[clang] [clang] Extract in-memory module cache writes from `ASTWriter` (PR #190062)

Mon Apr 6 10:25:56 PDT 2026

lei137 wrote:

This patch is causing the following AIX failures.  
```
******************** TEST 'Clang :: Modules/DebugInfoSubmodules.c' FAILED ********************
Exit Code: 1
Command Output (stdout):
--
# RUN: at line 1
rm -rf /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/DebugInfoSubmodules.c.tmp
# executed command: rm -rf /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/DebugInfoSubmodules.c.tmp
# RUN: at line 2
/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/clang -cc1 -internal-isystem /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/lib/clang/23/include -nostdsysteminc -fmodules -fmodule-format=obj -debug-info-kind=limited -dwarf-ext-refs      -fimplicit-module-maps -x c -fmodules-cache-path=/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/DebugInfoSubmodules.c.tmp -I /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/Inputs      /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/DebugInfoSubmodules.c -mllvm -debug-only=pchcontainer -emit-llvm -o /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/DebugInfoSubmodules.c.tmp.ll      2>&1 | /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/FileCheck /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/DebugInfoSubmodules.c
# executed command: /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/clang -cc1 -internal-isystem /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/lib/clang/23/include -nostdsysteminc -fmodules -fmodule-format=obj -debug-info-kind=limited -dwarf-ext-refs -fimplicit-module-maps -x c -fmodules-cache-path=/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/DebugInfoSubmodules.c.tmp -I /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/Inputs /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/DebugInfoSubmodules.c -mllvm -debug-only=pchcontainer -emit-llvm -o /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/DebugInfoSubmodules.c.tmp.ll
# note: command had no output on stdout or stderr
# error: command failed with exit status: 1
# executed command: /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/FileCheck /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/DebugInfoSubmodules.c
--
********************

******************** TEST 'Clang :: Modules/lsv-debuginfo.cpp' FAILED ********************
Exit Code: 1
Command Output (stdout):
--
# RUN: at line 3
rm -rf /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/lsv-debuginfo.cpp.tmp
# executed command: rm -rf /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/lsv-debuginfo.cpp.tmp
# RUN: at line 4
/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/clang -cc1 -internal-isystem /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/lib/clang/23/include -nostdsysteminc -triple powerpc64-ibm-aix-unknown -std=c++14    -fmodules-local-submodule-visibility /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/lsv-debuginfo.cpp    -dwarf-ext-refs -fmodule-format=obj -debug-info-kind=standalone    -dwarf-version=4 -fmodules -fimplicit-module-maps    -fmodules-cache-path="/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/lsv-debuginfo.cpp.tmp" -o /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/lsv-debuginfo.cpp.tmp.ll -I/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/Inputs/lsv-debuginfo    -mllvm -debug-only=pchcontainer &>/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/lsv-debuginfo.cpp.tmp-mod.ll
# executed command: /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/bin/clang -cc1 -internal-isystem /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/lib/clang/23/include -nostdsysteminc -triple powerpc64-ibm-aix-unknown -std=c++14 -fmodules-local-submodule-visibility /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/lsv-debuginfo.cpp -dwarf-ext-refs -fmodule-format=obj -debug-info-kind=standalone -dwarf-version=4 -fmodules -fimplicit-module-maps -fmodules-cache-path=/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/lsv-debuginfo.cpp.tmp -o /home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/lsv-debuginfo.cpp.tmp.ll -I/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/Inputs/lsv-debuginfo -mllvm -debug-only=pchcontainer
# .---redirected output from '/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/build/tools/clang/test/Modules/Output/lsv-debuginfo.cpp.tmp-mod.ll'
# | ; ModuleID = '/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/Inputs/lsv-debuginfo/module.modulemap'
# | source_filename = "/home/llvm/llvm-external-buildbots/workers/aix-ppc64/clang-flang-ppc64-aix/llvm-project/clang/test/Modules/Inputs/lsv-debuginfo/module.modulemap"
# | target datalayout = "E-m:a-Fi64-i64:64-i128:128-n32:64-f64:32:64-S128-v256:256:256-v512:512:512"
# | target triple = "powerpc64-ibm-aix-unknown"
# | 
# | @__clang_ast = internal constant [46148 x i8] c"CPCH\01\08\00\00\9B\0B\00\00\07\C1\B3\D0\8C\C2+\B8\02-\C8\C2+\B0\C2/\88\02+\BC\C2(\AC\C2C\12\B4B)\D0B(\90B(\D0B(<0F+\BC\02)\D4\02+\94\C2/\B8B(\B4B)<DH+\BC\02)\D4\02+\94\C2/\90B*\C8B)\8C\02-\BC\82,\E4\C2\03t\B4\C2+\90B-\B0B)\FCB+\84\02,\FC\82)\A4\02+\94\C2\C3!\A4B+\C0\C2+\C8\02-<8\C3+\C8B*\9CB*\B8B(\B0\C2/\98B*\B0B)<D\C4+\C8B*\9CB*\B8B(\B0\C2/\98B*\B0B)\FCB*\90\C2\C3T\A4\82+\C0B-\D0\C2/\98B*\B0B)\FC\C2+\98\82)\CCB)\D0\C2,\1C\04\D1B\F3\0A\B0@\0B\A9\F0\0A\AE0\0B\BF \0A\AC\F0\0A\A3\B0\0A\0FQ\C0\0A\A1\E0\0A\A
# | ...
# `---data was truncated--------
# note: command had no output on stdout or stderr
# error: command failed with exit status: 1
--
********************

https://github.com/llvm/llvm-project/pull/190062