diff options
| -rw-r--r-- | internal/compile/compile.go | 311 | ||||
| -rw-r--r-- | starlark/interp.go | 30 | ||||
| -rw-r--r-- | starlark/testdata/function.star | 17 |
3 files changed, 192 insertions, 166 deletions
diff --git a/internal/compile/compile.go b/internal/compile/compile.go index eb8e162..ab67018 100644 --- a/internal/compile/compile.go +++ b/internal/compile/compile.go @@ -46,7 +46,7 @@ var Disassemble = false const debug = false // make code generation verbose, for debugging the compiler // Increment this to force recompilation of saved bytecode files. -const Version = 10 +const Version = 11 type Opcode uint8 @@ -111,8 +111,6 @@ const ( SLICE // x lo hi step SLICE slice INPLACE_ADD // x y INPLACE_ADD z where z is x+y or x.extend(y) MAKEDICT // - MAKEDICT dict - SETCELL // value cell SETCELL - - CELL // cell CELL value // --- opcodes with an argument must go below this line --- @@ -122,21 +120,24 @@ const ( ITERJMP // - ITERJMP<addr> elem (and fall through) [acts on topmost iterator] // or: - ITERJMP<addr> - (and jump) - CONSTANT // - CONSTANT<constant> value - MAKETUPLE // x1 ... xn MAKETUPLE<n> tuple - MAKELIST // x1 ... xn MAKELIST<n> list - MAKEFUNC // defaults+freevars MAKEFUNC<func> fn - LOAD // from1 ... fromN module LOAD<n> v1 ... vN - SETLOCAL // value SETLOCAL<local> - - SETGLOBAL // value SETGLOBAL<global> - - LOCAL // - LOCAL<local> value - FREE // - FREE<freevar> cell - GLOBAL // - GLOBAL<global> value - PREDECLARED // - PREDECLARED<name> value - UNIVERSAL // - UNIVERSAL<name> value - ATTR // x ATTR<name> y y = x.name - SETFIELD // x y SETFIELD<name> - x.name = y - UNPACK // iterable UNPACK<n> vn ... v1 + CONSTANT // - CONSTANT<constant> value + MAKETUPLE // x1 ... xn MAKETUPLE<n> tuple + MAKELIST // x1 ... xn MAKELIST<n> list + MAKEFUNC // defaults+freevars MAKEFUNC<func> fn + LOAD // from1 ... fromN module LOAD<n> v1 ... vN + SETLOCAL // value SETLOCAL<local> - + SETGLOBAL // value SETGLOBAL<global> - + LOCAL // - LOCAL<local> value + FREE // - FREE<freevar> cell + FREECELL // - FREECELL<freevar> value (content of FREE cell) + LOCALCELL // - LOCALCELL<local> value (content of LOCAL cell) + SETLOCALCELL // value SETLOCALCELL<local> - (set content of LOCAL cell) + GLOBAL // - GLOBAL<global> value + PREDECLARED // - PREDECLARED<name> value + UNIVERSAL // - UNIVERSAL<name> value + ATTR // x ATTR<name> y y = x.name + SETFIELD // x y SETFIELD<name> - x.name = y + UNPACK // iterable UNPACK<n> vn ... v1 // n>>8 is #positional args and n&0xff is #named args (pairs). CALL // fn positional named CALL<n> result @@ -151,72 +152,73 @@ const ( // TODO(adonovan): add dynamic checks for missing opcodes in the tables below. var opcodeNames = [...]string{ - AMP: "amp", - APPEND: "append", - ATTR: "attr", - CALL: "call", - CALL_KW: "call_kw ", - CALL_VAR: "call_var", - CALL_VAR_KW: "call_var_kw", - CELL: "cell", - CIRCUMFLEX: "circumflex", - CJMP: "cjmp", - CONSTANT: "constant", - DUP2: "dup2", - DUP: "dup", - EQL: "eql", - EXCH: "exch", - FALSE: "false", - FREE: "free", - GE: "ge", - GLOBAL: "global", - GT: "gt", - GTGT: "gtgt", - IN: "in", - INDEX: "index", - INPLACE_ADD: "inplace_add", - ITERJMP: "iterjmp", - ITERPOP: "iterpop", - ITERPUSH: "iterpush", - JMP: "jmp", - LE: "le", - LOAD: "load", - LOCAL: "local", - LT: "lt", - LTLT: "ltlt", - MAKEDICT: "makedict", - MAKEFUNC: "makefunc", - MAKELIST: "makelist", - MAKETUPLE: "maketuple", - MANDATORY: "mandatory", - MINUS: "minus", - NEQ: "neq", - NONE: "none", - NOP: "nop", - NOT: "not", - PERCENT: "percent", - PIPE: "pipe", - PLUS: "plus", - POP: "pop", - PREDECLARED: "predeclared", - RETURN: "return", - SETCELL: "setcell", - SETDICT: "setdict", - SETDICTUNIQ: "setdictuniq", - SETFIELD: "setfield", - SETGLOBAL: "setglobal", - SETINDEX: "setindex", - SETLOCAL: "setlocal", - SLASH: "slash", - SLASHSLASH: "slashslash", - SLICE: "slice", - STAR: "star", - TILDE: "tilde", - TRUE: "true", - UMINUS: "uminus", - UNIVERSAL: "universal", - UNPACK: "unpack", - UPLUS: "uplus", + AMP: "amp", + APPEND: "append", + ATTR: "attr", + CALL: "call", + CALL_KW: "call_kw ", + CALL_VAR: "call_var", + CALL_VAR_KW: "call_var_kw", + CIRCUMFLEX: "circumflex", + CJMP: "cjmp", + CONSTANT: "constant", + DUP2: "dup2", + DUP: "dup", + EQL: "eql", + EXCH: "exch", + FALSE: "false", + FREE: "free", + FREECELL: "freecell", + GE: "ge", + GLOBAL: "global", + GT: "gt", + GTGT: "gtgt", + IN: "in", + INDEX: "index", + INPLACE_ADD: "inplace_add", + ITERJMP: "iterjmp", + ITERPOP: "iterpop", + ITERPUSH: "iterpush", + JMP: "jmp", + LE: "le", + LOAD: "load", + LOCAL: "local", + LOCALCELL: "localcell", + LT: "lt", + LTLT: "ltlt", + MAKEDICT: "makedict", + MAKEFUNC: "makefunc", + MAKELIST: "makelist", + MAKETUPLE: "maketuple", + MANDATORY: "mandatory", + MINUS: "minus", + NEQ: "neq", + NONE: "none", + NOP: "nop", + NOT: "not", + PERCENT: "percent", + PIPE: "pipe", + PLUS: "plus", + POP: "pop", + PREDECLARED: "predeclared", + RETURN: "return", + SETDICT: "setdict", + SETDICTUNIQ: "setdictuniq", + SETFIELD: "setfield", + SETGLOBAL: "setglobal", + SETINDEX: "setindex", + SETLOCAL: "setlocal", + SETLOCALCELL: "setlocalcell", + SLASH: "slash", + SLASHSLASH: "slashslash", + SLICE: "slice", + STAR: "star", + TILDE: "tilde", + TRUE: "true", + UMINUS: "uminus", + UNIVERSAL: "universal", + UNPACK: "unpack", + UPLUS: "uplus", } const variableStackEffect = 0x7f @@ -224,70 +226,71 @@ const variableStackEffect = 0x7f // stackEffect records the effect on the size of the operand stack of // each kind of instruction. For some instructions this requires computation. var stackEffect = [...]int8{ - AMP: -1, - APPEND: -2, - ATTR: 0, - CALL: variableStackEffect, - CALL_KW: variableStackEffect, - CALL_VAR: variableStackEffect, - CALL_VAR_KW: variableStackEffect, - CELL: 0, - CIRCUMFLEX: -1, - CJMP: -1, - CONSTANT: +1, - DUP2: +2, - DUP: +1, - EQL: -1, - FALSE: +1, - FREE: +1, - GE: -1, - GLOBAL: +1, - GT: -1, - GTGT: -1, - IN: -1, - INDEX: -1, - INPLACE_ADD: -1, - ITERJMP: variableStackEffect, - ITERPOP: 0, - ITERPUSH: -1, - JMP: 0, - LE: -1, - LOAD: -1, - LOCAL: +1, - LT: -1, - LTLT: -1, - MAKEDICT: +1, - MAKEFUNC: 0, - MAKELIST: variableStackEffect, - MAKETUPLE: variableStackEffect, - MANDATORY: +1, - MINUS: -1, - NEQ: -1, - NONE: +1, - NOP: 0, - NOT: 0, - PERCENT: -1, - PIPE: -1, - PLUS: -1, - POP: -1, - PREDECLARED: +1, - RETURN: -1, - SETCELL: -2, - SETDICT: -3, - SETDICTUNIQ: -3, - SETFIELD: -2, - SETGLOBAL: -1, - SETINDEX: -3, - SETLOCAL: -1, - SLASH: -1, - SLASHSLASH: -1, - SLICE: -3, - STAR: -1, - TRUE: +1, - UMINUS: 0, - UNIVERSAL: +1, - UNPACK: variableStackEffect, - UPLUS: 0, + AMP: -1, + APPEND: -2, + ATTR: 0, + CALL: variableStackEffect, + CALL_KW: variableStackEffect, + CALL_VAR: variableStackEffect, + CALL_VAR_KW: variableStackEffect, + CIRCUMFLEX: -1, + CJMP: -1, + CONSTANT: +1, + DUP2: +2, + DUP: +1, + EQL: -1, + FALSE: +1, + FREE: +1, + FREECELL: +1, + GE: -1, + GLOBAL: +1, + GT: -1, + GTGT: -1, + IN: -1, + INDEX: -1, + INPLACE_ADD: -1, + ITERJMP: variableStackEffect, + ITERPOP: 0, + ITERPUSH: -1, + JMP: 0, + LE: -1, + LOAD: -1, + LOCAL: +1, + LOCALCELL: +1, + LT: -1, + LTLT: -1, + MAKEDICT: +1, + MAKEFUNC: 0, + MAKELIST: variableStackEffect, + MAKETUPLE: variableStackEffect, + MANDATORY: +1, + MINUS: -1, + NEQ: -1, + NONE: +1, + NOP: 0, + NOT: 0, + PERCENT: -1, + PIPE: -1, + PLUS: -1, + POP: -1, + PREDECLARED: +1, + RETURN: -1, + SETLOCALCELL: -1, + SETDICT: -3, + SETDICTUNIQ: -3, + SETFIELD: -2, + SETGLOBAL: -1, + SETINDEX: -3, + SETLOCAL: -1, + SLASH: -1, + SLASHSLASH: -1, + SLICE: -3, + STAR: -1, + TRUE: +1, + UMINUS: 0, + UNIVERSAL: +1, + UNPACK: variableStackEffect, + UPLUS: 0, } func (op Opcode) String() string { @@ -994,9 +997,7 @@ func (fcomp *fcomp) set(id *syntax.Ident) { case resolve.Local: fcomp.emit1(SETLOCAL, uint32(bind.Index)) case resolve.Cell: - // TODO(adonovan): opt: make a single op for LOCAL<n>, SETCELL. - fcomp.emit1(LOCAL, uint32(bind.Index)) - fcomp.emit(SETCELL) + fcomp.emit1(SETLOCALCELL, uint32(bind.Index)) case resolve.Global: fcomp.emit1(SETGLOBAL, uint32(bind.Index)) default: @@ -1014,13 +1015,9 @@ func (fcomp *fcomp) lookup(id *syntax.Ident) { case resolve.Local: fcomp.emit1(LOCAL, uint32(bind.Index)) case resolve.Free: - // TODO(adonovan): opt: make a single op for FREE<n>, CELL. - fcomp.emit1(FREE, uint32(bind.Index)) - fcomp.emit(CELL) + fcomp.emit1(FREECELL, uint32(bind.Index)) case resolve.Cell: - // TODO(adonovan): opt: make a single op for LOCAL<n>, CELL. - fcomp.emit1(LOCAL, uint32(bind.Index)) - fcomp.emit(CELL) + fcomp.emit1(LOCALCELL, uint32(bind.Index)) case resolve.Global: fcomp.emit1(GLOBAL, uint32(bind.Index)) case resolve.Predeclared: diff --git a/starlark/interp.go b/starlark/interp.go index f00382c..642d8f5 100644 --- a/starlark/interp.go +++ b/starlark/interp.go @@ -547,11 +547,9 @@ loop: locals[arg] = stack[sp-1] sp-- - case compile.SETCELL: - x := stack[sp-2] - y := stack[sp-1] - sp -= 2 - y.(*cell).v = x + case compile.SETLOCALCELL: + locals[arg].(*cell).v = stack[sp-1] + sp-- case compile.SETGLOBAL: fn.module.globals[arg] = stack[sp-1] @@ -570,9 +568,23 @@ loop: stack[sp] = fn.freevars[arg] sp++ - case compile.CELL: - x := stack[sp-1] - stack[sp-1] = x.(*cell).v + case compile.LOCALCELL: + v := locals[arg].(*cell).v + if v == nil { + err = fmt.Errorf("local variable %s referenced before assignment", f.Locals[arg].Name) + break loop + } + stack[sp] = v + sp++ + + case compile.FREECELL: + v := fn.freevars[arg].(*cell).v + if v == nil { + err = fmt.Errorf("local variable %s referenced before assignment", f.Freevars[arg].Name) + break loop + } + stack[sp] = v + sp++ case compile.GLOBAL: x := fn.module.globals[arg] @@ -641,7 +653,7 @@ func (mandatory) Hash() (uint32, error) { return 0, nil } // A cell is a box containing a Value. // Local variables marked as cells hold their value indirectly // so that they may be shared by outer and inner nested functions. -// Cells are always accessed using indirect CELL/SETCELL instructions. +// Cells are always accessed using indirect {FREE,LOCAL,SETLOCAL}CELL instructions. // The FreeVars tuple contains only cells. // The FREE instruction always yields a cell. type cell struct{ v Value } diff --git a/starlark/testdata/function.star b/starlark/testdata/function.star index bdfa5ac..737df26 100644 --- a/starlark/testdata/function.star +++ b/starlark/testdata/function.star @@ -287,6 +287,23 @@ def e(): assert.fails(e, "local variable x referenced before assignment") +def f(): + def inner(): + return x + if False: + x = 0 + return x # fails (x is an uninitialized cell of this function) + +assert.fails(f, "local variable x referenced before assignment") + +def g(): + def inner(): + return x # fails (x is an uninitialized cell of the enclosing function) + if False: + x = 0 + return inner() + +assert.fails(g, "local variable x referenced before assignment") --- # A trailing comma is allowed in any function definition or call. |