shishantbiswas/c3c
1
1
Fork 0
mirror of https://github.com/c3lang/c3c.git synced 2026-02-27 12:01:16 +00:00
Code Issues Packages Projects Releases Wiki Activity

Added $$syscall builtin.

Browse Source
This commit is contained in:
Christoffer Lerno
2022-08-05 12:01:50 +02:00
parent 00b880e35e
commit 9866c7f9e9
6 changed files with 138 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

103
src/compiler/llvm_codegen_expr.c
View File

@@ -4373,6 +4373,7 @@ unsigned llvm_get_intrinsic(BuiltinFunction func)
return intrinsic_id.memset;
case BUILTIN_VOLATILE_STORE:
case BUILTIN_VOLATILE_LOAD:
case BUILTIN_SYSCALL:
UNREACHABLE
}
UNREACHABLE
@@ -4393,6 +4394,103 @@ LLVMAtomicOrdering llvm_atomic_ordering(Atomicity atomicity)
UNREACHABLE
}
static inline void llvm_syscall_write_regs_to_scratch(const char** registers, unsigned args)
{
for (unsigned i = 0; i < args; i++)
{
scratch_buffer_append(",{");
scratch_buffer_append(registers[i]);
scratch_buffer_append("}");
}
}
static inline LLVMValueRef llvm_syscall_asm(GenContext *c, LLVMTypeRef func_type, char *call)
{
return LLVMGetInlineAsm(func_type, call, strlen(call),
scratch_buffer_to_string(), scratch_buffer.len,
true, true, LLVMInlineAsmDialectATT
#if LLVM_VERSION_MAJOR >= 13
, false
#endif
);
}
static inline void llvm_emit_syscall(GenContext *c, BEValue *be_value, Expr *expr)
{
unsigned arguments = vec_size(expr->call_expr.arguments);
assert(arguments < 10 && "Only has room for 10");
LLVMValueRef arg_results[10];
LLVMTypeRef arg_types[10];
Expr **args = expr->call_expr.arguments;
LLVMTypeRef type = llvm_get_type(c, type_uptr);
for (unsigned i = 0; i < arguments; i++)
{
llvm_emit_expr(c, be_value, args[i]);
llvm_value_rvalue(c, be_value);
arg_results[i] = be_value->value;
arg_types[i] = type;
}
LLVMTypeRef func_type = LLVMFunctionType(type, arg_types, arguments, false);
scratch_buffer_clear();
LLVMValueRef inline_asm;
switch (platform_target.arch)
{
case ARCH_TYPE_AARCH64:
case ARCH_TYPE_AARCH64_BE:
scratch_buffer_append("={x0}");
assert(arguments < 8);
if (os_is_apple(platform_target.os))
{
static char const *regs[] = { "x16", "x0", "x1", "x2", "x3", "x4", "x5" };
llvm_syscall_write_regs_to_scratch(regs, arguments);
}
else
{
static char const *regs[] = { "x8", "x0", "x1", "x2", "x3", "x4", "x5" };
llvm_syscall_write_regs_to_scratch(regs, arguments);
}
inline_asm = llvm_syscall_asm(c, func_type, "svc #0x80");
break;
case ARCH_TYPE_X86:
scratch_buffer_append("={eax}");
assert(arguments < 8);
for (unsigned i = 0; i < arguments && i < 6; i++)
{
scratch_buffer_append(",{");
static char const *regs[] = { "eax", "ebx", "ecx", "edx", "esi", "edi" };
scratch_buffer_append(regs[i]);
scratch_buffer_append("}");
}
if (arguments == 7)
{
char *asm_str = "push %[arg6]\npush %%ebp\nmov 4(%%esp), %%ebp\nint $0x80\npop %%ebp\nadd $4, %%esp";
scratch_buffer_append(",rm");
inline_asm = LLVMGetInlineAsm(func_type, asm_str, strlen(asm_str), scratch_buffer_to_string(), scratch_buffer.len, true, false, LLVMInlineAsmDialectATT, false);
}
inline_asm = LLVMGetInlineAsm(func_type, "int $0x80", 9, scratch_buffer_to_string(), scratch_buffer.len, true, false, LLVMInlineAsmDialectATT, false);
break;
case ARCH_TYPE_X86_64:
scratch_buffer_append("={rax}");
assert(arguments < 8);
for (unsigned i = 0; i < arguments; i++)
{
scratch_buffer_append(",{");
static char const *regs[] = { "rax", "rdi", "rsi", "rdx", "r10", "r8", "r9" };
scratch_buffer_append(regs[i]);
scratch_buffer_append("}");
}
// Check clobbers on different OSes
scratch_buffer_append(",~{rcx},~{r11},~{memory}");
inline_asm = LLVMGetInlineAsm(func_type, "syscall", 7, scratch_buffer_to_string(), scratch_buffer.len, true, false, LLVMInlineAsmDialectATT, false);
break;
case ARCH_UNSUPPORTED:
default:
UNREACHABLE
}
LLVMValueRef result = LLVMBuildCall2(c->builder, func_type, inline_asm, arg_results, arguments, "syscall");
llvm_value_set(be_value, result, type_uptr);
}
void llvm_emit_builtin_call(GenContext *c, BEValue *result_value, Expr *expr)
{
BuiltinFunction func = exprptr(expr->call_expr.function)->builtin_expr.builtin;
@@ -4437,6 +4535,11 @@ void llvm_emit_builtin_call(GenContext *c, BEValue *result_value, Expr *expr)
LLVMSetVolatile(result_value->value, true);
return;
}
if (func == BUILTIN_SYSCALL)
{
llvm_emit_syscall(c, result_value, expr);
return;
}
llvm_emit_intrinsic_expr(c, llvm_get_intrinsic(func), result_value, expr);
}