mesa: Allow overriding GLSL version with environment variable

Override the context's GLSL version if the environment variable
MESA_GLSL_VERSION_OVERRIDE is set. Valid values for
MESA_GLSL_VERSION_OVERRIDE are integers, such as "130".

MESA_GLSL_VERSION_OVERRIDE has the same behavior as INTEL_GLSL_VERSION,
except that it applies to all drivers, not just Intel's. Since the former
supercedes the latter, this patch disables the latter.

Reviewed-by: Dave Airlie <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>
Signed-off-by: Chad Versace <[email protected]>

3 files changed, 27 insertions, 0 deletions

diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index b20063c33b2..2532c47de15 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -627,6 +627,7 @@ _mesa_init_constants(struct gl_context *ctx)
    /* Shading language version */
    if (ctx->API == API_OPENGL) {
       ctx->Const.GLSLVersion = 120;
+      _mesa_override_glsl_version(ctx);
    }
    else if (ctx->API == API_OPENGLES2) {
       ctx->Const.GLSLVersion = 100;
diff --git a/src/mesa/main/version.c b/src/mesa/main/version.c
index 00b423cd479..665b0e7ad28 100644
--- a/src/mesa/main/version.c
+++ b/src/mesa/main/version.c
@@ -52,6 +52,30 @@ override_version(struct gl_context *ctx, GLuint *major, GLuint *minor)
 }
 
 /**
+ * Override the context's GLSL version if the environment variable
+ * MESA_GLSL_VERSION_OVERRIDE is set. Valid values for
+ * MESA_GLSL_VERSION_OVERRIDE are integers, such as "130".
+ */
+void
+_mesa_override_glsl_version(struct gl_context *ctx)
+{
+   const char *env_var = "MESA_GLSL_VERSION_OVERRIDE";
+   const char *version;
+   int n;
+
+   version = getenv(env_var);
+   if (!version) {
+      return;
+   }
+
+   n = sscanf(version, "%d", &ctx->Const.GLSLVersion);
+   if (n != 1) {
+      fprintf(stderr, "error: invalid value for %s: %s\n", env_var, version);
+      return;
+   }
+}
+
+/**
  * Examine enabled GL extensions to determine GL version.
  * Return major and minor version numbers.
  */
diff --git a/src/mesa/main/version.h b/src/mesa/main/version.h
index 0a0512c339d..32e141f0e0e 100644
--- a/src/mesa/main/version.h
+++ b/src/mesa/main/version.h
@@ -56,5 +56,7 @@ struct gl_context;
 extern void
 _mesa_compute_version(struct gl_context *ctx);
 
+extern void
+_mesa_override_glsl_version(struct gl_context *ctx);
 
 #endif /* VERSION_H */