commit 65499b9040e42942c93dac1c2110948dc7565d8e
author Rafael Espindola <rafael.espindola@gmail.com> Fri Sep 23 20:10:47 2016 +0000
committer Rafael Espindola <rafael.espindola@gmail.com> Fri Sep 23 20:10:47 2016 +0000
tree d48d77857a83854b8454ed5a3412fcd44d2b3c8c
parent 0d26de39227ecf459cd0d617e9f98edfbba39e3e

Avoid counting sections twice.

We were counting the size of the bss section holding common symbols twice:

    Dot += CurOutSec->getSize();
    flush();

The new code is also simpler as now flush is the only function that
inserts in AlreadyOutputOS, which makes sense since the set hold fully
output sections.

llvm-svn: 282285

lld/ELF/LinkerScript.cpp

diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 8227182..b7c65ed 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -383,10 +383,13 @@
 }
 
 template <class ELFT> void LinkerScript<ELFT>::flush() {
-  if (auto *OutSec = dyn_cast_or_null<OutputSection<ELFT>>(CurOutSec)) {
+  if (!CurOutSec || !AlreadyOutputOS.insert(CurOutSec).second)
+    return;
+  if (auto *OutSec = dyn_cast<OutputSection<ELFT>>(CurOutSec)) {
     for (InputSection<ELFT> *I : OutSec->Sections)
       output(I);
-    AlreadyOutputOS.insert(CurOutSec);
+  } else {
+    Dot += CurOutSec->getSize();
   }
 }
 
@@ -421,8 +424,8 @@
     switchTo(IB->OutSec);
     if (auto *I = dyn_cast<InputSection<ELFT>>(IB))
       output(I);
-    else if (AlreadyOutputOS.insert(CurOutSec).second)
-      Dot += CurOutSec->getSize();
+    else
+      flush();
   }
 }
 
@@ -454,14 +457,9 @@
                .base();
   for (auto I = Cmd->Commands.begin(); I != E; ++I)
     process(**I);
-  flush();
-  for (OutputSectionBase<ELFT> *Base : Sections) {
-    if (AlreadyOutputOS.count(Base))
-      continue;
+  for (OutputSectionBase<ELFT> *Base : Sections)
     switchTo(Base);
-    Dot += CurOutSec->getSize();
-    flush();
-  }
+  flush();
   std::for_each(E, Cmd->Commands.end(),
                 [this](std::unique_ptr<BaseCommand> &B) { process(*B.get()); });
 }