[llvm] r175063 - [ms-inline-asm] Use an array_pod_sort, rather than a std:sort.

Timur Iskhodzhanov timurrrr at google.com
Fri Feb 15 22:40:45 PST 2013


Yes, my bot is green again since r175317 - thanks!

2013/2/16 Chad Rosier <mcrosier at apple.com>:
> I believe r175317 should take care of things.  Thanks for the great test case.
>
>  Chad
>
> On Feb 15, 2013, at 10:37 AM, Timur Iskhodzhanov <timurrrr at google.com> wrote:
>
>> I can do better than that =P
>>
>> Here's a minimized repro:
>> ---------
>> int f(int a, int b) {
>>  __asm{
>>    mov     ecx, b;
>>    mov     eax, dword ptr [a];
>>    mov     edx, dword ptr [a+4];
>>    shld    edx, eax, cl;
>>    shl     eax, cl;
>>  }
>> }
>> ---------
>> clang -Xclang -cxx-abi -Xclang microsoft source.cpp
>>
>> 2013/2/15 Chad Rosier <mcrosier at apple.com>:
>>> Would you mind attaching the preprocessed source and crash script?
>>>
>>> clang: note: diagnostic msg: C:/Users/timurrrr/AppData/Local/Temp/windowsh_pass-036380.cpp
>>> clang: note: diagnostic msg: C:/Users/timurrrr/AppData/Local/Temp/windowsh_pass-036380.sh
>>>
>>> Chad
>>>
>>> On Feb 15, 2013, at 9:39 AM, Timur Iskhodzhanov <timurrrr at google.com> wrote:
>>>
>>>> Attached is the stacktrace just in case
>>>>
>>>> 2013/2/15 Timur Iskhodzhanov <timurrrr at google.com>:
>>>>> OK, here we go.
>>>>>
>>>>> The crash happens if you "#include <windows.h>" on a machine with
>>>>> VS2010 installed (other versions might be affected too).
>>>>>
>>>>> Here's a patch that adds an assert that crashes:
>>>>> ---------------------------------------------------------------------------------
>>>>> diff --git lib/MC/MCParser/AsmParser.cpp lib/MC/MCParser/AsmParser.cpp
>>>>> index 2cce8b0..1cfd5f6 100644
>>>>> --- lib/MC/MCParser/AsmParser.cpp
>>>>> +++ lib/MC/MCParser/AsmParser.cpp
>>>>> @@ -4174,8 +4174,10 @@ bool AsmParser::ParseMSInlineAsm(void *AsmLoc,
>>>>> std::string &AsmString,
>>>>>
>>>>>    // Emit everything up to the immediate/expression.  If the previous rewrite
>>>>>    // was a size directive, then this has already been done.
>>>>> -    if (PrevKind != AOK_SizeDirective)
>>>>> +    if (PrevKind != AOK_SizeDirective) {
>>>>> +      assert(Loc >= Start);
>>>>>      OS << StringRef(Start, Loc - Start);
>>>>> +    }
>>>>>    PrevKind = Kind;
>>>>>
>>>>>    // Skip the original expression.
>>>>> ---------------------------------------------------------------------------------
>>>>>
>>>>>
>>>>> I hope that's enough info to debug :)
>>>>>
>>>>>
>>>>> FYI The bug was hard to debug as a substantial part of memory was
>>>>> corrupted (including EBPs, return addresses etc)
>>>>> so I propose something like this to prevent such bugs from re-appearing:
>>>>> ---------------------------------------------------------------------------------
>>>>> diff --git include/llvm/ADT/StringRef.h include/llvm/ADT/StringRef.h
>>>>> index 1e21d92..077c056 100644
>>>>> --- include/llvm/ADT/StringRef.h
>>>>> +++ include/llvm/ADT/StringRef.h
>>>>> @@ -84,6 +84,7 @@ namespace llvm {
>>>>>      : Data(data), Length(length) {
>>>>>        assert((data || length == 0) &&
>>>>>        "StringRef cannot be built from a NULL argument with non-null length");
>>>>> +        assert(length < 0x80000000 && "length looks suspicious");
>>>>>      }
>>>>>
>>>>>    /// Construct a string ref from an std::string.
>>>>> ---------------------------------------------------------------------------------
>>>>>
>>>>> 2013/2/15 Timur Iskhodzhanov <timurrrr at google.com>:
>>>>>> FYI this crashes on my Windows bot.
>>>>>>
>>>>>> I'll update with the details when I reproduce locally.
>>>>>>
>>>>>> 2013/2/13 Chad Rosier <mcrosier at apple.com>:
>>>>>>> Author: mcrosier
>>>>>>> Date: Wed Feb 13 12:38:58 2013
>>>>>>> New Revision: 175063
>>>>>>>
>>>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=175063&view=rev
>>>>>>> Log:
>>>>>>> [ms-inline-asm] Use an array_pod_sort, rather than a std:sort.
>>>>>>>
>>>>>>>
>>>>>>> Modified:
>>>>>>>   llvm/trunk/lib/MC/MCParser/AsmParser.cpp
>>>>>>>
>>>>>>> Modified: llvm/trunk/lib/MC/MCParser/AsmParser.cpp
>>>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCParser/AsmParser.cpp?rev=175063&r1=175062&r2=175063&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/lib/MC/MCParser/AsmParser.cpp (original)
>>>>>>> +++ llvm/trunk/lib/MC/MCParser/AsmParser.cpp Wed Feb 13 12:38:58 2013
>>>>>>> @@ -13,6 +13,7 @@
>>>>>>>
>>>>>>> #include "llvm/ADT/APFloat.h"
>>>>>>> #include "llvm/ADT/SmallString.h"
>>>>>>> +#include "llvm/ADT/STLExtras.h"
>>>>>>> #include "llvm/ADT/StringMap.h"
>>>>>>> #include "llvm/ADT/Twine.h"
>>>>>>> #include "llvm/MC/MCAsmInfo.h"
>>>>>>> @@ -4029,8 +4030,14 @@ bool AsmParser::ParseDirectiveMSAlign(SM
>>>>>>>  return false;
>>>>>>> }
>>>>>>>
>>>>>>> -bool AsmStringSort (AsmRewrite A, AsmRewrite B) {
>>>>>>> -  return A.Loc.getPointer() < B.Loc.getPointer();
>>>>>>> +static int RewritesSort (const void *A, const void *B) {
>>>>>>> +  const AsmRewrite *AsmRewriteA = static_cast<const AsmRewrite*>(A);
>>>>>>> +  const AsmRewrite *AsmRewriteB = static_cast<const AsmRewrite*>(B);
>>>>>>> +  if (AsmRewriteA->Loc.getPointer() < AsmRewriteB->Loc.getPointer())
>>>>>>> +    return -1;
>>>>>>> +  if (AsmRewriteB->Loc.getPointer() < AsmRewriteA->Loc.getPointer())
>>>>>>> +    return 1;
>>>>>>> +  return 0;
>>>>>>> }
>>>>>>>
>>>>>>> bool AsmParser::ParseMSInlineAsm(void *AsmLoc, std::string &AsmString,
>>>>>>> @@ -4157,7 +4164,7 @@ bool AsmParser::ParseMSInlineAsm(void *A
>>>>>>>  AsmRewriteKind PrevKind = AOK_Imm;
>>>>>>>  raw_string_ostream OS(AsmStringIR);
>>>>>>>  const char *Start = SrcMgr.getMemoryBuffer(0)->getBufferStart();
>>>>>>> -  std::sort (AsmStrRewrites.begin(), AsmStrRewrites.end(), AsmStringSort);
>>>>>>> +  array_pod_sort (AsmStrRewrites.begin(), AsmStrRewrites.end(), RewritesSort);
>>>>>>>  for (SmallVectorImpl<struct AsmRewrite>::iterator
>>>>>>>         I = AsmStrRewrites.begin(), E = AsmStrRewrites.end(); I != E; ++I) {
>>>>>>>    const char *Loc = (*I).Loc.getPointer();
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> llvm-commits mailing list
>>>>>>> llvm-commits at cs.uiuc.edu
>>>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>>>
>>>> 2013/2/15 Timur Iskhodzhanov <timurrrr at google.com>:
>>>>> OK, here we go.
>>>>>
>>>>> The crash happens if you "#include <windows.h>" on a machine with
>>>>> VS2010 installed (other versions might be affected too).
>>>>>
>>>>> Here's a patch that adds an assert that crashes:
>>>>> ---------------------------------------------------------------------------------
>>>>> diff --git lib/MC/MCParser/AsmParser.cpp lib/MC/MCParser/AsmParser.cpp
>>>>> index 2cce8b0..1cfd5f6 100644
>>>>> --- lib/MC/MCParser/AsmParser.cpp
>>>>> +++ lib/MC/MCParser/AsmParser.cpp
>>>>> @@ -4174,8 +4174,10 @@ bool AsmParser::ParseMSInlineAsm(void *AsmLoc,
>>>>> std::string &AsmString,
>>>>>
>>>>>    // Emit everything up to the immediate/expression.  If the previous rewrite
>>>>>    // was a size directive, then this has already been done.
>>>>> -    if (PrevKind != AOK_SizeDirective)
>>>>> +    if (PrevKind != AOK_SizeDirective) {
>>>>> +      assert(Loc >= Start);
>>>>>      OS << StringRef(Start, Loc - Start);
>>>>> +    }
>>>>>    PrevKind = Kind;
>>>>>
>>>>>    // Skip the original expression.
>>>>> ---------------------------------------------------------------------------------
>>>>>
>>>>>
>>>>> I hope that's enough info to debug :)
>>>>>
>>>>>
>>>>> FYI The bug was hard to debug as a substantial part of memory was
>>>>> corrupted (including EBPs, return addresses etc)
>>>>> so I propose something like this to prevent such bugs from re-appearing:
>>>>> ---------------------------------------------------------------------------------
>>>>> diff --git include/llvm/ADT/StringRef.h include/llvm/ADT/StringRef.h
>>>>> index 1e21d92..077c056 100644
>>>>> --- include/llvm/ADT/StringRef.h
>>>>> +++ include/llvm/ADT/StringRef.h
>>>>> @@ -84,6 +84,7 @@ namespace llvm {
>>>>>      : Data(data), Length(length) {
>>>>>        assert((data || length == 0) &&
>>>>>        "StringRef cannot be built from a NULL argument with non-null length");
>>>>> +        assert(length < 0x80000000 && "length looks suspicious");
>>>>>      }
>>>>>
>>>>>    /// Construct a string ref from an std::string.
>>>>> ---------------------------------------------------------------------------------
>>>>>
>>>>> 2013/2/15 Timur Iskhodzhanov <timurrrr at google.com>:
>>>>>> FYI this crashes on my Windows bot.
>>>>>>
>>>>>> I'll update with the details when I reproduce locally.
>>>>>>
>>>>>> 2013/2/13 Chad Rosier <mcrosier at apple.com>:
>>>>>>> Author: mcrosier
>>>>>>> Date: Wed Feb 13 12:38:58 2013
>>>>>>> New Revision: 175063
>>>>>>>
>>>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=175063&view=rev
>>>>>>> Log:
>>>>>>> [ms-inline-asm] Use an array_pod_sort, rather than a std:sort.
>>>>>>>
>>>>>>>
>>>>>>> Modified:
>>>>>>>   llvm/trunk/lib/MC/MCParser/AsmParser.cpp
>>>>>>>
>>>>>>> Modified: llvm/trunk/lib/MC/MCParser/AsmParser.cpp
>>>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCParser/AsmParser.cpp?rev=175063&r1=175062&r2=175063&view=diff
>>>>>>> ==============================================================================
>>>>>>> --- llvm/trunk/lib/MC/MCParser/AsmParser.cpp (original)
>>>>>>> +++ llvm/trunk/lib/MC/MCParser/AsmParser.cpp Wed Feb 13 12:38:58 2013
>>>>>>> @@ -13,6 +13,7 @@
>>>>>>>
>>>>>>> #include "llvm/ADT/APFloat.h"
>>>>>>> #include "llvm/ADT/SmallString.h"
>>>>>>> +#include "llvm/ADT/STLExtras.h"
>>>>>>> #include "llvm/ADT/StringMap.h"
>>>>>>> #include "llvm/ADT/Twine.h"
>>>>>>> #include "llvm/MC/MCAsmInfo.h"
>>>>>>> @@ -4029,8 +4030,14 @@ bool AsmParser::ParseDirectiveMSAlign(SM
>>>>>>>  return false;
>>>>>>> }
>>>>>>>
>>>>>>> -bool AsmStringSort (AsmRewrite A, AsmRewrite B) {
>>>>>>> -  return A.Loc.getPointer() < B.Loc.getPointer();
>>>>>>> +static int RewritesSort (const void *A, const void *B) {
>>>>>>> +  const AsmRewrite *AsmRewriteA = static_cast<const AsmRewrite*>(A);
>>>>>>> +  const AsmRewrite *AsmRewriteB = static_cast<const AsmRewrite*>(B);
>>>>>>> +  if (AsmRewriteA->Loc.getPointer() < AsmRewriteB->Loc.getPointer())
>>>>>>> +    return -1;
>>>>>>> +  if (AsmRewriteB->Loc.getPointer() < AsmRewriteA->Loc.getPointer())
>>>>>>> +    return 1;
>>>>>>> +  return 0;
>>>>>>> }
>>>>>>>
>>>>>>> bool AsmParser::ParseMSInlineAsm(void *AsmLoc, std::string &AsmString,
>>>>>>> @@ -4157,7 +4164,7 @@ bool AsmParser::ParseMSInlineAsm(void *A
>>>>>>>  AsmRewriteKind PrevKind = AOK_Imm;
>>>>>>>  raw_string_ostream OS(AsmStringIR);
>>>>>>>  const char *Start = SrcMgr.getMemoryBuffer(0)->getBufferStart();
>>>>>>> -  std::sort (AsmStrRewrites.begin(), AsmStrRewrites.end(), AsmStringSort);
>>>>>>> +  array_pod_sort (AsmStrRewrites.begin(), AsmStrRewrites.end(), RewritesSort);
>>>>>>>  for (SmallVectorImpl<struct AsmRewrite>::iterator
>>>>>>>         I = AsmStrRewrites.begin(), E = AsmStrRewrites.end(); I != E; ++I) {
>>>>>>>    const char *Loc = (*I).Loc.getPointer();
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> llvm-commits mailing list
>>>>>>> llvm-commits at cs.uiuc.edu
>>>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>>> <crashstack.txt>
>>>
>



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