[lld] Add more complete support for the INCLUDE command.

Patch by Ian Tessier.

This change adds INCLUDE support to the MEMORY and SECTION commands, and
to output sections, as per:

https://sourceware.org/binutils/docs/ld/File-Commands.html#File-Commands

Differential Revision: https://reviews.llvm.org/D52951

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@344368 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/ELF/ScriptParser.cpp b/ELF/ScriptParser.cpp
index 4d1dd75..d548689 100644
--- a/ELF/ScriptParser.cpp
+++ b/ELF/ScriptParser.cpp
@@ -501,6 +501,9 @@
       for (BaseCommand *Cmd : readOverlay())
         V.push_back(Cmd);
       continue;
+    } else if (Tok == "INCLUDE") {
+      readInclude();
+      continue;
     }
 
     if (BaseCommand *Cmd = readAssignment(Tok))
@@ -803,6 +806,8 @@
       Cmd->Filler = readFill();
     } else if (Tok == "SORT") {
       readSort();
+    } else if (Tok == "INCLUDE") {
+      readInclude();
     } else if (peek() == "(") {
       Cmd->SectionCommands.push_back(readInputSectionDescription(Tok));
     } else {
@@ -1429,7 +1434,11 @@
 void ScriptParser::readMemory() {
   expect("{");
   while (!errorCount() && !consume("}")) {
-    StringRef Name = next();
+    StringRef Tok = next();
+    if (Tok == "INCLUDE") {
+      readInclude();
+      continue;
+    }
 
     uint32_t Flags = 0;
     uint32_t NegFlags = 0;
@@ -1444,10 +1453,9 @@
     uint64_t Length = readMemoryAssignment("LENGTH", "len", "l");
 
     // Add the memory region to the region map.
-    MemoryRegion *MR =
-        make<MemoryRegion>(Name, Origin, Length, Flags, NegFlags);
-    if (!Script->MemoryRegions.insert({Name, MR}).second)
-      setError("region '" + Name + "' already defined");
+    MemoryRegion *MR = make<MemoryRegion>(Tok, Origin, Length, Flags, NegFlags);
+    if (!Script->MemoryRegions.insert({Tok, MR}).second)
+      setError("region '" + Tok + "' already defined");
   }
 }
 
diff --git a/test/ELF/linkerscript/memory-include.test b/test/ELF/linkerscript/memory-include.test
new file mode 100644
index 0000000..3403282
--- /dev/null
+++ b/test/ELF/linkerscript/memory-include.test
@@ -0,0 +1,23 @@
+# REQUIRES: x86
+
+# RUN: echo '.section .text,"ax"; .global _start; nop' > %t.s
+# RUN: echo '.section .data,"aw"; .quad 0' >> %t.s
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t.o
+
+# RUN: echo "RAM2 (rwx): ORIGIN = 0x3000, LENGTH = 0x100" > %t.inc
+# RUN: ld.lld -o %t.elf --script %s %t.o -L %T
+# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s
+# CHECK: .data         00000008 0000000000002000 DATA
+# CHECK: .data2        00000008 0000000000003000 DATA
+
+MEMORY {
+  ROM (rwx): ORIGIN = 0x1000, LENGTH = 0x100
+  RAM (rwx): ORIGIN = 0x2000, LENGTH = 0x100
+  INCLUDE "memory-include.test.tmp.inc"
+}
+
+SECTIONS {
+  .text : { *(.text*) } > ROM
+  .data : { *(.data*) } > RAM
+  .data2 : { QUAD(0) } > RAM2
+}
diff --git a/test/ELF/linkerscript/output-section-include.test b/test/ELF/linkerscript/output-section-include.test
new file mode 100644
index 0000000..b18a7ee
--- /dev/null
+++ b/test/ELF/linkerscript/output-section-include.test
@@ -0,0 +1,30 @@
+# REQUIRES: x86
+
+# RUN: echo '.section .text,"ax"; .global _start; nop' > %t.s
+# RUN: echo '.section .data,"aw"; .quad 0' >> %t.s
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t.o
+
+## Empty include file.
+# RUN: echo "" > %t.inc
+# RUN: ld.lld -o %t.elf --script %s %t.o -L %T
+# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s --check-prefix=CHECK1
+# CHECK1: .data         00000008 0000000000002000 DATA
+
+## Non-empty include file.
+# RUN: echo "QUAD(0)" > %t.inc
+# RUN: ld.lld -o %t.elf --script %s %t.o -L %T
+# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s --check-prefix=CHECK2
+# CHECK2: .data         00000010 0000000000002000 DATA
+
+MEMORY {
+  ROM (rwx): ORIGIN = 0x1000, LENGTH = 0x100
+  RAM (rwx): ORIGIN = 0x2000, LENGTH = 0x100
+}
+
+SECTIONS {
+  .text : { *(.text*) } > ROM
+  .data : {
+    *(.data*)
+    INCLUDE "output-section-include.test.tmp.inc"
+  } > RAM
+}
diff --git a/test/ELF/linkerscript/section-include.test b/test/ELF/linkerscript/section-include.test
new file mode 100644
index 0000000..9b6dfa0
--- /dev/null
+++ b/test/ELF/linkerscript/section-include.test
@@ -0,0 +1,32 @@
+# REQUIRES: x86
+
+# RUN: echo '.section .text,"ax"; .global _start; nop' > %t.s
+# RUN: echo '.section .data,"aw"; .quad 0' >> %t.s
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t.o
+
+## Empty include file.
+# RUN: echo "" > %t.inc
+# RUN: ld.lld -o %t.elf --script %s %t.o -L %T
+# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s --check-prefix=CHECK1
+# CHECK1:      .data         00000008 0000000000002000 DATA
+# CHECK1-NEXT: .data3        00000008 0000000000002008 DATA
+
+## Non-empty include file.
+# RUN: echo ".data2 : { QUAD(0) } > RAM" > %t.inc
+# RUN: ld.lld -o %t.elf --script %s %t.o -L %T
+# RUN: llvm-objdump -section-headers %t.elf | FileCheck %s --check-prefix=CHECK2
+# CHECK2:      .data         00000008 0000000000002000 DATA
+# CHECK2-NEXT: .data2        00000008 0000000000002008 DATA
+# CHECK2-NEXT: .data3        00000008 0000000000002010 DATA
+
+MEMORY {
+  ROM (rwx): ORIGIN = 0x1000, LENGTH = 0x100
+  RAM (rwx): ORIGIN = 0x2000, LENGTH = 0x100
+}
+
+SECTIONS {
+  .text : { *(.text*) } > ROM
+  .data : { *(.data*) } > RAM
+  INCLUDE "section-include.test.tmp.inc"
+  .data3 : { QUAD(0) } > RAM
+}