[lld] 6c62795 - [lld-macho] Ensure cached objects are affected by `-object_path_lto`
Leonard Grey via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 12 08:06:28 PDT 2022
Author: Leonard Grey
Date: 2022-08-12T10:56:58-04:00
New Revision: 6c627950585a5ddb6e3eed9d80da32be6f3a7336
URL: https://github.com/llvm/llvm-project/commit/6c627950585a5ddb6e3eed9d80da32be6f3a7336
DIFF: https://github.com/llvm/llvm-project/commit/6c627950585a5ddb6e3eed9d80da32be6f3a7336.diff
LOG: [lld-macho] Ensure cached objects are affected by `-object_path_lto`
This refactors LTO compile to look more like COFF, where cache hits and misses are all funneled through the same code path.
Previously, cache hits were *not* being saved to -object_path_lto, which led to them sometimes falling out of the cache before dsymutil could process them. As a side effect of the refactor, cached objects are now saved with -save-temps as well, which seems desirable.
(Deleted lld/test/MachO/lto-cache-dsymutil.ll and rolled it into lld/test/MachO/lto-object-path.ll, since the cache-only, non object path approach is unreliable anyway).
Differential Revision: https://reviews.llvm.org/D131624
Added:
Modified:
lld/MachO/LTO.cpp
lld/test/MachO/lto-object-path.ll
Removed:
lld/test/MachO/lto-cache-dsymutil.ll
################################################################################
diff --git a/lld/MachO/LTO.cpp b/lld/MachO/LTO.cpp
index 0b76216d24b5b..2cbee6179e0e1 100644
--- a/lld/MachO/LTO.cpp
+++ b/lld/MachO/LTO.cpp
@@ -131,13 +131,6 @@ std::vector<ObjFile *> BitcodeCompiler::compile() {
if (!config->thinLTOCacheDir.empty())
pruneCache(config->thinLTOCacheDir, config->thinLTOCachePolicy);
- if (config->saveTemps) {
- if (!buf[0].empty())
- saveBuffer(buf[0], config->outputFile + ".lto.o");
- for (unsigned i = 1; i != maxTasks; ++i)
- saveBuffer(buf[i], config->outputFile + Twine(i) + ".lto.o");
- }
-
// In ThinLTO mode, Clang passes a temporary directory in -object_path_lto,
// while the argument is a single file in FullLTO mode.
bool objPathIsDir = true;
@@ -156,9 +149,23 @@ std::vector<ObjFile *> BitcodeCompiler::compile() {
}
std::vector<ObjFile *> ret;
- for (unsigned i = 0; i != maxTasks; ++i) {
- if (buf[i].empty())
+ for (unsigned i = 0; i < maxTasks; ++i) {
+ // Get the native object contents either from the cache or from memory. Do
+ // not use the cached MemoryBuffer directly to ensure dsymutil does not
+ // race with the cache pruner.
+ StringRef objBuf;
+ if (files[i])
+ objBuf = files[i]->getBuffer();
+ else
+ objBuf = buf[i];
+ if (objBuf.empty())
continue;
+
+ // FIXME: should `saveTemps` and `ltoObjPath` use the same file name?
+ if (config->saveTemps)
+ saveBuffer(objBuf,
+ config->outputFile + ((i == 0) ? "" : Twine(i)) + ".lto.o");
+
SmallString<261> filePath("/tmp/lto.tmp");
uint32_t modTime = 0;
if (!config->ltoObjPath.empty()) {
@@ -167,14 +174,12 @@ std::vector<ObjFile *> BitcodeCompiler::compile() {
path::append(filePath, Twine(i) + "." +
getArchitectureName(config->arch()) +
".lto.o");
- saveBuffer(buf[i], filePath);
+ saveBuffer(objBuf, filePath);
modTime = getModTime(filePath);
}
ret.push_back(make<ObjFile>(
- MemoryBufferRef(buf[i], saver().save(filePath.str())), modTime, ""));
+ MemoryBufferRef(objBuf, saver().save(filePath.str())), modTime, ""));
}
- for (std::unique_ptr<MemoryBuffer> &file : files)
- if (file)
- ret.push_back(make<ObjFile>(*file, 0, ""));
+
return ret;
}
diff --git a/lld/test/MachO/lto-cache-dsymutil.ll b/lld/test/MachO/lto-cache-dsymutil.ll
deleted file mode 100644
index c09733f571034..0000000000000
--- a/lld/test/MachO/lto-cache-dsymutil.ll
+++ /dev/null
@@ -1,28 +0,0 @@
-; REQUIRES: x86
-
-; RUN: rm -rf %t; mkdir %t
-; RUN: opt -module-hash -module-summary %s -o %t/foo.o
-; RUN: %lld -cache_path_lto %t/cache -o %t/test %t/foo.o
-
-;; Check that dsymutil is able to read the .o file out of the thinlto cache.
-; RUN: dsymutil -f -o - %t/test | llvm-dwarfdump - | FileCheck %s
-; CHECK: DW_AT_name ("test.cpp")
-
-
-target triple = "x86_64-apple-macosx10.15.0"
-target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
-
-define void @main() #0 !dbg !4 {
- ret void
-}
-
-!llvm.module.flags = !{ !0, !1 }
-!llvm.dbg.cu = !{!2}
-
-!0 = !{i32 7, !"Dwarf Version", i32 4}
-!1 = !{i32 2, !"Debug Info Version", i32 3}
-!2 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !3, emissionKind: FullDebug)
-!3 = !DIFile(filename: "test.cpp", directory: "/tmp")
-!4 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 1, type: !5, scopeLine: 1, unit: !2)
-!5 = !DISubroutineType(types: !6)
-!6 = !{}
diff --git a/lld/test/MachO/lto-object-path.ll b/lld/test/MachO/lto-object-path.ll
index d61dc2d1eb953..44e71860a0639 100644
--- a/lld/test/MachO/lto-object-path.ll
+++ b/lld/test/MachO/lto-object-path.ll
@@ -2,7 +2,7 @@
; UNSUPPORTED: system-windows
; RUN: rm -rf %t; mkdir %t
-; RUN: llvm-as %s -o %t/test.o
+; RUN: opt -thinlto-bc %s -o %t/test.o
; RUN: %lld %t/test.o -o %t/test
; RUN: llvm-nm -pa %t/test | FileCheck %s --check-prefixes CHECK,NOOBJPATH
@@ -10,6 +10,12 @@
; RUN: %lld %t/test.o -o %t/test -object_path_lto %t/lto-temps
; RUN: llvm-nm -pa %t/test | FileCheck %s --check-prefixes CHECK,OBJPATH-DIR -DDIR=%t/lto-temps
+;; Ensure object path is still used if the cache is used
+; RUN: %lld %t/test.o -o %t/test -object_path_lto %t/lto-temps -prune_interval_lto 20 -cache_path_lto %t/cache --thinlto-cache-policy=cache_size_files=1:cache_size_bytes=10
+; RUN: llvm-nm -pa %t/test | FileCheck %s --check-prefixes CHECK,OBJPATH-DIR -DDIR=%t/lto-temps
+;; And that dsymutil can read the result
+; RUN: dsymutil -f -o - %t/test | llvm-dwarfdump - | FileCheck %s --check-prefix=DSYM
+
;; check that the object path can be an existing file
; RUN: touch %t/lto-tmp.o
; RUN: %lld %t/test.o -o %t/test -object_path_lto %t/lto-tmp.o
@@ -19,12 +25,13 @@
; CHECK: 0000000000000000 - 00 0000 SO /tmp/test.cpp
; NOOBJPATH-NEXT: 0000000000000000 - 03 0001 OSO /tmp/lto.tmp
;; check that modTime is nonzero when `-object_path_lto` is provided
-; OBJPATH-DIR-NEXT: {{[0-9a-f]*[1-9a-f]+[0-9a-f]*}} - 03 0001 OSO [[DIR]]/0.x86_64.lto.o
+; OBJPATH-DIR-NEXT: {{[0-9a-f]*[1-9a-f]+[0-9a-f]*}} - 03 0001 OSO [[DIR]]/1.x86_64.lto.o
; OBJPATH-FILE-NEXT: {{[0-9a-f]*[1-9a-f]+[0-9a-f]*}} - 03 0001 OSO [[FILE]]
; CHECK-NEXT: {{[0-9a-f]+}} - 01 0000 FUN _main
; CHECK-NEXT: 0000000000000001 - 00 0000 FUN
; CHECK-NEXT: 0000000000000000 - 01 0000 SO
; CHECK-NEXT: {{[0-9a-f]+}} T _main
+; DSYM: DW_AT_name ("test.cpp")
target triple = "x86_64-apple-macosx10.15.0"
target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
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