ld script expression parsing

[Jan Beulich]

On 24.07.2021 12:23, Alan Modra wrote:
> Commit 40726f16a8d7 broke references to sections within ADDR(), and
> overlays with weird section names.
> 
> 	* ldgram.y (paren_script_name): New rule.
> 	(exp): Use it for ALIGNOF, SIZEOF, ADDR, and LOADADDR.  Similarly
> 	ensure script mode parsing for section name in SEGMENT_START.
> 	(overlay_section): Delete unnecessary ldlex_script call.  Backup
> 	on a lookahead NAME parsed in expression mode.
> 	* testsuite/ld-elf/overlay.s: Add more sections.
> 	* testsuite/ld-elf/overlay.t: Test '-' in section names.

Thanks Alan. I'm sorry, I didn't get around to test your fix yet, as
I've just returned from vacation. But I had no reason anyway to believe
it wouldn't deal with the issue.

Jan

> diff --git a/ld/ldgram.y b/ld/ldgram.y
> index 31e0071c6fc..2f9de59321a 100644
> --- a/ld/ldgram.y
> +++ b/ld/ldgram.y
> @@ -96,8 +96,7 @@ static int error_index;
>  %type <wildcard_list> section_name_list
>  %type <flag_info_list> sect_flag_list
>  %type <flag_info> sect_flags
> -%type <name> memspec_opt casesymlist
> -%type <name> memspec_at_opt
> +%type <name> memspec_opt memspec_at_opt paren_script_name casesymlist
>  %type <cname> wildcard_name
>  %type <wildcard> section_name_spec filename_spec wildcard_maybe_exclude
>  %token <bigint> INT
> @@ -906,6 +905,10 @@ nocrossref_list:
>  		}
>  	;
>  
> +paren_script_name:
> +		{ ldlex_script (); } '(' NAME  { ldlex_popstate (); } ')'
> +			{ $$ = $3; }
> +
>  mustbe_exp:		 { ldlex_expression (); }
>  		exp
>  			 { ldlex_popstate (); $$=$2;}
> @@ -970,14 +973,14 @@ exp	:
>  	|	SIZEOF_HEADERS
>  			{ $$ = exp_nameop (SIZEOF_HEADERS,0); }
>  
> -	|	ALIGNOF '(' NAME ')'
> -			{ $$ = exp_nameop (ALIGNOF,$3); }
> -	|	SIZEOF '(' NAME ')'
> -			{ $$ = exp_nameop (SIZEOF,$3); }
> -	|	ADDR '(' NAME ')'
> -			{ $$ = exp_nameop (ADDR,$3); }
> -	|	LOADADDR '(' NAME ')'
> -			{ $$ = exp_nameop (LOADADDR,$3); }
> +	|	ALIGNOF paren_script_name
> +			{ $$ = exp_nameop (ALIGNOF, $2); }
> +	|	SIZEOF	paren_script_name
> +			{ $$ = exp_nameop (SIZEOF, $2); }
> +	|	ADDR	paren_script_name
> +			{ $$ = exp_nameop (ADDR, $2); }
> +	|	LOADADDR paren_script_name
> +			{ $$ = exp_nameop (LOADADDR, $2); }
>  	|	CONSTANT '(' NAME ')'
>  			{ $$ = exp_nameop (CONSTANT,$3); }
>  	|	ABSOLUTE '(' exp ')'
> @@ -992,15 +995,16 @@ exp	:
>  			{ $$ = exp_binop (DATA_SEGMENT_RELRO_END, $5, $3); }
>  	|	DATA_SEGMENT_END '(' exp ')'
>  			{ $$ = exp_unop (DATA_SEGMENT_END, $3); }
> -	|	SEGMENT_START '(' NAME ',' exp ')'
> +	|	SEGMENT_START { ldlex_script (); } '(' NAME
> +			{ ldlex_popstate (); } ',' exp ')'
>  			{ /* The operands to the expression node are
>  			     placed in the opposite order from the way
>  			     in which they appear in the script as
>  			     that allows us to reuse more code in
>  			     fold_binary.  */
>  			  $$ = exp_binop (SEGMENT_START,
> -					  $5,
> -					  exp_nameop (NAME, $3)); }
> +					  $7,
> +					  exp_nameop (NAME, $4)); }
>  	|	BLOCK '(' exp ')'
>  			{ $$ = exp_unop (ALIGN_K,$3); }
>  	|	NAME
> @@ -1186,13 +1190,17 @@ overlay_section:
>  	|	overlay_section
>  		NAME
>  			{
> -			  ldlex_script ();
>  			  lang_enter_overlay_section ($2);
>  			}
>  		'{' statement_list_opt '}'
> -			{ ldlex_popstate (); ldlex_expression (); }
> +			{ ldlex_expression (); }
>  		phdr_opt fill_opt
>  			{
> +			  if (yychar == NAME)
> +			    {
> +			      yyclearin;
> +			      ldlex_backup ();
> +			    }
>  			  ldlex_popstate ();
>  			  lang_leave_overlay_section ($9, $8);
>  			}
> diff --git a/ld/testsuite/ld-elf/overlay.s b/ld/testsuite/ld-elf/overlay.s
> index f153044e31b..20d8f4154dc 100644
> --- a/ld/testsuite/ld-elf/overlay.s
> +++ b/ld/testsuite/ld-elf/overlay.s
> @@ -2,5 +2,9 @@
>  	.space 0x10
>  	.section .text2,"ax",%progbits
>  	.space 0x20
> +	.section .silly-name1,"ax",%progbits
> +	.space 0x10
> +	.section .silly-name2,"ax",%progbits
> +	.space 0x20
>  	.text
>  	.space 0x30
> diff --git a/ld/testsuite/ld-elf/overlay.t b/ld/testsuite/ld-elf/overlay.t
> index dd374bb68b8..2c50a6b1a48 100644
> --- a/ld/testsuite/ld-elf/overlay.t
> +++ b/ld/testsuite/ld-elf/overlay.t
> @@ -6,6 +6,10 @@ SECTIONS
>    {
>      .text1 {*(.text1)}
>      .text2 {*(.text2)}
> -  } 
> +    .silly-name1 { *(.silly-name1) }
> +    .silly-name2 { *(.silly-name2) }
> +  }
>    /DISCARD/ : { *(.*) }
> +  ASSERT(ADDR(.text1)==ADDR(.text2), "overlay error")
> +  ASSERT(ADDR(.silly-name1)==ADDR(.silly-name2), "silly overlay error")
>  }
>