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Commit 5053722

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mbaludambaluda
authored
Package Contracts3 (#88)
Add RULE-22-8 RULE-22-9 RULE-22-10 from package Contracts3
1 parent f793d14 commit 5053722
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17 files changed

+501
-3
lines changed

‎c/common/src/codingstandards/c/Errno.qll

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/** Provides a library for errno-setting functions. */
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import cpp
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/*
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* An errno-setting function
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*/
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abstract class ErrnoSettingFunction extends Function { }
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/*
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* An errno-setting function that return out-of-band errors indicators
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*/
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class OutOfBandErrnoSettingFunction extends ErrnoSettingFunction {
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OutOfBandErrnoSettingFunction() {
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this.hasGlobalName(["ftell", "fgetpos", "fsetpos", "mbrtowc", "wcrtomb", "wcsrtombs"])
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}
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}
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/*
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* An errno-setting function that return in-band errors indicators
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*/
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class InBandErrnoSettingFunction extends ErrnoSettingFunction {
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InBandErrnoSettingFunction() {
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this.hasGlobalName([
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"fgetwc", "fputwc", "strtol", "wcstol", "strtoll", "wcstoll", "strtoul", "wcstoul",
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"strtoull", "wcstoull", "strtoumax", "wcstoumax", "strtod", "wcstod", "strtof", "wcstof",
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"strtold", "wcstold", "strtoimax", "wcstoimax"
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])
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}
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}
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/*
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* A assignment expression setting `errno` to 0
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*/
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class ErrnoZeroed extends AssignExpr {
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ErrnoZeroed() {
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this.getLValue() = any(MacroInvocation ma | ma.getMacroName() = "errno").getExpr() and
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this.getRValue().getValue() = "0"
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}
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}
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/*
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* A guard controlled by a errno comparison
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*/
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abstract class ErrnoGuard extends StmtParent {
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abstract ControlFlowNode getZeroedSuccessor();
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abstract ControlFlowNode getNonZeroedSuccessor();
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}
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class ErrnoIfGuard extends EqualityOperation, ErrnoGuard {
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ControlStructure i;
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ErrnoIfGuard() {
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this.getAnOperand() = any(MacroInvocation ma | ma.getMacroName() = "errno").getExpr() and
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this.getAnOperand().getValue() = "0" and
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i.getControllingExpr() = this
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}
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Stmt getThenSuccessor() {
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i.getControllingExpr() = this and
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(result = i.(IfStmt).getThen() or result = i.(Loop).getStmt())
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}
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Stmt getElseSuccessor() {
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i.getControllingExpr() = this and
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(
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i.(IfStmt).hasElse() and result = i.(IfStmt).getElse()
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or
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result = i.getFollowingStmt()
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)
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}
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override ControlFlowNode getZeroedSuccessor() {
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if this instanceof EQExpr then result = this.getThenSuccessor() else result = getElseSuccessor()
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}
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override ControlFlowNode getNonZeroedSuccessor() {
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if this instanceof NEExpr then result = this.getThenSuccessor() else result = getElseSuccessor()
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}
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}
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class ErrnoSwitchGuard extends SwitchCase, ErrnoGuard {
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ErrnoSwitchGuard() {
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this.getSwitchStmt().getExpr() = any(MacroInvocation ma | ma.getMacroName() = "errno").getExpr()
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}
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override ControlFlowNode getZeroedSuccessor() {
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result = this.getAStmt() and this.getExpr().getValue() = "0"
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}
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override ControlFlowNode getNonZeroedSuccessor() {
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result = this.getAStmt() and this.getExpr().getValue() != "0"
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}
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}

‎c/misra/src/rules/RULE-22-10/OnlyTestErrnoRightAfterErrnoSettingFunction.ql

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+64Lines changed: 64 additions & 0 deletions
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/**
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* @id c/misra/only-test-errno-right-after-errno-setting-function
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* @name RULE-22-10: The value of errno shall only be tested when the last called function is errno-setting
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* @description The value of errno shall only be tested when the last function to be called was an
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* errno-setting-function. Testing the value in these conditions does not guarantee the
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* absence of an errors.
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* @kind problem
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* @precision high
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* @problem.severity warning
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* @tags external/misra/id/rule-22-10
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* correctness
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* external/misra/obligation/required
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*/
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import cpp
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import codingstandards.c.misra
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import codingstandards.c.Errno
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/*
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* A call to an `ErrnoSettingFunction`
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*/
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class ErrnoSettingFunctionCall extends FunctionCall {
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ErrnoSettingFunctionCall() { this.getTarget() instanceof ErrnoSettingFunction }
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}
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/*
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* A function call that is not part of the `errno` macro expansion
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*/
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class MaySetErrnoCall extends FunctionCall {
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MaySetErrnoCall() {
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not inmacroexpansion(this, any(MacroInvocation ma | ma.getMacroName() = "errno"))
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}
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}
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/*
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* CFG nodes preceding a `errno` test where `errno` is not set
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*/
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ControlFlowNode notSetPriorToErrnoTest(EqualityOperation eg) {
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result = eg
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or
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exists(ControlFlowNode mid |
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result = mid.getAPredecessor() and
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mid = notSetPriorToErrnoTest(eg) and
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// stop recursion on an errno-setting function call
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not result = any(ErrnoSettingFunctionCall c)
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)
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}
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from EqualityOperation eq, ControlFlowNode cause
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where
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not isExcluded(eq, Contracts3Package::onlyTestErrnoRightAfterErrnoSettingFunctionQuery()) and
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cause = notSetPriorToErrnoTest(eq) and
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eq.getAnOperand() = any(MacroInvocation ma | ma.getMacroName() = "errno").getExpr() and
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(
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// `errno` is not set anywhere in the function
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cause = eq.getEnclosingFunction().getBlock()
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or
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// `errno` is not set after a non-errno-setting function call
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cause = any(MaySetErrnoCall c)
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)
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select eq, "Value of `errno` is tested but not after an errno-setting function call."

‎c/misra/src/rules/RULE-22-8/ErrnoSetToZeroPriorToCall.ql

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+60Lines changed: 60 additions & 0 deletions
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/**
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* @id c/misra/errno-set-to-zero-prior-to-call
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* @name RULE-22-8: The value of errno shall be set to zero prior to a call to an errno-setting-function
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* @description The value of errno shall be set to zero prior to a call to an
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* errno-setting-function. Not setting the value leads to incorrectly identifying
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* errors.
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* @kind problem
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* @precision very-high
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* @problem.severity error
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* @tags external/misra/id/rule-22-8
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* correctness
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* external/misra/obligation/required
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*/
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import cpp
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import codingstandards.c.misra
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import codingstandards.c.Errno
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/*
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* A call to an `ErrnoSettingFunction`
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*/
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class ErrnoSettingFunctionCall extends FunctionCall {
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ErrnoSettingFunctionCall() { this.getTarget() instanceof ErrnoSettingFunction }
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}
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/*
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* CFG nodes preceding a `ErrnoSettingFunctionCall`
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*/
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ControlFlowNode notZeroedPriorToErrnoSet(ErrnoSettingFunctionCall fc) {
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result = fc
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or
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exists(ControlFlowNode mid |
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result = mid.getAPredecessor() and
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mid = notZeroedPriorToErrnoSet(fc) and
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// stop recursion when `errno` is set to zero
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not result instanceof ErrnoZeroed and
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not result = any(ErrnoGuard g).getZeroedSuccessor()
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)
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}
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from ErrnoSettingFunctionCall fc, ControlFlowNode cause
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where
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not isExcluded(fc, Contracts3Package::errnoSetToZeroAfterCallQuery()) and
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cause = notZeroedPriorToErrnoSet(fc) and
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(
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// `errno` is not reset anywhere in the function
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cause = fc.getEnclosingFunction().getBlock()
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or
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// `errno` is not reset after a call to an errno-setting function
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cause = any(ErrnoSettingFunctionCall ec | ec != fc)
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or
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// `errno` is not reset after a call to a function
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cause = any(FunctionCall fc2 | fc2 != fc)
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or
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// `errno` value is known to be != 0
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cause = any(ErrnoGuard g).getNonZeroedSuccessor()
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)
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select fc, "The value of `errno` may be different than `0` when this function is called."

‎c/misra/src/rules/RULE-22-9/ErrnoSetToZeroAfterCall.ql

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+52Lines changed: 52 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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/**
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* @id c/misra/errno-set-to-zero-after-call
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* @name RULE-22-9: The value of errno shall be tested against zero after calling an errno-setting-function
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* @description The value of errno shall be tested against zero after calling an
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* errno-setting-function. Not testing the value leads to unidentified errors.
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* @kind problem
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* @precision very-high
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* @problem.severity error
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* @tags external/misra/id/rule-22-9
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* correctness
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* external/misra/obligation/required
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*/
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import cpp
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import codingstandards.c.misra
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import codingstandards.c.Errno
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/*
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* A call to an `ErrnoSettingFunction`
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*/
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class InBandErrnoSettingFunctionCall extends FunctionCall {
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InBandErrnoSettingFunctionCall() { this.getTarget() instanceof InBandErrnoSettingFunction }
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}
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/*
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* CFG nodes following a `ErrnoSettingFunctionCall`
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*/
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ControlFlowNode notTestedAfterErrnoSet(InBandErrnoSettingFunctionCall fc) {
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result = fc
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or
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exists(ControlFlowNode mid |
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result = mid.getASuccessor() and
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mid = notTestedAfterErrnoSet(fc) and
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// stop recursion when `errno` is checked
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not result = any(ControlStructure i | i.getControllingExpr() instanceof ErrnoGuard)
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)
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}
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from InBandErrnoSettingFunctionCall fc, ControlFlowNode cause
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where
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not isExcluded(fc, Contracts3Package::errnoSetToZeroAfterCallQuery()) and
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cause = notTestedAfterErrnoSet(fc) and
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(
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// `errno` is not checked anywhere in the function
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cause = fc.getEnclosingFunction()
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or
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// `errno` is not checked before a call to a function
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cause = any(FunctionCall fc2 | fc2 != fc)
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)
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select fc, "The value of `errno` is not tested against `0` after the call."

‎c/misra/test/rules/RULE-22-10/OnlyTestErrnoRightAfterErrnoSettingFunction.expected

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+3Lines changed: 3 additions & 0 deletions
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| test.c:7:7:7:16 | ... == ... | Value of `errno` is tested but not after an errno-setting function call. |
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| test.c:16:7:16:21 | ... == ... | Value of `errno` is tested but not after an errno-setting function call. |
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| test.c:17:10:17:23 | ... == ... | Value of `errno` is tested but not after an errno-setting function call. |

‎c/misra/test/rules/RULE-22-10/OnlyTestErrnoRightAfterErrnoSettingFunction.qlref

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+1Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
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rules/RULE-22-10/OnlyTestErrnoRightAfterErrnoSettingFunction.ql

‎c/misra/test/rules/RULE-22-10/test.c

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+26Lines changed: 26 additions & 0 deletions
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#include <errno.h>
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#include <stdlib.h>
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void f1(void) {
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errno = 0;
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int i = atoi("0"); // non errno-setting function
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if (0 == errno) { // NON_COMPLIANT
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}
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errno = 0;
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strtod("0", NULL); // errno-setting function
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if (0 == errno) { // COMPLIANT
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}
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}
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void f2(void) {
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if (EAGAIN == errno // NON_COMPLIANT
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|| errno == EINTR) { // NON_COMPLIANT
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}
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}
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void f3(void) {
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errno = 0;
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strtod("0", NULL);
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if (errno == EAGAIN || errno == EINTR) { // COMPLIANT
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}
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}

‎c/misra/test/rules/RULE-22-8/ErrnoSetToZeroPriorToCall.expected

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+5Lines changed: 5 additions & 0 deletions
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| test.c:5:3:5:8 | call to strtod | The value of `errno` may be different than `0` when this function is called. |
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| test.c:20:5:20:10 | call to strtod | The value of `errno` may be different than `0` when this function is called. |
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| test.c:24:5:24:10 | call to strtof | The value of `errno` may be different than `0` when this function is called. |
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| test.c:32:3:32:8 | call to strtod | The value of `errno` may be different than `0` when this function is called. |
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| test.c:41:5:41:10 | call to strtod | The value of `errno` may be different than `0` when this function is called. |

‎c/misra/test/rules/RULE-22-8/ErrnoSetToZeroPriorToCall.qlref

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+1Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1 @@
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rules/RULE-22-8/ErrnoSetToZeroPriorToCall.ql

‎c/misra/test/rules/RULE-22-8/test.c

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+43Lines changed: 43 additions & 0 deletions
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#include <errno.h>
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#include <stdlib.h>
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void f1(void) {
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strtod("0", NULL); // NON_COMPLIANT
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if (0 == errno) {
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strtod("0", NULL); // COMPLIANT
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if (0 == errno) {
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}
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} else {
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errno = 0;
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strtod("0", NULL); // COMPLIANT
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if (0 == errno) {
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}
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}
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}
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void f2(void) {
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if (0 != errno) {
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strtod("0", NULL); // NON_COMPLIANT
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} else {
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errno = 0;
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strtod("0", NULL); // COMPLIANT
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strtof("0", NULL); // NON_COMPLIANT
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}
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}
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void f3_helper() {}
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void f3(void) {
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errno = 0;
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f3_helper();
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strtod("0", NULL); // NON_COMPLIANT
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}
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void f4(void) {
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errno = 0;
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switch (errno) {
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case 0:
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strtod("0", NULL); // COMPLIANT
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case 1:
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strtod("0", NULL); // NON_COMPLIANT
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}
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}

‎c/misra/test/rules/RULE-22-9/ErrnoSetToZeroAfterCall.expected

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+2Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
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| test.c:9:3:9:8 | call to strtod | The value of `errno` is not tested against `0` after the call. |
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| test.c:19:3:19:8 | call to strtod | The value of `errno` is not tested against `0` after the call. |

‎c/misra/test/rules/RULE-22-9/ErrnoSetToZeroAfterCall.qlref

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+1Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1 @@
1+
rules/RULE-22-9/ErrnoSetToZeroAfterCall.ql

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