From e23e75036ef71d0132165f3d4e2f302297697726 Mon Sep 17 00:00:00 2001
From: Tom Osika <tom.osika@kitware.com>
Date: Wed, 2 Sep 2026 15:35:09 -0400
Subject: [PATCH] [workspace] Update dependency abseil_cpp_internal to
 20260817.0

---
 .../patches/inline_namespace.patch            |  4 +--
 .../patches/upstream/include_bmi2intrin.patch | 20 -----------
 .../patches/upstream/internal_c_symbol.patch  | 35 -------------------
 .../abseil_cpp_internal/repository.bzl        |  9 ++---
 4 files changed, 7 insertions(+), 61 deletions(-)
 delete mode 100644 tools/workspace/abseil_cpp_internal/patches/upstream/include_bmi2intrin.patch
 delete mode 100644 tools/workspace/abseil_cpp_internal/patches/upstream/internal_c_symbol.patch

diff --git a/tools/workspace/abseil_cpp_internal/patches/inline_namespace.patch b/tools/workspace/abseil_cpp_internal/patches/inline_namespace.patch
index 8d980fac00b8..b0e52a060a81 100644
--- a/tools/workspace/abseil_cpp_internal/patches/inline_namespace.patch
+++ b/tools/workspace/abseil_cpp_internal/patches/inline_namespace.patch
@@ -8,12 +8,12 @@ designed for end-user customization, and that's basically all we're doing here.
 
 --- absl/base/options.h
 +++ absl/base/options.h
-@@ -123,8 +123,8 @@
+@@ -150,8 +150,8 @@
  // be changed to a new, unique identifier name.  In particular "head" is not
  // allowed.
  
  #define ABSL_OPTION_USE_INLINE_NAMESPACE 1
--#define ABSL_OPTION_INLINE_NAMESPACE_NAME lts_20260526
+-#define ABSL_OPTION_INLINE_NAMESPACE_NAME lts_20260817
 +#define ABSL_OPTION_INLINE_NAMESPACE_NAME drake_vendor
  
  // ABSL_OPTION_HARDENED
diff --git a/tools/workspace/abseil_cpp_internal/patches/upstream/include_bmi2intrin.patch b/tools/workspace/abseil_cpp_internal/patches/upstream/include_bmi2intrin.patch
deleted file mode 100644
index b8514536959a..000000000000
--- a/tools/workspace/abseil_cpp_internal/patches/upstream/include_bmi2intrin.patch
+++ /dev/null
@@ -1,20 +0,0 @@
-[abseil-cpp] Include preffered intrinsics header
-
-Cherry-picking
-https://github.com/abseil/abseil-cpp/commit/d851fdd768b27c02b3fb786fd0987faddd279ece.
-
-GCC 15 rejects including this header directly, as a private implementation.
-Drake uses BMI2 when amd64v3 packages are enabled, which is by default on most
-Ubuntu 26.04 builds.
-
---- absl/container/internal/raw_hash_set.h
-+++ absl/container/internal/raw_hash_set.h
-@@ -226,7 +226,7 @@
- #endif
-
- #ifdef __BMI2__
--#include <bmi2intrin.h>
-+#include <immintrin.h>
- #endif  // __BMI2__
-
- namespace absl {
diff --git a/tools/workspace/abseil_cpp_internal/patches/upstream/internal_c_symbol.patch b/tools/workspace/abseil_cpp_internal/patches/upstream/internal_c_symbol.patch
deleted file mode 100644
index d1409e81fba2..000000000000
--- a/tools/workspace/abseil_cpp_internal/patches/upstream/internal_c_symbol.patch
+++ /dev/null
@@ -1,35 +0,0 @@
-[abseil-cpp] Fix AbslInternalGetFileMappingHint ...
-
-Cherry-picking https://github.com/abseil/abseil-cpp/pull/2098.
-
---- absl/debugging/internal/symbolize.h
-+++ absl/debugging/internal/symbolize.h
-@@ -156,8 +156,8 @@ ABSL_NAMESPACE_END
- extern "C"
- #endif  // __cplusplus
- 
--    bool
--    AbslInternalGetFileMappingHint(const void** start, const void** end,
--                                   uint64_t* offset, const char** filename);
-+    bool ABSL_INTERNAL_C_SYMBOL(AbslInternalGetFileMappingHint)(
-+        const void** start, const void** end, uint64_t* offset,
-+        const char** filename);
- 
- #endif  // ABSL_DEBUGGING_INTERNAL_SYMBOLIZE_H_
-
---- absl/debugging/symbolize_elf.inc
-+++ absl/debugging/symbolize_elf.inc
-@@ -1697,10 +1697,9 @@ bool Symbolize(const void *pc, char *out, int out_size) {
- ABSL_NAMESPACE_END
- }  // namespace absl
- 
--extern "C" bool AbslInternalGetFileMappingHint(const void **start,
--                                               const void **end,
--                                               uint64_t *offset,
--                                               const char **filename) {
-+extern "C" bool ABSL_INTERNAL_C_SYMBOL(AbslInternalGetFileMappingHint)(
-+    const void **start, const void **end, uint64_t *offset,
-+    const char **filename) {
-   return absl::debugging_internal::GetFileMappingHint(start, end, offset,
-                                                       filename);
- }
diff --git a/tools/workspace/abseil_cpp_internal/repository.bzl b/tools/workspace/abseil_cpp_internal/repository.bzl
index 06019be60a7b..61103f8a1a28 100644
--- a/tools/workspace/abseil_cpp_internal/repository.bzl
+++ b/tools/workspace/abseil_cpp_internal/repository.bzl
@@ -7,11 +7,9 @@ def abseil_cpp_internal_repository(
         name = name,
         repository = "abseil/abseil-cpp",
         upgrade_type = "release",
-        commit = "20260526.0",
-        sha256 = "6e1aee535473414164bf83e4ebc40240dec71a4701f8a642d906e95bea1aea0c",  # noqa
+        commit = "20260817.0",
+        sha256 = "f7e05179df39c45434cad433f5783840bb3788ef322976f9138bc6b72b3a107d",  # noqa
         patches = [
-            ":patches/upstream/include_bmi2intrin.patch",
-            ":patches/upstream/internal_c_symbol.patch",
             ":patches/hidden_visibility.patch",
             ":patches/inline_namespace.patch",
         ],
@@ -21,6 +19,9 @@ def abseil_cpp_internal_repository(
             # uses so that we don't get "duplicate kwarg" errors. Then, add it
             # anywhere that linkopts already appears.
             "sed -i -e 's|linkstatic = 1,||; s|linkopts = |linkstatic = 1, linkopts = |' $(find absl -name BUILD.bazel)",  # noqa
+            # Remove `visibility = ...` annotations for gloop. Drake doesn't use
+            # gloop, so the references fail to resolve at analysis-time.
+            "sed -i -e '/@do_not_use_for_gloop_visibility_only/d;' $(find absl -name BUILD.bazel)",  # noqa
         ],
         mirrors = mirrors,
     )