[ELF] Allow an expression to follow = in a symbol assignment

GNU ld doesn't require whitespace before =. Match it.

Author: MaskRay

lld/ELF/ScriptParser.cpp

@@ -32,6 +32,7 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/Path.h"
+#include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Support/TimeProfiler.h"
 #include <cassert>
 #include <limits>
@@ -1030,14 +1031,22 @@ SymbolAssignment *ScriptParser::readAssignment(StringRef tok) {
 
   size_t oldPos = pos;
   SymbolAssignment *cmd = nullptr;
-  if (peek() == "=" || peek() == "+=")
+  if (peek().startswith("=")) {
+    // Support = followed by an expression without whitespace.
+    SaveAndRestore<bool> saved(inExpr, true);
     cmd = readSymbolAssignment(tok);
-  else if (tok == "PROVIDE")
+  } else if (peek() == "+=") {
+    cmd = readSymbolAssignment(tok);
+  } else if (tok == "PROVIDE") {
+    SaveAndRestore<bool> saved(inExpr, true);
     cmd = readProvideHidden(true, false);
-  else if (tok == "HIDDEN")
+  } else if (tok == "HIDDEN") {
+    SaveAndRestore<bool> saved(inExpr, true);
     cmd = readProvideHidden(false, true);
-  else if (tok == "PROVIDE_HIDDEN")
+  } else if (tok == "PROVIDE_HIDDEN") {
+    SaveAndRestore<bool> saved(inExpr, true);
     cmd = readProvideHidden(true, true);
+  }
 
   if (cmd) {
     cmd->commandString =

lld/test/ELF/linkerscript/symbol-assignexpr.s

@@ -8,9 +8,9 @@
 # RUN:         symbol4 = symbol + -4; \
 # RUN:         symbol5 = symbol - ~0xfffb; \
 # RUN:         symbol6 = symbol - ~(0xfff0 + 0xb); \
-# RUN:         symbol7 = symbol - ~ 0xfffb + 4; \
-# RUN:         symbol8 = ~ 0xffff + 4; \
-# RUN:         symbol9 = - 4; \
+# RUN:         symbol7 =symbol - ~ 0xfffb + 4; \
+# RUN:         symbol8 =~ 0xffff + 4; \
+# RUN:         symbol9 =- 4; \
 # RUN:         symbol10 = 0xfedcba9876543210; \
 # RUN:         symbol11 = ((0x28000 + 0x1fff) & ~(0x1000 + -1)); \
 # RUN:         symbol12 = 0x1234; \

lld/test/ELF/linkerscript/symbols.s

@@ -22,20 +22,20 @@
 
 # Provide existing symbol. The value should be 0, even though we
 # have value of 1 in PROVIDE()
-# RUN: echo "SECTIONS { PROVIDE(somesym = 1);}" > %t.script
+# RUN: echo "SECTIONS { PROVIDE(somesym =1);}" > %t.script
 # RUN: ld.lld -o %t1 --script %t.script %t
 # RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=PROVIDE2 %s
 # PROVIDE2: 0000000000000000 g       *ABS*  0000000000000000 somesym
 
 # Provide existing symbol. The value should be 0, even though we
 # have value of 1 in PROVIDE_HIDDEN(). Visibility should not change
-# RUN: echo "SECTIONS { PROVIDE_HIDDEN(somesym = 1);}" > %t.script
+# RUN: echo "SECTIONS { PROVIDE_HIDDEN(somesym =1);}" > %t.script
 # RUN: ld.lld -o %t1 --script %t.script %t
 # RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=HIDDEN2 %s
 # HIDDEN2: 0000000000000000 g       *ABS*  0000000000000000 somesym
 
 # Hidden symbol assignment.
-# RUN: echo "SECTIONS { HIDDEN(newsym = 1);}" > %t.script
+# RUN: echo "SECTIONS { HIDDEN(newsym =1);}" > %t.script
 # RUN: ld.lld -o %t1 --script %t.script %t
 # RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=HIDDEN3 %s
 # HIDDEN3: 0000000000000001 l       *ABS*  0000000000000000 .hidden newsym