[LLD][ELF] - Linker script: accept using a file name without a list of sections.

[grimar]

Summary

This is a part of
https://bugs.llvm.org/show_bug.cgi?id=39885

Linker script specification says:
"You can specify a file name to include sections from a particular file. You would do this
if one or more of your files contain special data that needs to be at a particular location in memory."
(https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/4/html/Using_ld_the_GNU_Linker/sections.html#INPUT-SECTION)

LLD did not accept this yet. The patch implements it.

[grimar]

• Added a forgotten changes for the existent test.

[ruiu]

LGTM

ELF/ScriptParser.cpp

860 ↗

(On Diff #176816)

auto

lld/trunk/ELF/LinkerScript.h

struct MemoryRegion {
   uint64_t CurPos = 0;
 };
 
 // This struct represents one section match pattern in SECTIONS() command.
 // It can optionally have negative match pattern for EXCLUDED_FILE command.
 // Also it may be surrounded with SORT() command, so contains sorting rules.
 struct SectionPattern {
   SectionPattern(StringMatcher &&Pat1, StringMatcher &&Pat2)
-      : ExcludedFilePat(Pat1), SectionPat(Pat2) {}
+      : ExcludedFilePat(Pat1), SectionPat(Pat2),
+        SortOuter(SortSectionPolicy::Default),
+        SortInner(SortSectionPolicy::Default) {}
 
   StringMatcher ExcludedFilePat;
   StringMatcher SectionPat;
   SortSectionPolicy SortOuter;
   SortSectionPolicy SortInner;
 };
 
 struct InputSectionDescription : BaseCommand {

lld/trunk/ELF/ScriptParser.cpp

if (Tok == ";") {
       Cmd->Filler = readFill();
     } else if (Tok == "SORT") {
       readSort();
     } else if (Tok == "INCLUDE") {
       readInclude();
     } else if (peek() == "(") {
       Cmd->SectionCommands.push_back(readInputSectionDescription(Tok));
     } else {
-      setError("unknown command " + Tok);
+      // We have a file name and no input sections description. It is not a
+      // commonly used syntax, but still acceptable. In that case, all sections
+      // from the file will be included.
+      InputSectionDescription *ISD = make<InputSectionDescription>(Tok);
+      ISD->SectionPatterns.push_back({{}, StringMatcher({"*"})});
+      Cmd->SectionCommands.push_back(ISD);
     }
   }
 
   if (consume(">"))
     Cmd->MemoryRegionName = next();
 
   if (consume("AT")) {
     expect(">");

lld/trunk/test/ELF/linkerscript/no-filename-spec.s

+# REQUIRES: x86
+# RUN: echo '.section .bar, "a"; .quad 1;' | \
+# RUN:   llvm-mc -filetype=obj -triple=x86_64-pc-linux - -o %tfile1.o
+# RUN: echo '.section .zed, "a"; .quad 2;' | \
+# RUN:   llvm-mc -filetype=obj -triple=x86_64-pc-linux - -o %tfile2.o
+
+## We have a file name and no input sections description. In that case, all
+## sections from the file specified should be included. Check that.
+# RUN: ld.lld -o %t --script %s %tfile1.o %tfile2.o
+# RUN: llvm-objdump -s %t | FileCheck %s
+
+# CHECK:      Contents of section .foo:
+# CHECK-NEXT:  01000000 00000000 02000000 00000000
+
+SECTIONS {
+ .foo : { *file1.o *file2.o }
+}

lld/trunk/test/ELF/linkerscript/sort.s

 # RUN: ld.lld --sort-section name -o %t10 --script %t9.script %t2.o %t1.o
 # RUN: llvm-objdump -s %t10 | FileCheck -check-prefix=UNSORTED %s
 
 ## SORT_NONE as a inner sort directive.
 # RUN: echo "SECTIONS { .aaa : { *(SORT_BY_NAME(SORT_NONE(.aaa.*))) } }" > %t10.script
 # RUN: ld.lld -o %t11 --script %t10.script %t2.o %t1.o
 # RUN: llvm-objdump -s %t11 | FileCheck -check-prefix=SORTED_A %s
 
-## There is no SORTFOO command, check we handle it properly.
-# RUN: echo "SECTIONS { .aaa : { SORTFOO } }" > %t3.script
-# RUN: not ld.lld -o %t3 --script %t3.script %t1.o 2>&1 | FileCheck %s -check-prefix=SORTFOO
-# SORTFOO: unknown command SORTFOO
-
 .global _start
 _start:
  nop
 
 .section .aaa.5, "a"
 .align 32
 .quad 5