1 files changed, 170 insertions, 0 deletions

diff --git a/src/lua/lparser.h b/src/lua/lparser.h
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--- /dev/null
+++ b/src/lua/lparser.h
@@ -0,0 +1,170 @@
+/*
+** $Id: lparser.h $
+** Lua Parser
+** See Copyright Notice in lua.h
+*/
+
+#ifndef lparser_h
+#define lparser_h
+
+#include "llimits.h"
+#include "lobject.h"
+#include "lzio.h"
+
+
+/*
+** Expression and variable descriptor.
+** Code generation for variables and expressions can be delayed to allow
+** optimizations; An 'expdesc' structure describes a potentially-delayed
+** variable/expression. It has a description of its "main" value plus a
+** list of conditional jumps that can also produce its value (generated
+** by short-circuit operators 'and'/'or').
+*/
+
+/* kinds of variables/expressions */
+typedef enum {
+  VVOID,  /* when 'expdesc' describes the last expression a list,
+             this kind means an empty list (so, no expression) */
+  VNIL,  /* constant nil */
+  VTRUE,  /* constant true */
+  VFALSE,  /* constant false */
+  VK,  /* constant in 'k'; info = index of constant in 'k' */
+  VKFLT,  /* floating constant; nval = numerical float value */
+  VKINT,  /* integer constant; ival = numerical integer value */
+  VKSTR,  /* string constant; strval = TString address;
+             (string is fixed by the lexer) */
+  VNONRELOC,  /* expression has its value in a fixed register;
+                 info = result register */
+  VLOCAL,  /* local variable; var.sidx = stack index (local register);
+              var.vidx = relative index in 'actvar.arr'  */
+  VUPVAL,  /* upvalue variable; info = index of upvalue in 'upvalues' */
+  VCONST,  /* compile-time constant; info = absolute index in 'actvar.arr'  */
+  VINDEXED,  /* indexed variable;
+                ind.t = table register;
+                ind.idx = key's R index */
+  VINDEXUP,  /* indexed upvalue;
+                ind.t = table upvalue;
+                ind.idx = key's K index */
+  VINDEXI, /* indexed variable with constant integer;
+                ind.t = table register;
+                ind.idx = key's value */
+  VINDEXSTR, /* indexed variable with literal string;
+                ind.t = table register;
+                ind.idx = key's K index */
+  VJMP,  /* expression is a test/comparison;
+            info = pc of corresponding jump instruction */
+  VRELOC,  /* expression can put result in any register;
+              info = instruction pc */
+  VCALL,  /* expression is a function call; info = instruction pc */
+  VVARARG  /* vararg expression; info = instruction pc */
+} expkind;
+
+
+#define vkisvar(k)      (VLOCAL <= (k) && (k) <= VINDEXSTR)
+#define vkisindexed(k)  (VINDEXED <= (k) && (k) <= VINDEXSTR)
+
+
+typedef struct expdesc {
+  expkind k;
+  union {
+    lua_Integer ival;    /* for VKINT */
+    lua_Number nval;  /* for VKFLT */
+    TString *strval;  /* for VKSTR */
+    int info;  /* for generic use */
+    struct {  /* for indexed variables */
+      short idx;  /* index (R or "long" K) */
+      lu_byte t;  /* table (register or upvalue) */
+    } ind;
+    struct {  /* for local variables */
+      lu_byte sidx;  /* index in the stack */
+      unsigned short vidx;  /* compiler index (in 'actvar.arr')  */
+    } var;
+  } u;
+  int t;  /* patch list of 'exit when true' */
+  int f;  /* patch list of 'exit when false' */
+} expdesc;
+
+
+/* kinds of variables */
+#define VDKREG          0   /* regular */
+#define RDKCONST        1   /* constant */
+#define RDKTOCLOSE      2   /* to-be-closed */
+#define RDKCTC          3   /* compile-time constant */
+
+/* description of an active local variable */
+typedef union Vardesc {
+  struct {
+    TValuefields;  /* constant value (if it is a compile-time constant) */
+    lu_byte kind;
+    lu_byte sidx;  /* index of the variable in the stack */
+    short pidx;  /* index of the variable in the Proto's 'locvars' array */
+    TString *name;  /* variable name */
+  } vd;
+  TValue k;  /* constant value (if any) */
+} Vardesc;
+
+
+
+/* description of pending goto statements and label statements */
+typedef struct Labeldesc {
+  TString *name;  /* label identifier */
+  int pc;  /* position in code */
+  int line;  /* line where it appeared */
+  lu_byte nactvar;  /* number of active variables in that position */
+  lu_byte close;  /* goto that escapes upvalues */
+} Labeldesc;
+
+
+/* list of labels or gotos */
+typedef struct Labellist {
+  Labeldesc *arr;  /* array */
+  int n;  /* number of entries in use */
+  int size;  /* array size */
+} Labellist;
+
+
+/* dynamic structures used by the parser */
+typedef struct Dyndata {
+  struct {  /* list of all active local variables */
+    Vardesc *arr;
+    int n;
+    int size;
+  } actvar;
+  Labellist gt;  /* list of pending gotos */
+  Labellist label;   /* list of active labels */
+} Dyndata;
+
+
+/* control of blocks */
+struct BlockCnt;  /* defined in lparser.c */
+
+
+/* state needed to generate code for a given function */
+typedef struct FuncState {
+  Proto *f;  /* current function header */
+  struct FuncState *prev;  /* enclosing function */
+  struct LexState *ls;  /* lexical state */
+  struct BlockCnt *bl;  /* chain of current blocks */
+  int pc;  /* next position to code (equivalent to 'ncode') */
+  int lasttarget;   /* 'label' of last 'jump label' */
+  int previousline;  /* last line that was saved in 'lineinfo' */
+  int nk;  /* number of elements in 'k' */
+  int np;  /* number of elements in 'p' */
+  int nabslineinfo;  /* number of elements in 'abslineinfo' */
+  int firstlocal;  /* index of first local var (in Dyndata array) */
+  int firstlabel;  /* index of first label (in 'dyd->label->arr') */
+  short ndebugvars;  /* number of elements in 'f->locvars' */
+  lu_byte nactvar;  /* number of active local variables */
+  lu_byte nups;  /* number of upvalues */
+  lu_byte freereg;  /* first free register */
+  lu_byte iwthabs;  /* instructions issued since last absolute line info */
+  lu_byte needclose;  /* function needs to close upvalues when returning */
+} FuncState;
+
+
+LUAI_FUNC int luaY_nvarstack (FuncState *fs);
+LUAI_FUNC LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
+                                 Dyndata *dyd, const char *name, int firstchar);
+
+
+#endif