[ELF][Driver] Fix precedence of symbol ordering file and CGProfile

This patch is a fix for https://bugs.llvm.org/show_bug.cgi?id=41804.
We try to solve the precedence of user-specified symbol ordering file and C3 ordering provided as call graph. It deals with two case:
(1) When both --symbol-ordering-file=<file> and --call-graph-order-file=<file> are present, whichever flag comes later will take precedence.
(2) When only --symbol-ordering-file=<file> is present, it takes precedence over implicit call graph (CGProfile) generated by CGProfilePass enabled in new pass manager.

llvm-svn: 361190
This commit is contained in:
Tiancong Wang 2019-05-20 19:13:34 +00:00
parent e1d38ec811
commit a5d8d01d6f
2 changed files with 76 additions and 3 deletions

View File

@ -975,9 +975,17 @@ static void readConfigs(opt::InputArgList &Args) {
std::tie(Config->AndroidPackDynRelocs, Config->RelrPackDynRelocs) =
getPackDynRelocs(Args);
if (auto *Arg = Args.getLastArg(OPT_symbol_ordering_file))
if (Optional<MemoryBufferRef> Buffer = readFile(Arg->getValue()))
if (auto *Arg = Args.getLastArg(OPT_symbol_ordering_file)){
if (Args.hasArg(OPT_call_graph_ordering_file))
error("--symbol-ordering-file and --call-graph-order-file "
"may not be used together");
if (Optional<MemoryBufferRef> Buffer = readFile(Arg->getValue())){
Config->SymbolOrderingFile = getSymbolOrderingFile(*Buffer);
// Also need to disable CallGraphProfileSort to prevent
// LLD order symbols with CGProfile
Config->CallGraphProfileSort = false;
}
}
// If --retain-symbol-file is used, we'll keep only the symbols listed in
// the file and discard all others.
@ -1727,7 +1735,6 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
readCallGraphsFromObjectFiles<ELFT>();
}
// Write the result to the file.
writeResult<ELFT>();
}

View File

@ -0,0 +1,66 @@
// REQUIRES: x86
// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
// RUN: ld.lld -e A %t.o --no-call-graph-profile-sort -o %t
// RUN: llvm-nm --numeric-sort %t | FileCheck %s --check-prefix=NO_ORDERING
// NO_ORDERING: 0000000000201000 t D
// NO_ORDERING-NEXT: 0000000000201001 T C
// NO_ORDERING-NEXT: 0000000000201002 T B
// NO_ORDERING-NEXT: 0000000000201003 T A
// RUN: ld.lld -e A %t.o -o %t
// RUN: llvm-nm --numeric-sort %t | FileCheck %s --check-prefix=CALL_GRAPH
// CALL_GRAPH: 0000000000201000 T A
// CALL_GRAPH-NEXT: 0000000000201000 t Aa
// CALL_GRAPH-NEXT: 0000000000201001 T B
// CALL_GRAPH-NEXT: 0000000000201002 T C
// CALL_GRAPH-NEXT: 0000000000201003 t D
// RUN: rm -f %t.symbol_order
// RUN: echo "C" >> %t.symbol_order
// RUN: echo "B" >> %t.symbol_order
// RUN: echo "D" >> %t.symbol_order
// RUN: echo "A" >> %t.symbol_order
// RUN: ld.lld -e A %t.o --symbol-ordering-file %t.symbol_order -o %t
// RUN: llvm-nm --numeric-sort %t | FileCheck %s --check-prefix=SYMBOL_ORDER
// SYMBOL_ORDER: 0000000000201000 T C
// SYMBOL_ORDER-NEXT: 0000000000201001 T B
// SYMBOL_ORDER-NEXT: 0000000000201002 t D
// SYMBOL_ORDER-NEXT: 0000000000201003 T A
// RUN: rm -f %t.call_graph
// RUN: echo "A B 5" > %t.call_graph
// RUN: echo "B C 50" >> %t.call_graph
// RUN: echo "C D 40" >> %t.call_graph
// RUN: echo "D B 10" >> %t.call_graph
// RUN: not ld.lld -e A %t.o --symbol-ordering-file %t.symbol_order --call-graph-ordering-file %t.call_graph -o %t 2>&1 | FileCheck %s
// RUN: not ld.lld -e A %t.o --call-graph-ordering-file %t.call_graph --symbol-ordering-file %t.symbol_order -o %t 2>&1 | FileCheck %s
// CHECK: error: --symbol-ordering-file and --call-graph-order-file may not be used together
.section .text.D,"ax",@progbits
D:
retq
.section .text.C,"ax",@progbits
.globl C
C:
retq
.section .text.B,"ax",@progbits
.globl B
B:
retq
.section .text.A,"ax",@progbits
.globl A
A:
Aa:
retq
.cg_profile A, B, 10
.cg_profile A, B, 10
.cg_profile Aa, B, 80
.cg_profile A, C, 40
.cg_profile B, C, 30
.cg_profile C, D, 90