[lld] r339000 - Merging r338679, r338684, r338697, r338699:

Mon Aug 6 03:15:52 PDT 2018

Author: hans
Date: Mon Aug  6 03:15:52 2018
New Revision: 339000

URL: http://llvm.org/viewvc/llvm-project?rev=339000&view=rev
Log:
Merging r338679, r338684, r338697, r338699:

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r338679 | grimar | 2018-08-02 10:07:07 +0200 (Thu, 02 Aug 2018) | 10 lines

[LLD] - Improve handling of AT> linker script commands

Patch by Konstantin Schwarz!

The condition to create a new phdr must also check the usage of "AT>" 
linker script command, and create a new PT_LOAD header if a new LMARegion is used.

This fixes PR38307

Differential revision: https://reviews.llvm.org/D50052
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r338684 | grimar | 2018-08-02 10:13:56 +0200 (Thu, 02 Aug 2018) | 9 lines

[LLD] Only increase LMARegion if different from MemRegion

Patch by Konstantin Schwarz!

If both the MemRegion and LMARegion are set for an output section in
a linker script, we should only increase the LMARegion if it is
different from the MemRegion. Otherwise, we reserve the memory twice.

Differential revision: https://reviews.llvm.org/D50065
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r338697 | grimar | 2018-08-02 12:45:46 +0200 (Thu, 02 Aug 2018) | 9 lines

[LLD] Do not overwrite LMAOffset of PT_LOAD header

Patch by Konstantin Schwarz!

If more than a single output section is added to a PT_LOAD header,
only the first section should set the LMAOffset of the segment.
Otherwise, we get a load-address overlap error

Differential revision: https://reviews.llvm.org/D50133
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r338699 | grimar | 2018-08-02 12:59:28 +0200 (Thu, 02 Aug 2018) | 5 lines

[LLD][ELF] - Simplify. NFC.

isHeaderSection can be useful I believe,
but probably not right now and not
for this case.
------------------------------------------------------------------------

Added:
    lld/branches/release_70/test/ELF/linkerscript/Inputs/at6.s
      - copied unchanged from r338679, lld/trunk/test/ELF/linkerscript/Inputs/at6.s
    lld/branches/release_70/test/ELF/linkerscript/Inputs/at7.s
      - copied unchanged from r338684, lld/trunk/test/ELF/linkerscript/Inputs/at7.s
    lld/branches/release_70/test/ELF/linkerscript/Inputs/at8.s
      - copied unchanged from r338697, lld/trunk/test/ELF/linkerscript/Inputs/at8.s
    lld/branches/release_70/test/ELF/linkerscript/at6.test
      - copied unchanged from r338679, lld/trunk/test/ELF/linkerscript/at6.test
    lld/branches/release_70/test/ELF/linkerscript/at7.test
      - copied unchanged from r338684, lld/trunk/test/ELF/linkerscript/at7.test
    lld/branches/release_70/test/ELF/linkerscript/at8.test
      - copied unchanged from r338697, lld/trunk/test/ELF/linkerscript/at8.test
Modified:
    lld/branches/release_70/   (props changed)
    lld/branches/release_70/ELF/LinkerScript.cpp
    lld/branches/release_70/ELF/Writer.cpp

Propchange: lld/branches/release_70/
------------------------------------------------------------------------------
    svn:mergeinfo = /lld/trunk:338679,338684,338697,338699

Modified: lld/branches/release_70/ELF/LinkerScript.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/branches/release_70/ELF/LinkerScript.cpp?rev=339000&r1=338999&r2=339000&view=diff
==============================================================================

--- lld/branches/release_70/ELF/LinkerScript.cpp (original)
+++ lld/branches/release_70/ELF/LinkerScript.cpp Mon Aug  6 03:15:52 2018
@@ -116,7 +116,8 @@ void LinkerScript::expandMemoryRegions(u
   if (Ctx->MemRegion)
     expandMemoryRegion(Ctx->MemRegion, Size, Ctx->MemRegion->Name,
                        Ctx->OutSec->Name);
-  if (Ctx->LMARegion)
+  // Only expand the LMARegion if it is different from MemRegion.
+  if (Ctx->LMARegion && Ctx->MemRegion != Ctx->LMARegion)
     expandMemoryRegion(Ctx->LMARegion, Size, Ctx->LMARegion->Name,
                        Ctx->OutSec->Name);
 }
@@ -750,6 +751,13 @@ MemoryRegion *LinkerScript::findMemoryRe
   return nullptr;
 }
 
+static OutputSection *findFirstSection(PhdrEntry *Load) {
+  for (OutputSection *Sec : OutputSections)
+    if (Sec->PtLoad == Load)
+      return Sec;
+  return nullptr;
+}
+
 // This function assigns offsets to input sections and an output section
 // for a single sections command (e.g. ".text { *(.text); }").
 void LinkerScript::assignOffsets(OutputSection *Sec) {
@@ -775,8 +783,11 @@ void LinkerScript::assignOffsets(OutputS
   // will set the LMA such that the difference between VMA and LMA for the
   // section is the same as the preceding output section in the same region
   // https://sourceware.org/binutils/docs-2.20/ld/Output-Section-LMA.html
+  // This, however, should only be done by the first "non-header" section
+  // in the segment.
   if (PhdrEntry *L = Ctx->OutSec->PtLoad)
-    L->LMAOffset = Ctx->LMAOffset;
+    if (Sec == findFirstSection(L))
+      L->LMAOffset = Ctx->LMAOffset;
 
   // We can call this method multiple times during the creation of
   // thunks and want to start over calculation each time.
@@ -953,13 +964,6 @@ void LinkerScript::adjustSectionsAfterSo
   }
 }
 
-static OutputSection *findFirstSection(PhdrEntry *Load) {
-  for (OutputSection *Sec : OutputSections)
-    if (Sec->PtLoad == Load)
-      return Sec;
-  return nullptr;
-}
-
 static uint64_t computeBase(uint64_t Min, bool AllocateHeaders) {
   // If there is no SECTIONS or if the linkerscript is explicit about program
   // headers, do our best to allocate them.

Modified: lld/branches/release_70/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/branches/release_70/ELF/Writer.cpp?rev=339000&r1=338999&r2=339000&view=diff
==============================================================================
--- lld/branches/release_70/ELF/Writer.cpp (original)
+++ lld/branches/release_70/ELF/Writer.cpp Mon Aug  6 03:15:52 2018
@@ -1815,12 +1815,14 @@ template <class ELFT> std::vector<PhdrEn
     // Segments are contiguous memory regions that has the same attributes
     // (e.g. executable or writable). There is one phdr for each segment.
     // Therefore, we need to create a new phdr when the next section has
-    // different flags or is loaded at a discontiguous address using AT linker
-    // script command. At the same time, we don't want to create a separate
-    // load segment for the headers, even if the first output section has
-    // an AT attribute.
+    // different flags or is loaded at a discontiguous address or memory
+    // region using AT or AT> linker script command, respectively. At the same
+    // time, we don't want to create a separate load segment for the headers,
+    // even if the first output section has an AT or AT> attribute.
     uint64_t NewFlags = computeFlags(Sec->getPhdrFlags());
-    if ((Sec->LMAExpr && Load->LastSec != Out::ProgramHeaders) ||
+    if (((Sec->LMAExpr ||
+          (Sec->LMARegion && (Sec->LMARegion != Load->FirstSec->LMARegion))) &&
+         Load->LastSec != Out::ProgramHeaders) ||
         Sec->MemRegion != Load->FirstSec->MemRegion || Flags != NewFlags) {
 
       Load = AddHdr(PT_LOAD, NewFlags);


