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path: root/clang/lib/CodeGen/CGExpr.cpp
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2017-08-15Extract IRGen's constant-emitter into its own helper class and clean upJohn McCall
the interface. The ultimate goal here is to make it easier to do some more interesting things in constant emission, like emit constant initializers that have ignorable side-effects, or doing the majority of an initialization in-place and then patching up the last few things with calls. But for now this is mostly just a refactoring. llvm-svn: 310964
2017-08-04Add OpenCL 2.0 atomic builtin functions as Clang builtinYaxun Liu
OpenCL 2.0 atomic builtin functions have a scope argument which is ideally represented as synchronization scope argument in LLVM atomic instructions. Clang supports translating Clang atomic builtin functions to LLVM atomic instructions. However it currently does not support synchronization scope of LLVM atomic instructions. Without this, users have to use LLVM assembly code to implement OpenCL atomic builtin functions. This patch adds OpenCL 2.0 atomic builtin functions as Clang builtin functions, which supports generating LLVM atomic instructions with synchronization scope operand. Currently only constant memory scope argument is supported. Support of non-constant memory scope argument will be added later. Differential Revision: https://reviews.llvm.org/D28691 llvm-svn: 310082
2017-08-02[ubsan] Have -fsanitize=vptr emit a null check if -fsanitize=null isn't ↵Vedant Kumar
available In r309007, I made -fsanitize=null a hard prerequisite for -fsanitize=vptr. I did not see the need for the two checks to have separate null checking logic for the same pointer. I expected the two checks to either always be enabled together, or to be mutually compatible. In the mailing list discussion re: r309007 it became clear that that isn't the case. If a codebase is -fsanitize=vptr clean but not -fsanitize=null clean, it's useful to have -fsanitize=vptr emit its own null check. That's what this patch does: with it, -fsanitize=vptr can be used without -fsanitize=null. Differential Revision: https://reviews.llvm.org/D36112 llvm-svn: 309846
2017-07-25[ubsan] Null-check pointers in -fsanitize=vptr (PR33881)Vedant Kumar
The instrumentation generated by -fsanitize=vptr does not null check a user pointer before loading from it. This causes crashes in the face of UB member calls (this=nullptr), i.e it's causing user programs to crash only after UBSan is turned on. The fix is to make run-time null checking a prerequisite for enabling -fsanitize=vptr, and to then teach UBSan to reuse these run-time null checks to make -fsanitize=vptr safe. Testing: check-clang, check-ubsan, a stage2 ubsan-enabled build Differential Revision: https://reviews.llvm.org/D35735 https://bugs.llvm.org/show_bug.cgi?id=33881 llvm-svn: 309007
2017-07-18CodeGen: Insert addr space cast for automatic/temp var at right positionYaxun Liu
The uses of alloca may be in different blocks other than the block containing the alloca. Therefore if the alloca addr space is non-zero and it needs to be casted to default address space, the cast needs to be inserted in the same BB as the alloca insted of the current builder insert point since the current insert point may be in a different BB. Differential Revision: https://reviews.llvm.org/D35438 llvm-svn: 308313
2017-07-13[ubsan] Teach the pointer overflow check that "p - <unsigned> <= p" (PR33430)Vedant Kumar
The pointer overflow check gives false negatives when dealing with expressions in which an unsigned value is subtracted from a pointer. This is summarized in PR33430 [1]: ubsan permits the result of the subtraction to be greater than "p", but it should not. To fix the issue, we should track whether or not the pointer expression is a subtraction. If it is, and the indices are unsigned, we know to expect "p - <unsigned> <= p". I've tested this by running check-{llvm,clang} with a stage2 ubsan-enabled build. I've also added some tests to compiler-rt, which are in D34122. [1] https://bugs.llvm.org/show_bug.cgi?id=33430 Differential Revision: https://reviews.llvm.org/D34121 llvm-svn: 307955
2017-07-08CodeGen: Fix address space of global variableYaxun Liu
Certain targets (e.g. amdgcn) require global variable to stay in global or constant address space. In C or C++ global variables are emitted in the default (generic) address space. This patch introduces virtual functions TargetCodeGenInfo::getGlobalVarAddressSpace and TargetInfo::getConstantAddressSpace to handle this in a general approach. It only affects IR generated for amdgcn target. Differential Revision: https://reviews.llvm.org/D33842 llvm-svn: 307470
2017-06-19CodeGen: Cast temporary variable to proper address spaceYaxun Liu
In C++ all variables are in default address space. Previously change has been made to cast automatic variables to default address space. However that is not sufficient since all temporary variables need to be casted to default address space. This patch casts all temporary variables to default address space except those for passing indirect arguments since they are only used for load/store. This patch only affects target having non-zero alloca address space. Differential Revision: https://reviews.llvm.org/D33706 llvm-svn: 305711
2017-06-16[ubsan] PR33081: Skip the standard type checks for volatileVedant Kumar
Skip checks for null dereference, alignment violation, object size violation, and dynamic type violation if the pointer points to volatile data. Differential Revision: https://reviews.llvm.org/D34262 llvm-svn: 305546
2017-06-15[coroutines] Allow co_await and co_yield expressions that return an lvalue ↵Eric Fiselier
to compile Summary: The title says it all. Reviewers: GorNishanov, rsmith Reviewed By: GorNishanov Subscribers: rjmccall, cfe-commits Differential Revision: https://reviews.llvm.org/D34194 llvm-svn: 305496
2017-06-12[ubsan] Detect invalid unsigned pointer index expression (clang)Vedant Kumar
Adding an unsigned offset to a base pointer has undefined behavior if the result of the expression would precede the base. An example from @regehr: int foo(char *p, unsigned offset) { return p + offset >= p; // This may be optimized to '1'. } foo(p, -1); // UB. This patch extends the pointer overflow check in ubsan to detect invalid unsigned pointer index expressions. It changes the instrumentation to only permit non-negative offsets in pointer index expressions when all of the GEP indices are unsigned. Testing: check-llvm, check-clang run on a stage2, ubsan-instrumented build. Differential Revision: https://reviews.llvm.org/D33910 llvm-svn: 305216
2017-06-09[DebugInfo] Add kind of ImplicitParamDecl for emission of FlagObjectPointer.Alexey Bataev
Summary: If the first parameter of the function is the ImplicitParamDecl, codegen automatically marks it as an implicit argument with `this` or `self` pointer. Added internal kind of the ImplicitParamDecl to separate 'this', 'self', 'vtt' and other implicit parameters from other kind of parameters. Reviewers: rjmccall, aaron.ballman Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D33735 llvm-svn: 305075
2017-06-01Don't assume that a store source is a vector type just because the ↵Simon Pilgrim
destination is (PR26099) llvm-svn: 304465
2017-06-01[ubsan] Add a check for pointer overflow UBVedant Kumar
Check pointer arithmetic for overflow. For some more background on this check, see: https://wdtz.org/catching-pointer-overflow-bugs.html https://reviews.llvm.org/D20322 Patch by Will Dietz and John Regehr! This version of the patch is different from the original in a few ways: - It introduces the EmitCheckedInBoundsGEP utility which inserts checks when the pointer overflow check is enabled. - It does some constant-folding to reduce instrumentation overhead. - It does not check some GEPs in CGExprCXX. I'm not sure that inserting checks here, or in CGClass, would catch many bugs. Possible future directions for this check: - Introduce CGF.EmitCheckedStructGEP, to detect overflows when accessing structures. Testing: Apart from the added lit test, I ran check-llvm and check-clang with a stage2, ubsan-instrumented clang. Will and John have also done extensive testing on numerous open source projects. Differential Revision: https://reviews.llvm.org/D33305 llvm-svn: 304459
2017-06-01Emit invariant.group.barrier when using union fieldPiotr Padlewski
Summary: We need to emit barrier if the union field is CXXRecordDecl because it might have vptrs. The testcode was wrongly devirtualized. It also proves that having different groups for different dynamic types is not sufficient. Reviewers: rjmccall, rsmith, mehdi_amini Subscribers: amharc, cfe-commits Differential Revision: https://reviews.llvm.org/D31830 llvm-svn: 304448
2017-05-25[CodeGen] Pessimize aliasing for member unions (and may-alias) objectsKrzysztof Parzyszek
Use the TBAA info of the omnipotent char for these objects. Differential Revision: https://reviews.llvm.org/D33328 llvm-svn: 303851
2017-05-18[CodeGen] Propagate LValueBaseInfo instead of AlignmentSourceKrzysztof Parzyszek
The functions creating LValues propagated information about alignment source. Extend the propagated data to also include information about possible unrestricted aliasing. A new class LValueBaseInfo will contain both AlignmentSource and MayAlias info. This patch should not introduce any functional changes. Differential Revision: https://reviews.llvm.org/D33284 llvm-svn: 303358
2017-05-09Suppress all uses of LLVM_END_WITH_NULL. NFC.Serge Guelton
Use variadic templates instead of relying on <cstdarg> + sentinel. This enforces better type checking and makes code more readable. Differential revision: https://reviews.llvm.org/D32550 llvm-svn: 302572
2017-04-26[ubsan] nullability-assign: Check assignments into C++ structsVedant Kumar
Fix the nullability-assign check so that it can handle assignments into C++ structs. Previously, such assignments were not instrumented. Testing: check-clang, check-ubsan, enabling the existing test in ObjC++ mode, and building some Apple frameworks with -fsanitize=nullability. llvm-svn: 301482
2017-04-26[ubsan] Skip alignment checks on allocas with known alignmentVedant Kumar
It's possible to determine the alignment of an alloca at compile-time. Use this information to skip emitting some runtime alignment checks. Testing: check-clang, check-ubsan. This significantly reduces the amount of alignment checks we emit when compiling X86ISelLowering.cpp. Here are the numbers from patched/unpatched clangs based on r301361. ------------------------------------------ | Setup | # of alignment checks | ------------------------------------------ | unpatched, -O0 | 47195 | | patched, -O0 | 30876 | (-34.6%) ------------------------------------------ llvm-svn: 301377
2017-04-17[ubsan] Skip null checks if they are constant-folded awayVedant Kumar
The IR builder can constant-fold null checks if the pointer operand points to a constant. If the "is-non-null" check is folded away to "true", don't emit the null check + branch. Testing: check-clang, check-ubsan. This slightly reduces the amount of null checks we emit when compiling X86ISelLowering.cpp. Here are the numbers from patched/unpatched clangs based on r300371. ------------------------------------- | Setup | # of null checks | ------------------------------------- | unpatched, -O0 | 25251 | | patched, -O0 | 23925 | (-5.3%) ------------------------------------- llvm-svn: 300509
2017-04-17[ubsan] Skip null checks on pointers to the start of an allocaVedant Kumar
Pointers to the start of an alloca are non-null, so we don't need to emit runtime null checks for them. Testing: check-clang, check-ubsan. This significantly reduces the amount of null checks we emit when compiling X86ISelLowering.cpp. Here are the numbers from patched / unpatched clangs based on r300371. ------------------------------------- | Setup | # of null checks | ------------------------------------- | unpatched, -O0 | 45439 | | patched, -O0 | 25251 | (-44.4%) ------------------------------------- llvm-svn: 300508
2017-04-14[ubsan] Don't check alignment if the alignment is 1Vedant Kumar
If a pointer is 1-byte aligned, there's no use in checking its alignment. Somewhat surprisingly, ubsan can spend a significant amount of time doing just that! This loosely depends on D30283. Testing: check-clang, check-ubsan, and a stage2 ubsan build. Differential Revision: https://reviews.llvm.org/D30285 llvm-svn: 300371
2017-04-14[ubsan] Reduce alignment checking of C++ object pointersVedant Kumar
This patch teaches ubsan to insert an alignment check for the 'this' pointer at the start of each method/lambda. This allows clang to emit significantly fewer alignment checks overall, because if 'this' is aligned, so are its fields. This is essentially the same thing r295515 does, but for the alignment check instead of the null check. One difference is that we keep the alignment checks on member expressions where the base is a DeclRefExpr. There's an opportunity to diagnose unaligned accesses in this situation (as pointed out by Eli, see PR32630). Testing: check-clang, check-ubsan, and a stage2 ubsan build. Along with the patch from D30285, this roughly halves the amount of alignment checks we emit when compiling X86FastISel.cpp. Here are the numbers from patched/unpatched clangs based on r298160. ------------------------------------------ | Setup | # of alignment checks | ------------------------------------------ | unpatched, -O0 | 24326 | | patched, -O0 | 12717 | (-47.7%) ------------------------------------------ Differential Revision: https://reviews.llvm.org/D30283 llvm-svn: 300370
2017-04-10Update for AllocaInst construction changesMatt Arsenault
llvm-svn: 299889
2017-04-07[cfi] Emit __cfi_check stub in the frontend.Evgeniy Stepanov
Previously __cfi_check was created in LTO optimization pipeline, which means LLD has no way of knowing about the existence of this symbol without rescanning the LTO output object. As a result, LLD fails to export __cfi_check, even when given --export-dynamic-symbol flag. llvm-svn: 299806
2017-04-04Preserve vec3 type.Jin-Gu Kang
Summary: Preserve vec3 type with CodeGen option. Reviewers: Anastasia, bruno Reviewed By: Anastasia Subscribers: bruno, ahatanak, cfe-commits Differential Revision: https://reviews.llvm.org/D30810 llvm-svn: 299445
2017-03-21Let llvm.objectsize be conservative with null pointersGeorge Burgess IV
D28494 adds another parameter to @llvm.objectsize. Clang needs to be sure to pass that third arg whenever applicable. llvm-svn: 298431
2017-03-21Update Clang for LLVM rename AttributeSet -> AttributeListReid Kleckner
llvm-svn: 298394
2017-03-09Retry: [ubsan] Detect UB loads from bitfieldsVedant Kumar
It's possible to load out-of-range values from bitfields backed by a boolean or an enum. Check for UB loads from bitfields. This is the motivating example: struct S { BOOL b : 1; // Signed ObjC BOOL. }; S s; s.b = 1; // This is actually stored as -1. if (s.b == 1) // Evaluates to false, -1 != 1. ... Changes since the original commit: - Single-bit bools are a special case (see CGF::EmitFromMemory), and we can't avoid dealing with them when loading from a bitfield. Don't try to insert a check in this case. Differential Revision: https://reviews.llvm.org/D30423 llvm-svn: 297389
2017-03-09Revert "[ubsan] Detect UB loads from bitfields"Vedant Kumar
This reverts commit r297298. It breaks the self-host on this bot: http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/962/steps/build%20clang%2Fubsan/logs/stdio llvm-svn: 297331
2017-03-08[ubsan] Detect UB loads from bitfieldsVedant Kumar
It's possible to load out-of-range values from bitfields backed by a boolean or an enum. Check for UB loads from bitfields. This is the motivating example: struct S { BOOL b : 1; // Signed ObjC BOOL. }; S s; s.b = 1; // This is actually stored as -1. if (s.b == 1) // Evaluates to false, -1 != 1. ... Differential Revision: https://reviews.llvm.org/D30423 llvm-svn: 297298
2017-03-06Don't assume cleanup emission preserves dominance in expr evaluationReid Kleckner
Summary: Because of the existence branches out of GNU statement expressions, it is possible that emitting cleanups for a full expression may cause the new insertion point to not be dominated by the result of the inner expression. Consider this example: struct Foo { Foo(); ~Foo(); int x; }; int g(Foo, int); int f(bool cond) { int n = g(Foo(), ({ if (cond) return 0; 42; })); return n; } Before this change, result of the call to 'g' did not dominate its use in the store to 'n'. The early return exit from the statement expression branches to a shared cleanup block, which ends in a switch between the fallthrough destination (the assignment to 'n') or the function exit block. This change solves the problem by spilling and reloading expression evaluation results when any of the active cleanups have branches. I audited the other call sites of enterFullExpression, and they don't appear to keep and Values live across the site of the cleanup, except in ARC code. I wasn't able to create a test case for ARC that exhibits this problem, though. Reviewers: rjmccall, rsmith Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D30590 llvm-svn: 297084
2017-02-27[ubsan] Factor out logic to emit a range check. NFC.Vedant Kumar
This is a readability improvement, but it will also help prep an upcoming patch to detect UB loads from bitfields. llvm-svn: 296374
2017-02-23Rename a helper function, NFC.Vedant Kumar
llvm-svn: 295918
2017-02-17Retry^2: [ubsan] Reduce null checking of C++ object pointers (PR27581)Vedant Kumar
This patch teaches ubsan to insert exactly one null check for the 'this' pointer per method/lambda. Previously, given a load of a member variable from an instance method ('this->x'), ubsan would insert a null check for 'this', and another null check for '&this->x', before allowing the load to occur. Similarly, given a call to a method from another method bound to the same instance ('this->foo()'), ubsan would a redundant null check for 'this'. There is also a redundant null check in the case where the object pointer is a reference ('Ref.foo()'). This patch teaches ubsan to remove the redundant null checks identified above. Testing: check-clang, check-ubsan, and a stage2 ubsan build. I also compiled X86FastISel.cpp with -fsanitize=null using patched/unpatched clangs based on r293572. Here are the number of null checks emitted: ------------------------------------- | Setup | # of null checks | ------------------------------------- | unpatched, -O0 | 21767 | | patched, -O0 | 10758 | ------------------------------------- Changes since the initial commit: - Don't introduce any unintentional object-size or alignment checks. - Don't rely on IRGen of C labels in the test. Differential Revision: https://reviews.llvm.org/D29530 llvm-svn: 295515
2017-02-17[ubsan] Pass a set of checks to skip to EmitTypeCheck() (NFC)Vedant Kumar
CodeGenFunction::EmitTypeCheck accepts a bool flag which controls whether or not null checks are emitted. Make this a bit more flexible by changing the bool to a SanitizerSet. Needed for an upcoming change which deals with a scenario in which we only want to emit null checks. llvm-svn: 295514
2017-02-17Revert "Retry: [ubsan] Reduce null checking of C++ object pointers (PR27581)"Vedant Kumar
This reverts commit r295401. It breaks the ubsan self-host. It inserts object size checks once per C++ method which fire when the structure is empty. llvm-svn: 295494
2017-02-17Retry: [ubsan] Reduce null checking of C++ object pointers (PR27581)Vedant Kumar
This patch teaches ubsan to insert exactly one null check for the 'this' pointer per method/lambda. Previously, given a load of a member variable from an instance method ('this->x'), ubsan would insert a null check for 'this', and another null check for '&this->x', before allowing the load to occur. Similarly, given a call to a method from another method bound to the same instance ('this->foo()'), ubsan would a redundant null check for 'this'. There is also a redundant null check in the case where the object pointer is a reference ('Ref.foo()'). This patch teaches ubsan to remove the redundant null checks identified above. Testing: check-clang and check-ubsan. I also compiled X86FastISel.cpp with -fsanitize=null using patched/unpatched clangs based on r293572. Here are the number of null checks emitted: ------------------------------------- | Setup | # of null checks | ------------------------------------- | unpatched, -O0 | 21767 | | patched, -O0 | 10758 | ------------------------------------- Changes since the initial commit: don't rely on IRGen of C labels in the test. Differential Revision: https://reviews.llvm.org/D29530 llvm-svn: 295401
2017-02-17Revert "[ubsan] Reduce null checking of C++ object pointers (PR27581)"Vedant Kumar
This reverts commit r295391. It breaks this bot: http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/1898 I need to not rely on labels in the IR test. llvm-svn: 295396
2017-02-17[ubsan] Reduce null checking of C++ object pointers (PR27581)Vedant Kumar
This patch teaches ubsan to insert exactly one null check for the 'this' pointer per method/lambda. Previously, given a load of a member variable from an instance method ('this->x'), ubsan would insert a null check for 'this', and another null check for '&this->x', before allowing the load to occur. Similarly, given a call to a method from another method bound to the same instance ('this->foo()'), ubsan would a redundant null check for 'this'. There is also a redundant null check in the case where the object pointer is a reference ('Ref.foo()'). This patch teaches ubsan to remove the redundant null checks identified above. Testing: check-clang and check-ubsan. I also compiled X86FastISel.cpp with -fsanitize=null using patched/unpatched clangs based on r293572. Here are the number of null checks emitted: ------------------------------------- | Setup | # of null checks | ------------------------------------- | unpatched, -O0 | 21767 | | patched, -O0 | 10758 | ------------------------------------- Differential Revision: https://reviews.llvm.org/D29530 llvm-svn: 295391
2017-01-06[ubsan] Minimize size of data for type_mismatch (Redo of D19667)Filipe Cabecinhas
Summary: This patch makes the type_mismatch static data 7 bytes smaller (and it ends up being 16 bytes smaller due to alignment restrictions, at least on some x86-64 environments). It revs up the type_mismatch handler version since we're breaking binary compatibility. I will soon post a patch for the compiler-rt side. Reviewers: rsmith, kcc, vitalybuka, pgousseau, gbedwell Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D28242 llvm-svn: 291236
2016-12-23Fix problems in "[OpenCL] Enabling the usage of CLK_NULL_QUEUE as compare ↵Egor Churaev
operand." Summary: Fixed warnings in commit: https://reviews.llvm.org/rL290171 Reviewers: djasper, Anastasia Subscribers: yaxunl, cfe-commits, bader Differential Revision: https://reviews.llvm.org/D27981 llvm-svn: 290431
2016-12-15CodeGen: ubsan is built static on windows, give handlers local storageSaleem Abdulrasool
The UBSAN runtime is built static on Windows. This requires that we give local storage always. This impacts Windows where the linker would otherwise have to generate a thunk to access the symbol via the IAT. This should repair the windows clang build bots. llvm-svn: 289829
2016-12-13CodeGen: clean up -Wpedantic warning (NFC)Saleem Abdulrasool
lib/CodeGen/CGExpr.cpp:2511:2: warning: extra ';' [-Wpedantic] }; ^ Clean up warning from gcc 6. llvm-svn: 289514
2016-12-12Avoid use of std::to_string. NFC.Vedant Kumar
Apparently this routine isn't available on some Android platforms. See the mailing list thread re: D21695. llvm-svn: 289452
2016-12-12[Fix] Add missing include from r289444.Filipe Cabecinhas
llvm-svn: 289446
2016-12-12[clang] Version support for UBSan handlersFilipe Cabecinhas
This adds a way for us to version any UBSan handler by itself. The patch overrides D21289 for a better implementation (we're able to rev up a single handler). After this, then we can land a slight modification of D19667+D19668. We probably don't want to keep all the versions in compiler-rt (maybe we want to deprecate on one release and remove the old handler on the next one?), but with this patch we will loudly fail to compile when mixing incompatible handler calls, instead of silently compiling and then providing bad error messages. Reviewers: kcc, samsonov, rsmith, vsk Subscribers: cfe-commits Differential Revision: https://reviews.llvm.org/D21695 llvm-svn: 289444
2016-12-09[ubsan] Treat ObjC's BOOL as if its range is always {0, 1}Vedant Kumar
On some Apple platforms, the ObjC BOOL type is defined as a signed char. When performing instrumentation for -fsanitize=bool, we'd like to treat the range of BOOL like it's always {0, 1}. While we can't change clang's IRGen for char-backed BOOL's due to ABI compatibility concerns, we can teach ubsan to catch potential abuses of this type. rdar://problem/29502773 Differential Revision: https://reviews.llvm.org/D27607 llvm-svn: 289290
2016-12-06[c++17] P0135R1: Guaranteed copy elision.Richard Smith
When an object of class type is initialized from a prvalue of the same type (ignoring cv qualifications), use the prvalue to initialize the object directly instead of inserting a redundant elidable call to a copy constructor. llvm-svn: 288866