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- Added @format attribute for compile time printf validation #2057.

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- Bug when printing a boolean value as an integer using printf.
This commit is contained in:
Christoffer Lerno
2025-03-24 13:32:44 +01:00
parent 50d7919fec
commit d760378b02
10 changed files with 186 additions and 8 deletions
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1
src/compiler/compiler_internal.h
View File

@@ -254,6 +254,7 @@ typedef struct
bool is_pure : 1;
bool noreturn : 1;
bool always_const : 1;
uint8_t format : 8;
} CalleeAttributes;
typedef struct

1
src/compiler/enums.h
View File

@@ -275,6 +275,7 @@ typedef enum
ATTRIBUTE_EXPORT,
ATTRIBUTE_EXTERN,
ATTRIBUTE_FINALIZER,
ATTRIBUTE_FORMAT,
ATTRIBUTE_IF,
ATTRIBUTE_INLINE,
ATTRIBUTE_INIT,

63
src/compiler/sema_decls.c
View File

@@ -1097,6 +1097,7 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
// Check return type
ASSERT(sig->rtype || sig->is_macro);
Type *rtype = NULL;
int format_index = (int)sig->attrs.format - 1;
if (sig->rtype)
{
TypeInfo *rtype_info = type_infoptr(sig->rtype);
@@ -1180,6 +1181,22 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
type_to_error_string(method_parent->type), decl->name, type_to_error_string(method_parent->type));
}
if (format_index >= 0)
{
if (format_index >= param_count)
{
RETURN_SEMA_ERROR(decl, "The format '@format()' index was out of range.");
}
if (sig->variadic != VARIADIC_ANY)
{
RETURN_SEMA_ERROR(decl, "'@format()' is only valid for a function or macro with 'args...' style vaargs.");
}
if (sig->vararg_index == format_index)
{
RETURN_SEMA_ERROR(decl, "The format string cannot be a vaarg parameter.");
}
}
// Check parameters
for (unsigned i = 0; i < param_count; i++)
{
@@ -1231,6 +1248,15 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
: RESOLVE_TYPE_DEFAULT)) return decl_poison(param);
param->type = type_info->type;
}
if (i == format_index)
{
if (!type_info || type_info->type->canonical != type_string)
{
SourceSpan span = type_info ? type_info->span : param->span;
sema_error_at(context, span, "The '@format()' format string must be be of type 'String'.");
return decl_poison(param);
}
}
if (type_info && param->var.no_alias && !type_is_pointer(param->type) && type_flatten(param->type)->type_kind != TYPE_SLICE)
{
SEMA_ERROR(param, "The parameter was set to @noalias, but it was neither a slice nor a pointer. You need to either remove '@noalias' or use pointer/slice type.");
@@ -1239,6 +1265,11 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
switch (var_kind)
{
case VARDECL_PARAM_EXPR:
if (i == format_index)
{
SEMA_ERROR(param, "'@format()' cannot be used with lazy arguments, please remove '@format' or make this a regular parameter.");
return decl_poison(param);
}
if (!is_macro)
{
SEMA_ERROR(param, "Only regular parameters are allowed for functions.");
@@ -2486,6 +2517,7 @@ static bool sema_analyse_attribute(SemaContext *context, ResolvedAttrData *attr_
[ATTRIBUTE_EXPORT] = ATTR_FUNC | ATTR_GLOBAL | ATTR_CONST | USER_DEFINED_TYPES | ATTR_ALIAS,
[ATTRIBUTE_EXTERN] = ATTR_FUNC | ATTR_GLOBAL | ATTR_CONST | USER_DEFINED_TYPES,
[ATTRIBUTE_FINALIZER] = ATTR_FUNC,
[ATTRIBUTE_FORMAT] = ATTR_FUNC | ATTR_MACRO | ATTR_FNTYPE,
[ATTRIBUTE_IF] = (AttributeDomain)~(ATTR_CALL | ATTR_LOCAL | ATTR_PARAM),
[ATTRIBUTE_INIT] = ATTR_FUNC,
[ATTRIBUTE_INLINE] = ATTR_FUNC | ATTR_CALL,
@@ -2740,6 +2772,37 @@ static bool sema_analyse_attribute(SemaContext *context, ResolvedAttrData *attr_
decl->func_decl.attr_finalizer = true;
// Ugly
goto PARSE;
case ATTRIBUTE_FORMAT:
if (args != 1) RETURN_SEMA_ERROR(attr, "'@format' expects the index of the format string as the argument, e.g. '@format(1)'.");
if (!sema_analyse_expr(context, expr)) return false;
if (!type_is_integer(expr->type) || !sema_cast_const(expr))
{
RETURN_SEMA_ERROR(expr, "Expected an integer compile time constant value.");
}
else
{
Int i = expr->const_expr.ixx;
if (int_is_neg(i) || int_icomp(i, 127, BINARYOP_GT))
{
RETURN_SEMA_ERROR(expr, "The index must be between 0 and 127.");
}
uint16_t val = (uint16_t)i.i.low;
switch (decl->decl_kind)
{
case DECL_FUNC:
case DECL_MACRO:
if (decl->func_decl.signature.attrs.format) break;
decl->func_decl.signature.attrs.format = val + 1;
return true;
case DECL_FNTYPE:
if (decl->fntype_decl.attrs.format) break;
decl->fntype_decl.attrs.format = val + 1;
return true;
default:
UNREACHABLE;
}
RETURN_SEMA_ERROR(attr, "'@format' may not appear twice.");
}
case ATTRIBUTE_LINK:
if (args < 1) RETURN_SEMA_ERROR(attr, "'@link' requires at least one argument.");
Expr *cond = args > 1 ? attr->exprs[0] : NULL;

93
src/compiler/sema_expr.c
View File

@@ -1518,7 +1518,7 @@ INLINE bool sema_call_evaluate_arguments(SemaContext *context, CalledDecl *calle
unsigned vaarg_index = sig->vararg_index;
Variadic variadic = sig->variadic;
Decl **decl_params = callee->params;
int format_index = (int)sig->attrs.format - 1;
// If this is a type call, then we have an implicit first argument.
if (callee->struct_var)
{
@@ -1811,6 +1811,97 @@ SPLAT_NORMAL:;
RETURN_SEMA_FUNC_ERROR(callee->definition, call, "The parameter '%s' must be set, did you forget it?", param->name);
}
call->call_expr.arguments = actual_args;
if (format_index >= 0) goto CHECK_FORMAT;
return true;
CHECK_FORMAT:;
// Check
Expr *expr = actual_args[format_index];
if (!sema_cast_const(expr) || call->call_expr.va_is_splat) return true;
assert(expr_is_const_string(expr));
const char *data = expr->const_expr.bytes.ptr;
size_t len = expr->const_expr.bytes.len;
size_t idx = 0;
Expr **vaargs = call->call_expr.varargs;
unsigned vacount = vec_size(vaargs);
for (size_t i = 0; i < len; i++)
{
if (data[i] != '%') continue;
i++;
char c = data[i];
if (c == '%') continue;
if (idx == vacount)
{
RETURN_SEMA_FUNC_ERROR(callee->definition, call, "Too few arguments provided for the formatting string.");
}
if (c == '.' && data[++i] == '*')
{
idx++;
}
expr = vaargs[idx];
assert(expr->expr_kind == EXPR_MAKE_ANY);
Type *type = expr->make_any_expr.typeid->const_expr.typeid;
type = type_flatten(type);
while (true)
{
switch (c)
{
case 's':
goto NEXT;
case 'c':
if (!type_is_integer(type))
{
RETURN_SEMA_ERROR(vaargs[idx], "Expected an integer here.");
}
goto NEXT;
case 'd':
case 'X':
case 'x':
case 'B':
case 'b':
case 'o':
case 'a':
case 'A':
case 'F':
case 'f':
case 'e':
case 'E':
case 'g':
case 'G':
if (!type_is_number_or_bool(type))
{
RETURN_SEMA_ERROR(vaargs[idx], "Expected a number here, but was %s", type_quoted_error_string(type));
}
goto NEXT;
case 'p':
if (!type_is_pointer(type) && !type_is_integer(type))
{
RETURN_SEMA_ERROR(vaargs[idx], "Expected a pointer here.");
}
goto NEXT;
case 'H':
case 'h':
if (!type_flat_is_char_array(type))
{
RETURN_SEMA_ERROR(vaargs[idx], "Expected a char array here.");
}
goto NEXT;
case '\0':
goto DONE;
case '+':
case '-':
default:
break;
}
c = data[++i];
}
NEXT:
idx++;
}
DONE:
if (idx < vacount)
{
RETURN_SEMA_FUNC_ERROR(callee->definition, call, "Too many arguments were provided for the formatting string.");
}
return true;
NO_MATCH_REF:
*no_match_ref = true;

1
src/compiler/symtab.c
View File

@@ -327,6 +327,7 @@ void symtab_init(uint32_t capacity)
attribute_list[ATTRIBUTE_EXPORT] = KW_DEF("@export");
attribute_list[ATTRIBUTE_EXTERN] = KW_DEF("@extern");
attribute_list[ATTRIBUTE_FINALIZER] = KW_DEF("@finalizer");
attribute_list[ATTRIBUTE_FORMAT] = KW_DEF("@format");
attribute_list[ATTRIBUTE_IF] = KW_DEF("@if");
attribute_list[ATTRIBUTE_INIT] = KW_DEF("@init");
attribute_list[ATTRIBUTE_INLINE] = KW_DEF("@inline");