fix: expand RTT debugger compatibility

mikesmitty · mikesmitty · commit 613bc1f3b64e · 2025-09-05T08:46:36.000-04:00
diff --git a/compiler/symbol.go b/compiler/symbol.go
@@ -702,6 +702,13 @@ func (c *compilerContext) getGlobal(g *ssa.Global) llvm.Value {
 			})
 			llvmGlobal.AddMetadata(0, diglobal)
 		}
+
+		if info.linkName == "machine.rttSerialInstance" {
+			// Create the symbol alias and make sure neither gets optimized away.
+			alias := llvm.AddAlias(c.mod, llvmType, 0, llvmGlobal, "_SEGGER_RTT")
+			llvmutil.AppendToGlobal(c.mod, "llvm.used", alias)
+			llvmutil.AppendToGlobal(c.mod, "llvm.used", llvmGlobal)
+		}
 	}
 	return llvmGlobal
 }

Original file line number	Diff line number	Diff line change
`@@ -702,6 +702,13 @@ func (c compilerContext) getGlobal(g ssa.Global) llvm.Value {`
`702`	`702`	`})`
`703`	`703`	`llvmGlobal.AddMetadata(0, diglobal)`
`704`	`704`	`}`
	`705`	`+`
	`706`	`+ if info.linkName == "machine.rttSerialInstance" {`
	`707`	`+ // Create the symbol alias and make sure neither gets optimized away.`
	`708`	`+ alias := llvm.AddAlias(c.mod, llvmType, 0, llvmGlobal, "_SEGGER_RTT")`
	`709`	`+ llvmutil.AppendToGlobal(c.mod, "llvm.used", alias)`
	`710`	`+ llvmutil.AppendToGlobal(c.mod, "llvm.used", llvmGlobal)`
	`711`	`+ }`
`705`	`712`	`}`
`706`	`713`	`return llvmGlobal`
`707`	`714`	`}`