[master] 88c596859 assert() for VGC and arm assertions on ctx->method

[Nils Goroll]

commit 88c59685951ea9bedb90e0daf7b2f602c0fa92f2
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Sat Jan 30 17:16:55 2021 +0100

    assert() for VGC and arm assertions on ctx->method
    
    We wrap VAS_Fail() as VPI_Fail() and add an assert() macro to the
    Varnish Generated C (VGC) code. This assert() definition is basically
    a copy of that in vas.h, but deliberately added to a source file which
    is only used by generate.py for VGC, such that this slightly different
    definition be only visible to VGC.
    
    I also pondered the option to include VCL source information in
    VPI_Fail: By using the information updated by VPI_count(), we could
    have that, but as the assert is, for now, intended only to ensure
    correctness of VCC and core VRT code, I decided against this
    complication.
    
    With assert() in place for VGC, we arm the assertions from
    75acb5cc7aa73fcd22b150dd1a3b899c6ec9bc44

diff --git a/bin/varnishd/cache/cache_vpi.c b/bin/varnishd/cache/cache_vpi.c
index 06eb802d5..24a3c58b9 100644
--- a/bin/varnishd/cache/cache_vpi.c
+++ b/bin/varnishd/cache/cache_vpi.c
@@ -133,3 +133,10 @@ VPI_vcl_select(VRT_CTX, VCL_VCL vcl)
 	VSLb(ctx->req->vsl, SLT_VCL_use, "%s via %s",
 	    req->vcl->loaded_name, vcl->loaded_name);
 }
+
+void v_noreturn_
+VPI_Fail(const char *func, const char *file, int line,
+    const char *cond)
+{
+	VAS_Fail(func, file, line, cond, VAS_ASSERT);
+}
diff --git a/include/Makefile.am b/include/Makefile.am
index 818011d3d..25a2c9c8f 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -83,6 +83,7 @@ nobase_noinst_HEADERS = \
 	compat/daemon.h \
 	vfl.h \
 	libvcc.h \
+	vcc_assert.h \
 	vcc_interface.h \
 	vcli_serve.h \
 	vcs_version.h \
@@ -109,6 +110,7 @@ nobase_noinst_HEADERS = \
 ## keep in sync with lib/libvcc/Makefile.am
 vcl.h: \
 	    $(top_srcdir)/lib/libvcc/generate.py \
+	    $(top_srcdir)/include/vcc_assert.h \
 	    $(top_srcdir)/include/vcc_interface.h \
 	    $(top_srcdir)/include/vdef.h \
 	    $(top_srcdir)/include/vrt.h \
diff --git a/include/vcc_assert.h b/include/vcc_assert.h
new file mode 100644
index 000000000..7e1c7026b
--- /dev/null
+++ b/include/vcc_assert.h
@@ -0,0 +1,6 @@
+#define assert(e)							\
+do {									\
+	if (!(e)) {							\
+		VPI_Fail(__func__, __FILE__, __LINE__, #e);		\
+	}								\
+} while (0)
diff --git a/include/vcc_interface.h b/include/vcc_interface.h
index 865c8504e..1d46dc0b0 100644
--- a/include/vcc_interface.h
+++ b/include/vcc_interface.h
@@ -38,6 +38,8 @@
 VCL_VCL VPI_vcl_get(VRT_CTX, const char *);
 void VPI_vcl_rel(VRT_CTX, VCL_VCL);
 void VPI_vcl_select(VRT_CTX, VCL_VCL);
+void v_noreturn_ VPI_Fail(const char *func, const char *file, int line,
+    const char *cond);
 
 /***********************************************************************
  * VPI_count() refers to this structure for coordinates into the VCL source.
diff --git a/lib/libvcc/Makefile.am b/lib/libvcc/Makefile.am
index 1e3d6f2d0..17a30de39 100644
--- a/lib/libvcc/Makefile.am
+++ b/lib/libvcc/Makefile.am
@@ -44,6 +44,7 @@ dist_pkgdata_SCRIPTS = \
 ## keep in sync with include/Makefile.am
 vcc_obj.c: \
 	    $(top_srcdir)/lib/libvcc/generate.py \
+	    $(top_srcdir)/include/vcc_assert.h \
 	    $(top_srcdir)/include/vcc_interface.h \
 	    $(top_srcdir)/include/vdef.h \
 	    $(top_srcdir)/include/vrt.h \
diff --git a/lib/libvcc/generate.py b/lib/libvcc/generate.py
index 823fedc5b..b0668498b 100755
--- a/lib/libvcc/generate.py
+++ b/lib/libvcc/generate.py
@@ -788,6 +788,7 @@ emit_file(fo, srcroot, "include/vrt.h")
 emit_file(fo, buildroot, "include/vcl.h")
 emit_file(fo, buildroot, "include/vrt_obj.h")
 emit_file(fo, srcroot, "include/vcc_interface.h")
+emit_file(fo, srcroot, "include/vcc_assert.h")
 
 fo.write("\n}\n")
 fo.close()
diff --git a/lib/libvcc/vcc_compile.c b/lib/libvcc/vcc_compile.c
index 1a2182f41..41277b7f2 100644
--- a/lib/libvcc/vcc_compile.c
+++ b/lib/libvcc/vcc_compile.c
@@ -189,7 +189,7 @@ vcc_EmitProc(struct vcc *tl, struct proc *p)
 		AN(vsbm);
 		vcc_vcl_met2c(vsbm, p->method->bitval);
 		AZ(VSB_finish(vsbm));
-		Fc(tl, 1, "  // assert(ctx->method == (%s));\n",
+		Fc(tl, 1, "  assert(ctx->method == (%s));\n",
 		   VSB_data(vsbm));
 		VSB_destroy(&vsbm);
 	}