4coder/4coder_auto_indent.cpp

600 lines
23 KiB
C++

#ifndef FCODER_AUTO_INDENT_INC
#define FCODER_AUTO_INDENT_INC
//
// Generic Line Indenter
//
struct Hard_Start_Result{
int32_t char_pos;
int32_t indent_pos;
int32_t all_whitespace;
int32_t all_space;
};
static Hard_Start_Result
buffer_find_hard_start(Application_Links *app, Buffer_Summary *buffer, int32_t line_start, int32_t tab_width){
Hard_Start_Result result = {0};
char data_chunk[1024];
Stream_Chunk stream = {0};
char c;
tab_width -= 1;
result.all_space = 1;
result.indent_pos = 0;
result.char_pos = line_start;
stream.add_null = 1;
if (init_stream_chunk(&stream, app, buffer, line_start, data_chunk, sizeof(data_chunk))){
int32_t still_looping = 1;
do{
for (; result.char_pos < stream.end; ++result.char_pos){
c = stream.data[result.char_pos];
if (c == '\n' || c == 0){
result.all_whitespace = 1;
goto double_break;
}
if (c >= '!' && c <= '~'){
goto double_break;
}
if (c == '\t'){
result.indent_pos += tab_width;
}
if (c != ' '){
result.all_space = 0;
}
result.indent_pos += 1;
}
still_looping = forward_stream_chunk(&stream);
}while(still_looping);
}
double_break:;
return(result);
}
struct Indent_Options{
bool32 empty_blank_lines;
bool32 use_tabs;
int32_t tab_width;
};
static Buffer_Batch_Edit
make_batch_from_indent_marks(Application_Links *app, Partition *part, Buffer_Summary *buffer,
int32_t line_start, int32_t line_end, int32_t *indent_marks,
Indent_Options opts){
Buffer_Batch_Edit result = {0};
int32_t edit_max = line_end - line_start;
int32_t edit_count = 0;
Buffer_Edit *edits = push_array(part, Buffer_Edit, edit_max);
char *str_base = (char*)part->base + part->pos;
int32_t str_size = 0;
// NOTE(allen): Shift the array so that line_i can just operate in
// it's natural value range.
indent_marks -= line_start;
for (int32_t line_i = line_start; line_i < line_end; ++line_i){
int32_t line_start_pos = buffer_get_line_start(app, buffer, line_i);
Hard_Start_Result hard_start =
buffer_find_hard_start(app, buffer, line_start_pos, opts.tab_width);
int32_t correct_indentation = indent_marks[line_i];
if (hard_start.all_whitespace && opts.empty_blank_lines){
correct_indentation = 0;
}
if (correct_indentation == -1){
correct_indentation = hard_start.indent_pos;
}
// TODO(allen): Only replace spaces if we are using space based indentation.
if (!hard_start.all_space || correct_indentation != hard_start.indent_pos){
Buffer_Edit new_edit;
new_edit.str_start = str_size;
str_size += correct_indentation;
char *str = push_array(part, char, correct_indentation);
int32_t j = 0;
if (opts.use_tabs){
int32_t i = 0;
for (; i + opts.tab_width <= correct_indentation; i += opts.tab_width){
str[j++] = '\t';
}
for (; i < correct_indentation; ++i){
str[j++] = ' ';
}
}
else{
for (; j < correct_indentation; ++j){
str[j] = ' ';
}
}
new_edit.len = j;
new_edit.start = line_start_pos;
new_edit.end = hard_start.char_pos;
edits[edit_count++] = new_edit;
}
Assert(edit_count <= edit_max);
}
result.str = str_base;
result.str_len = str_size;
result.edits = edits;
result.edit_count = edit_count;
return(result);
}
static void
set_line_indents(Application_Links *app, Partition *part, Buffer_Summary *buffer,
int32_t line_start, int32_t line_end, int32_t *indent_marks, Indent_Options opts){
Buffer_Batch_Edit batch =
make_batch_from_indent_marks(app, part, buffer, line_start, line_end, indent_marks, opts);
if (batch.edit_count > 0){
buffer_batch_edit(app, buffer, batch.str, batch.str_len,
batch.edits, batch.edit_count, BatchEdit_PreserveTokens);
}
}
static Cpp_Token*
seek_matching_token_backwards(Cpp_Token_Array tokens, Cpp_Token *token,
Cpp_Token_Type open_type, Cpp_Token_Type close_type){
int32_t nesting_level = 0;
if (token <= tokens.tokens){
token = tokens.tokens;
}
else{
for (; token > tokens.tokens; --token){
if (!(token->flags & CPP_TFLAG_PP_BODY)){
if (token->type == close_type){
++nesting_level;
}
else if (token->type == open_type){
if (nesting_level == 0){
break;
}
else{
--nesting_level;
}
}
}
}
}
return(token);
}
static Cpp_Token*
find_anchor_token(Application_Links *app, Buffer_Summary *buffer, Cpp_Token_Array tokens,
int32_t line_start, int32_t tab_width, int32_t *current_indent_out){
Cpp_Token *token = get_first_token_at_line(app, buffer, tokens, line_start);
if (token == 0 && tokens.count == 0){
// In this case just let the null token pointer be returned.
}
else{
if (token == 0){
token = tokens.tokens + (tokens.count - 1);
}
if (token != tokens.tokens){
--token;
for (; token > tokens.tokens; --token){
if (!(token->flags & CPP_TFLAG_PP_BODY)){
switch(token->type){
case CPP_TOKEN_BRACE_OPEN:
case CPP_TOKEN_BRACE_CLOSE:
goto out_of_loop;
}
}
}
out_of_loop:;
}
int32_t current_indent = 0;
int32_t found_safe_start_position = 0;
do{
int32_t line = buffer_get_line_index(app, buffer, token->start);
int32_t start = buffer_get_line_start(app, buffer, line);
Hard_Start_Result hard_start = buffer_find_hard_start(app, buffer, start, tab_width);
current_indent = hard_start.indent_pos;
Cpp_Token *start_token = get_first_token_at_line(app, buffer, tokens, line);
Cpp_Token *brace_token = token;
if (start_token->type == CPP_TOKEN_PARENTHESE_OPEN){
if (start_token == tokens.tokens){
found_safe_start_position = 1;
}
else{
token = start_token-1;
}
}
else{
int32_t close = 0;
for (token = brace_token; token > start_token; --token){
switch(token->type){
case CPP_TOKEN_PARENTHESE_CLOSE:
case CPP_TOKEN_BRACKET_CLOSE:
case CPP_TOKEN_BRACE_CLOSE:
close = token->type;
goto out_of_loop2;
}
}
out_of_loop2:;
switch (close){
case 0: token = start_token; found_safe_start_position = 1; break;
case CPP_TOKEN_PARENTHESE_CLOSE:
token = seek_matching_token_backwards(tokens, token-1,
CPP_TOKEN_PARENTHESE_OPEN,
CPP_TOKEN_PARENTHESE_CLOSE);
break;
case CPP_TOKEN_BRACKET_CLOSE:
token = seek_matching_token_backwards(tokens, token-1,
CPP_TOKEN_BRACKET_OPEN,
CPP_TOKEN_BRACKET_CLOSE);
break;
case CPP_TOKEN_BRACE_CLOSE:
token = seek_matching_token_backwards(tokens, token-1,
CPP_TOKEN_BRACE_OPEN,
CPP_TOKEN_BRACE_CLOSE);
break;
}
}
} while(found_safe_start_position == 0);
*current_indent_out = current_indent;
}
return(token);
}
//
// Indent Rules
//
struct Indent_Parse_State{
int32_t current_indent;
int32_t previous_line_indent;
int32_t paren_nesting;
int32_t paren_anchor_indent[16];
int32_t comment_shift;
int32_t previous_comment_indent;
};
static int32_t*
get_indentation_marks(Application_Links *app, Partition *part, Buffer_Summary *buffer,
Cpp_Token_Array tokens, int32_t line_start, int32_t line_end,
bool32 exact_align, int32_t tab_width){
int32_t indent_mark_count = line_end - line_start;
int32_t *indent_marks = push_array(part, int32_t, indent_mark_count);
// Shift the array so line_index works correctly.
indent_marks -= line_start;
// Decide where to start indentation parsing.
Indent_Parse_State indent = {0};
Cpp_Token *token_ptr = find_anchor_token(app, buffer, tokens, line_start,
tab_width, &indent.current_indent);
if (token_ptr == 0){
for (int32_t line_index = line_start; line_index < line_end; ++line_index){
indent_marks[line_index] = 0;
}
}
else{
int32_t line_index = buffer_get_line_index(app, buffer, token_ptr->start);
if (line_index > line_start){
line_index = line_start;
}
int32_t next_line_start_pos = buffer_get_line_start(app, buffer, line_index+1);
switch (token_ptr->type){
case CPP_TOKEN_BRACKET_OPEN: indent.current_indent += tab_width; break;
case CPP_TOKEN_BRACE_OPEN: indent.current_indent += tab_width; break;
case CPP_TOKEN_PARENTHESE_OPEN: indent.current_indent += tab_width; break;
}
indent.previous_line_indent = indent.current_indent;
for (;line_index < line_end;){
Cpp_Token prev_token = *token_ptr, token = {0};
++token_ptr;
if (token_ptr < tokens.tokens + tokens.count){
token = *token_ptr;
}
else{
token.type = CPP_TOKEN_EOF;
token.start = buffer->size;
token.flags = 0;
}
for (;token.start >= next_line_start_pos && line_index < line_end;){
next_line_start_pos = buffer_get_line_start(app, buffer, line_index+1);
int32_t this_indent = 0;
{
int32_t previous_indent = indent.previous_line_indent;
int32_t this_line_start = buffer_get_line_start(app, buffer, line_index);
int32_t next_line_start = buffer_get_line_start(app, buffer, line_index+1);
bool32 did_special_behavior = false;
if (prev_token.start <= this_line_start && prev_token.start + prev_token.size > this_line_start){
if (prev_token.type == CPP_TOKEN_COMMENT){
Hard_Start_Result hard_start = buffer_find_hard_start(app, buffer, this_line_start, tab_width);
if (exact_align){
this_indent = indent.previous_comment_indent;
}
else{
if (hard_start.all_whitespace){
this_indent = previous_indent;
}
else{
int32_t line_pos = hard_start.char_pos - this_line_start;
this_indent = line_pos + indent.comment_shift;
if (this_indent < 0){
this_indent = 0;
}
}
}
if (!hard_start.all_whitespace){
if (line_index >= line_start){
indent.previous_comment_indent = this_indent;
}
else{
indent.previous_comment_indent = hard_start.indent_pos;
}
}
did_special_behavior = true;
}
else if (prev_token.type == CPP_TOKEN_STRING_CONSTANT){
this_indent = previous_indent;
did_special_behavior = true;
}
}
if (!did_special_behavior){
this_indent = indent.current_indent;
if (token.start < next_line_start){
if (token.flags & CPP_TFLAG_PP_DIRECTIVE){
this_indent = 0;
}
else{
switch (token.type){
case CPP_TOKEN_BRACKET_CLOSE: this_indent -= tab_width; break;
case CPP_TOKEN_BRACE_CLOSE: this_indent -= tab_width; break;
case CPP_TOKEN_BRACE_OPEN: break;
default:
if (indent.current_indent > 0){
if (!(prev_token.flags & CPP_TFLAG_PP_BODY) && !(prev_token.flags & CPP_TFLAG_PP_DIRECTIVE)){
switch (prev_token.type){
case CPP_TOKEN_BRACKET_OPEN: case CPP_TOKEN_BRACE_OPEN: case CPP_TOKEN_BRACE_CLOSE: case CPP_TOKEN_SEMICOLON: case CPP_TOKEN_COLON: case CPP_TOKEN_COMMA: case CPP_TOKEN_COMMENT: break;
default: this_indent += tab_width;
}
}
}
}
}
}
if (this_indent < 0) this_indent = 0;
}
if (indent.paren_nesting > 0){
if (prev_token.type != CPP_TOKEN_PARENTHESE_OPEN){
int32_t level = indent.paren_nesting-1;
if (level >= ArrayCount(indent.paren_anchor_indent)){
level = ArrayCount(indent.paren_anchor_indent)-1;
}
this_indent = indent.paren_anchor_indent[level];
}
}
}
// Rebase the paren anchor if the first token
// after the open paren is on the next line.
if (indent.paren_nesting > 0){
if (prev_token.type == CPP_TOKEN_PARENTHESE_OPEN){
int32_t level = indent.paren_nesting-1;
if (level >= ArrayCount(indent.paren_anchor_indent)){
level = ArrayCount(indent.paren_anchor_indent)-1;
}
indent.paren_anchor_indent[level] = this_indent;
}
}
if (line_index >= line_start){
indent_marks[line_index] = this_indent;
}
++line_index;
indent.previous_line_indent = this_indent;
}
// Update indent state.
switch (token.type){
case CPP_TOKEN_BRACKET_OPEN: indent.current_indent += 4; break;
case CPP_TOKEN_BRACKET_CLOSE: indent.current_indent -= 4; break;
case CPP_TOKEN_BRACE_OPEN: indent.current_indent += 4; break;
case CPP_TOKEN_BRACE_CLOSE: indent.current_indent -= 4; break;
case CPP_TOKEN_COMMENT:
{
int32_t line = buffer_get_line_index(app, buffer, token.start);
int32_t start = buffer_get_line_start(app, buffer, line);
indent.comment_shift = (indent.current_indent - (token.start - start));
indent.previous_comment_indent = (token.start - start);
}break;
case CPP_TOKEN_PARENTHESE_OPEN:
if (!(token.flags & CPP_TFLAG_PP_BODY)){
if (indent.paren_nesting < ArrayCount(indent.paren_anchor_indent)){
int32_t line = buffer_get_line_index(app, buffer, token.start);
int32_t start = buffer_get_line_start(app, buffer, line);
int32_t char_pos = token.start - start;
Hard_Start_Result hard_start =
buffer_find_hard_start(app, buffer, start, tab_width);
int32_t line_pos = hard_start.char_pos - start;
indent.paren_anchor_indent[indent.paren_nesting] =
char_pos - line_pos + indent.previous_line_indent + 1;
}
++indent.paren_nesting;
}
break;
case CPP_TOKEN_PARENTHESE_CLOSE:
if (!(token.flags & CPP_TFLAG_PP_BODY)){
if (indent.paren_nesting > 0){
--indent.paren_nesting;
}
}
break;
}
}
}
// Unshift the indent_marks array.
indent_marks += line_start;
return(indent_marks);
}
static void
get_indent_lines_minimum(Application_Links *app, Buffer_Summary *buffer,
int32_t start_pos, int32_t end_pos,
int32_t *line_start_out, int32_t *line_end_out){
int32_t line_start = buffer_get_line_index(app, buffer, start_pos);
int32_t line_end = buffer_get_line_index(app, buffer, end_pos) + 1;
*line_start_out = line_start;
*line_end_out = line_end;
}
static void
get_indent_lines_whole_tokens(Application_Links *app, Buffer_Summary *buffer, Cpp_Token_Array tokens,
int32_t start_pos, int32_t end_pos,
int32_t *line_start_out, int32_t *line_end_out){
int32_t line_start = buffer_get_line_index(app, buffer, start_pos);
int32_t line_end = buffer_get_line_index(app, buffer, end_pos);
for (;line_start > 0;){
int32_t line_start_pos = 0;
Cpp_Token *token = get_first_token_at_line(app, buffer, tokens, line_start, &line_start_pos);
if (token && token->start < line_start_pos){
line_start = buffer_get_line_index(app, buffer, token->start);
}
else{
break;
}
}
for (;line_end+1 < buffer->line_count;){
int32_t next_line_start_pos = 0;
Cpp_Token *token = get_first_token_at_line(app, buffer, tokens, line_end+1, &next_line_start_pos);
if (token && token->start < next_line_start_pos){
line_end = buffer_get_line_index(app, buffer, token->start+token->size);
}
else{
break;
}
}
if (line_end >= buffer->line_count){
line_end = buffer->line_count;
}
else{
line_end += 1;
}
*line_start_out = line_start;
*line_end_out = line_end;
}
static bool32
buffer_auto_indent(Application_Links *app, Partition *part, Buffer_Summary *buffer,
int32_t start, int32_t end, int32_t tab_width, Auto_Indent_Flag flags){
bool32 result = 0;
if (buffer->exists && buffer->tokens_are_ready){
result = 1;
Temp_Memory temp = begin_temp_memory(part);
// Stage 1: Read the tokens to be used for indentation.
Cpp_Token_Array tokens;
tokens.count = buffer_token_count(app, buffer);
tokens.max_count = tokens.count;
tokens.tokens = push_array(part, Cpp_Token, tokens.count);
buffer_read_tokens(app, buffer, 0, tokens.count, tokens.tokens);
// Stage 2: Decide where the first and last lines are.
// The lines in the range [line_start,line_end) will be indented.
int32_t line_start = 0, line_end = 0;
if (flags & AutoIndent_FullTokens){
get_indent_lines_whole_tokens(app, buffer, tokens, start, end, &line_start, &line_end);
}
else{
get_indent_lines_minimum(app, buffer, start, end, &line_start, &line_end);
}
// Stage 3: Decide Indent Amounts
// Get an array representing how much each line in
// the range [line_start,line_end) should be indented.
int32_t *indent_marks =
get_indentation_marks(app, part, buffer, tokens, line_start, line_end,
(flags & AutoIndent_ExactAlignBlock), tab_width);
// Stage 4: Set the Line Indents
Indent_Options opts = {0};
opts.empty_blank_lines = (flags & AutoIndent_ClearLine);
opts.use_tabs = (flags & AutoIndent_UseTab);
opts.tab_width = tab_width;
set_line_indents(app, part, buffer, line_start, line_end, indent_marks, opts);
end_temp_memory(temp);
}
return(result);
}
static bool32
buffer_auto_indent(Application_Links *app, Buffer_Summary *buffer, int32_t start, int32_t end,
int32_t tab_width, Auto_Indent_Flag flags){
bool32 result = buffer_auto_indent(app, &global_part, buffer, start, end, tab_width, flags);
return(result);
}
#endif