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Subject: Re: [9front] [PATCH] Fix assert macro to not break on commas
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Quoth Blue-Maned_Hawk <bluemanedhawk@gmail.com>:
> This is a pair of patches that changes the assert macro to be variadic, 
> allowing expressions with commas in them to be used without needing a 
> spare pair of parentheses, and updates the manpage accordingly.

Alternative proposal.

This prints the pid, which means you can now get a full
stack trace trivially with:

	lstk $pid

and plumb the paths into your editor, instead of getting
a pretty dumb context-free copy of the expression that
failed.

diff 276c090a9536c0165d10d908862a93e743d3b344 uncommitted
--- a/sys/include/libc.h
+++ b/sys/include/libc.h
@@ -3,7 +3,6 @@
 
 #define	nelem(x)	(sizeof(x)/sizeof((x)[0]))
 #define	offsetof(s, m)	(ulong)(&(((s*)0)->m))
-#define	assert(x)	if(x){}else _assert("x")
 
 /*
  * mem routines
@@ -384,7 +383,7 @@
 	PNGROUP		= 2,
 };
 
-extern	void	_assert(char*);
+extern	void	assert(int);
 extern	int	abs(int);
 extern	int	atexit(void(*)(void));
 extern	void	atexitdont(void(*)(void));
--- a/sys/man/2/assert
+++ b/sys/man/2/assert
@@ -6,17 +6,12 @@
 .br
 .B #include <libc.h>
 .PP
-.B
-#define assert(cond) if(cond);else _assert("cond")
+.B void assert(int cond)
 .PP
 .B
-void _assert(char* cond)
 .SH DESCRIPTION
 .I Assert
-is a preprocessor macro that
-(via
-.IR _assert )
-prints a message and calls
+is a function that prints the current process id and calls
 .I abort
 when
 .I cond
--- a/sys/src/libc/port/_assert.c
+++ b/sys/src/libc/port/_assert.c
@@ -1,13 +1,13 @@
 #include <u.h>
 #include <libc.h>
 
-void (*__assert)(char*);
+void (*__assert)(int);
 
 void
-_assert(char *s)
+assert(int cond)
 {
-	if(__assert)
-		(*__assert)(s);
-	fprint(2, "assert failed: %s\n", s);
+	if(cond)
+		return;
+	fprint(2, "pid %d: assert failed\n", getpid());
 	abort();
 }
--- a/sys/src/libthread/debug.c
+++ b/sys/src/libthread/debug.c
@@ -29,10 +29,3 @@
 	fmtprint(&f, "\n");
 	fmtfdflush(&f);
 }
-
-void
-_threadassert(char *s)
-{
-	_threadprint("%s: assertion failed", s);
-	abort();
-}