gh-106149: move CFG and basicblock definitions into flowgraph.c, use them as opaque types in compile.c (#107639)

Author: iritkatriel

Include/internal/pycore_compile.h

@@ -54,6 +54,11 @@ typedef struct {
     int s_next_free_label; /* next free label id */
 } _PyCompile_InstructionSequence;
 
+int _PyCompile_InstructionSequence_UseLabel(_PyCompile_InstructionSequence *seq, int lbl);
+int _PyCompile_InstructionSequence_Addop(_PyCompile_InstructionSequence *seq,
+                                         int opcode, int oparg,
+                                         _PyCompilerSrcLocation loc);
+
 typedef struct {
     PyObject *u_name;
     PyObject *u_qualname;  /* dot-separated qualified name (lazy) */

Include/internal/pycore_flowgraph.h

@@ -11,88 +11,26 @@ extern "C" {
 #include "pycore_opcode_utils.h"
 #include "pycore_compile.h"
 
-
-typedef struct {
-    int i_opcode;
-    int i_oparg;
-    _PyCompilerSrcLocation i_loc;
-    struct _PyCfgBasicblock_ *i_target; /* target block (if jump instruction) */
-    struct _PyCfgBasicblock_ *i_except; /* target block when exception is raised */
-} _PyCfgInstruction;
-
 typedef struct {
     int id;
 } _PyCfgJumpTargetLabel;
 
+struct _PyCfgBuilder;
 
-typedef struct {
-    struct _PyCfgBasicblock_ *handlers[CO_MAXBLOCKS+1];
-    int depth;
-} _PyCfgExceptStack;
-
-typedef struct _PyCfgBasicblock_ {
-    /* Each basicblock in a compilation unit is linked via b_list in the
-       reverse order that the block are allocated.  b_list points to the next
-       block in this list, not to be confused with b_next, which is next by
-       control flow. */
-    struct _PyCfgBasicblock_ *b_list;
-    /* The label of this block if it is a jump target, -1 otherwise */
-    _PyCfgJumpTargetLabel b_label;
-    /* Exception stack at start of block, used by assembler to create the exception handling table */
-    _PyCfgExceptStack *b_exceptstack;
-    /* pointer to an array of instructions, initially NULL */
-    _PyCfgInstruction *b_instr;
-    /* If b_next is non-NULL, it is a pointer to the next
-       block reached by normal control flow. */
-    struct _PyCfgBasicblock_ *b_next;
-    /* number of instructions used */
-    int b_iused;
-    /* length of instruction array (b_instr) */
-    int b_ialloc;
-    /* Used by add_checks_for_loads_of_unknown_variables */
-    uint64_t b_unsafe_locals_mask;
-    /* Number of predecessors that a block has. */
-    int b_predecessors;
-    /* depth of stack upon entry of block, computed by stackdepth() */
-    int b_startdepth;
-    /* Basic block is an exception handler that preserves lasti */
-    unsigned b_preserve_lasti : 1;
-    /* Used by compiler passes to mark whether they have visited a basic block. */
-    unsigned b_visited : 1;
-    /* b_except_handler is used by the cold-detection algorithm to mark exception targets */
-    unsigned b_except_handler : 1;
-    /* b_cold is true if this block is not perf critical (like an exception handler) */
-    unsigned b_cold : 1;
-    /* b_warm is used by the cold-detection algorithm to mark blocks which are definitely not cold */
-    unsigned b_warm : 1;
-} _PyCfgBasicblock;
+int _PyCfgBuilder_UseLabel(struct _PyCfgBuilder *g, _PyCfgJumpTargetLabel lbl);
+int _PyCfgBuilder_Addop(struct _PyCfgBuilder *g, int opcode, int oparg, _PyCompilerSrcLocation loc);
 
-int _PyBasicblock_InsertInstruction(_PyCfgBasicblock *block, int pos, _PyCfgInstruction *instr);
+struct _PyCfgBuilder* _PyCfgBuilder_New(void);
+void _PyCfgBuilder_Free(struct _PyCfgBuilder *g);
+int _PyCfgBuilder_CheckSize(struct _PyCfgBuilder* g);
 
-typedef struct cfg_builder_ {
-    /* The entryblock, at which control flow begins. All blocks of the
-       CFG are reachable through the b_next links */
-    _PyCfgBasicblock *g_entryblock;
-    /* Pointer to the most recently allocated block.  By following
-       b_list links, you can reach all allocated blocks. */
-    _PyCfgBasicblock *g_block_list;
-    /* pointer to the block currently being constructed */
-    _PyCfgBasicblock *g_curblock;
-    /* label for the next instruction to be placed */
-    _PyCfgJumpTargetLabel g_current_label;
-} _PyCfgBuilder;
-
-int _PyCfgBuilder_UseLabel(_PyCfgBuilder *g, _PyCfgJumpTargetLabel lbl);
-int _PyCfgBuilder_Addop(_PyCfgBuilder *g, int opcode, int oparg, _PyCompilerSrcLocation loc);
-
-int _PyCfgBuilder_Init(_PyCfgBuilder *g);
-void _PyCfgBuilder_Fini(_PyCfgBuilder *g);
-
-int _PyCfg_OptimizeCodeUnit(_PyCfgBuilder *g, PyObject *consts, PyObject *const_cache,
+int _PyCfg_OptimizeCodeUnit(struct _PyCfgBuilder *g, PyObject *consts, PyObject *const_cache,
                             int nlocals, int nparams, int firstlineno);
-int _PyCfg_Stackdepth(_PyCfgBuilder *g);
-void _PyCfg_ConvertPseudoOps(_PyCfgBasicblock *entryblock);
-int _PyCfg_ResolveJumps(_PyCfgBuilder *g);
+
+int _PyCfg_ToInstructionSequence(struct _PyCfgBuilder *g, _PyCompile_InstructionSequence *seq);
+int _PyCfg_OptimizedCfgToInstructionSequence(struct _PyCfgBuilder *g, _PyCompile_CodeUnitMetadata *umd,
+                                             int code_flags, int *stackdepth, int *nlocalsplus,
+                                             _PyCompile_InstructionSequence *seq);
 
 PyCodeObject *
 _PyAssemble_MakeCodeObject(_PyCompile_CodeUnitMetadata *u, PyObject *const_cache,