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 <whitequ...@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 <hinto...@gmail.com>
wrote:

On Mon, Dec 25, 2017 at 11:09 AM, whitequark
<whitequ...@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@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"

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Links:
------
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[2]

http://llvm.org/viewvc/llvm-project/libunwind/trunk/src/DwarfParser.hpp?rev=321440&amp;r1=321439&amp;r2=321440&amp;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&amp;view=rev
[2]
http://llvm.org/viewvc/llvm-project/libunwind/trunk/src/DwarfParser.hpp?rev=321440&amp;r1=321439&amp;r2=321440&amp;view=diff
[3] http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
[4] http://llvm.org/viewvc/llvm-project?rev=321440&amp;amp;view=rev
[5]
http://llvm.org/viewvc/llvm-project/libunwind/trunk/src/DwarfParser.hpp?rev=321440&amp;amp;r1=321439&amp;amp;r2=321440&amp;amp;view=diff

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