From 83eea6075b8f4746d632a792b1d1b97c19797acb Mon Sep 17 00:00:00 2001
From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Fri, 7 Aug 2020 17:04:04 -0700
Subject: [PATCH] change errorv calling convention to explicitly take a format
 string

This function implicitly assumed its variable arguments contained a format
string as the first argument. This change pushes the assumption into the calling
convention, making it visible to the compiler.
---
 lib/ast/error.c | 12 +++++++-----
 lib/ast/error.h |  2 +-
 lib/gvpr/gvpr.c |  4 +++-
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/lib/ast/error.c b/lib/ast/error.c
index 8d98682ef..983938255 100644
--- a/lib/ast/error.c
+++ b/lib/ast/error.c
@@ -40,9 +40,8 @@ void setErrorErrors (int errors) { error_info.errors = errors; }
 int  getErrorErrors () { return error_info.errors; }
 void setTraceLevel (int i) { error_info.trace = i; }
 
-void errorv(const char *id, int level, va_list ap)
+void errorv(const char *id, int level, const char *s, va_list ap)
 {
-    const char *s;
     int flags;
 
     if (level < error_info.trace) return;
@@ -80,7 +79,6 @@ void errorv(const char *id, int level, va_list ap)
 	    sfprintf(sfstderr, "line %d: ", error_info.line);
 	}
     }
-    s = va_arg(ap, char *);
     sfvprintf(sfstderr, s, ap);
     if (flags & ERROR_SYSTEM)
 	sfprintf(sfstderr, "\n%s", strerror(errno));
@@ -92,18 +90,22 @@ void errorv(const char *id, int level, va_list ap)
 void error(int level, ...)
 {
     va_list ap;
+    const char *s;
 
     va_start(ap, level);
-    errorv(NiL, level, ap);
+    s = va_arg(ap, char *);
+    errorv(NiL, level, s, ap);
     va_end(ap);
 }
 
 void errorf(void *handle, void *discipline, int level, ...)
 {
     va_list ap;
+    const char *s;
 
     va_start(ap, level);
+    s = va_arg(ap, char *);
     errorv((discipline
-	    && handle) ? *((char **) handle) : (char *) handle, level, ap);
+	    && handle) ? *((char **) handle) : (char *) handle, level, s, ap);
     va_end(ap);
 }
diff --git a/lib/ast/error.h b/lib/ast/error.h
index 58106b07e..47b0a681c 100644
--- a/lib/ast/error.h
+++ b/lib/ast/error.h
@@ -64,7 +64,7 @@ extern "C" {
 
     extern void error(int, ...);
     extern void errorf(void *, void *, int, ...);
-    extern void errorv(const char *, int, va_list);
+    extern void errorv(const char *, int, const char *, va_list);
 
 #endif
 
diff --git a/lib/gvpr/gvpr.c b/lib/gvpr/gvpr.c
index d3e08b0cb..ce8c26f0a 100644
--- a/lib/gvpr/gvpr.c
+++ b/lib/gvpr/gvpr.c
@@ -906,10 +906,12 @@ static int
 gverrorf (Expr_t *handle, Exdisc_t *discipline, int level, ...)
 {
     va_list ap;
+    const char *s;
 
     va_start(ap, level);
+    s = va_arg(ap, char *);
     errorv((discipline
-	    && handle) ? *((char **) handle) : (char *) handle, level, ap);
+	    && handle) ? *((char **) handle) : (char *) handle, level, s, ap);
     va_end(ap);
 
     if (level >= ERROR_ERROR) {
-- 
2.40.0