Export of internal Abseil changes

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167cd2647144583746311129b0cc98a89a9897e1 by Andy Soffer <asoffer@google.com>:

Internal Changes

PiperOrigin-RevId: 268000987

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ab44fea7dfdaf763c69609a08ddfac22480ce520 by Derek Mauro <dmauro@google.com>:

Fix flags Cmake tests on Windows

PiperOrigin-RevId: 267859442

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d7ec9f7611370b01bc9a5aed7e18460df2a15429 by Abseil Team <absl-team@google.com>:

Fix undefined behavior in symbolize_elf.inc

PiperOrigin-RevId: 267684904

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e7c5f8e472a91ed99bdf4876942f2bda5751aa6c by Abseil Team <absl-team@google.com>:

Turn off ABSL_HAS_ALARM on Fuchsia.

PiperOrigin-RevId: 267666090

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b7d25d5c71a49e697a8bf6440ed30f2e3f036420 by Chris Kennelly <ckennelly@google.com>:

Mark once initialization function as no inline.

We expect this code to run infrequently.

PiperOrigin-RevId: 267649713

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dc2a5e5f1e39a03fff837d34a319033fde55d9ba by Derek Mauro <dmauro@google.com>:

Fix the MSVC CMake random build

PiperOrigin-RevId: 267624074

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ba2751b67fa17d1b6c53e5ba79f81a5371e4a03a by Abseil Team <absl-team@google.com>:

Move "internal/flag.*" files to the "internal" build target.

PiperOrigin-RevId: 267588996

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05b985a33eec4f8acff1809ad9218a1e22220f34 by Abseil Team <absl-team@google.com>:

Move "internal/flag.*" files to the "internal" build target.

PiperOrigin-RevId: 267580412
GitOrigin-RevId: 167cd2647144583746311129b0cc98a89a9897e1
Change-Id: Ibd334f46a5671c7c1d3fcf5354029e2fbb7ba91f
This commit is contained in:
Abseil Team 2019-09-09 08:20:10 -07:00 committed by Shaindel Schwartz
parent 325fd7b042
commit 97c1664b4b
14 changed files with 154 additions and 62 deletions

View file

@ -624,6 +624,13 @@ static bool InSection(const void *address, const ElfW(Shdr) * section) {
return start <= address && address < (start + size);
}
static const char *ComputeOffset(const char *base, ptrdiff_t offset) {
// Note: cast to uintptr_t to avoid undefined behavior when base evaluates to
// zero and offset is non-zero.
return reinterpret_cast<const char *>(
reinterpret_cast<uintptr_t>(base) + offset);
}
// Read a symbol table and look for the symbol containing the
// pc. Iterate over symbols in a symbol table and look for the symbol
// containing "pc". If the symbol is found, and its name fits in
@ -676,7 +683,8 @@ static ABSL_ATTRIBUTE_NOINLINE FindSymbolResult FindSymbol(
// We keep the original address for opd redirection below.
const char *const original_start_address =
reinterpret_cast<const char *>(symbol.st_value);
const char *start_address = original_start_address + relocation;
const char *start_address =
ComputeOffset(original_start_address, relocation);
if (deref_function_descriptor_pointer &&
InSection(original_start_address, opd)) {
@ -688,8 +696,7 @@ static ABSL_ATTRIBUTE_NOINLINE FindSymbolResult FindSymbol(
// If pc is inside the .opd section, it points to a function descriptor.
const size_t size = pc_in_opd ? kFunctionDescriptorSize : symbol.st_size;
const void *const end_address =
reinterpret_cast<const char *>(start_address) + size;
const void *const end_address = ComputeOffset(start_address, size);
if (symbol.st_value != 0 && // Skip null value symbols.
symbol.st_shndx != 0 && // Skip undefined symbols.
#ifdef STT_TLS