[libunwind] r321440 - [libunwind] Avoid using C++ headers.
whitequark via cfe-commits
cfe-commits at lists.llvm.org
Mon Dec 25 12:06:23 PST 2017
On 2017-12-25 19:43, Don Hinton wrote:
> Here's the patch I applied locally.
>
> hth...
> don
> [snip]
I've committed a slightly beautified version of the patch (below)
as r321446. Cheers!
From 8a4760bafc1123f09438587ee5432eabdec3d33d Mon Sep 17 00:00:00 2001
From: whitequark <whitequark at whitequark.org>
Date: Mon, 25 Dec 2017 20:03:40 +0000
Subject: [PATCH] [libunwind] Unbreak debug builds after r321440.
---
src/DwarfParser.hpp | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/src/DwarfParser.hpp b/src/DwarfParser.hpp
index 518101e..645ac21 100644
--- a/src/DwarfParser.hpp
+++ b/src/DwarfParser.hpp
@@ -17,7 +17,6 @@
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
-#include <limits.h>
#include "libunwind.h"
#include "dwarf2.h"
@@ -26,6 +25,10 @@
namespace libunwind {
+// Avoid relying on C++ headers.
+template <class T>
+static constexpr T pint_max_value() { return ~0; }
+
/// CFI_Parser does basic parsing of a CFI (Call Frame Information)
records.
/// See DWARF Spec for details:
///
http://refspecs.linuxbase.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
@@ -540,7 +543,7 @@ bool CFI_Parser<A>::parseInstructions(A
&addressSpace, pint_t instructions,
results->cfaRegister = 0;
results->cfaExpression = (int64_t)p;
length = addressSpace.getULEB128(p, instructionsEnd);
- assert(length < std::numeric_limits<pint_t>::max() && "pointer
overflow");
+ assert(length < pint_max_value<pint_t>() && "pointer overflow");
p += static_cast<pint_t>(length);
_LIBUNWIND_TRACE_DWARF("DW_CFA_def_cfa_expression(expression=0x%"
PRIx64
", length=%" PRIu64 ")\n",
@@ -556,7 +559,7 @@ bool CFI_Parser<A>::parseInstructions(A
&addressSpace, pint_t instructions,
results->savedRegisters[reg].location = kRegisterAtExpression;
results->savedRegisters[reg].value = (int64_t)p;
length = addressSpace.getULEB128(p, instructionsEnd);
- assert(length < std::numeric_limits<pint_t>::max() && "pointer
overflow");
+ assert(length < pint_max_value<pint_t>() && "pointer overflow");
p += static_cast<pint_t>(length);
_LIBUNWIND_TRACE_DWARF("DW_CFA_expression(reg=%" PRIu64 ", "
"expression=0x%" PRIx64 ", "
@@ -642,7 +645,7 @@ bool CFI_Parser<A>::parseInstructions(A
&addressSpace, pint_t instructions,
results->savedRegisters[reg].location = kRegisterIsExpression;
results->savedRegisters[reg].value = (int64_t)p;
length = addressSpace.getULEB128(p, instructionsEnd);
- assert(length < std::numeric_limits<pint_t>::max() && "pointer
overflow");
+ assert(length < pint_max_value<pint_t>() && "pointer overflow");
p += static_cast<pint_t>(length);
_LIBUNWIND_TRACE_DWARF("DW_CFA_val_expression(reg=%" PRIu64 ", "
"expression=0x%" PRIx64 ", length=%"
PRIu64 ")\n",
--
2.11.0
>
> On Mon, Dec 25, 2017 at 11:26 AM, Don Hinton <hintonda at gmail.com>
> wrote:
>
>> On Mon, Dec 25, 2017 at 11:09 AM, whitequark
>> <whitequark at whitequark.org> wrote:
>> On 2017-12-25 19:04, Don Hinton wrote:
>> Hi:
>>
>> This change breaks in a local debug build, e.g.,:
>>
>>
> /Users/dhinton/projects/llvm_project/libunwind/src/DwarfParser.hpp:559:28:
>> error: no member named 'numeric_limits' in namespace 'std'
>> assert(length < std::numeric_limits<pint_t>::max() && "pointer
>> overflow");
>> ~~~~~^
>>
>> Sorry, I missed this. Any idea on reformulating the assert in a way
>> that does not require libcxx headers? Not having them significantly
>> simplifies bare-metal builds...
>
> Well, assuming pint_t is some unsigned integer type, the max can be
> found like this:
>
> pint_t max_pint_t = ~0;
>
> So, that could be used in a pinch.
>
>> thanks...
>> don
>>
>> On Mon, Dec 25, 2017 at 5:06 AM, whitequark via cfe-commits
>> <cfe-commits at lists.llvm.org> wrote:
>>
>> Author: whitequark
>> Date: Mon Dec 25 05:06:09 2017
>> New Revision: 321440
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=321440&view=rev [1]
>> [1]
>> Log:
>> [libunwind] Avoid using C++ headers.
>>
>> This is useful for building libunwind on libcxx-free systems.
>>
>> Modified:
>> libunwind/trunk/src/DwarfParser.hpp
>>
>> Modified: libunwind/trunk/src/DwarfParser.hpp
>> URL:
>>
>>
> http://llvm.org/viewvc/llvm-project/libunwind/trunk/src/DwarfParser.hpp?rev=321440&r1=321439&r2=321440&view=diff
>> [2]
>> [2]
>>
>>
> ==============================================================================
>> --- libunwind/trunk/src/DwarfParser.hpp (original)
>> +++ libunwind/trunk/src/DwarfParser.hpp Mon Dec 25 05:06:09 2017
>> @@ -17,7 +17,7 @@
>> #include <stdint.h>
>> #include <stdio.h>
>> #include <stdlib.h>
>> -#include <limits>
>> +#include <limits.h>
>>
>> #include "libunwind.h"
>> #include "dwarf2.h"
>>
>> _______________________________________________
>> cfe-commits mailing list
>> cfe-commits at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits [3] [3]
>>
>> Links:
>> ------
>> [1] http://llvm.org/viewvc/llvm-project?rev=321440&view=rev [4]
>> [2]
>>
> http://llvm.org/viewvc/llvm-project/libunwind/trunk/src/DwarfParser.hpp?rev=321440&r1=321439&r2=321440&view=diff
>> [5]
>> [3] http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits [3]
>
> --
> whitequark
>
>
>
> Links:
> ------
> [1] http://llvm.org/viewvc/llvm-project?rev=321440&view=rev
> [2]
> http://llvm.org/viewvc/llvm-project/libunwind/trunk/src/DwarfParser.hpp?rev=321440&r1=321439&r2=321440&view=diff
> [3] http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
> [4] http://llvm.org/viewvc/llvm-project?rev=321440&view=rev
> [5]
> http://llvm.org/viewvc/llvm-project/libunwind/trunk/src/DwarfParser.hpp?rev=321440&r1=321439&r2=321440&view=diff
--
whitequark
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