Add exported variable (only functions for now), export main func, start execution from main func

4 files changed, 56 insertions, 32 deletions

diff --git a/include/bytecode/bytecode.h b/include/bytecode/bytecode.h
index 1e4c35d..64b54b4 100644
--- a/include/bytecode/bytecode.h
+++ b/include/bytecode/bytecode.h
@@ -25,7 +25,7 @@
     6.1 Opcode(u8) + register(i8) + offset(i16)\
     6.2 Opcode(u8) + register(i8) + intermediate(u16)\
     6.3 Opcode(u8) + register(i8) + data(u16)\
-    6.4 Opcode(u8) + num_param_reg(u8) + num_local_var_reg(u16)
+    6.4 Opcode(u8) + flags(u8) + num_local_var_reg(u16)
     7. 5 bytes: Opcode(u8) + index(u16) + num_args(u8) + register(i8)
     # Registers
     Registers have a range of 128. Local variables start from register 0 and increment while parameters start from -1
@@ -33,30 +33,42 @@
 */
 typedef enum {
     AMAL_OP_NOP,         /* No operation (do nothing). This can be used for patching code */
-    AMAL_OP_SETZ,        /* setz reg                                     - Set register value to 0 */
-    AMAL_OP_MOV,         /* mov dst, src                                 - Move src register to dst register */
-    AMAL_OP_MOVI,        /* movi dst, src                                - Move src intermediate to dst register */
-    AMAL_OP_MOVD,        /* movd dst, src                                - Move src data to dst register */
-    AMAL_OP_ADD,         /* add dst, reg1, reg2                          - Add reg1 and reg2 and put the result in dst */
-    AMAL_OP_SUB,         /* sub dst, reg1, reg2                          - Substract reg2 from reg1 and put the result in dst */
-    AMAL_OP_IMUL,        /* imul dst, reg1, reg2                         - Signed multiplication */
-    AMAL_OP_MUL,         /* mul dst, reg1, reg2                          - Unsigned multiplication */
-    AMAL_OP_IDIV,        /* idiv dst, reg1, reg2                         - Signed division */
-    AMAL_OP_DIV,         /* div dst, reg1, reg2                          - Unsigned division */
-    AMAL_OP_PUSH,        /* push reg                                     - Push register onto stack */
-    AMAL_OP_PUSHI,       /* pushi int                                    - Push intermediate onto stack */
-    AMAL_OP_PUSHD,       /* pushd data                                   - Push data onto stack */
-    AMAL_OP_CALL,        /* call fi, num_args, dst                       - Call a function using function index (fi) and num_args arguments. The result is stored in register dst. fi is u16 and num_args is u8 */
-    AMAL_OP_CALLR,       /* callr reg, num_args                          - Call a function using a register. Used for function pointers. num_args is u8 */
-    AMAL_OP_CALLE,       /* calle efi, num_args, dst                     - Call an extern function using extern function index (efi) and num_args arguments. The result is stored in register dst. efi is u16 and num_args is u8 */
-    AMAL_OP_CMP,         /* cmp dst, reg1, reg2                          - Set dst to 1 if reg1 equals reg2, otherwise set it to 0 */
-    AMAL_OP_JZ,          /* jz reg, offset                               - Jump to offset if reg is zero. offset is i16 */
-    AMAL_OP_JMP,         /* jmp offset                                   - Unconditional jump to offset. offset is i16 */
-    AMAL_OP_RET,         /* ret reg                                      - Return from the function with reg result */
-    AMAL_OP_FUNC_START,  /* func_start num_param_reg, num_local_var_reg  - Start of a function which has num_param_reg parameter registers allocated and num_local_var_reg local variable registers allocated. num_param_reg is u8 and num_local_var_reg is u16 */
-    AMAL_OP_FUNC_END     /* func_end                                     - End of a function. Implementation should do a ret here */
+    AMAL_OP_SETZ,        /* setz reg                             - Set register value to 0 */
+    AMAL_OP_MOV,         /* mov dst, src                         - Move src register to dst register */
+    AMAL_OP_MOVI,        /* movi dst, src                        - Move src intermediate to dst register */
+    AMAL_OP_MOVD,        /* movd dst, src                        - Move src data to dst register */
+    AMAL_OP_ADD,         /* add dst, reg1, reg2                  - Add reg1 and reg2 and put the result in dst */
+    AMAL_OP_SUB,         /* sub dst, reg1, reg2                  - Substract reg2 from reg1 and put the result in dst */
+    AMAL_OP_IMUL,        /* imul dst, reg1, reg2                 - Signed multiplication */
+    AMAL_OP_MUL,         /* mul dst, reg1, reg2                  - Unsigned multiplication */
+    AMAL_OP_IDIV,        /* idiv dst, reg1, reg2                 - Signed division */
+    AMAL_OP_DIV,         /* div dst, reg1, reg2                  - Unsigned division */
+    AMAL_OP_PUSH,        /* push reg                             - Push register onto stack */
+    AMAL_OP_PUSHI,       /* pushi int                            - Push intermediate onto stack */
+    AMAL_OP_PUSHD,       /* pushd data                           - Push data onto stack */
+    AMAL_OP_CALL,        /* call fi, num_args, dst               - Call a function using function index (fi) and num_args arguments. The result is stored in register dst. fi is u16 and num_args is u8 */
+    AMAL_OP_CALLR,       /* callr reg, num_args                  - Call a function using a register. Used for function pointers. num_args is u8 */
+    AMAL_OP_CALLE,       /* calle efi, num_args, dst             - Call an extern function using extern function index (efi) and num_args arguments. The result is stored in register dst. efi is u16 and num_args is u8 */
+    AMAL_OP_CMP,         /* cmp dst, reg1, reg2                  - Set dst to 1 if reg1 equals reg2, otherwise set it to 0 */
+    AMAL_OP_JZ,          /* jz reg, offset                       - Jump to offset if reg is zero. offset is i16 */
+    AMAL_OP_JMP,         /* jmp offset                           - Unconditional jump to offset. offset is i16 */
+    AMAL_OP_RET,         /* ret reg                              - Return from the function with reg result */
+    AMAL_OP_FUNC_START,  /* func_start flags, num_local_var_reg  - Start of a function which has @num_local_var_reg local variable registers allocated and has the flag @flag. @flag is u8 and @num_local_var_reg is u16 */
+    AMAL_OP_FUNC_END     /* func_end                             - End of a function. Implementation should do a ret here */
 } AmalOpcode;
 
+#define AMAL_BYTECODE_MAGIC_NUMBER (u32)0xdec05eba
+#define AMAL_BYTECODE_MAJOR_VERSION 1
+#define AMAL_BYTECODE_MINOR_VERSION 0
+#define AMAL_BYTECODE_PATCH_VERSION 0
+
+#define AMAL_BYTECODE_NUM_REGISTERS 256
+
+typedef enum {
+    FUNC_FLAG_NONE       = 0,
+    FUNC_FLAG_EXPORTED   = (1 << 1)
+} amal_func_flag;
+
 typedef u8 AmalOpcodeType;
 
 typedef struct {
@@ -71,6 +83,8 @@ typedef struct {
 
 CHECK_RESULT int bytecode_init(Bytecode *self, ArenaAllocator *allocator);
 
+CHECK_RESULT int buffer_append_header(Buffer *program_data);
+
 /* longjump to self->env on failure */
 void generate_bytecode_from_ssa(BytecodeCompilerContext *self);
 
diff --git a/include/program.h b/include/program.h
index 075bfca..e3a4ac9 100644
--- a/include/program.h
+++ b/include/program.h
@@ -31,13 +31,10 @@
 #define AMAL_PROGRAM_INSTRUCTION_INVALID_EXTERN_FUNC_INDEX -19
 #define AMAL_PROGRAM_NO_SUCH_EXTERNAL_FUNCTION -20
 #define AMAL_PROGRAM_EXTERN_FUNC_ALREADY_EXISTS -21
-
-#define AMAL_PROGRAM_MAGIC_NUMBER (u32)0xdec05eba
-#define AMAL_PROGRAM_MAJOR_VERSION 1
-#define AMAL_PROGRAM_MINOR_VERSION 0
-#define AMAL_PROGRAM_PATCH_VERSION 0
-
-#define AMAL_PROGRAM_NUM_REGISTERS 256
+#define AMAL_PROGRAM_INVALID_EXPORTED_FUNCTIONS -22
+#define AMAL_PROGRAM_INVALID_EXPORTED_FUNCTIONS_SIZE -23
+#define AMAL_PROGRAM_INSTRUCTION_INVALID_EXPORTED_FUNC_INDEX -24
+#define AMAL_PROGRAM_NO_MAIN_FUNC -25
 
 #define AMAL_PROGRAM_ARGS_SIZE_VARARGS -1
 
@@ -53,12 +50,17 @@ typedef struct {
     u8 *intermediates_start;  /* Reference inside @data */
     u8 *strings_start;        /* Reference inside @data */
     u8 *extern_funcs_start;   /* Reference inside @data */
+    u8 *exported_funcs;       /* Reference inside @data */
+    u8 *exported_funcs_end;   /* Reference inside @data */
+
     usize read_index;
+    u32 main_func_instruction_offset;
 
     u16 num_intermediates;
     u16 num_strings;
     u16 num_functions;
     u16 num_extern_functions;
+    u16 num_exported_functions;
 
     ArenaAllocator allocator; /* Owned. Used by @extern_funcs_map */
     HashMapType(BufferView, ProgramExternFunc) extern_funcs_map;
diff --git a/include/ssa/ssa.h b/include/ssa/ssa.h
index b2c8065..ed147bf 100644
--- a/include/ssa/ssa.h
+++ b/include/ssa/ssa.h
@@ -49,11 +49,17 @@ typedef struct {
     BufferView name;
 } SsaExternFunc;
 
+typedef struct {
+    FunctionSignature *func_sig;
+    BufferView name;
+} SsaExportFunc;
+
 typedef i16 JumpOffset;
 typedef i16 SsaRegister;
 typedef u16 SsaIntermediateIndex;
 typedef u16 SsaStringIndex;
 typedef u16 SsaExternFuncIndex;
+typedef u16 SsaExportFuncIndex;
 typedef u16 SsaFuncIndex;
 
 typedef struct {
@@ -64,9 +70,11 @@ typedef struct {
     Buffer/*BufferView*/ strings;
     HashMapType(BufferView, SsaExternFuncIndex) extern_funcs_map;
     Buffer/*SsaExternFunc*/ extern_funcs;
+    Buffer/*SsaExportFunc*/ export_funcs;
     SsaIntermediateIndex intermediate_counter;
     SsaStringIndex string_counter;
     SsaExternFuncIndex extern_func_counter;
+    SsaExportFuncIndex export_func_counter;
     SsaRegister reg_counter;
     SsaRegister param_counter;
     SsaFuncIndex func_counter;
@@ -85,8 +93,7 @@ typedef struct {
 } SsaInsForm2;
 
 typedef struct {
-    SsaFuncIndex func_index;
-    u16 num_params_regs;
+    u8 flags;
     u16 num_local_vars_regs;
 } SsaInsFuncStart;
 
diff --git a/include/tokenizer.h b/include/tokenizer.h
index 16123cc..57ed9de 100644
--- a/include/tokenizer.h
+++ b/include/tokenizer.h
@@ -38,6 +38,7 @@ typedef enum {
     TOK_ELSE,
     TOK_WHILE,
     TOK_EXTERN,
+    TOK_EXPORT,
     TOK_RETURN
 } Token;