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Implement SIZE_FMT and vec_append_fmt

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SIZE_FMT gets the size of a cstr with the given sprintf formatted
string and arguments using `snprintf`.

vec_append_fmt formats a cstr with the given sprintf arguments then
appends it to the given vector.

This simplifies a little bit of the wordy implementation of the
assembler.
This commit is contained in:
Aryadev Chavali
2024-12-24 23:08:52 +00:00
parent 70cfeac995
commit 3c39df6c95
2 changed files with 52 additions and 49 deletions
Download Patch File Download Diff File Expand all files Collapse all files

91
assembler.c
View File

@@ -72,53 +72,49 @@ void asm_translate_nodes(vec_t *asm_buffer, struct PResult nodes,
for (size_t i = 0; i < nodes.size; ++i)
{
node_t node = nodes.nodes[i];
if (node.type == LIN || node.type == LOUT)
{
// Translate the node-relative addresses to assembly-label-relative
// addresses
i64 cur_asm_label = 0, next_asm_label = 0;
ast_ref_to_asm_label(i, labels, nodes.labels * 2, &cur_asm_label,
&next_asm_label);
if (cur_asm_label == -1 || next_asm_label == -1)
{
print_error(
src_name, node.row, node.col,
"[ASSEMBLY ERROR]: Could not find label for current jump!\n");
exit(1);
}
// Format labels
char current_label[128], next_label[128];
sprintf(current_label, ".L%lu", cur_asm_label);
sprintf(next_label, ".L%lu", next_asm_label);
// Setup format string for assembly jump code
char *format_string = NULL;
if (node.type == LIN)
{
format_string = "%s:\n"
" cmp byte [r9], 0\n"
" je %s\n";
}
else
{
format_string = "%s:\n"
" cmp byte [r9], 0\n"
" jne %s\n";
}
char formatted_string[snprintf(NULL, 0, format_string, current_label,
next_label) +
1];
snprintf(formatted_string, sizeof(formatted_string), format_string,
current_label, next_label);
vec_append(asm_buffer, formatted_string, sizeof(formatted_string) - 1);
}
else
// Something we can compile with only the information at hand
if (!(node.type == LIN || node.type == LOUT))
{
// I love tables so goddamn much
vec_append(asm_buffer, table[node.type].str, table[node.type].len);
continue;
}
// NOTE: Must be a label
// Translate the node-relative addresses to assembly-label-relative
// addresses
i64 cur_asm_label = 0, next_asm_label = 0;
ast_ref_to_asm_label(i, labels, nodes.labels * 2, &cur_asm_label,
&next_asm_label);
if (cur_asm_label == -1 || next_asm_label == -1)
{
print_error(src_name, node.row, node.col,
"[ASSEMBLY ERROR]: Could not find label for current jump!\n");
exit(1);
}
// Format labels
char current_label[128], next_label[128];
sprintf(current_label, ".L%lu", cur_asm_label);
sprintf(next_label, ".L%lu", next_asm_label);
// Setup format string for assembly jump code
char *format_string = NULL;
if (node.type == LIN)
{
format_string = "%s:\n"
" cmp byte [r9], 0\n"
" je %s\n";
}
else
{
format_string = "%s:\n"
" cmp byte [r9], 0\n"
" jne %s\n";
}
vec_append_fmt(asm_buffer, format_string, current_label, next_label);
}
asm_write_exit(asm_buffer);
}
@@ -151,10 +147,7 @@ void asm_write_init(vec_t *asm_buffer)
"global _start\n"
"_start:\n"
" mov r9, memory\n";
char initial_assembly[snprintf(NULL, 0, format_string, MEMORY_DEFAULT) + 1];
snprintf(initial_assembly, sizeof(initial_assembly), format_string,
MEMORY_DEFAULT);
vec_append(asm_buffer, initial_assembly, sizeof(initial_assembly) - 1);
vec_append_fmt(asm_buffer, format_string, MEMORY_DEFAULT);
}
// Write the exit code for the assembly file
@@ -183,7 +176,7 @@ int asm_assemble(const char *asm_name, const char *objname)
#else
char *format_str = "yasm -f elf64 -o %s %s";
#endif
char command[snprintf(NULL, 0, format_str, objname, asm_name) + 1];
char command[SIZE_FMT(format_str, objname, asm_name) + 1];
sprintf(command, format_str, objname, asm_name);
return system(command);
}
@@ -191,7 +184,7 @@ int asm_assemble(const char *asm_name, const char *objname)
int asm_link(const char *objname, const char *outname)
{
char *format_str = "ld -o %s %s";
char command[snprintf(NULL, 0, format_str, outname, objname) + 1];
char command[SIZE_FMT(format_str, outname, objname) + 1];
sprintf(command, format_str, outname, objname);
return system(command);
}

10
lib.h
View File

@@ -26,6 +26,8 @@ char *fread_all(FILE *fp);
void print_error(const char *handle, size_t row, size_t column,
const char *reason);
#define SIZE_FMT(FMT, ...) (snprintf(NULL, 0, (FMT), __VA_ARGS__))
typedef struct Buffer
{
const char *name;
@@ -46,4 +48,12 @@ void vec_ensure(vec_t *vec, u64 abs_size);
void vec_ensure_free(vec_t *vec, u64 rel_size);
void vec_free(vec_t *vec);
#define vec_append_fmt(VEC, FMT, ...) \
do \
{ \
char f[SIZE_FMT(FMT, __VA_ARGS__) + 1]; \
snprintf(f, sizeof(f), (FMT), __VA_ARGS__); \
vec_append((VEC), f, sizeof(f) - 1); \
} while (0)
#endif