[ELF] - Report LMA region overflows.

[grimar]

Summary

We do not report LMA region overflows currently.
Both GNU linkers do that. The patch implements it.

[ruiu]

LGTM

test/ELF/linkerscript/lma-overflow.test

3–4

You can write two assembly lines in one line by separating with ';'.

5

And you don't need to create a temporary file --

echo '.section .foo,"a"; .quad 1' | llvm-mc -filetype=obj -triple=x86_64-unknown-linux - -o %t.o

[• espindola]

LGTM

ELF/LinkerScript.cpp

error("section '" + SecName + "' will not fit in region '" + RegionName +
           "': overflowed by " + Twine(NewSize - MemRegion->Length) + " bytes");
 }
 
 void LinkerScript::expandOutputSection(uint64_t Size) {
   Ctx->OutSec->Size += Size;
   if (Ctx->MemRegion)
     expandMemoryRegion(Ctx->MemRegion, Size, Ctx->MemRegion->Name,
                        Ctx->OutSec->Name);
-  // FIXME: check LMA region overflow too.
   if (Ctx->LMARegion)
-    Ctx->LMARegion->CurPos += Size;
+    expandMemoryRegion(Ctx->LMARegion, Size, Ctx->LMARegion->Name,
+                       Ctx->OutSec->Name);
 }
 
 void LinkerScript::setDot(Expr E, const Twine &Loc, bool InSec) {
   uint64_t Val = E().getValue();
   if (Val < Dot && InSec)
     error(Loc + ": unable to move location counter backward for: " +
           Ctx->OutSec->Name);
 

test/ELF/linkerscript/lma-overflow.test

+# REQUIRES: x86
+
+# RUN: echo ".section .foo,\"a\"" > %t.s
+# RUN: echo ".quad 1" >> %t.s
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t.o
+# RUN: not ld.lld -o %t %t.o --script %s 2>&1 | FileCheck %s
+# CHECK: error: section '.foo' will not fit in region 'flash': overflowed by 264 bytes
+
+MEMORY {
+  ram (rwx) : org = 0x1000, len = 0x300
+  flash (rwx) : org = 0x1000, len = 0x100
+}
+SECTIONS {
+  .foo : {
+    *(.foo)
+    . += 0x200;
+  } > ram AT>flash
+}