From e2aebdd0bfef45036c0e1242c55efd86773ecca4 Mon Sep 17 00:00:00 2001 From: dkf Date: Wed, 5 Jun 2013 07:19:02 +0000 Subject: Stack cleanup works now even in the most evil expansion cases. --- generic/tclAssembly.c | 2 +- generic/tclCompCmds.c | 62 ++++++----------------------- generic/tclCompile.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++-- generic/tclCompile.h | 7 ++++ generic/tclExecute.c | 11 ++--- tests/for.test | 30 ++++++++++++++ 6 files changed, 160 insertions(+), 60 deletions(-) diff --git a/generic/tclAssembly.c b/generic/tclAssembly.c index d1af8c6..62641e6 100644 --- a/generic/tclAssembly.c +++ b/generic/tclAssembly.c @@ -20,7 +20,7 @@ *- break and continue - if exception ranges can be sorted out. *- foreach_start4, foreach_step4 *- returnImm, returnStk - *- expandStart, expandStkTop, invokeExpanded + *- expandStart, expandStkTop, invokeExpanded, expandDrop *- dictFirst, dictNext, dictDone *- dictUpdateStart, dictUpdateEnd *- jumpTable testing diff --git a/generic/tclCompCmds.c b/generic/tclCompCmds.c index 3d6abcf..365e647 100644 --- a/generic/tclCompCmds.c +++ b/generic/tclCompCmds.c @@ -493,40 +493,21 @@ TclCompileBreakCmd( rangePtr = TclGetInnermostExceptionRange(envPtr, TCL_BREAK, &auxPtr); if (rangePtr && rangePtr->type == LOOP_EXCEPTION_RANGE) { - int toPop; - - /* - * Ditch the extra elements from the auxiliary stack. - */ - - toPop = envPtr->expandCount - auxPtr->expandTarget; - while (toPop > 0) { - TclEmitOpcode(INST_EXPAND_DROP, envPtr); - toPop--; - } - - /* - * Pop off the extra stack frames. - */ - - toPop = envPtr->currStackDepth - auxPtr->stackDepth; - while (toPop > 0) { - TclEmitOpcode(INST_POP, envPtr); - TclAdjustStackDepth(1, envPtr); - toPop--; - } - /* * Found the target! No need for a nasty INST_BREAK here. */ + TclCleanupStackForBreakContinue(envPtr, auxPtr); TclAddLoopBreakFixup(envPtr, auxPtr); } else { /* - * Emit a break instruction. + * Emit a real break. */ - TclEmitOpcode(INST_BREAK, envPtr); + PushStringLiteral(envPtr, ""); + TclEmitOpcode(INST_DUP, envPtr); + TclEmitInstInt4(INST_RETURN_IMM, TCL_BREAK, envPtr); + TclEmitInt4(0, envPtr); } /* @@ -846,40 +827,21 @@ TclCompileContinueCmd( rangePtr = TclGetInnermostExceptionRange(envPtr, TCL_CONTINUE, &auxPtr); if (rangePtr && rangePtr->type == LOOP_EXCEPTION_RANGE) { - int toPop; - - /* - * Ditch the extra elements from the auxiliary stack. - */ - - toPop = envPtr->expandCount - auxPtr->expandTarget; - while (toPop > 0) { - TclEmitOpcode(INST_EXPAND_DROP, envPtr); - toPop--; - } - - /* - * Pop off the extra stack frames. - */ - - toPop = envPtr->currStackDepth - auxPtr->stackDepth; - while (toPop > 0) { - TclEmitOpcode(INST_POP, envPtr); - TclAdjustStackDepth(1, envPtr); - toPop--; - } - /* * Found the target! No need for a nasty INST_CONTINUE here. */ + TclCleanupStackForBreakContinue(envPtr, auxPtr); TclAddLoopContinueFixup(envPtr, auxPtr); } else { /* - * Emit a continue instruction. + * Emit a real continue. */ - TclEmitOpcode(INST_CONTINUE, envPtr); + PushStringLiteral(envPtr, ""); + TclEmitOpcode(INST_DUP, envPtr); + TclEmitInstInt4(INST_RETURN_IMM, TCL_CONTINUE, envPtr); + TclEmitInt4(0, envPtr); } /* diff --git a/generic/tclCompile.c b/generic/tclCompile.c index f8dd504..69517bc 100644 --- a/generic/tclCompile.c +++ b/generic/tclCompile.c @@ -541,7 +541,8 @@ InstructionDesc const tclInstructionTable[] = { * Stack: ... list1 list2 => ... [lconcat list1 list2] */ {"expandDrop", 1, 0, 0, {OPERAND_NONE}}, - /* Drops an element from the auxiliary stack. */ + /* Drops an element from the auxiliary stack, popping stack elements + * until the matching stack depth is reached. */ {NULL, 0, 0, 0, {OPERAND_NONE}} }; @@ -574,6 +575,7 @@ static void RecordByteCodeStats(ByteCode *codePtr); static void RegisterAuxDataType(const AuxDataType *typePtr); static int SetByteCodeFromAny(Tcl_Interp *interp, Tcl_Obj *objPtr); +static void StartExpanding(CompileEnv *envPtr); static int FormatInstruction(ByteCode *codePtr, const unsigned char *pc, Tcl_Obj *bufferObj); static void PrintSourceToObj(Tcl_Obj *appendObj, @@ -2063,8 +2065,7 @@ TclCompileScript( */ if (expand) { - TclEmitOpcode(INST_EXPAND_START, envPtr); - envPtr->expandCount++; + StartExpanding(envPtr); } /* @@ -3469,6 +3470,7 @@ TclCreateExceptRange( auxPtr->supportsContinue = 1; auxPtr->stackDepth = envPtr->currStackDepth; auxPtr->expandTarget = envPtr->expandCount; + auxPtr->expandTargetDepth = -1; auxPtr->numBreakTargets = 0; auxPtr->breakTargets = NULL; auxPtr->allocBreakTargets = 0; @@ -3589,6 +3591,103 @@ TclAddLoopContinueFixup( /* * --------------------------------------------------------------------- * + * TclCleanupStackForBreakContinue -- + * + * Ditch the extra elements from the auxiliary stack and the main + * stack. How to do this exactly depends on whether there are any + * elements on the auxiliary stack to pop. + * + * --------------------------------------------------------------------- + */ + +void +TclCleanupStackForBreakContinue( + CompileEnv *envPtr, + ExceptionAux *auxPtr) +{ + int toPop = envPtr->expandCount - auxPtr->expandTarget; + + if (toPop > 0) { + while (toPop > 0) { + TclEmitOpcode(INST_EXPAND_DROP, envPtr); + toPop--; + } + toPop = auxPtr->expandTargetDepth - auxPtr->stackDepth; + while (toPop > 0) { + TclEmitOpcode(INST_POP, envPtr); + TclAdjustStackDepth(1, envPtr); + toPop--; + } + } else { + toPop = envPtr->currStackDepth - auxPtr->stackDepth; + while (toPop > 0) { + TclEmitOpcode(INST_POP, envPtr); + TclAdjustStackDepth(1, envPtr); + toPop--; + } + } +} + +/* + * --------------------------------------------------------------------- + * + * StartExpanding -- + * + * Pushes an INST_EXPAND_START and does some additional housekeeping so + * that the [break] and [continue] compilers can use an exception-free + * issue to discard it. + * + * --------------------------------------------------------------------- + */ + +static void +StartExpanding( + CompileEnv *envPtr) +{ + int i; + + TclEmitOpcode(INST_EXPAND_START, envPtr); + + /* + * Update inner exception ranges with information about the environment + * where this expansion started. + */ + + for (i=0 ; iexceptArrayNext ; i++) { + ExceptionRange *rangePtr = &envPtr->exceptArrayPtr[i]; + ExceptionAux *auxPtr = &envPtr->exceptAuxArrayPtr[i]; + + /* + * Ignore loops unless they're still being built. + */ + + if (rangePtr->codeOffset > CurrentOffset(envPtr)) { + continue; + } + if (rangePtr->numCodeBytes != -1) { + continue; + } + + /* + * Adequate condition: further out loops and further in exceptions + * don't actually need this information. + */ + + if (auxPtr->expandTarget == envPtr->expandCount) { + auxPtr->expandTargetDepth = envPtr->currStackDepth; + } + } + + /* + * There's now one more expansion being processed on the auxiliary stack. + */ + + envPtr->expandCount++; +} + +/* + * --------------------------------------------------------------------- + * * TclFinalizeLoopExceptionRange -- * * Finalizes a loop exception range, binding the registered [break] and @@ -3629,7 +3728,8 @@ TclFinalizeLoopExceptionRange( int j; /* - * WTF? Can't bind, so revert to an INST_CONTINUE. + * WTF? Can't bind, so revert to an INST_CONTINUE. Not enough + * space to do anything else. */ *site = INST_CONTINUE; diff --git a/generic/tclCompile.h b/generic/tclCompile.h index 75de025..15b5477 100644 --- a/generic/tclCompile.h +++ b/generic/tclCompile.h @@ -120,6 +120,11 @@ typedef struct ExceptionAux { * we can't currently discard them except by * doing INST_INVOKE_EXPANDED; this is a known * problem. */ + int expandTargetDepth; /* The stack depth expected at the outermost + * expansion within the loop. Not meaningful + * if there have are no open expansions + * between the looping level and the point of + * jump issue. */ int numBreakTargets; /* The number of [break]s that want to be * targeted to the place where this loop * exception will be bound to. */ @@ -987,6 +992,8 @@ MODULE_SCOPE ByteCode * TclCompileObj(Tcl_Interp *interp, Tcl_Obj *objPtr, */ MODULE_SCOPE void TclCleanupByteCode(ByteCode *codePtr); +MODULE_SCOPE void TclCleanupStackForBreakContinue(CompileEnv *envPtr, + ExceptionAux *auxPtr); MODULE_SCOPE void TclCompileCmdWord(Tcl_Interp *interp, Tcl_Token *tokenPtr, int count, CompileEnv *envPtr); diff --git a/generic/tclExecute.c b/generic/tclExecute.c index 559df0b..fc50a74 100644 --- a/generic/tclExecute.c +++ b/generic/tclExecute.c @@ -2720,14 +2720,15 @@ TEBCresume( case INST_EXPAND_DROP: /* - * Drops an element of the auxObjList. Does not do any clean up of the - * actual stack. - * - * TODO: POP MAIN STACK BACK TO MARKER + * Drops an element of the auxObjList, popping stack elements to + * restore the stack to the state before the point where the aux + * element was created. */ + CLANG_ASSERT(auxObjList); + objc = CURR_DEPTH - auxObjList->internalRep.ptrAndLongRep.value; POP_TAUX_OBJ(); - NEXT_INST_F(1, 0, 0); + NEXT_INST_V(1, objc, 0); case INST_EXPAND_STKTOP: { int i; diff --git a/tests/for.test b/tests/for.test index cfba1fe..c5803ee 100644 --- a/tests/for.test +++ b/tests/for.test @@ -882,6 +882,36 @@ test for-7.4 {Bug 3614226: ensure that continue cleans up the expansion stack} m expr {$end - $tmp} }} } 0 +test for-7.5 {Bug 3614226: ensure that break cleans up the expansion stack} memory { + apply {{} { + set l [lrepeat 50 p q r] + # Can't use [memtest]; must be careful when we change stack frames + set end [meminfo] + for {set i 0} {$i < 5} {incr i} { + for {set x 0} {[incr x]<50} {} { + puts [puts {*}$l {*}[puts a b c {*}$l {*}[break] d e f]] + } + set tmp $end + set end [meminfo] + } + expr {$end - $tmp} + }} +} 0 +test for-7.6 {Bug 3614226: ensure that continue cleans up the expansion stack} memory { + apply {{} { + set l [lrepeat 50 p q r] + # Can't use [memtest]; must be careful when we change stack frames + set end [meminfo] + for {set i 0} {$i < 5} {incr i} { + for {set x 0} {[incr x]<50} {} { + puts [puts {*}$l {*}[puts a b c {*}$l {*}[continue] d e f]] + } + set tmp $end + set end [meminfo] + } + expr {$end - $tmp} + }} +} 0 # cleanup ::tcltest::cleanupTests -- cgit v0.12