[DTrace-devel] [PATCH 1/3] Rename "path" helper to "tstring1" helper

[eugene.loh at oracle.com]

From: Eugene Loh <eugene.loh at oracle.com>

When the code generator sets up a call to a precompiled BPF function,
it emits a lot of boilerplate code.  The implementations of DTrace
subroutines typically make such calls.  So there is potential for
much code reuse.

The "path" helper is one such attempt.  Since its usefulness is
broader than just for a "path name" argument, rename this helper to
suggest its broader usage more clearly.

Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
---
 libdtrace/dt_cg.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/libdtrace/dt_cg.c b/libdtrace/dt_cg.c
index c40fef41..b78c6e02 100644
--- a/libdtrace/dt_cg.c
+++ b/libdtrace/dt_cg.c
@@ -3316,20 +3316,21 @@ dt_cg_array_op(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
 }
 
 /*
- * This function is a helper function for subroutines that take a path
+ * This function is a helper function for subroutines that take one
  * argument and return the tstring resulting from applying a given BPF
  * function (passed by name) on it.
  */
 static void
-dt_cg_subr_path_helper(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
-		       const char *fname)
+dt_cg_subr_tstring1_helper(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
+			   const char *fname, int isptr)
 {
 	dt_ident_t	*idp;
-	dt_node_t	*str = dnp->dn_args;
+	dt_node_t	*arg = dnp->dn_args;
 
-	TRACE_REGSET("    subr-path_helper:Begin");
-	dt_cg_node(str, dlp, drp);
-	dt_cg_check_notnull(dlp, drp, str->dn_reg);
+	TRACE_REGSET("    subr-tstring1_helper:Begin");
+	dt_cg_node(arg, dlp, drp);
+	if (isptr)
+		dt_cg_check_notnull(dlp, drp, arg->dn_reg);
 
 	/*
 	 * The result needs be be a temporary string, so we request one.
@@ -3346,9 +3347,9 @@ dt_cg_subr_path_helper(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
 	if (dt_regset_xalloc_args(drp) == -1)
 		longjmp(yypcb->pcb_jmpbuf, EDT_NOREG);
 
-	emit(dlp, BPF_MOV_REG(BPF_REG_1, str->dn_reg));
-	dt_regset_free(drp, str->dn_reg);
-	dt_cg_tstring_free(yypcb, str);
+	emit(dlp, BPF_MOV_REG(BPF_REG_1, arg->dn_reg));
+	dt_regset_free(drp, arg->dn_reg);
+	dt_cg_tstring_free(yypcb, arg);
 
 	emit(dlp,  BPF_MOV_REG(BPF_REG_2, dnp->dn_reg));
 
@@ -3359,19 +3360,19 @@ dt_cg_subr_path_helper(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp,
 	dt_regset_free_args(drp);
 	dt_regset_free(drp, BPF_REG_0);
 
-	TRACE_REGSET("    subr-path_helper:End  ");
+	TRACE_REGSET("    subr-tstring1_helper:End  ");
 }
 
 static void
 dt_cg_subr_basename(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
 {
-	dt_cg_subr_path_helper(dnp, dlp, drp, "dt_basename");
+	dt_cg_subr_tstring1_helper(dnp, dlp, drp, "dt_basename", 1);
 }
 
 static void
 dt_cg_subr_dirname(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
 {
-	dt_cg_subr_path_helper(dnp, dlp, drp, "dt_dirname");
+	dt_cg_subr_tstring1_helper(dnp, dlp, drp, "dt_dirname", 1);
 }
 
 /*
-- 
2.18.4