[lld] r358547 - Fix a crash bug caused by a nested call of parallelForEach.

[Rui Ueyama via llvm-commits]

Author: ruiu
Date: Tue Apr 16 19:12:47 2019
New Revision: 358547

URL: http://llvm.org/viewvc/llvm-project?rev=358547&view=rev
Log:
Fix a crash bug caused by a nested call of parallelForEach.

parallelForEach is not reentrant. We use parallelForEach to call
each section's writeTo(), so calling the same function within writeTo()
is not safe.

Fixes https://bugs.llvm.org/show_bug.cgi?id=41508

Differential Revision: https://reviews.llvm.org/D60757

Modified:
    lld/trunk/wasm/OutputSections.cpp

Modified: lld/trunk/wasm/OutputSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/wasm/OutputSections.cpp?rev=358547&r1=358546&r2=358547&view=diff
==============================================================================
--- lld/trunk/wasm/OutputSections.cpp (original)
+++ lld/trunk/wasm/OutputSections.cpp Tue Apr 16 19:12:47 2019
@@ -110,8 +110,8 @@ void CodeSection::writeTo(uint8_t *Buf)
   memcpy(Buf, CodeSectionHeader.data(), CodeSectionHeader.size());
 
   // Write code section bodies
-  parallelForEach(Functions,
-                  [&](const InputChunk *Chunk) { Chunk->writeTo(Buf); });
+  for (const InputChunk *Chunk : Functions)
+    Chunk->writeTo(Buf);
 }
 
 uint32_t CodeSection::numRelocations() const {
@@ -175,7 +175,7 @@ void DataSection::writeTo(uint8_t *Buf)
   // Write data section headers
   memcpy(Buf, DataSectionHeader.data(), DataSectionHeader.size());
 
-  parallelForEach(Segments, [&](const OutputSegment *Segment) {
+  for (const OutputSegment *Segment : Segments) {
     // Write data segment header
     uint8_t *SegStart = Buf + Segment->SectionOffset;
     memcpy(SegStart, Segment->Header.data(), Segment->Header.size());
@@ -183,7 +183,7 @@ void DataSection::writeTo(uint8_t *Buf)
     // Write segment data payload
     for (const InputChunk *Chunk : Segment->InputSegments)
       Chunk->writeTo(Buf);
-  });
+  }
 }
 
 uint32_t DataSection::numRelocations() const {
@@ -231,8 +231,8 @@ void CustomSection::writeTo(uint8_t *Buf
   Buf += NameData.size();
 
   // Write custom sections payload
-  parallelForEach(InputSections,
-                  [&](const InputSection *Section) { Section->writeTo(Buf); });
+  for (const InputSection *Section : InputSections)
+    Section->writeTo(Buf);
 }
 
 uint32_t CustomSection::numRelocations() const {