commit 8f66df92ba28f7db8c63bee46780b825750ad8d7
author George Rimar <grimar@accesssoftek.com> Fri Aug 12 20:38:20 2016 +0000
committer George Rimar <grimar@accesssoftek.com> Fri Aug 12 20:38:20 2016 +0000
tree c1ab6711f82f74471a595559ce2af0c220073b46
parent f4fdb5ddf3f18348393516bea845d406805e497b

[ELF] - Linkerscript: fix VA value assigned to sections when using constraints.

Previously we searched output section by name to assign VA. That did not
work in the case when multiple output sections with different constraints were defined in script.
Testcase shows the possible issue scenario, patch fixes the issue.

Differential revision: https://reviews.llvm.org/D23451

llvm-svn: 278561

lld/ELF/LinkerScript.cpp

diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 95b28e2..ca5ab37 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -215,14 +215,20 @@
   }
 }
 
+static bool checkConstraint(uint64_t Flags, ConstraintKind Kind) {
+  bool RO = (Kind == ConstraintKind::ReadOnly);
+  bool RW = (Kind == ConstraintKind::ReadWrite);
+  bool Writable = Flags & SHF_WRITE;
+  return !((RO && Writable) || (RW && !Writable));
+}
+
 template <class ELFT>
 static bool matchConstraints(ArrayRef<InputSectionBase<ELFT> *> Sections,
                              ConstraintKind Kind) {
-  bool RO = (Kind == ConstraintKind::ReadOnly);
-  bool RW = (Kind == ConstraintKind::ReadWrite);
-  return !llvm::any_of(Sections, [=](InputSectionBase<ELFT> *Sec) {
-    bool Writable = Sec->getSectionHdr()->sh_flags & SHF_WRITE;
-    return (RO && Writable) || (RW && !Writable);
+  if (Kind == ConstraintKind::NoConstraint)
+    return true;
+  return llvm::all_of(Sections, [=](InputSectionBase<ELFT> *Sec) {
+    return checkConstraint(Sec->getSectionHdr()->sh_flags, Kind);
   });
 }
 
@@ -330,6 +336,19 @@
   }
 }
 
+template <class ELFT>
+static OutputSectionBase<ELFT> *
+findSection(OutputSectionCommand &Cmd,
+            ArrayRef<OutputSectionBase<ELFT> *> Sections) {
+  for (OutputSectionBase<ELFT> *Sec : Sections) {
+    if (Sec->getName() != Cmd.Name)
+      continue;
+    if (checkConstraint(Sec->getFlags(), Cmd.Constraint))
+      return Sec;
+  }
+  return nullptr;
+}
+
 template <class ELFT> void LinkerScript<ELFT>::assignAddresses() {
   // Orphan sections are sections present in the input files which
   // are not explicitly placed into the output file by the linker script.
@@ -363,12 +382,9 @@
     }
 
     auto *Cmd = cast<OutputSectionCommand>(Base.get());
-    auto I = llvm::find_if(*OutputSections, [&](OutputSectionBase<ELFT> *S) {
-      return S->getName() == Cmd->Name;
-    });
-    if (I == OutputSections->end())
+    OutputSectionBase<ELFT> *Sec = findSection<ELFT>(*Cmd, *OutputSections);
+    if (!Sec)
       continue;
-    OutputSectionBase<ELFT> *Sec = *I;
 
     if (Cmd->AddrExpr)
       Dot = Cmd->AddrExpr(Dot);