I wrote:
> Andres Freund <and...@anarazel.de> writes:
>> The way that pg_bsd_indent defines its variables isn't standard C, as
>> far as I can tell, which explains the errors I was getting. All the
>> individual files include indent_globs.h, which declares/defines a bunch
>> of variables. Since it doesn't use extern, they'll all end up as full
>> definitions in each .o when -fno-common is used (the default now), hence
>> the multiple definition errors. The only reason it works with -fcommon
>> is that they'll end up processed as weak symbols and 'deduplicated' at
>> link time.
> Ugh. I agree that's pretty bogus, even if there's anything in the
> C standard that allows it. I'll put it on my to-do list.
I pushed the attached patch to the pg_bsd_indent repo. Perhaps Piotr
would like to absorb it into upstream.
I don't intend to mark pg_bsd_indent with a new release number for
this --- for people who successfully compiled, it's the same as before.
regards, tom lane
commit acb2f0a7f3689805b954ea19a927b5021fc69409
Author: Tom Lane <t...@sss.pgh.pa.us>
Date: Mon Jun 29 21:19:16 2020 -0400
Avoid duplicate declarations of bsdindent's global variables.
Arrange for all the variable declarations in indent_globs.h to look
like "extern" declarations to every .c file except indent.c.
This prevents linker failure due to duplicated global variables when
the code is built with -fno-common, which is soon to be gcc's default.
The method of temporarily #define'ing "extern" to empty is a hack,
no doubt, but it avoids requiring a duplicate set of variable
definitions, so it seemed like the best way.
Discussion: https://postgr.es/m/20200629165051.xlfqhstajf6yn...@alap3.anarazel.de
diff --git a/indent.c b/indent.c
index 62d4d01..d3a0ece 100644
--- a/indent.c
+++ b/indent.c
@@ -49,6 +49,10 @@ static char sccsid[] = "@(#)indent.c 5.17 (Berkeley) 6/7/93";
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
+
+/* Tell indent_globs.h to define our global variables here */
+#define DECLARE_INDENT_GLOBALS 1
+
#include "indent_globs.h"
#include "indent_codes.h"
#include "indent.h"
diff --git a/indent_globs.h b/indent_globs.h
index d018af1..398784b 100644
--- a/indent_globs.h
+++ b/indent_globs.h
@@ -50,9 +50,16 @@
#define true 1
#endif
+/*
+ * Exactly one calling file should define this symbol. The global variables
+ * will be defined in that file, and just referenced elsewhere.
+ */
+#ifdef DECLARE_INDENT_GLOBALS
+#define extern
+#endif
-FILE *input; /* the fid for the input file */
-FILE *output; /* the output file */
+extern FILE *input; /* the fid for the input file */
+extern FILE *output; /* the output file */
#define CHECK_SIZE_CODE(desired_size) \
if (e_code + (desired_size) >= l_code) { \
@@ -106,94 +113,94 @@ FILE *output; /* the output file */
s_token = tokenbuf + 1; \
}
-char *labbuf; /* buffer for label */
-char *s_lab; /* start ... */
-char *e_lab; /* .. and end of stored label */
-char *l_lab; /* limit of label buffer */
+extern char *labbuf; /* buffer for label */
+extern char *s_lab; /* start ... */
+extern char *e_lab; /* .. and end of stored label */
+extern char *l_lab; /* limit of label buffer */
-char *codebuf; /* buffer for code section */
-char *s_code; /* start ... */
-char *e_code; /* .. and end of stored code */
-char *l_code; /* limit of code section */
+extern char *codebuf; /* buffer for code section */
+extern char *s_code; /* start ... */
+extern char *e_code; /* .. and end of stored code */
+extern char *l_code; /* limit of code section */
-char *combuf; /* buffer for comments */
-char *s_com; /* start ... */
-char *e_com; /* ... and end of stored comments */
-char *l_com; /* limit of comment buffer */
+extern char *combuf; /* buffer for comments */
+extern char *s_com; /* start ... */
+extern char *e_com; /* ... and end of stored comments */
+extern char *l_com; /* limit of comment buffer */
#define token s_token
-char *tokenbuf; /* the last token scanned */
-char *s_token;
-char *e_token;
-char *l_token;
+extern char *tokenbuf; /* the last token scanned */
+extern char *s_token;
+extern char *e_token;
+extern char *l_token;
-char *in_buffer; /* input buffer */
-char *in_buffer_limit; /* the end of the input buffer */
-char *buf_ptr; /* ptr to next character to be taken from
+extern char *in_buffer; /* input buffer */
+extern char *in_buffer_limit; /* the end of the input buffer */
+extern char *buf_ptr; /* ptr to next character to be taken from
* in_buffer */
-char *buf_end; /* ptr to first after last char in in_buffer */
+extern char *buf_end; /* ptr to first after last char in in_buffer */
-char sc_buf[sc_size]; /* input text is saved here when looking for
+extern char sc_buf[sc_size]; /* input text is saved here when looking for
* the brace after an if, while, etc */
-char *save_com; /* start of the comment stored in sc_buf */
-char *sc_end; /* pointer into save_com buffer */
+extern char *save_com; /* start of the comment stored in sc_buf */
+extern char *sc_end; /* pointer into save_com buffer */
-char *bp_save; /* saved value of buf_ptr when taking input
+extern char *bp_save; /* saved value of buf_ptr when taking input
* from save_com */
-char *be_save; /* similarly saved value of buf_end */
+extern char *be_save; /* similarly saved value of buf_end */
-int found_err;
-int blanklines_after_declarations;
-int blanklines_before_blockcomments;
-int blanklines_after_procs;
-int blanklines_around_conditional_compilation;
-int swallow_optional_blanklines;
-int n_real_blanklines;
-int prefix_blankline_requested;
-int postfix_blankline_requested;
-int break_comma; /* when true and not in parens, break after a
+extern int found_err;
+extern int blanklines_after_declarations;
+extern int blanklines_before_blockcomments;
+extern int blanklines_after_procs;
+extern int blanklines_around_conditional_compilation;
+extern int swallow_optional_blanklines;
+extern int n_real_blanklines;
+extern int prefix_blankline_requested;
+extern int postfix_blankline_requested;
+extern int break_comma; /* when true and not in parens, break after a
* comma */
-int btype_2; /* when true, brace should be on same line as
+extern int btype_2; /* when true, brace should be on same line as
* if, while, etc */
-float case_ind; /* indentation level to be used for a "case
+extern float case_ind; /* indentation level to be used for a "case
* n:" */
-int code_lines; /* count of lines with code */
-int had_eof; /* set to true when input is exhausted */
-int line_no; /* the current line number. */
-int max_col; /* the maximum allowable line length */
-int verbose; /* when true, non-essential error messages are
+extern int code_lines; /* count of lines with code */
+extern int had_eof; /* set to true when input is exhausted */
+extern int line_no; /* the current line number. */
+extern int max_col; /* the maximum allowable line length */
+extern int verbose; /* when true, non-essential error messages are
* printed */
-int cuddle_else; /* true if else should cuddle up to '}' */
-int star_comment_cont; /* true iff comment continuation lines should
+extern int cuddle_else; /* true if else should cuddle up to '}' */
+extern int star_comment_cont; /* true iff comment continuation lines should
* have stars at the beginning of each line. */
-int comment_delimiter_on_blankline;
-int troff; /* true iff were generating troff input */
-int procnames_start_line; /* if true, the names of procedures
+extern int comment_delimiter_on_blankline;
+extern int troff; /* true iff were generating troff input */
+extern int procnames_start_line; /* if true, the names of procedures
* being defined get placed in column
* 1 (ie. a newline is placed between
* the type of the procedure and its
* name) */
-int proc_calls_space; /* If true, procedure calls look like:
+extern int proc_calls_space; /* If true, procedure calls look like:
* foo(bar) rather than foo (bar) */
-int format_block_comments; /* true if comments beginning with
+extern int format_block_comments; /* true if comments beginning with
* `/ * \n' are to be reformatted */
-int format_col1_comments; /* If comments which start in column 1
+extern int format_col1_comments; /* If comments which start in column 1
* are to be magically reformatted
* (just like comments that begin in
* later columns) */
-int inhibit_formatting; /* true if INDENT OFF is in effect */
-int suppress_blanklines;/* set iff following blanklines should be
+extern int inhibit_formatting; /* true if INDENT OFF is in effect */
+extern int suppress_blanklines;/* set iff following blanklines should be
* suppressed */
-int continuation_indent;/* set to the indentation between the edge of
+extern int continuation_indent;/* set to the indentation between the edge of
* code and continuation lines */
-int lineup_to_parens; /* if true, continued code within parens will
+extern int lineup_to_parens; /* if true, continued code within parens will
* be lined up to the open paren */
-int lineup_to_parens_always; /* if true, do not attempt to keep
+extern int lineup_to_parens_always; /* if true, do not attempt to keep
* lined-up code within the margin */
-int Bill_Shannon; /* true iff a blank should always be inserted
+extern int Bill_Shannon; /* true iff a blank should always be inserted
* after sizeof */
-int blanklines_after_declarations_at_proctop; /* This is vaguely
+extern int blanklines_after_declarations_at_proctop; /* This is vaguely
* similar to
* blanklines_after_decla
* rations except that
@@ -206,26 +213,28 @@ int blanklines_after_declarations_at_proctop; /* This is vaguely
* to be generated even
* if there are no
* declarations */
-int block_comment_max_col;
-int extra_expression_indent; /* true if continuation lines from the
+extern int block_comment_max_col;
+extern int extra_expression_indent; /* true if continuation lines from the
* expression part of "if(e)",
* "while(e)", "for(e;e;e)" should be
* indented an extra tab stop so that
* they don't conflict with the code
* that follows */
-int function_brace_split; /* split function declaration and
+extern int function_brace_split; /* split function declaration and
* brace onto separate lines */
-int use_tabs; /* set true to use tabs for spacing,
+extern int use_tabs; /* set true to use tabs for spacing,
* false uses all spaces */
-int auto_typedefs; /* set true to recognize identifiers
+extern int auto_typedefs; /* set true to recognize identifiers
* ending in "_t" like typedefs */
-int space_after_cast; /* "b = (int) a" vs "b = (int)a" */
-int postgres_tab_rules; /* use Postgres tab-vs-space rules */
-int tabsize; /* the size of a tab */
-int else_endif_com_ind; /* the column in which comments to
+extern int space_after_cast; /* "b = (int) a" vs "b = (int)a" */
+extern int postgres_tab_rules; /* use Postgres tab-vs-space rules */
+extern int tabsize; /* the size of a tab */
+extern int else_endif_com_ind; /* the column in which comments to
* the right of #else and #endif
* should start */
+extern int ifdef_level;
+
struct parser_state {
int last_token;
int p_stack[256]; /* this is the parsers stack */
@@ -322,8 +331,13 @@ struct parser_state {
int tos; /* pointer to top of stack */
char procname[100]; /* The name of the current procedure */
int just_saw_decl;
-} ps;
+};
-int ifdef_level;
-struct parser_state state_stack[5];
-struct parser_state match_state[5];
+extern struct parser_state ps;
+extern struct parser_state state_stack[5];
+extern struct parser_state match_state[5];
+
+/* Undo previous hackery */
+#ifdef DECLARE_INDENT_GLOBALS
+#undef extern
+#endif
