7 files changed, 214 insertions, 0 deletions
diff --git a/debian/patches/configure.diff b/debian/patches/configure.diff
new file mode 100644
index 00000000..a5a5eef3
--- /dev/null
+++ b/debian/patches/configure.diff
@@ -0,0 +1,82 @@
+From: Benjamin Barenblat <bbaren@google.com>
+Subject: Set package configuration options
+Forwarded: not-needed
+
+Configure Abseil for Debian.
+
+  - Set the SONAME appropriately.
+
+  - To minimize the possibility of future ABI breakage, treat absl::any,
+    absl::optional, absl::string_view, and absl::variant as their own types
+    (rather than aliases for the std:: versions), and compile everything in an
+    inline namespace.
+
+  - Enable upstream's hardened build mode.
+
+--- a/CMake/AbseilHelpers.cmake
++++ b/CMake/AbseilHelpers.cmake
+@@ -298,7 +298,8 @@
+     if(ABSL_ENABLE_INSTALL)
+       set_target_properties(${_NAME} PROPERTIES
+         OUTPUT_NAME "absl_${_NAME}"
+-        SOVERSION "2308.0.0"
++        SOVERSION 20230802
++        VERSION "20230802.0.0"
+       )
+     endif()
+   else()
+--- a/absl/base/options.h
++++ b/absl/base/options.h
+@@ -94,7 +94,7 @@
+ // User code should not inspect this macro.  To check in the preprocessor if
+ // absl::any is a typedef of std::any, use the feature macro ABSL_USES_STD_ANY.
+ 
+-#define ABSL_OPTION_USE_STD_ANY 2
++#define ABSL_OPTION_USE_STD_ANY 0
+ 
+ 
+ // ABSL_OPTION_USE_STD_OPTIONAL
+@@ -121,7 +121,7 @@
+ // absl::optional is a typedef of std::optional, use the feature macro
+ // ABSL_USES_STD_OPTIONAL.
+ 
+-#define ABSL_OPTION_USE_STD_OPTIONAL 2
++#define ABSL_OPTION_USE_STD_OPTIONAL 0
+ 
+ 
+ // ABSL_OPTION_USE_STD_STRING_VIEW
+@@ -148,7 +148,7 @@
+ // absl::string_view is a typedef of std::string_view, use the feature macro
+ // ABSL_USES_STD_STRING_VIEW.
+ 
+-#define ABSL_OPTION_USE_STD_STRING_VIEW 2
++#define ABSL_OPTION_USE_STD_STRING_VIEW 0
+ 
+ // ABSL_OPTION_USE_STD_VARIANT
+ //
+@@ -174,7 +174,7 @@
+ // absl::variant is a typedef of std::variant, use the feature macro
+ // ABSL_USES_STD_VARIANT.
+ 
+-#define ABSL_OPTION_USE_STD_VARIANT 2
++#define ABSL_OPTION_USE_STD_VARIANT 0
+ 
+ 
+ // ABSL_OPTION_USE_INLINE_NAMESPACE
+@@ -200,7 +200,7 @@
+ // allowed.
+ 
+ #define ABSL_OPTION_USE_INLINE_NAMESPACE 1
+-#define ABSL_OPTION_INLINE_NAMESPACE_NAME lts_20230802
++#define ABSL_OPTION_INLINE_NAMESPACE_NAME debian5
+ 
+ // ABSL_OPTION_HARDENED
+ //
+@@ -227,6 +227,6 @@
+ // checks enabled by this option may abort the program in a different way and
+ // log additional information when `NDEBUG` is not defined.
+ 
+-#define ABSL_OPTION_HARDENED 0
++#define ABSL_OPTION_HARDENED 1
+ 
+ #endif  // ABSL_BASE_OPTIONS_H_
diff --git a/debian/patches/cordz-info-statistics-test.diff b/debian/patches/cordz-info-statistics-test.diff
new file mode 100644
index 00000000..646133a1
--- /dev/null
+++ b/debian/patches/cordz-info-statistics-test.diff
@@ -0,0 +1,11 @@
+--- a/absl/strings/internal/cordz_info_statistics_test.cc
++++ b/absl/strings/internal/cordz_info_statistics_test.cc
+@@ -468,6 +468,8 @@
+ }
+ 
+ TEST(CordzInfoStatisticsTest, ThreadSafety) {
++  GTEST_SKIP() << "Skipping test; see https://bugs.debian.org/1018804";
++
+   Notification stop;
+   static constexpr int kNumThreads = 8;
+   int64_t sampled_node_count = 0;
diff --git a/debian/patches/cpu-features.diff b/debian/patches/cpu-features.diff
new file mode 100644
index 00000000..614c7dcb
--- /dev/null
+++ b/debian/patches/cpu-features.diff
@@ -0,0 +1,55 @@
+From: Benjamin Barenblat <bbaren@google.com>
+Subject: Canonicalize supported CPU feature set
+Forwarded: not-needed
+
+Explicitly set supported CPU features.
+
+  - Disable Intel SSE and SSE2 on i386, since Debian supports some i386
+    processors without those extensions. Keep them enabled on amd64, since all
+    amd64 processors have them.
+
+  - Disable Intel SSSE3 entirely, since no i386 processor supports it and Debian
+    supports amd64 processors without it.
+
+  - Disable NEON on armel and armhf, since no armel processor supports NEON and
+    Debian supports some armhf processors without it. Keep it enabled on arm64,
+    since all arm64 processors have it.
+
+--- a/absl/base/config.h
++++ b/absl/base/config.h
+@@ -848,7 +848,7 @@
+ // which architectures support the various x86 instruction sets.
+ #ifdef ABSL_INTERNAL_HAVE_SSE
+ #error ABSL_INTERNAL_HAVE_SSE cannot be directly set
+-#elif defined(__SSE__)
++#elif defined(__x86_64__)
+ #define ABSL_INTERNAL_HAVE_SSE 1
+ #elif (defined(_M_X64) || (defined(_M_IX86_FP) && _M_IX86_FP >= 1)) && \
+     !defined(_M_ARM64EC)
+@@ -864,7 +864,7 @@
+ // which architectures support the various x86 instruction sets.
+ #ifdef ABSL_INTERNAL_HAVE_SSE2
+ #error ABSL_INTERNAL_HAVE_SSE2 cannot be directly set
+-#elif defined(__SSE2__)
++#elif defined(__x86_64__)
+ #define ABSL_INTERNAL_HAVE_SSE2 1
+ #elif (defined(_M_X64) || (defined(_M_IX86_FP) && _M_IX86_FP >= 2)) && \
+     !defined(_M_ARM64EC)
+@@ -886,8 +886,6 @@
+ // by the CPU.
+ #ifdef ABSL_INTERNAL_HAVE_SSSE3
+ #error ABSL_INTERNAL_HAVE_SSSE3 cannot be directly set
+-#elif defined(__SSSE3__)
+-#define ABSL_INTERNAL_HAVE_SSSE3 1
+ #endif
+ 
+ // ABSL_INTERNAL_HAVE_ARM_NEON is used for compile-time detection of NEON (ARM
+@@ -899,7 +897,7 @@
+ // https://llvm.org/docs/CompileCudaWithLLVM.html#detecting-clang-vs-nvcc-from-code
+ #ifdef ABSL_INTERNAL_HAVE_ARM_NEON
+ #error ABSL_INTERNAL_HAVE_ARM_NEON cannot be directly set
+-#elif defined(__ARM_NEON) && !defined(__CUDA_ARCH__)
++#elif defined(__aarch64__)
+ #define ABSL_INTERNAL_HAVE_ARM_NEON 1
+ #endif
+ 
diff --git a/debian/patches/empty-flags-library.diff b/debian/patches/empty-flags-library.diff
new file mode 100644
index 00000000..d47d44be
--- /dev/null
+++ b/debian/patches/empty-flags-library.diff
@@ -0,0 +1,19 @@
+From: Benjamin Barenblat <bbaren@google.com>
+Subject: Eliminate libabsl_flags.so and libabsl_flags.a
+Forwarded: not-needed
+
+The libabsl_flags library only contains code when compiling with MSVC, which
+Debian doesn't use. Skip compiling absl/flags/flag.cc, and make the Abseil flags
+library header-only.
+
+--- a/absl/flags/CMakeLists.txt
++++ b/absl/flags/CMakeLists.txt
+@@ -200,8 +200,6 @@
+ absl_cc_library(
+   NAME
+     flags
+-  SRCS
+-    "flag.cc"
+   HDRS
+     "declare.h"
+     "flag.h"
diff --git a/debian/patches/latomic.diff b/debian/patches/latomic.diff
new file mode 100644
index 00000000..ef952275
--- /dev/null
+++ b/debian/patches/latomic.diff
@@ -0,0 +1,20 @@
+From: Benjamin Barenblat <bbaren@google.com>
+Subject: Use libatomic if necessary
+Bug-Debian: https://bugs.debian.org/973492
+
+On some architectures, notably armel, Abseil needs symbols defined in
+libatomic. Abseil does not currently have a well-developed system to
+declare external library dependencies, so just have the linker determine
+if anything needs libatomic and add the DT_NEEDED entry where necessary.
+
+--- a/absl/copts/AbseilConfigureCopts.cmake
++++ b/absl/copts/AbseilConfigureCopts.cmake
+@@ -103,4 +103,8 @@
+   set(ABSL_TEST_COPTS "")
+ endif()
+ 
++list(APPEND ABSL_DEFAULT_LINKOPTS
++    "-Wl,--push-state,--as-needed" "-latomic" "-Wl,--pop-state"
++)
++
+ set(ABSL_CXX_STANDARD "${CMAKE_CXX_STANDARD}")
diff --git a/debian/patches/pkg-config-directives.diff b/debian/patches/pkg-config-directives.diff
new file mode 100644
index 00000000..726d6aec
--- /dev/null
+++ b/debian/patches/pkg-config-directives.diff
@@ -0,0 +1,21 @@
+From: Benjamin Barenblat <bbaren@google.com>
+Subject: Do not propagate -Wno-... flags into pkg-config files
+Forwarded: not-needed
+
+Lintian doesn't like any -W flags in pkg-config files, even if those flags
+disable warnings.
+
+--- a/CMake/AbseilHelpers.cmake
++++ b/CMake/AbseilHelpers.cmake
+@@ -187,10 +187,7 @@
+       endif()
+     endforeach()
+     foreach(cflag ${ABSL_CC_LIB_COPTS})
+-      if(${cflag} MATCHES "^(-Wno|/wd)")
+-        # These flags are needed to suppress warnings that might fire in our headers.
+-        set(PC_CFLAGS "${PC_CFLAGS} ${cflag}")
+-      elseif(${cflag} MATCHES "^(-W|/w[1234eo])")
++      if(${cflag} MATCHES "^(-W|/w[1234eo])")
+         # Don't impose our warnings on others.
+       elseif(${cflag} MATCHES "^-m")
+         # Don't impose CPU instruction requirements on others, as
diff --git a/debian/patches/series b/debian/patches/series
new file mode 100644
index 00000000..29630f3c
--- /dev/null
+++ b/debian/patches/series
@@ -0,0 +1,6 @@
+configure.diff
+cpu-features.diff
+latomic.diff
+empty-flags-library.diff
+cordz-info-statistics-test.diff
+pkg-config-directives.diff