/10051, PR bootstrap/10169. 2003-03-26 21:56:34 +00:00
mkconfig.sh Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
mkdeps.c Merge from pch-branch. 2003-01-10 02:22:34 +00:00
mkdeps.h Merge from pch-branch. 2003-01-10 02:22:34 +00:00
mkheaders.in Makefile.in (INSTALL_HEADERS): Add 'install-mkheaders'. 2002-05-27 04:24:54 +00:00
mkinstalldirs
mklibgcc.in mklibgcc.in (libgcc-stage-start): For every multilib directory containing a libgcc.a... 2003-04-12 09:06:46 +00:00
mkmap-flat.awk
mkmap-symver.awk mkmap-symver.awk (BEGIN): Set sawsymbol false. 2002-11-27 12:00:14 -08:00
move-if-change
optabs.c optabs.c (expand_binop): In multi-word add cases, ensure XTARGET is copied to TARGET if they are different. 2003-04-15 09:06:58 -04:00
optabs.h optabs.h (enum optab_index): Add new OTI_pow and OTI_atan2. 2003-02-11 19:34:11 +00:00
output.h rtl.def (SYMBOL_REF): Add two 0 fields. 2003-04-11 14:15:36 -07:00
params.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
params.def params.def: Introduce parameter max-inline-insns-rtl for a separate limit for the RTL inliner. 2003-03-02 21:18:16 +00:00
params.h params.def: Introduce parameter max-inline-insns-rtl for a separate limit for the RTL inliner. 2003-03-02 21:18:16 +00:00
predict.c predict.c (estimate_bb_frequencies): Correctly set real_values_initialized after initialization. 2003-03-01 15:11:59 +00:00
predict.def builtins.def: Fix comment formatting. 2002-09-29 13:16:44 +00:00
predict.h cfglayout.c (function_tail_eff_head): Rename to ... 2002-05-08 09:17:27 +00:00
prefix.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
prefix.h
pretty-print.h diagnostic.h (output_formatted_scalar): Rename from output_formatted_integer. 2002-08-12 18:34:51 +00:00
print-rtl.c rtl.def (SYMBOL_REF): Add two 0 fields. 2003-04-11 14:15:36 -07:00
print-tree.c tree.h (DECL_BUILT_IN_NONANSI): Remove. 2003-04-14 03:13:07 +00:00
profile.c tree.c (build_constructor): New function. 2003-04-13 01:45:35 +00:00
profile.h gcov-dump.c (print_prefix): Fix signedness warning. 2003-02-26 16:55:10 +00:00
protoize.c dbxout.c (lastfile, cwd): Fix `unused' warning. 2003-01-16 15:37:57 +00:00
ra-build.c calls.c: Fix comment formatting. 2003-03-08 01:38:27 +00:00
ra-colorize.c c-cppbuiltin.c (builtin_define_with_value_n): Fix whitespace. 2003-03-15 13:43:33 +00:00
ra-debug.c c-cppbuiltin.c (builtin_define_with_value_n): Fix whitespace. 2003-03-15 13:43:33 +00:00
ra-rewrite.c * ra-rewrite.c (rewrite_program2): Initialize bb to avoid warning. 2003-01-22 19:40:08 +00:00
ra.c df.h (enum df_ref_flags.DF_REF_STRIPPED): New. 2003-03-07 22:06:16 +00:00
ra.h df.h (enum df_ref_flags.DF_REF_STRIPPED): New. 2003-03-07 22:06:16 +00:00
read-rtl.c collect2.c (ldgetname): Expand declaration to prototype. 2003-01-19 21:25:07 -05:00
real.c * real.c (decode_ieee_single): Fix decoding of SNaN bit. 2003-04-02 09:13:33 +00:00
real.h real.h (EXP_BITS): Make room for... 2003-04-01 21:45:28 +00:00
recog.c sbitmap.c (sbitmap_resize): New function. 2003-02-18 19:35:08 +00:00
recog.h gcse.c (try_replace_reg): Use num_changes_pending. 2002-07-23 12:08:10 +00:00
reg-stack.c c-cppbuiltin.c (builtin_define_with_value_n): Fix whitespace. 2003-03-15 13:43:33 +00:00
regclass.c combine.c (gen_lowpart_for_combine): Update handling of subregs_of_mode 2003-02-28 10:11:47 +00:00
regmove.c regmove.c (optimize_reg_copy_1): Do not replace a hard register in an asm. 2003-02-22 03:17:24 +00:00
regrename.c regrename.c (struct du_chain): Use a bitfield for reg_class. 2003-04-10 05:24:26 +00:00
regs.h combine.c (gen_lowpart_for_combine): Update handling of subregs_of_mode 2003-02-28 10:11:47 +00:00
reload.c re PR target/7784 ([Sparc] ICE in extract_insn, at recog.c:2148) 2003-03-26 07:48:15 +00:00
reload.h reload.c (reload_adjust_reg_for_mode): New function. 2003-03-04 05:54:39 +00:00
reload1.c optabs.c: Comment that gen_add2_insn and others may actually return emitted insns... 2003-04-09 17:50:08 +00:00
reorg.c reorg.c (fill_slots_from_thread): When considering changing the insn following a reg-to-reg copy insn to use the... 2003-04-08 20:16:54 +00:00
resource.c regmove.c: Fix comment typos. 2002-12-24 08:30:34 +00:00
resource.h
rtl-error.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
rtl.c combine.c (distribute_notes): Kill REG_EXEC_COUNT. 2003-02-20 08:54:48 +00:00
rtl.def rtl.def (SYMBOL_REF): Add two 0 fields. 2003-04-11 14:15:36 -07:00
rtl.h rtl.h (SYMBOL_REF_TLS_MODEL): Fix mask value. 2003-04-14 22:35:45 +00:00
rtlanal.c cfgbuild.c (make_edges): Use tablejump_p. 2003-03-30 12:46:57 -08:00
sbitmap.c calls.c: Fix comment formatting. 2003-03-08 01:38:27 +00:00
sbitmap.h sbitmap.c (sbitmap_resize): New function. 2003-02-18 19:35:08 +00:00
scan-decls.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
scan-types.sh
scan.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
scan.h coretypes.h (cpp_reader): Forward declare struct. 2003-01-28 23:26:28 +00:00
sched-deps.c sched-deps.c (reg_pending_barrier_mode): New enumeration. 2003-04-09 18:51:54 +00:00
sched-ebb.c sched-ebb.c (add_deps_for_risky_insns): Add the dependence when there is no similar load. 2003-02-25 21:43:16 +00:00
sched-int.h sched-int.h (INSN_TRAP_CLASS, [...]): Move them from sched-rgn.c. 2003-02-25 20:40:57 +00:00
sched-rgn.c sched-int.h (INSN_TRAP_CLASS, [...]): Move them from sched-rgn.c. 2003-02-25 20:40:57 +00:00
sched-vis.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
sdbout.c dbxout.c (scope_labelno): Add GTY. 2003-04-05 07:01:51 +00:00
sdbout.h
sibcall.c regmove.c: Fix comment typos. 2002-12-24 08:30:34 +00:00
simplify-rtx.c * simplify-rtx.c: Fix formatting. 2003-04-05 20:06:37 +00:00
sort-protos
sreal.c Makefile.in (sreal.o): Added. 2003-02-10 12:34:24 +00:00
sreal.h Makefile.in (sreal.o): Added. 2003-02-10 12:34:24 +00:00
ssa-ccp.c cfgbuild.c (make_edges): Use tablejump_p. 2003-03-30 12:46:57 -08:00
ssa-dce.c ssa-dce.c (EXECUTE_IF_UNNECESSARY): Verify INSN is an INSN_P before checking to see if it is dead. 2002-12-26 11:15:56 -07:00
ssa.c regmove.c: Fix comment typos. 2002-12-24 08:30:34 +00:00
ssa.h Mon Jun 10 20:42:34 CEST 2002 Jan Hubicka <jh@suse.cz> 2002-06-20 17:51:06 +00:00
stab.def builtins.def: Fix comment formatting. 2002-09-29 13:16:44 +00:00
stack.h
stmt.c re PR c++/7086 (compile time regression) 2003-03-24 08:31:36 +00:00
stor-layout.c stor-layout.c (layout_type, [...]): Add missing code to handle "superflat arrays" in Ada. 2003-04-14 17:36:35 -04:00
stringpool.c cpppch.c (reset_ht): Remove. 2003-04-03 21:00:56 +00:00
sys-protos.h
sys-types.h
system.h gengtype-lex.l (IWORD): Add CHAR_BITFIELD. 2003-04-03 15:42:16 +00:00
target-def.h rtl.def (SYMBOL_REF): Add two 0 fields. 2003-04-11 14:15:36 -07:00
target.h tm.texi: Document TARGET_DWARF_REGISTER_SPAN. 2003-03-05 22:37:52 +00:00
timevar.c timevar.c (getrusage): Don't ever declare if not HAVE_GETRUSAGE. 2003-01-31 07:33:56 +00:00
timevar.def objc-act.c: Include cgraph.h 2003-02-26 11:09:33 +00:00
timevar.h timevar.h (POP_TIMEVAR_AND_RETURN): New macro. 2003-02-13 04:57:20 +00:00
tlink.c * tlink.c (scan_linker_output): Drop leading '.' from symbol names. 2003-02-26 15:51:26 +10:30
toplev.c re PR c++/9393 (Anonymous namespaces and compiling the same file twice) 2003-04-12 02:16:46 +00:00
toplev.h toplev.c (aux_base_name): Moved from toplev.h. 2003-03-02 20:00:36 +00:00
tracer.c c-cppbuiltin.c (builtin_define_with_value_n): Fix whitespace. 2003-03-15 13:43:33 +00:00
tree-dump.c Change base class access representation. 2003-02-20 17:51:46 +00:00
tree-dump.h target.h: Fix formatting. 2002-05-31 22:15:42 +00:00
tree-inline.c tree-inline.c (inlinable_function_p): Disable inlining for synchronized methods. 2003-04-10 15:00:03 +00:00
tree-inline.h genattrtab.h, [...]: Replace "GNU CC" with "GCC". 2003-03-13 03:51:01 +00:00
tree.c tree.c (next_decl_uid): Mark with GTY. 2003-04-15 20:48:04 +00:00
tree.def tree.c (tree_size): For all 'c' and 'x' nodes... 2003-04-07 06:03:17 +00:00
tree.h tree.c (int_fits_type_p): Extract generic checks from the case of constant type bounds. 2003-04-14 17:59:54 -04:00
tsystem.h fixproto: Define NULL and size_t in generated stdlib.h and unistd.h. 2003-03-22 00:15:53 +00:00
typeclass.h
unroll.c re PR rtl-optimization/10171 (wrong code for inlined function) 2003-03-25 15:24:42 -05:00
unwind-dw2-fde-darwin.c unwind-dw2-fde-darwin.c (DESTRUCTOR_MAY_BE_CALLED_LIVE): New. 2003-04-01 21:02:25 +00:00
unwind-dw2-fde-glibc.c c-pch.c, [...]: Replace "GNU CC" with "GCC". 2003-03-13 03:48:31 +00:00
unwind-dw2-fde.c unwind-dw2-fde.c (frame_downheap): Split out from... 2002-12-18 11:27:56 -05:00
unwind-dw2-fde.h ChangeLog (configure.in): Don't include ansidecl.h in tconfig.h. 2003-01-24 01:46:50 +00:00
unwind-dw2.c libgcc-std.ver (_Unwind_GetCFA): New. 2003-04-02 18:06:55 -08:00
unwind-libunwind.c libgcc-std.ver (_Unwind_GetCFA): New. 2003-04-02 18:06:55 -08:00
unwind-pe.h unwind.h (_Unwind_Ptr): Make 64 bits on IA64 HP-UX. 2002-08-15 18:01:30 +00:00
unwind-sjlj.c libgcc-std.ver (_Unwind_GetCFA): New. 2003-04-02 18:06:55 -08:00
unwind.h unwind.inc (_Unwind_Backtrace): New function. 2003-04-15 16:24:18 +00:00
unwind.inc unwind.inc (_Unwind_Backtrace): New function. 2003-04-15 16:24:18 +00:00
varasm.c varasm.c (output_constant_def): Do not consult CONSTANT_AFTER_FUNCTION_P. 2003-04-15 20:57:12 +00:00
varray.c varray.c (element_size): Remove. 2003-02-13 00:41:28 +00:00
varray.h varray.c (element_size): Remove. 2003-02-13 00:41:28 +00:00
version.c Daily bump. 2003-04-16 00:17:06 +00:00
version.h system.h (GCCBUGURL): Delete. 2002-10-08 17:27:39 +00:00
vmsdbg.h target.h: Fix formatting. 2002-05-31 22:15:42 +00:00
vmsdbgout.c dbxout.c (scope_labelno): Add GTY. 2003-04-05 07:01:51 +00:00
xcoffout.c Merge basic-improvements-branch to trunk 2002-12-16 18:23:00 +00:00
xcoffout.h dbxout.c (FORCE_TEXT): Switch to current_function_decl, not text_section. 2002-09-26 23:08:38 -04:00

README.Portability

Copyright (C) 2000 Free Software Foundation, Inc.

This file is intended to contain a few notes about writing C code
within GCC so that it compiles without error on the full range of
compilers GCC needs to be able to compile on.

The problem is that many ISO-standard constructs are not accepted by
either old or buggy compilers, and we keep getting bitten by them.
This knowledge until know has been sparsely spread around, so I
thought I'd collect it in one useful place.  Please add and correct
any problems as you come across them.

I'm going to start from a base of the ISO C89 standard, since that is
probably what most people code to naturally.  Obviously using
constructs introduced after that is not a good idea.

The first section of this file deals strictly with portability issues,
the second with common coding pitfalls.


			Portability Issues
			==================

Unary +
-------

K+R C compilers and preprocessors have no notion of unary '+'.  Thus
the following code snippet contains 2 portability problems.

int x = +2;  /* int x = 2;  */
#if +1       /* #if 1  */
#endif


Pointers to void
----------------

K+R C compilers did not have a void pointer, and used char * as the
pointer to anything.  The macro PTR is defined as either void * or
char * depending on whether you have a standards compliant compiler or
a K+R one.  Thus

  free ((void *) h->value.expansion);

should be written

  free ((PTR) h->value.expansion);

Further, an initial investigation indicates that pointers to functions
returning void are okay.  Thus the example given by "Calling functions
through pointers to functions" below appears not to cause a problem.


String literals
---------------

Some SGI compilers choke on the parentheses in:-

const char string[] = ("A string");

This is unfortunate since this is what the GNU gettext macro N_
produces.  You need to find a different way to code it.

K+R C did not allow concatenation of string literals like

  "This is a " "single string literal".

Moreover, some compilers like MSVC++ have fairly low limits on the
maximum length of a string literal; 509 is the lowest we've come
across.  You may need to break up a long printf statement into many
smaller ones.


Empty macro arguments
---------------------

ISO C (6.8.3 in the 1990 standard) specifies the following:

If (before argument substitution) any argument consists of no
preprocessing tokens, the behavior is undefined.

This was relaxed by ISO C99, but some older compilers emit an error,
so code like

#define foo(x, y) x y
foo (bar, )

needs to be coded in some other way.


signed keyword
--------------

The signed keyword did not exist in K+R compilers; it was introduced
in ISO C89, so you cannot use it.  In both K+R and standard C,
unqualified char and bitfields may be signed or unsigned.  There is no
way to portably declare signed chars or signed bitfields.

All other arithmetic types are signed unless you use the 'unsigned'
qualifier.  For instance, it is safe to write

  short paramc;

instead of

  signed short paramc;

If you have an algorithm that depends on signed char or signed
bitfields, you must find another way to write it before it can be
integrated into GCC.


Function prototypes
-------------------

You need to provide a function prototype for every function before you
use it, and functions must be defined K+R style.  The function
prototype should use the PARAMS macro, which takes a single argument.
Therefore the parameter list must be enclosed in parentheses.  For
example,

int myfunc PARAMS ((double, int *));

int
myfunc (var1, var2)
     double var1;
     int *var2;
{
  ...
}

This implies that if the function takes no arguments, it should be
declared and defined as follows:

int myfunc PARAMS ((void));

int
myfunc ()
{
  ...
}

You also need to use PARAMS when referring to function protypes in
other circumstances, for example see "Calling functions through
pointers to functions" below.

Variable-argument functions are best described by example:-

void cpp_ice PARAMS ((cpp_reader *, const char *msgid, ...));

void
cpp_ice VPARAMS ((cpp_reader *pfile, const char *msgid, ...))
{
  VA_OPEN (ap, msgid);
  VA_FIXEDARG (ap, cpp_reader *, pfile);
  VA_FIXEDARG (ap, const char *, msgid);

  ...
  VA_CLOSE (ap);
}

See ansidecl.h for the definitions of the above macros and more.

One aspect of using K+R style function declarations, is you cannot
have arguments whose types are char, short, or float, since without
prototypes (ie, K+R rules), these types are promoted to int, int, and
double respectively.

Calling functions through pointers to functions
-----------------------------------------------

K+R C compilers require parentheses around the dereferenced function
pointer expression in the call, whereas ISO C relaxes the syntax.  For
example

typedef void (* cl_directive_handler) PARAMS ((cpp_reader *, const char *));
      *p->handler (pfile, p->arg);

needs to become

      (*p->handler) (pfile, p->arg);


Macros
------

The rules under K+R C and ISO C for achieving stringification and
token pasting are quite different.  Therefore some macros have been
defined which will get it right depending upon the compiler.

  CONCAT2(a,b) CONCAT3(a,b,c) and CONCAT4(a,b,c,d)

will paste the tokens passed as arguments.  You must not leave any
space around the commas.  Also,

  STRINGX(x)

will stringify an argument; to get the same result on K+R and ISO
compilers x should not have spaces around it.


Passing structures by value
---------------------------

Avoid passing structures by value, either to or from functions.  It
seems some K+R compilers handle this differently or not at all.


Enums
-----

In K+R C, you have to cast enum types to use them as integers, and
some compilers in particular give lots of warnings for using an enum
as an array index.


Bitfields
---------

See also "signed keyword" above.  In K+R C only unsigned int bitfields
were defined (i.e. unsigned char, unsigned short, unsigned long.
Using plain int/short/long was not allowed).


free and realloc
----------------

Some implementations crash upon attempts to free or realloc the null
pointer.  Thus if mem might be null, you need to write

  if (mem)
    free (mem);


Reserved Keywords
-----------------

K+R C has "entry" as a reserved keyword, so you should not use it for
your variable names.


Type promotions
---------------

K+R used unsigned-preserving rules for arithmetic expresssions, while
ISO uses value-preserving.  This means an unsigned char compared to an
int is done as an unsigned comparison in K+R (since unsigned char
promotes to unsigned) while it is signed in ISO (since all of the
values in unsigned char fit in an int, it promotes to int).

Trigraphs
---------

You weren't going to use them anyway, but trigraphs were not defined
in K+R C, and some otherwise ISO C compliant compilers do not accept
them.


Suffixes on Integer Constants
-----------------------------

K+R C did not accept a 'u' suffix on integer constants.  If you want
to declare a constant to be be unsigned, you must use an explicit
cast.

You should never use a 'l' suffix on integer constants ('L' is fine),
since it can easily be confused with the number '1'.


			Common Coding Pitfalls
			======================

errno
-----

errno might be declared as a macro.


Implicit int
------------

In C, the 'int' keyword can often be omitted from type declarations.
For instance, you can write

  unsigned variable;

as shorthand for

  unsigned int variable;

There are several places where this can cause trouble.  First, suppose
'variable' is a long; then you might think

  (unsigned) variable

would convert it to unsigned long.  It does not.  It converts to
unsigned int.  This mostly causes problems on 64-bit platforms, where
long and int are not the same size.

Second, if you write a function definition with no return type at
all:

  operate (a, b)
       int a, b;
  {
    ...
  }

that function is expected to return int, *not* void.  GCC will warn
about this.  K+R C has no problem with 'void' as a return type, so you
need not worry about that.

Implicit function declarations always have return type int.  So if you
correct the above definition to

  void
  operate (a, b)
       int a, b;
  ...

but operate() is called above its definition, you will get an error
about a "type mismatch with previous implicit declaration".  The cure
is to prototype all functions at the top of the file, or in an
appropriate header.

Char vs unsigned char vs int
----------------------------

In C, unqualified 'char' may be either signed or unsigned; it is the
implementation's choice.  When you are processing 7-bit ASCII, it does
not matter.  But when your program must handle arbitrary binary data,
or fully 8-bit character sets, you have a problem.  The most obvious
issue is if you have a look-up table indexed by characters.

For instance, the character '\341' in ISO Latin 1 is SMALL LETTER A
WITH ACUTE ACCENT.  In the proper locale, isalpha('\341') will be
true.  But if you read '\341' from a file and store it in a plain
char, isalpha(c) may look up character 225, or it may look up
character -31.  And the ctype table has no entry at offset -31, so
your program will crash.  (If you're lucky.)

It is wise to use unsigned char everywhere you possibly can.  This
avoids all these problems.  Unfortunately, the routines in <string.h>
take plain char arguments, so you have to remember to cast them back
and forth - or avoid the use of strxxx() functions, which is probably
a good idea anyway.

Another common mistake is to use either char or unsigned char to
receive the result of getc() or related stdio functions.  They may
return EOF, which is outside the range of values representable by
char.  If you use char, some legal character value may be confused
with EOF, such as '\377' (SMALL LETTER Y WITH UMLAUT, in Latin-1).
The correct choice is int.

A more subtle version of the same mistake might look like this:

  unsigned char pushback[NPUSHBACK];
  int pbidx;
  #define unget(c) (assert(pbidx < NPUSHBACK), pushback[pbidx++] = (c))
  #define get(c) (pbidx ? pushback[--pbidx] : getchar())
  ...
  unget(EOF);

which will mysteriously turn a pushed-back EOF into a SMALL LETTER Y
WITH UMLAUT.


Other common pitfalls
---------------------

o Expecting 'plain' char to be either sign or unsigned extending

o Shifting an item by a negative amount or by greater than or equal to
  the number of bits in a type (expecting shifts by 32 to be sensible
  has caused quite a number of bugs at least in the early days).

o Expecting ints shifted right to be sign extended.

o Modifying the same value twice within one sequence point.

o Host vs. target floating point representation, including emitting NaNs
  and Infinities in a form that the assembler handles.

o qsort being an unstable sort function (unstable in the sense that
  multiple items that sort the same may be sorted in different orders
  by different qsort functions).

o Passing incorrect types to fprintf and friends.

o Adding a function declaration for a module declared in another file to
  a .c file instead of to a .h file.