Add a dynamic check for pointer arithmetic of null pointers #663
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This is a cleaned-up version of #647 with all git merge conflicts resolved. |
Pointer arithmetic was done before checking for null. This bug is uncovered by inserting dynamic null ptr checks in checkedc/checkedc-clang#663.
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This patch uncovered a bug in checkedc-parson: microsoft/checkedc-parson#18 |
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This change looks good. There appears to be a typo where a function is called twice.
Could you add dynamic tests for the Checked C repo that check the null pointer arithmetic properly fails? These tests should be placed in a new subdirectory of tests/dynamic_checking.
lib/CodeGen/CGDynamicCheck.cpp
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| ++NumDynamicChecksNonNull; | ||
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| Value *ConditionVal = Builder.CreateIsNotNull(Val, "_Dynamic_check.non_null"); | ||
| EmitDynamicCheckBlocks(ConditionVal); EmitDynamicCheckBlocks(ConditionVal); |
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It looks like EmitDynamicCheckBlocks is being called twice here.
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| // RUN: %clang_cc1 -fcheckedc-extension -verify -verify-ignore-unexpected=note %s -ast-dump | FileCheck %s --check-prefix=CHECK-AST | |||
| // RUN: %clang_cc1 -fcheckedc-extension -verify -verify-ignore-unexpected=note %s -emit-llvm -O0 -o - | FileCheck %s --check-prefix=CHECK-IR | |||
| // RUN: %clang_cc1 -fcheckedc-extension -fno-checkedc-null-ptr-arith -verify -verify-ignore-unexpected=note %s -emit-llvm -O0 -o - | FileCheck %s --check-prefix=CHECK-IR | |||
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By default, null ptr arithmetic checks are enabled. This breaks a few test cases which perform ptr arithmetic but which do not expect the checks. So I had to add the flag -fno-checkedc-null-ptr-arith to keep these tests from breaking.
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The runtime tests for null ptr arithmetic have been added in checkedc/checkedc#378 |
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Looks great, thank you!
Please open a GitHub issue for improving the tests. You and I discuss this in-person. We should update the codegen tests where we are currently disabling null-pointer arithmetic checks. In addition, the tests should cover local variables and parameters.
Done #669. |
Cherry-picked from commit b242b14 * Add a dynamic check for pointer arithmetic of null pointers
…crosoft-20210803 Merge from Microsoft 2021-08-03
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