[FFmpeg-devel] [PATCH 2/6] Improve error reporting.

[Stefano Sabatini]

---
 libavutil/eval.c |   15 +++++++++------
 1 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/libavutil/eval.c b/libavutil/eval.c
index cfe71e1..5506822 100644
--- a/libavutil/eval.c
+++ b/libavutil/eval.c
@@ -182,7 +182,7 @@ void av_free_expr(AVExpr *e)
 static int parse_primary(AVExpr **e, Parser *p)
 {
     AVExpr *d = av_mallocz(sizeof(AVExpr));
-    char *next= p->s;
+    char *s0, *s1, *next= p->s;
     int ret, i;
 
     if (!d)
@@ -209,9 +209,10 @@ static int parse_primary(AVExpr **e, Parser *p)
         }
     }
 
-    p->s= strchr(p->s, '(');
+    s0 = p->s;
+    p->s = strchr(p->s, '(');
     if (p->s==NULL) {
-        av_log(p, AV_LOG_ERROR, "undefined constant or missing (\n");
+        av_log(p, AV_LOG_ERROR, "Undefined constant or missing '(' in '%s'\n", s0);
         p->s= next;
         av_free_expr(d);
         return AVERROR(EINVAL);
@@ -219,10 +220,11 @@ static int parse_primary(AVExpr **e, Parser *p)
     p->s++; // "("
     if (*next == '(') { // special case do-nothing
         av_freep(&d);
+        s1 = p->s;
         if ((ret = parse_expr(&d, p)) < 0)
             return ret;
         if (p->s[0] != ')') {
-            av_log(p, AV_LOG_ERROR, "missing )\n");
+            av_log(p, AV_LOG_ERROR, "Missing ')' in '%s'\n", s0);
             av_free_expr(d);
             return AVERROR(EINVAL);
         }
@@ -230,6 +232,7 @@ static int parse_primary(AVExpr **e, Parser *p)
         *e = d;
         return 0;
     }
+    s1 = p->s;
     if ((ret = parse_expr(&(d->param[0]), p)) < 0) {
         av_free_expr(d);
         return ret;
@@ -239,7 +242,7 @@ static int parse_primary(AVExpr **e, Parser *p)
         parse_expr(&d->param[1], p);
     }
     if (p->s[0] != ')') {
-        av_log(p, AV_LOG_ERROR, "missing )\n");
+        av_log(p, AV_LOG_ERROR, "Missing ')' or too many args in '%s'\n", s0);
         av_free_expr(d);
         return AVERROR(EINVAL);
     }
@@ -290,7 +293,7 @@ static int parse_primary(AVExpr **e, Parser *p)
             }
         }
 
-        av_log(p, AV_LOG_ERROR, "unknown function\n");
+        av_log(p, AV_LOG_ERROR, "Unknown function in '%s'\n", s0);
         av_free_expr(d);
         return AVERROR(EINVAL);
     }
-- 
1.7.1