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ifdef/ifndef/else/endif

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This commit is contained in:
pommicket 2022-01-10 18:04:53 -05:00
parent b963bc91e6
commit 34dfc3238d
3 changed files with 143 additions and 1 deletions
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3
05/constants.b
View file

@ -142,6 +142,9 @@
:str_else
string else
byte 0
:str_endif
string endif
byte 0
:str___FILE__
string __FILE__
byte 0

7
05/main.c
View file

@ -9,6 +9,13 @@ F(2
#include INC_FILE /* include macro test */
a
#ifndef INC_FILEd
xglue(LINE_,NUMBER)
#else
Hello
#endif
b
#pragma

134
05/preprocess.b
View file

@ -531,6 +531,14 @@ function translation_phase_4
if b != 0 goto pp_directive_line
b = str_equals(in, .str_include)
if b != 0 goto pp_directive_include
b = str_equals(in, .str_ifdef)
if b != 0 goto pp_directive_ifdef
b = str_equals(in, .str_ifndef)
if b != 0 goto pp_directive_ifndef
b = str_equals(in, .str_else)
if b != 0 goto pp_directive_else
b = str_equals(in, .str_endif)
if b != 0 goto pp_directive_endif
goto unrecognized_directive
:pp_directive_error
fputs(2, filename)
@ -784,7 +792,43 @@ function translation_phase_4
out += 1
goto process_pptoken
:pp_directive_ifdef
pptoken_skip(&in)
pptoken_skip_spaces(&in)
macro_name = in
pptoken_skip(&in)
pptoken_skip_spaces(&in)
if *1in != 10 goto bad_ifdef
p = look_up_object_macro(macro_name)
if p != 0 goto process_pptoken ; macro is defined; keep processing
p = look_up_function_macro(macro_name)
if p != 0 goto process_pptoken ; macro is defined; keep processing
preprocessor_skip_if(filename, &line_number, &in, &out)
goto process_pptoken
:pp_directive_ifndef
pptoken_skip(&in)
pptoken_skip_spaces(&in)
macro_name = in
pptoken_skip(&in)
pptoken_skip_spaces(&in)
if *1in != 10 goto bad_ifdef
p = look_up_object_macro(macro_name)
if p != 0 goto ifndef_skip ; macro is defined; skip
p = look_up_function_macro(macro_name)
if p != 0 goto ifndef_skip ; macro is defined; skip
goto process_pptoken ; macro not defined; keep processing
:ifndef_skip
preprocessor_skip_if(filename, &line_number, &in, &out)
goto process_pptoken
:pp_directive_else
; assume we got here from an if, so skip this
pptoken_skip(&in)
preprocessor_skip_if(filename, &line_number, &in, &out)
goto process_pptoken
:pp_directive_endif
; assume we got here from an if/elif/else, just ignore it.
pptoken_skip(&in)
goto process_pptoken
:unrecognized_directive
compile_error(filename, line_number, .str_unrecognized_directive)
:str_unrecognized_directive
@ -810,6 +854,11 @@ function translation_phase_4
:str_bad_undef
string Bad #undef.
byte 0
:bad_ifdef
compile_error(filename, line_number, .str_bad_ifdef)
:str_bad_ifdef
string Bad #ifdef.
byte 0
:bad_line_directive
compile_error(filename, line_number, .str_bad_line_directive)
:str_bad_line_directive
@ -825,6 +874,89 @@ function translation_phase_4
:phase4_end
return out
; skip body of #if / #elif / #else. This will advance *p_in to:
; - the next unmatched #elif
; OR - right after the next #else
; OR - right after the next #endif
; whichever comes first
; @NONSTANDARD: this doesn't properly handle #endif's, etc. which appear in a different file from their corresponding #if's.
; NOTE: p_out is needed for newlines
function preprocessor_skip_if
argument filename
argument p_line_number
argument p_in
argument p_out
local in
local out
local p
local b
local line_number_start
local prev_if_depth
local if_depth
in = *8p_in
out = *8p_out
if_depth = 0
line_number_start = *8p_line_number
:preprocessor_skip_if_loop
prev_if_depth = if_depth
if *1in == 0 goto no_matching_endif
if *1in == 10 goto skip_if_newline
if *1in == '# goto skip_if_hash
pptoken_skip(&in)
goto preprocessor_skip_if_loop
:skip_if_newline
*8p_line_number += 1
pptoken_copy_and_advance(&in, &out)
goto preprocessor_skip_if_loop
:skip_if_hash
p = in + 1
if *1p != '# goto skip_if_directive
; it's ##, not #
pptoken_skip(&in)
goto preprocessor_skip_if_loop
:skip_if_directive
pptoken_skip(&in) ; skip #
b = str_equals(in, .str_else)
if b != 0 goto skip_if_else
b = str_equals(in, .str_endif)
if b != 0 goto skip_if_endif
b = str_equals(in, .str_elif)
if b != 0 goto skip_if_elif
b = str_equals(in, .str_if)
if b != 0 goto skip_if_inc_depth
b = str_equals(in, .str_ifdef)
if b != 0 goto skip_if_inc_depth
b = str_equals(in, .str_ifndef)
if b != 0 goto skip_if_inc_depth
goto preprocessor_skip_if_loop ; some unimportant directive
:skip_if_elif
if if_depth > 0 goto preprocessor_skip_if_loop
in -= 2 ; return to #
goto preprocessor_skip_if_loop_end
:skip_if_inc_depth
if_depth += 1
goto preprocessor_skip_if_loop
:skip_if_endif
if_depth -= 1
; (fallthrough)
:skip_if_else
pptoken_skip(&in) ; skip endif/else
if prev_if_depth > 0 goto preprocessor_skip_if_loop
goto preprocessor_skip_if_loop_end
:preprocessor_skip_if_loop_end
*8p_in = in
*8p_out = out
return
:no_matching_endif
compile_error(filename, line_number_start, .str_no_matching_endif)
:str_no_matching_endif
string #if/#elif/#else without matching #endif.
byte 0
; returns a pointer to the replacement pptokens, or 0 if this macro is not defined
function look_up_macro
argument macros